Motor Neurone Disease (ALS)

1. Topic Overview

Summary

Motor neurone disease (MND) is a progressive, fatal neurodegenerative disorder characterised by selective degeneration of upper motor neurons (UMN) in the motor cortex and lower motor neurons (LMN) in the brainstem and spinal cord anterior horn cells. [1] The condition is known as amyotrophic lateral sclerosis (ALS) internationally, reflecting the pathological hallmarks of muscle wasting (amyotrophy) and lateral corticospinal tract sclerosis. [2]

The clinical presentation is characterised by the combination of UMN signs (spasticity, hyperreflexia, Babinski sign) and LMN signs (muscle wasting, fasciculations, weakness) occurring simultaneously in multiple body regions, crucially without sensory involvement. [1,3] This mixed UMN-LMN pattern with sensory sparing is pathognomonic and distinguishes MND from other neuromuscular conditions.

There is currently no cure for MND. Riluzole, a glutamate antagonist, is the only disease-modifying therapy proven to extend survival, providing a modest benefit of approximately 2-3 months. [4,5] However, multidisciplinary team (MDT) care significantly improves quality of life and survival, with studies demonstrating survival benefits of 6-12 months with specialist MND clinic attendance. [6] Non-invasive ventilation (NIV) for respiratory support is the single most important intervention for extending survival, improving both quantity and quality of life. [7]

Key Facts

Parameter	Details
Definition	Progressive degeneration of upper and lower motor neurons with sensory sparing
Incidence	2-3 per 100,000 per year worldwide [8]
Prevalence	5-7 per 100,000 (reflects short survival) [8]
Lifetime Risk	1 in 300-400 individuals [1]
Peak Age	55-75 years; mean onset 65 years [8]
Male:Female	1.3-1.5:1 (slight male predominance) [8]
Median Survival	2-4 years from symptom onset (variable by phenotype) [1,2]
10-Year Survival	Approximately 5-10% of patients [1]
Familial Cases	5-10% (remainder sporadic) [9]

Clinical Pearls

"Weakness Without Sensory Loss": The hallmark of MND is progressive motor weakness WITHOUT sensory involvement. If there is significant sensory loss, actively exclude alternative diagnoses (myelopathy, peripheral neuropathy, multifocal motor neuropathy). Mild sensory symptoms may occur in up to 20% but should never dominate the clinical picture. [1,3]

"Split Hand Sign" (Dissociated Small Hand Muscle Atrophy): In MND, the thenar muscles (APB, opponens pollicis) are preferentially wasted compared to hypothenar muscles. This distinctive pattern has high sensitivity (65%) and specificity (75%) for ALS and is thought to reflect cortical motor neuron vulnerability. [10]

"Eye Movements and Sphincters are Spared": Even in advanced disease, patients retain eye movement control (oculomotor nuclei spared) and sphincter continence (Onuf's nucleus spared). This allows use of eye-gaze communication technology. If these are affected early, reconsider the diagnosis. [1,11]

"The Stiff, Wasted Tongue": Finding both wasting/fasciculations (LMN) AND spasticity/brisk jaw jerk (UMN) in the bulbar region is virtually pathognomonic of MND. This combination is rarely seen in other conditions. [3]

Why This Matters Clinically

MND is a devastating diagnosis with major implications for patients, families, and healthcare systems. Early diagnosis is crucial as it enables:

Timely interventions: Riluzole initiation, early NIV assessment, proactive PEG insertion before respiratory compromise
Advance care planning: Discussions regarding end-of-life care, DNAR decisions, lasting power of attorney
MDT access: Referral to specialist MND centres improves outcomes significantly
Family support: Genetic counselling for familial cases, carer support services
Clinical trials: Many patients wish to participate in research

Recognition of the characteristic pattern of mixed UMN and LMN signs without sensory involvement is essential. Diagnostic delay averages 12-14 months from symptom onset, during which time patients may receive incorrect diagnoses including cervical radiculopathy, carpal tunnel syndrome, or stroke. [12]

2. Epidemiology

Incidence & Prevalence

Parameter	Value	Notes
Incidence	2-3 per 100,000 per year	Relatively uniform worldwide [8]
Prevalence	5-7 per 100,000	Low prevalence reflects short survival [8]
Lifetime Risk	1 in 300-400	Higher than commonly perceived [1]
Trend	Possibly increasing	May reflect improved diagnosis and aging population [8]

The low prevalence-to-incidence ratio (approximately 2.5:1) reflects the short median survival of 2-4 years, meaning that while new cases occur frequently, patients do not live long with the disease.

Demographics

Factor	Details	Evidence
Age at Onset	Peak 55-75 years; mean 65 years; rare less than 40 years	[8]
Sex	Male:Female ratio 1.3-1.5:1	Higher in limb-onset; more equal in bulbar-onset [8]
Ethnicity	Higher in Caucasian populations	Lower in Asian, African populations [8]
Geography	Higher in Western Pacific (Guam, Japan - historical)	Environmental factors implicated [8]
Socioeconomic	No clear association	[8]

Risk Factors

Established Risk Factors:

Risk Factor	Relative Risk	Evidence Level
Age > 50 years	Major risk factor	Level I [8]
Male sex	RR 1.3-1.5	Level I [8]
Family history (first-degree relative)	RR 8-10	Level II [9]
Genetic mutations (SOD1, C9orf72)	High penetrance	Level II [9]

Potential Risk Factors (Under Investigation):

Factor	Association	Current Evidence
Military service	OR 1.5-2.0 in some studies	Level III - inconsistent [8]
Professional athletes (footballers)	OR 4-6 in some studies	Level III - controversial [8]
Head trauma (repeated)	Possible association	Level III - conflicting data [8]
Smoking	OR 1.2-1.5	Level III - modest if any [13]
Agricultural occupation	OR 1.5	Level III - pesticide exposure implicated [8]
Lead/heavy metal exposure	Possible association	Level III [8]

Protective Factors (Limited Evidence):

Higher body mass index (pre-disease)
Physical activity (paradoxically - controversial)
Mediterranean diet (observational data)

Genetics

Approximately 5-10% of MND cases are familial (FALS), with the remainder sporadic (SALS). However, this distinction is increasingly blurred as genetic testing identifies mutations in apparently sporadic cases. [9]

Gene	Frequency	Phenotype
C9orf72	40% of FALS, 7% of SALS	Classic ALS, ALS-FTD, behavioural changes [9]
SOD1	20% of FALS, 2% of SALS	Classic ALS, variable progression [9]
TARDBP (TDP-43)	4% of FALS	Classic ALS [9]
FUS	4% of FALS	Often younger onset, rapid progression [9]
Other genes	Numerous rare	VCP, OPTN, UBQLN2, etc. [9]

C9orf72 Expansion: A hexanucleotide repeat expansion (GGGGCC) in the C9orf72 gene is the most common genetic cause of both familial ALS and frontotemporal dementia (FTD), explaining the clinical overlap between these conditions. [9,14]

3. Pathophysiology

Mechanism of Neurodegeneration

The pathophysiology of MND involves a complex interplay of multiple cellular mechanisms leading to motor neuron death:

Step 1: Protein Aggregation

The hallmark pathological finding in > 97% of sporadic ALS is cytoplasmic aggregation of TDP-43 (TAR DNA-binding protein 43). [1,14] In familial cases:

SOD1 mutations (20% of FALS): Toxic gain-of-function of mutant SOD1 protein
C9orf72 expansion (40% of FALS): Dipeptide repeat proteins from aberrant translation
TDP-43/FUS mutations: Direct RNA metabolism disruption

Step 2: Cellular Stress Pathways

Multiple interconnected mechanisms contribute to neuronal injury:

Mechanism	Description	Evidence
Excitotoxicity	Excess glutamate leads to calcium influx and neuronal death	Basis for riluzole therapy [4]
Oxidative stress	Free radical damage; SOD1 protects against this normally	SOD1 mutations cause toxic gain-of-function [9]
Mitochondrial dysfunction	Impaired energy metabolism in motor neurons	Histological evidence [14]
RNA metabolism disruption	TDP-43/FUS regulate RNA processing	Core to disease pathogenesis [14]
Impaired autophagy	Failure to clear misfolded proteins	Ubiquitinated inclusions [14]
Neuroinflammation	Microglial activation, astrocyte dysfunction	Glial cells contribute to toxicity [14]
Axonal transport defects	Disrupted transport of organelles and proteins	Early pathological feature [14]

Step 3: Selective Motor Neuron Vulnerability

Motor neurons are particularly susceptible due to:

Large size and high metabolic demands
Long axons requiring extensive transport
Calcium buffering requirements for rapid firing
Dependence on glial support

Step 4: Clinical Manifestations

Affected Region	Pathology	Clinical Signs
Motor cortex UMN	Betz cell degeneration	Spasticity, hyperreflexia, Babinski
Brainstem motor nuclei	LMN loss	Dysarthria, dysphagia, tongue fasciculations
Spinal anterior horn	LMN loss	Wasting, weakness, fasciculations
Corticospinal tracts	Lateral sclerosis	Spasticity, UMN signs below level

Clinical Phenotypes (Subtypes)

MND is a heterogeneous disease with several recognised clinical phenotypes: [1,2,15]

Phenotype	Defining Features	% of Cases	Median Survival	Prognosis
ALS (Classic/Typical)	Mixed UMN + LMN signs; limb ± bulbar involvement	65-70%	2-4 years	Variable
Progressive Bulbar Palsy (PBP)	Predominant bulbar onset; dysarthria, dysphagia first	20-25%	2-3 years	Poor
Progressive Muscular Atrophy (PMA)	LMN only; no clinical UMN signs	5-10%	4-5+ years	Better
Primary Lateral Sclerosis (PLS)	UMN only; no clinical LMN signs (≥4 years to declare)	2-5%	10+ years	Best
ALS-FTD	ALS + frontotemporal dementia	10-15%	Shorter	Worst
Flail Arm (Vulpian-Bernhardt)	Proximal arm weakness, symmetric	5%	4-5 years	Intermediate
Flail Leg	Distal leg weakness	3%	4-5 years	Intermediate

Exam Detail: Exam Point - PLS Diagnosis: Primary lateral sclerosis requires isolated UMN signs for at least 4 years before the diagnosis can be confidently made. Many patients initially labelled as PLS will develop LMN signs, converting to typical ALS. EMG may show subclinical LMN involvement. [15]

Exam Point - PMA and Pathology: Although PMA presents with pure LMN signs clinically, post-mortem studies often reveal corticospinal tract pathology, suggesting it lies on the ALS spectrum. [15]

Areas SPARED in MND

A critical diagnostic feature is that certain neuronal populations are characteristically spared: [1,11]

Spared Region	Clinical Implication
Sensory neurons	Sensation remains intact throughout
Oculomotor nuclei (III, IV, VI)	Eye movements preserved; enables eye-gaze technology
Onuf's nucleus (S2-4)	Sphincter control preserved (bladder/bowel continence)
Cardiac muscle	No cardiac involvement
Smooth muscle	Autonomic function largely preserved

Important: If eye movements, sphincter function, or sensory examination are significantly abnormal, alternative diagnoses must be actively considered.

4. Clinical Presentation

Symptom Onset Patterns

Limb Onset (65-70%):

The most common presentation, typically with insidious onset over months: [1,3]

Upper limb onset: Difficulty with fine motor tasks (buttons, writing), grip weakness, dropping objects
Lower limb onset: Foot drop, tripping, difficulty climbing stairs, leg stiffness
Often asymmetric initially, becoming bilateral over time
Muscle cramps and fasciculations are common early symptoms
Fatigue with use (motor neuron depletion)

Bulbar Onset (20-25%):

Associated with poorer prognosis: [1,3]

Speech: Dysarthria (slurred, nasal, strained quality)
Swallowing: Dysphagia (initially to liquids, then solids), choking episodes
Drooling: Sialorrhoea (pooling of saliva, reduced swallowing frequency)
Emotional lability: Pseudobulbar affect (pathological laughing/crying)
Often progresses more rapidly than limb-onset disease

Respiratory Onset (5%):

May present to respiratory or sleep physicians: [1,7]

Dyspnoea on exertion, orthopnoea
Morning headaches (CO2 retention)
Excessive daytime somnolence
Nocturnal hypoventilation symptoms
Poor prognosis due to early respiratory involvement

Cognitive/Behavioural Onset:

Frontotemporal dysfunction occurs in 30-50% of patients to varying degrees: [1,14]

Executive dysfunction (planning, problem-solving)
Behavioural changes (apathy, disinhibition)
Language difficulties (word-finding, semantic)
10-15% meet full criteria for frontotemporal dementia (FTD)
Associated with C9orf72 mutations

Symptoms by System

System	Symptoms	Frequency
Motor - Limbs	Weakness, wasting, cramps, fasciculations, stiffness	> 90% eventually
Bulbar	Dysarthria, dysphagia, sialorrhoea, weak cough	25% at onset, 80%+ eventually
Respiratory	Dyspnoea, orthopnoea, morning headache, poor sleep	Universal eventually
Cognitive	Executive dysfunction, language problems, apathy	30-50% some involvement
Emotional	Pseudobulbar affect, depression, anxiety	20-50%
Autonomic	Usually minimal	Rarely prominent

Clinical Signs

Upper Motor Neuron Signs (Corticospinal Tract):

Sign	Examination Finding	Significance
Spasticity	Increased tone, velocity-dependent	Pyramidal tract involvement
Hyperreflexia	Brisk tendon reflexes	UMN pathology
Clonus	> 3 beats at ankle/patella	Sustained UMN involvement
Babinski sign	Extensor plantar response	Corticospinal tract lesion
Hoffmann sign	Thumb flexion on finger flick	Cervical UMN involvement
Brisk jaw jerk	Exaggerated jaw jerk reflex	Bulbar UMN involvement

Lower Motor Neuron Signs (Anterior Horn Cell):

Sign	Examination Finding	Significance
Wasting	Visible muscle atrophy	Denervation
Fasciculations	Visible twitching at rest	Spontaneous motor unit firing
Weakness	MRC grading reduced	Loss of motor neurons
Hyporeflexia	Reduced or absent reflexes	LMN predominant areas
Flaccid tone	Reduced tone	Pure LMN (rare in ALS)

Bulbar Signs:

Sign	Finding	Interpretation
Tongue wasting	Visible atrophy, especially lateral borders	LMN hypoglossal involvement
Tongue fasciculations	Visible twitching at rest (examine in mouth)	LMN involvement
Brisk jaw jerk	Exaggerated	UMN bulbar involvement
Spastic tongue	Slow, stiff movement	UMN involvement
Dysarthria	Slurred, nasal, or strained speech	Mixed UMN/LMN
Weak palatal movement	"Curtaining" to one side	LMN vagal involvement
Weak cough	Bovine cough, poor explosive quality	Bulbar weakness

Clinical Pearl: The Split Hand Sign (Dissociated Hand Muscle Atrophy): In MND, compare thenar (APB) and hypothenar (ADM) muscles. Preferential wasting of thenar muscles (especially first dorsal interosseous and APB) compared to hypothenar muscles is characteristic. This pattern has 65% sensitivity and 75% specificity for ALS and helps differentiate from cervical radiculopathy. [10]

Red Flags Requiring Urgent Action

[!CAUTION] Red Flags — Require urgent attention:

Respiratory compromise: Orthopnoea, morning headaches, FVC less than 50% predicted, sleep disturbance

Severe dysphagia: Weight loss > 10%, dehydration, aspiration risk

Acute choking episode: Airway emergency

Rapid deterioration: > 5 points ALSFRS-R decline per month

Suicidal ideation: Psychiatric emergency

Severe sialorrhoea: Aspiration risk

5. Clinical Examination

Structured Examination Approach

A systematic examination should assess all four body regions defined in diagnostic criteria (bulbar, cervical, thoracic, lumbosacral):

General Inspection:

Finding	Significance
Nutritional status	Weight loss common and prognostic
Respiratory pattern	Use of accessory muscles, paradoxical breathing
Affect	Pseudobulbar affect (inappropriate emotional responses)
Mobility aids	Wheelchair, walking aids indicate progression
Communication aids	Speech devices suggest bulbar involvement

Respiratory Assessment:

Count to 20 in one breath (normal > 15)
Observe for accessory muscle use
Note respiratory rate and pattern
Assess cough strength

Motor Examination Protocol:

Component	Assessment	Documentation
Bulk	Inspect for wasting pattern; compare sides	Split hand sign, segmental wasting
Fasciculations	Observe relaxed muscles for 30+ seconds	Location, frequency
Tone	Assess at rest; velocity-dependent	Spasticity vs flaccidity
Power	MRC scale 0-5 all muscle groups	Pattern of weakness
Reflexes	Deep tendon reflexes, plantar response	Hyper/hypo, Babinski

Cranial Nerve Examination (Bulbar Focus):

Test	Finding	Interpretation
Tongue inspection	Wasting, fasciculations (at rest in mouth)	LMN bulbar
Tongue protrusion	Weakness, deviation	Hypoglossal involvement
Jaw jerk	Brisk (exaggerated)	UMN bulbar
Palatal movement	"Ahh"

weak/asymmetric | Vagal involvement | | Gag reflex | May be absent or exaggerated | Variable | | Speech | Dysarthria quality | Spastic vs flaccid | | Swallow assessment | Wet voice, cough after sip | Aspiration risk | | Eye movements | Should be normal | Spared in MND |

Key Diagnostic Signs

Sign	Technique	Finding	Sensitivity/Specificity
Split Hand Sign	Compare APB to ADM bulk	APB more wasted	65%/75% [10]
Tongue Fasciculations	Observe tongue at rest in mouth	Visible twitching	Highly specific when present
Brisk Jaw Jerk	Tap chin with reflex hammer	Exaggerated jerk	Indicates UMN bulbar
Hoffmann Sign	Flick middle finger DIP	Thumb/index flexion	UMN cervical
Mixed UMN+LMN Same Limb	Wasting + hyperreflexia together	Pathognomonic	Highly specific
Preserved Sensation	Full sensory examination	Normal	Expected in MND

Respiratory Assessment Tools

Test	Method	Significance
Forced Vital Capacity (FVC)	Spirometry sitting and supine	less than 80% abnormal; less than 50% = NIV indication
Supine FVC drop	Compare sitting to supine FVC	> 20% drop = diaphragm weakness
Sniff Nasal Inspiratory Pressure (SNIP)	Maximal sniff through one nostril	less than 40 cmH₂O = significant weakness
Peak Cough Flow	Cough into peak flow meter	less than 270 L/min = ineffective cough
Nocturnal Oximetry	Overnight pulse oximetry	Desaturations indicate hypoventilation

Exam Detail: Supine FVC Drop: Diaphragm weakness causes a postural drop in FVC. Measure FVC sitting then supine. A drop of > 20-25% indicates significant diaphragmatic involvement and predicts nocturnal hypoventilation. This is a key indicator for NIV initiation even when sitting FVC appears acceptable. [7]

6. Investigations

Diagnostic Algorithm

The diagnosis of MND remains clinical, supported by electrophysiological evidence of widespread denervation. Investigations serve to:

Confirm LMN involvement (EMG)
Exclude structural and treatable mimics (MRI, bloods)
Assess disease extent and prognosis

First-Line Investigations

Investigation	Purpose	Expected Findings in MND
EMG/Nerve Conduction Studies	Confirm widespread LMN involvement	Active denervation in ≥3 regions [16]
MRI Brain + Whole Spine	Exclude structural pathology	Usually normal; may show corticospinal tract hyperintensity
Blood Tests	Exclude metabolic/inflammatory mimics	Usually normal in MND

Electrodiagnostic Studies (EMG/NCS)

EMG is the most important diagnostic test, demonstrating LMN involvement in clinically affected and unaffected regions. [16]

Electromyography (EMG) Findings:

Finding	Significance	Location
Fibrillation potentials	Active denervation	At rest
Positive sharp waves	Acute denervation	At rest
Fasciculation potentials	Spontaneous motor unit activity	At rest
Large motor unit potentials	Reinnervation/collateral sprouting	On activation
Reduced recruitment	Motor neuron loss	On activation
Polyphasic units	Remodelling	On activation

Nerve Conduction Studies (NCS):

Parameter	Expected Finding	Significance
Motor conduction velocities	Normal or mildly reduced	Pure motor disorder
Sensory conduction	Normal	Critical - excludes neuropathy
Compound muscle action potential (CMAP)	May be reduced	Reflects motor axon loss
Conduction block	Absent	If present, consider MMN

Exam Detail: Awaji-Shima Criteria: These criteria give fasciculation potentials the same diagnostic weight as fibrillation potentials/positive sharp waves, increasing diagnostic sensitivity without losing specificity. This is particularly important for earlier diagnosis. [16]

Neuroimaging

Modality	Purpose	Findings
MRI Brain	Exclude structural lesions	May show T2 hyperintensity in motor cortex/corticospinal tracts
MRI Whole Spine	Exclude cord compression, tumour	Usually normal; excludes myelopathy
PET (Research)	Assess cortical function	Frontal hypometabolism in ALS-FTD

Blood Tests (Exclude Mimics)

Test	What It Excludes	Expected in MND
Vitamin B12, Folate	Subacute combined degeneration	Normal
TFTs	Thyroid myopathy	Normal
CK	Primary myopathy	Mildly elevated (1-2× normal)
HIV	HIV-associated motor neuronopathy	Negative
Anti-GM1 antibodies (IgM)	Multifocal motor neuropathy (MMN)	Negative (CRITICAL)
Protein electrophoresis	Paraprotein-associated neuropathy	Normal
ANA, anti-dsDNA	Connective tissue disease	Usually negative
HbA1c	Diabetic amyotrophy	May be abnormal (comorbidity)
Copper, Caeruloplasmin	Wilson's disease (if young)	Normal

Genetic Testing

Indication	Genes to Test	Counselling
Family history of MND/FTD	C9orf72, SOD1, TARDBP, FUS	Genetic counselling essential
Young onset (less than 40 years)	Consider panel testing	Genetic counselling essential
Sporadic ALS	Consider C9orf72 (7% positive)	Discuss implications
ALS-FTD phenotype	C9orf72 highly likely	Genetic counselling essential

Clinical Pearl: Multifocal Motor Neuropathy (MMN) is the critical treatable mimic. It can closely resemble MND with asymmetric limb weakness and fasciculations. Key differences: MMN has conduction block on NCS, often positive anti-GM1 IgM antibodies, and responds to IVIg. Always check anti-GM1 antibodies before diagnosing MND. [1,17]

Diagnostic Criteria

El Escorial Revised Criteria [16]

The diagnosis of ALS requires evidence of:

UMN AND LMN degeneration by clinical, electrophysiological, or neuropathological examination
Progressive spread within or between regions
Absence of alternative explanation

Body Regions: Bulbar, Cervical, Thoracic, Lumbosacral (4 regions)

Diagnostic Category	Criteria
Clinically Definite ALS	UMN + LMN signs in ≥3 regions
Clinically Probable ALS	UMN + LMN signs in ≥2 regions with UMN signs rostral to LMN signs
Clinically Probable - Laboratory Supported	UMN + LMN signs in 1 region OR UMN signs only with EMG evidence of LMN in ≥2 regions
Clinically Possible ALS	UMN + LMN signs in 1 region only, OR UMN signs in ≥2 regions

Awaji-Shima Criteria [16]

Modified criteria that increase diagnostic sensitivity:

Fasciculation potentials on EMG given equal weight to fibrillation potentials
Allows earlier diagnosis
Particularly useful when LMN signs are subclinical

Respiratory Function Tests

Test	Normal Value	Action Threshold	Intervention
FVC (sitting)	> 80% predicted	less than 80% = monitor closely	less than 50% = offer NIV
Supine FVC drop	less than 10%	> 20% drop	Consider NIV
SNIP	> 70 cmH₂O	less than 40 cmH₂O	NIV indication
Peak Cough Flow	> 360 L/min	less than 270 L/min	Cough assist needed
Nocturnal oximetry	SpO₂ > 94%	Desaturation episodes	NIV indication

7. Differential Diagnosis

Critical Differentials (Must Exclude)

Condition	Key Features	How to Differentiate
Multifocal Motor Neuropathy (MMN)	Asymmetric weakness, fasciculations	Conduction block on NCS, anti-GM1 IgM positive, responds to IVIg [17]
Cervical Spondylotic Myelopathy	UMN legs, LMN arms	MRI shows cord compression, sensory level, sphincter dysfunction common
Kennedy Disease (SBMA)	X-linked, LMN pattern, slow	Gynecomastia, facial fasciculations, sensory involvement, CAG repeat expansion
Inclusion Body Myositis	Weakness (finger flexors, quads)	CK elevated, EMG myopathic, muscle biopsy diagnostic
Cervical Radiculopathy	Dermatomal pain and weakness	Sensory involvement, MRI shows disc/foraminal stenosis
Myasthenia Gravis	Fatigable weakness, ptosis	Antibodies (AChR, MuSK), decremental response on repetitive stimulation

Broader Differential by Presentation

UMN Predominant:

Primary lateral sclerosis (if > 4 years isolated UMN)
Hereditary spastic paraplegia
Multiple sclerosis
Vitamin B12 deficiency (combined)
HIV-associated myelopathy
Structural myelopathy

LMN Predominant:

Spinal muscular atrophy
Post-polio syndrome
Multifocal motor neuropathy
Chronic inflammatory demyelinating polyneuropathy (CIDP)
Diabetic amyotrophy
Lead neuropathy

Bulbar Predominant:

Myasthenia gravis (bulbar)
Brainstem stroke
Syringobulbia
Motor neuron disease mimics (structural)

Exam Detail: Exam Favourite - Kennedy Disease (SBMA): X-linked bulbospinal muscular atrophy. Key distinguishing features: only affects males, gynecomastia, perioral fasciculations, mild sensory neuropathy, very slow progression (decades), elevated CK, genetic test confirms CAG repeat expansion in androgen receptor gene. [1]

8. Management

Management Philosophy

MND management is palliative rather than curative. Goals are:

Maximise quality of life
Extend survival where meaningful
Enable patient autonomy and choice
Provide excellent symptom control
Support patients and families through end of life

Management Algorithm

                        CONFIRMED MND
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              REFER TO SPECIALIST MND CENTRE                       │
│                                                                   │
│ • Multidisciplinary team care improves survival by 6-12 months   │
│ • Regular (3-monthly) reviews recommended                         │
│ • Coordinate all aspects of care                                  │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              DISEASE-MODIFYING THERAPY                            │
│                                                                   │
│ RILUZOLE 50mg BD                                                  │
│ • Glutamate antagonist (reduces excitotoxicity)                   │
│ • Extends tracheostomy-free survival by 2-3 months [4,5]          │
│ • NNT approximately 18 for 1 additional survivor at 1 year        │
│ • Monitor LFTs monthly x3 months, then 3-monthly (hepatotoxicity) │
│ • Common side effects: nausea, fatigue, dizziness                 │
│ • Continue until unable to swallow or intolerant                  │
│                                                                   │
│ EDARAVONE (Radicava) - Limited availability                      │
│ • Free radical scavenger (IV infusion cycles)                     │
│ • May slow functional decline in early disease [18]               │
│ • Approved in USA, Japan; limited UK/Europe availability          │
│ • High cost, IV administration limits practicality                │
│                                                                   │
│ SODIUM PHENYLBUTYRATE-TAURURSODIOL (Relyvrio)                     │
│ • Recently approved in some countries                              │
│ • Targets mitochondrial/ER stress                                 │
│ • Evidence remains under evaluation                               │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              RESPIRATORY MANAGEMENT                               │
│                                                                   │
│ Regular FVC/SNIP monitoring (every 3 months)                      │
│                                                                   │
│ INDICATIONS FOR NIV:                                              │
│ • Symptoms of hypoventilation (orthopnoea, morning headache)      │
│ • FVC less than 50% predicted (or less than 80% if symptoms present)                │
│ • SNIP less than 40 cmH₂O                                                  │
│ • Nocturnal desaturation (SpO₂ less than 88% for > 5% of night)            │
│                                                                   │
│ NIV BENEFITS: [7]                                                 │
│ • Extends median survival by 7-11 months (non-bulbar)             │
│ • Improves quality of life and sleep                              │
│ • Improves cognitive function                                     │
│ • Reduces symptoms of hypoventilation                             │
│                                                                   │
│ COUGH ASSIST:                                                     │
│ • Mechanical insufflation-exsufflation                            │
│ • Indicated if peak cough flow less than 270 L/min                         │
│ • Essential for secretion clearance                               │
│                                                                   │
│ AVOID: Sedatives, opioids (unless palliative), oxygen alone       │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              NUTRITIONAL MANAGEMENT                               │
│                                                                   │
│ Weight loss is an independent predictor of poor survival          │
│                                                                   │
│ NUTRITIONAL SUPPORT:                                              │
│ • High-calorie diet (30-35 kcal/kg/day)                           │
│ • Dietitian assessment every 3 months                             │
│ • Modified texture diet if dysphagia                              │
│ • Monitor weight at every visit                                   │
│                                                                   │
│ PEG/RIG INDICATIONS:                                              │
│ • Weight loss > 10% body weight                                    │
│ • Prolonged mealtimes (> 30-45 minutes)                            │
│ • Unsafe swallow assessment (SALT)                                │
│ • Recurrent aspiration                                            │
│                                                                   │
│ TIMING IS CRITICAL:                                               │
│ • Insert PEG while FVC > 50% predicted (safer procedure) [6]       │
│ • RIG (radiologically-inserted gastrostomy) if FVC less than 50%           │
│ • Early referral - don't wait until emergency                     │
│                                                                   │
│ SIALORRHOEA MANAGEMENT:                                           │
│ • Glycopyrronium bromide 1-2mg TDS                                │
│ • Hyoscine patches                                                │
│ • Botulinum toxin to salivary glands                              │
│ • Suction if severe                                               │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              SYMPTOM MANAGEMENT                                   │
│                                                                   │
│ SPASTICITY:                                                       │
│ • Baclofen 5-20mg TDS (titrate slowly)                            │
│ • Tizanidine 2-4mg TDS (alternative)                              │
│ • Physiotherapy, stretching                                       │
│ • Intrathecal baclofen (severe cases)                             │
│                                                                   │
│ CRAMPS:                                                           │
│ • Quinine 300mg nocte (limited evidence, cardiac risk)            │
│ • Gabapentin 300-1200mg TDS                                       │
│ • Magnesium supplementation                                       │
│                                                                   │
│ PSEUDOBULBAR AFFECT:                                              │
│ • Amitriptyline 10-50mg                                           │
│ • SSRIs (fluoxetine, sertraline)                                  │
│ • Dextromethorphan-quinidine (if available)                       │
│                                                                   │
│ PAIN (common in late stages):                                     │
│ • Paracetamol, NSAIDs                                             │
│ • Gabapentinoids (neuropathic component)                          │
│ • Opioids (with caution re: respiratory depression)               │
│ • Physiotherapy                                                   │
│                                                                   │
│ DEPRESSION/ANXIETY:                                               │
│ • SSRIs (sertraline, citalopram)                                  │
│ • Psychological support                                           │
│ • Mirtazapine (also helps sleep, appetite)                        │
│                                                                   │
│ CONSTIPATION:                                                     │
│ • Proactive laxatives (immobility, reduced oral intake)           │
│ • Adequate hydration                                              │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              COMMUNICATION & EQUIPMENT                            │
│                                                                   │
│ SPEECH/COMMUNICATION:                                             │
│ • SALT assessment at diagnosis and regular review                 │
│ • Voice banking (record voice early while possible)               │
│ • Low-tech aids: alphabet boards, writing                         │
│ • High-tech aids: lightwriters, tablet apps                       │
│ • Eye-gaze technology (advanced disease)                          │
│                                                                   │
│ MOBILITY & ENVIRONMENT:                                           │
│ • OT home assessment                                              │
│ • Wheelchair assessment early                                     │
│ • Hoisting, hospital bed                                          │
│ • Stair lift, ramps                                               │
│ • Environmental controls                                          │
│                                                                   │
│ PHYSIOTHERAPY:                                                    │
│ • Maintain range of motion                                        │
│ • Prevent contractures                                            │
│ • Respiratory physiotherapy                                       │
│ • Falls prevention                                                │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│              ADVANCE CARE PLANNING                                │
│                                                                   │
│ DISCUSSIONS (at appropriate time):                                │
│ • Honest prognostic information when patient ready                │
│ • Lasting power of attorney (health and welfare)                  │
│ • Advance decision to refuse treatment (ADRT)                     │
│ • DNAR/ReSPECT discussion and documentation                       │
│ • Preferences for place of care and death                         │
│                                                                   │
│ END-OF-LIFE CONSIDERATIONS:                                       │
│ • NIV withdrawal if patient wishes                                │
│ • Symptom control in dying phase                                  │
│ • Hospice/palliative care involvement early                       │
│ • Family and carer support                                        │
│                                                                   │
│ WHAT PATIENTS WANT TO KNOW:                                       │
│ • "Will I suffocate?"
- No, death is usually peaceful with care   │
│ • "Will I be in pain?"
- Good symptom control is achievable       │
│ • "Can I choose when to stop treatment?"
- Yes, autonomy respected│
└─────────────────────────────────────────────────────────────────┘

Multidisciplinary Team (MDT)

Regular MDT clinic attendance is associated with 6-12 months survival benefit: [6]

Team Member	Role
Neurologist	Diagnosis, disease monitoring, disease-modifying therapy
Palliative Care	Symptom control, advance care planning, end-of-life care
Respiratory Physician	NIV, respiratory assessment
SALT	Swallowing assessment, communication aids
Dietitian	Nutritional support, PEG feeding
Physiotherapist	Mobility, respiratory exercises, falls prevention
Occupational Therapist	Equipment, home adaptation, activities of daily living
Social Worker	Benefits, care packages, social support
Psychology/Psychiatry	Mental health, adjustment, family support
Clinical Nurse Specialist	Coordination, education, ongoing support
Respiratory Physiotherapist	Secretion clearance, cough assist
Palliative Care Nurse	Community support, symptom management

Palliative Care Principles

Palliative care should be involved from diagnosis, not just end-of-life: [6]

Symptom management throughout disease course
Advance care planning
Psychosocial support for patient and family
Coordination of end-of-life care
Bereavement support for family

9. Complications

Complication	Frequency	Risk Factors	Prevention/Management
Respiratory failure	Universal	Rapid progression, bulbar onset	NIV, cough assist, monitor FVC
Aspiration pneumonia	60-70%	Bulbar involvement, poor cough	SALT, modified diet, PEG, cough assist
Malnutrition	50-80%	Dysphagia, hypermetabolism	High-calorie diet, PEG
Venous thromboembolism	2-5%	Immobility	Prophylaxis if hospitalised
Falls and fractures	30-40%	Weakness, spasticity	Mobility aids, home assessment
Pressure ulcers	10-20%	Immobility	Regular repositioning, mattress
Depression	30-50%	Disease burden	Screen and treat actively
Constipation	60-80%	Immobility, medications	Proactive laxatives
Pseudobulbar affect	20-50%	Bulbar involvement	Amitriptyline, SSRIs
Sleep disturbance	70-80%	Hypoventilation, anxiety	NIV, treat underlying cause

Treatment	Complication	Frequency	Management
Riluzole	Elevated LFTs	10-15%	Monitor LFTs; discontinue if ALT > 5× ULN
Riluzole	Nausea, fatigue	10-20%	Take with food; usually transient
NIV	Mask discomfort	20-30%	Mask fitting, different interfaces
NIV	Aerophagia	10-20%	Adjust pressures
NIV	Claustrophobia	5-10%	Desensitisation, psychology
PEG	Insertion complications	5-10%	Insert while FVC > 50%
PEG	Tube blockage	10-20%	Flush with water, replace if needed
PEG	Skin site infection	5-10%	Site care, antibiotics if needed
Baclofen	Drowsiness, weakness	20-30%	Slow titration

10. Prognosis & Outcomes

Natural History

MND is a progressive, ultimately fatal disease. However, survival is highly variable: [1,2]

Statistic	Value
Median survival (from symptom onset)	2-4 years
Median survival (from diagnosis)	1-2 years
5-year survival	20-30%
10-year survival	5-10%
20+ year survival	Rare but documented (e.g., Stephen Hawking)

Cause of Death:

Respiratory failure (primary cause in 85%)
Aspiration pneumonia
Pulmonary embolism
Sudden death (5-10%)

Survival by Phenotype

Phenotype	Median Survival	Notes
Classic ALS (limb onset)	3-5 years	Most common
Bulbar onset	2-3 years	Poorer prognosis
PMA (LMN only)	4-6 years	Better than classic
PLS (UMN only)	10-20 years	Best prognosis
ALS-FTD	2-3 years	Worst prognosis
Flail arm/leg	4-6 years	Intermediate
Respiratory onset	1-2 years	Poor prognosis

Prognostic Factors

Poor Prognostic Indicators: [1,2]

Factor	Impact
Bulbar onset	HR 1.5-2.0
Older age at onset (> 70 years)	HR 1.3-1.5
Rapid progression (ALSFRS-R decline)	Strong predictor
Short diagnosis-to-symptoms interval	Suggests aggressive disease
Frontotemporal dementia features	HR 1.5-2.0
Low FVC at diagnosis	HR 1.5-2.0
Malnutrition/weight loss	HR 1.5-2.0
Diagnostic delay > 12 months	Paradoxically worse outcomes
C9orf72 expansion	Associated with FTD, poorer prognosis

Better Prognostic Indicators:

Factor	Impact
Younger age at onset (less than 40 years)	Better (but rare)
Limb onset	Better than bulbar
Slow progression	Better outcomes
PLS phenotype	Best prognosis
MDT care attendance	+6-12 months survival
Higher BMI	Protective

Impact of Interventions on Survival

Intervention	Survival Benefit	Evidence Level
MDT care	+6-12 months	Level II [6]
NIV (non-bulbar)	+7-11 months	Level I [7]
NIV (bulbar)	Variable, improves QoL	Level II [7]
Riluzole	+2-3 months	Level I [4,5]
PEG feeding	Unclear survival benefit, maintains nutrition	Level III
Edaravone	May slow decline in early disease	Level I [18]

Functional Assessment

ALSFRS-R (ALS Functional Rating Scale - Revised):

The ALSFRS-R is a 12-item scale (0-48 points) assessing:

Bulbar function (speech, salivation, swallowing)
Fine motor function (handwriting, cutting food, dressing/hygiene)
Gross motor function (turning in bed, walking, climbing stairs)
Respiratory function (dyspnoea, orthopnoea, respiratory insufficiency)

Interpretation:

Decline of 1-2 points/month typical
Decline > 3-5 points/month indicates rapid progression
Useful for monitoring and clinical trial endpoints

11. Evidence & Guidelines

Key Guidelines

Guideline	Organisation	Year	Key Points
Motor Neurone Disease: Assessment and Management	NICE (NG42)	2016, updated 2019	Comprehensive UK guidance: diagnosis, MDT care, respiratory, nutrition, end-of-life [6]
European ALS Consortium Guidelines	EFNS/EAN	2012	European diagnostic criteria and management
American Academy of Neurology Practice Parameter	AAN	2009, updated 2022	US diagnostic and management guidance

Landmark Clinical Trials

Riluzole Trials (Bensimon 1994, Lacomblez 1996): [4,5]

First disease-modifying therapy
Demonstrated ~3-month survival benefit
NNT ~18 for one additional survivor at 1 year
Established riluzole as standard of care

NIV in ALS (Bourke 2006): [7]

Randomised controlled trial of NIV in ALS
Showed 7-11 month survival benefit in non-bulbar patients
Also improved quality of life
Established NIV as essential intervention

Edaravone (Writing Group 2017): [18]

Free radical scavenger
Showed slowed functional decline in selected early-stage patients
Led to FDA approval
Post-marketing studies ongoing

Evidence Summary Table

Intervention	Level of Evidence	Recommendation
Riluzole	Level I (RCTs, Cochrane)	Standard of care
NIV	Level I (RCT)	Essential intervention
MDT care	Level II (cohort studies)	Strongly recommended
PEG feeding	Level III (observational)	Recommended for appropriate patients
Edaravone	Level I (RCT)	Consider in early disease (limited access)
Stem cell therapy	Level IV (experimental)	Not recommended outside trials

12. Patient/Layperson Explanation

What is Motor Neurone Disease?

Motor neurone disease (MND), also called ALS, is a condition where the nerve cells (motor neurons) that control your muscles gradually stop working. This causes muscles to weaken and waste away over time.

Important things to know:

It does NOT affect your senses (sight, hearing, touch, taste, smell)
It does NOT affect your bladder or bowel control until very late
It does NOT affect your thinking in most cases (though some people have changes)
Your eye movements remain normal even when other muscles are weak

Why does it happen?

We don't fully understand why MND happens. In about 10% of people, it runs in families (genetic). For most people, it appears without a clear cause. Research suggests a combination of genetic susceptibility and environmental factors.

What are the symptoms?

Symptoms depend on which nerves are affected first:

If arm or leg muscles affected first (most common):

Weakness in hands, difficulty with buttons or writing
Tripping, difficulty with stairs
Muscle cramps and twitching
Muscles getting smaller (wasting)

If throat muscles affected first:

Slurred speech
Difficulty swallowing, choking on food
Drooling
Emotional changes (laughing or crying easily)

What treatments are available?

There is currently no cure, but treatments can help:

Riluzole - A tablet taken twice daily that slightly slows the disease
Breathing support (NIV) - A mask worn at night helps you breathe better and improves sleep and energy
Feeding tube (PEG) - If swallowing becomes unsafe, a tube into your stomach ensures you get enough nutrition
Specialist team - A team of doctors, nurses, therapists, and others work together to manage symptoms and maintain quality of life
Symptom treatments - Medications can help with muscle stiffness, cramps, drooling, and other problems

What to expect

The disease progresses at different rates for different people
Average survival is 2-4 years, but some people live much longer
Throughout the illness, you will be supported by a specialist team
Modern care means most symptoms can be well-controlled
Planning ahead (like making a will, talking about your wishes) is an important part of care

When to seek urgent help

Contact your team urgently if:

You develop breathing difficulties, especially when lying down
You're unable to swallow safely or are choking frequently
You're losing weight rapidly
You develop a chest infection
You have any sudden changes in your condition

Support organisations

MND Association UK: mndassociation.org - 0808 802 6262
ALS Association (US): als.org
Motor Neurone Disease Australia: mndaustralia.org.au

13. Exam-Focused Content

Common Exam Questions

MRCP/Clinical Examination:

"What are the causes of combined upper and lower motor neuron signs?"
"How would you investigate suspected motor neurone disease?"
"A 60-year-old man presents with progressive weakness and wasting of the hands with brisk reflexes. What is your differential diagnosis?"
"Describe the management of motor neurone disease."
"What are the indications for non-invasive ventilation in MND?"

Viva Points

Viva Point: Opening Statement: "Motor neurone disease is a progressive, fatal neurodegenerative condition characterised by degeneration of both upper and lower motor neurons, causing a combination of spasticity, hyperreflexia, wasting, weakness, and fasciculations, crucially without sensory involvement. It has an incidence of 2-3 per 100,000 and median survival of 2-4 years."

Key Facts to Mention:

Incidence 2-3 per 100,000 per year
Male predominance 1.3-1.5:1
El Escorial/Awaji criteria for diagnosis
Riluzole extends survival by 2-3 months (Bensimon 1994)
NIV extends survival by 7-11 months in non-bulbar patients (Bourke 2006)
MDT care improves survival by 6-12 months

Model Viva Answers

Q: "How would you differentiate MND from cervical spondylotic myelopathy?"

A: "These can be challenging to differentiate as both can cause UMN signs in the legs and mixed signs in the arms.

Key differentiating features favouring cervical myelopathy:

Sensory involvement (dermatomal sensory loss, Lhermitte's sign)
Sphincter dysfunction (bladder urgency/retention)
Neck pain, limited range of motion
MRI showing cord compression and signal change

Key features favouring MND:

Sensory examination entirely normal
Sphincters preserved
Bulbar involvement (tongue wasting, dysarthria)
Widespread fasciculations beyond cervical segments
EMG showing active denervation in multiple regions

MRI of the whole spine is essential to exclude structural pathology. Both conditions may coexist, and MRI changes in the elderly cervical spine may be incidental."

Q: "What are the clinical subtypes of MND?"

A: "MND encompasses a spectrum of clinical phenotypes based on the pattern of motor neuron involvement:

Classic ALS (65-70%): Mixed UMN and LMN signs affecting limbs and bulbar region. Median survival 2-4 years.
Progressive Bulbar Palsy (20-25%): Predominantly bulbar onset with dysarthria, dysphagia, tongue wasting. Worst prognosis, 2-3 years median survival.
Progressive Muscular Atrophy (5-10%): LMN signs only clinically, though pathology often shows UMN involvement. Better prognosis, 4-5+ years.
Primary Lateral Sclerosis (2-5%): UMN signs only for at least 4 years. Best prognosis, 10+ years. May convert to ALS.
ALS-FTD (10-15%): ALS with frontotemporal dementia features. Associated with C9orf72 mutations. Worst prognosis.
Regional variants: Flail arm (Vulpian-Bernhardt syndrome), flail leg - intermediate prognosis."

Common Mistakes (What Fails Candidates)

❌ Mistakes that fail candidates:

Missing sensory sparing as a key diagnostic feature
Forgetting to examine the tongue for fasciculations and wasting
Not knowing riluzole survival benefit (~3 months)
Not knowing NIV indications and survival benefit
Failing to mention multifocal motor neuropathy as a treatable mimic
Not recognising the importance of MDT care
Forgetting to discuss advance care planning
Missing respiratory involvement assessment
Not knowing El Escorial criteria categories

14. References

Hardiman O, Al-Chalabi A, Chio A, et al. Amyotrophic lateral sclerosis. Nat Rev Dis Primers. 2017;3:17071. doi:10.1038/nrdp.2017.71
Brown RH, Al-Chalabi A. Amyotrophic Lateral Sclerosis. N Engl J Med. 2017;377(2):162-172. doi:10.1056/NEJMra1603471
Kiernan MC, Vucic S, Cheah BC, et al. Amyotrophic lateral sclerosis. Lancet. 2011;377(9769):942-955. doi:10.1016/S0140-6736(10)61156-7
Bensimon G, Lacomblez L, Meininger V; ALS/Riluzole Study Group. A controlled trial of riluzole in amyotrophic lateral sclerosis. N Engl J Med. 1994;330(9):585-591. doi:10.1056/NEJM199403033300901
Lacomblez L, Bensimon G, Leigh PN, Guillet P, Meininger V. Dose-ranging study of riluzole in amyotrophic lateral sclerosis. Lancet. 1996;347(9013):1425-1431. doi:10.1016/S0140-6736(96)91680-3
National Institute for Health and Care Excellence. Motor neurone disease: assessment and management (NG42). 2016, updated 2019. https://www.nice.org.uk/guidance/ng42
Bourke SC, Tomlinson M, Williams TL, et al. Effects of non-invasive ventilation on survival and quality of life in patients with amyotrophic lateral sclerosis: a randomised controlled trial. Lancet Neurol. 2006;5(2):140-147. doi:10.1016/S1474-4422(05)70326-4
Logroscino G, Traynor BJ, Hardiman O, et al. Incidence of amyotrophic lateral sclerosis in Europe. J Neurol Neurosurg Psychiatry. 2010;81(4):385-390. doi:10.1136/jnnp.2009.183525
Renton AE, Chiò A, Traynor BJ. State of play in amyotrophic lateral sclerosis genetics. Nat Neurosci. 2014;17(1):17-23. doi:10.1038/nn.3584
Kuwabara S, Sonoo M, Komori T, et al. Dissociated small hand muscle atrophy in amyotrophic lateral sclerosis: frequency, extent, and specificity. Muscle Nerve. 2008;37(4):426-430. doi:10.1002/mus.20949
Sharma R, Hicks S, Berna CM, Kennard C, Talbot K, Turner MR. Oculomotor dysfunction in amyotrophic lateral sclerosis: a comprehensive review. Arch Neurol. 2011;68(7):857-861. doi:10.1001/archneurol.2011.130
Paganoni S, Macklin EA, Lee A, et al. Diagnostic timelines and delays in diagnosing amyotrophic lateral sclerosis (ALS). Amyotroph Lateral Scler Frontotemporal Degener. 2014;15(5-6):453-456. doi:10.3109/21678421.2014.903974
Wang MD, Little J, Bhutani M, et al. Smoking and amyotrophic lateral sclerosis: a systematic review and meta-analysis. J Neurol Neurosurg Psychiatry. 2017;88(9):778-785. doi:10.1136/jnnp-2017-315829
Ling SC, Polymenidou M, Cleveland DW. Converging mechanisms in ALS and FTD: disrupted RNA and protein homeostasis. Neuron. 2013;79(3):416-438. doi:10.1016/j.neuron.2013.07.033
Chiò A, Calvo A, Moglia C, Mazzini L, Mora G; PARALS study group. Phenotypic heterogeneity of amyotrophic lateral sclerosis: a population based study. J Neurol Neurosurg Psychiatry. 2011;82(7):740-746. doi:10.1136/jnnp.2010.235952
Costa J, Swash M, de Carvalho M. Awaji criteria for the diagnosis of amyotrophic lateral sclerosis: a systematic review. Arch Neurol. 2012;69(11):1410-1416. doi:10.1001/archneurol.2012.254
Joint Task Force of the EFNS and the PNS. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of multifocal motor neuropathy. J Peripher Nerv Syst. 2010;15(4):295-301. doi:10.1111/j.1529-8027.2010.00291.x
Writing Group; Edaravone (MCI-186) ALS 19 Study Group. Safety and efficacy of edaravone in well defined patients with amyotrophic lateral sclerosis: a randomised, double-blind, placebo-controlled trial. Lancet Neurol. 2017;16(7):505-512. doi:10.1016/S1474-4422(17)30115-1
Andersen PM, Abrahams S, Borasio GD, et al. EFNS guidelines on the clinical management of amyotrophic lateral sclerosis (MALS) - revised report of an EFNS task force. Eur J Neurol. 2012;19(3):360-375. doi:10.1111/j.1468-1331.2011.03501.x
Miller RG, Jackson CE, Kasarskis EJ, et al. Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: multidisciplinary care, symptom management, and cognitive/behavioral impairment (an evidence-based review). Neurology. 2009;73(15):1227-1233. doi:10.1212/WNL.0b013e3181bc01a4

Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate guidelines and specialists for patient care.

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