Papilloedema and optic nerve disorders: SAQ

This girl has the classic presentation of the idiopathic intracranial hypertension with the daily headache, the transient visual obscurations, the diplopia and the bilateral disc swelling, confirmed by the normal neuroimaging and the opening pressure of three hundred and forty millimetres of cerebrospinal fluid, and the task is to outline the diagnosis, the management, the surveillance and the surgical options, contrasting the idiopathic form with the optic neuritis of the myelin oligodendrocyte glycoprotein antibody disease. [1][2]

Question 1 (10 marks)

Outline the diagnosis and the initial management of this twelve-year-old girl with the papilloedema. [1]

A full-mark answer covers the diagnosis, the Friedman criteria, the visual assessment and the medical management. [2]

The diagnosis and the Friedman criteria (3 marks). The diagnosis is the idiopathic intracranial hypertension, formerly the pseudotumour cerebri, defined by the Friedman criteria of the bilateral papilloedema, the normal neurological examination except for the cranial-nerve palsy, the normal neuroimaging that excludes the tumour, the hydrocephalus and the venous cause, the normal cerebrospinal fluid composition, and the opening pressure above two hundred and eighty millimetres of cerebrospinal fluid in the child. The opening pressure of three hundred and forty millimetres confirms the raised pressure, and the normal composition excludes the meningitis and the inflammation, and the idiopathic label is given after the secondary cause is excluded. [1]

The visual assessment and the urgency (3 marks). The vision is the outcome that drives the urgency, and the visual acuity, the colour vision, the visual fields and the optical coherence tomography are performed at the baseline and at each visit. The transient visual obscurations and the diplopia of the sixth-nerve palsy are the classic symptoms, and the enlarged blind spot and the field constriction are the early defects. The surveillance is non-negotiable, because the field loss may appear without the symptom, and the secondary optic atrophy is the complication of the chronic untreated papilloedema. [2][3]

The medical management (4 marks). The weight loss is the cornerstone of the management in the obese adolescent, and the modest reduction of the five to ten percent may resolve the papilloedema. The acetazolamide is the carbonic anhydrase inhibitor that reduces the cerebrospinal fluid production, given at approximately fifteen to twenty-five milligrams per kilogram per day in the divided doses in the child, with the gradual titration and the monitoring for the paraesthesia, the taste disturbance and the metabolic acidosis. The topiramate is the alternative, with the additional weight-loss and the migraine benefit. The family is counselled about the diagnosis, the surveillance and the prognosis, and the school and the dietetic support are engaged. [2][3]

Question 2 (10 marks)

Discuss the surveillance and the surgical options, contrasting the idiopathic intracranial hypertension with the optic neuritis of the myelin oligodendrocyte glycoprotein antibody disease. [9]

A full-mark answer reproduces the surveillance, the surgery, the antibody disease and the contrast. [10]

The surveillance (2 marks). The visual acuity, the colour vision, the visual fields and the optical coherence tomography are reviewed at the regular intervals, with the Frisén grading of the disc, until the papilloedema resolves and the symptoms settle. The field loss is the indication for the escalation, because the vision loss may occur without the warning symptom, and the secondary optic atrophy is the irreversible complication of the chronic papilloedema. [3][6]

The surgical options (3 marks). The optic nerve sheath fenestration is the ophthalmic procedure that opens the sheath of the optic nerve to decompress the nerve and protect the vision, and it is the procedure of the choice for the dominant or the asymmetric vision loss. The cerebrospinal fluid shunting, the ventriculoperitoneal or the lumboperitoneal shunt, diverts the cerebrospinal fluid and lowers the pressure, and it is the procedure of the choice for the refractory headache and the generalised pressure. The venous sinus stenting is the interventional option for the selected case with the demonstrated venous stenosis. [2]

The myelin oligodendrocyte glycoprotein antibody disease (3 marks). The contrast with the optic neuritis begins with the recognition that the optic neuritis presents with the painful visual loss and the relative afferent pupillary defect, not with the headache and the raised pressure. The myelin oligodendrocyte glycoprotein antibody disease is the commonest antibody-mediated form in the child, presenting with the bilateral optic neuritis, the disc swelling and the frequent association with the acute disseminated encephalomyelitis, and it carries the generally favourable recovery but the high relapse rate. The antibody testing and the magnetic resonance imaging define the diagnosis, and the intravenous methylprednisolone at twenty to thirty milligrams per kilogram per day to a maximum of one gram for three to five days is the first-line treatment of the acute attack, with the maintenance immunotherapy for the relapsing form. [8][9]

The key contrast (2 marks). The idiopathic intracranial hypertension is the raised pressure with the mechanical disc swelling, treated with the acetazolamide and the weight loss, while the myelin oligodendrocyte glycoprotein optic neuritis is the inflammation of the optic nerve, treated with the corticosteroid and the immunotherapy. The aquaporin-four antibody neuromyelitis optica spectrum disorder carries the poor recovery, and it demands the early maintenance immunotherapy to prevent the relapse and the disability. [9][10]