Antiglutamate acid decarboxylase seropositive brain stem encephalitis.

This is a case of a previously healthy female in her fourties presenting with a subacute presentation of bilateral horizontal gaze restriction, with bilateral lower motor facial palsy. The patient's daughter has type 1 diabetes. On investigation, the patient's MRI revealed a lesion in the dorsal medial pons. Cerebrospinal fluid analysis revealed albuminocytological dissociation, with a negative autoimmune panel. The patient was treated with intravenous immunoglobulin, and methylprednisolone for a total of 5 days and showed mild improvement. The patient had raised serum antiglutamic acid decarboxylase (anti-GAD) levels, and the final diagnosis of GAD seropositive brain stem encephalitis was made.

Bickerstaff's brainstem encephalitis mimicking herpetic encephalomyelitis in a liver transplant patient with anti-GQ1b antibodies.

A woman in her late 70s with a history of liver transplant presented with ophthalmoplegia, ataxia, areflexia, positive Babinski's sign and reduced consciousness. This followed an antecedent illness in the form of a herpes zoster infection. MRI of the brain/spinal cord, cerebrospinal fluid analysis with viral PCR and routine blood tests were normal, and tacrolimus neurotoxicity was ruled out. Serum anti-GQ1b antibodies were positive. A diagnosis of Bickerstaff's brainstem encephalitis was made, forming part of the continuum that involves Miller-Fisher syndrome, entitled the 'anti-GQ1b syndrome'. Complete recovery ensued without intravenous immunoglobulins or plasma exchange. The role of monitoring anti-ganglioside pattern change to predict or confirm disease recurrence and disease severity is further discussed.

Optic ataxia in a patient with HaNDL syndrome.

We present a woman in her 40s who arrived at the emergency room with hypertension and optic ataxia. Her medical history is only relevant for obesity. Her lumbar puncture revealed high intracranial pressure and lymphocytic pleocytosis, and her neuroimaging tests, including angiography and venography, were normal. The patient improved after a cerebrospinal fluid drainage with a lumbar puncture, and her clinical manifestations resolved in parallel to the lymphocytic pleocytosis.The patient was diagnosed with a syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis and fully recovered 21 days after her discharge.

Non-arteritic anterior ischaemic optic neuropathy (NA-AION) and COVID-19 vaccination.

A woman in her 50s presented with diminution of vision in her left eye (OS) 4 days after COVISHIELDTM vaccination. She had been diagnosed with non-arteritic anterior ischaemic optic neuropathy (NA-AION) of right eye (OD) 8 months earlier. The present episode revealed a best-corrected visual acuity (BCVA) of 20/50 in OD and 20/20 in OS with grade 1 relative afferent pupillary defect. Fundus evaluation showed pale disc in OD and temporal disc oedema in OS. Humphrey's visual field analysis showed incomplete inferior altitudinal defect in OD and a centro-caecal scotoma in OS. Systemic investigations were normal. OS was diagnosed with NA-AION. She was started on oral aspirin 75 mg. At 1-month follow-up, disc oedema of OS had resolved with BCVA maintaining at 20/20. The patient was lost to follow-up later. The relationship between the vaccine and the ocular event is temporal with no causal association.

Rare presentation of sarcoidosis with optic neuropathy and third nerve palsy.

Sarcoidosis is a systemic, idiopathic and granulomatous disease, which most commonly affects the skin, lungs and lymph nodes but can affect virtually any organ. Neurosarcoidosis can be the presenting or the only clinical manifestation accounting for 5%-15% of sarcoid diagnoses. In contrast to uveitis which is the most common ophthalmic manifestation, neuro-ophthalmic signs are uncommon in sarcoidosis. Optic neuropathy is the most common neuro-ophthalmic sign (70% in one series). Sarcoid-related optic neuropathy commonly presents with a picture similar to optic neuritis. Less commonly, optic nerve involvement occurs secondary to compressive lesions, or from direct granulomatous infiltration. Neuroimaging is crucial to identify the location of the lesion. We describe a case of sarcoid-related compressive optic neuropathy and third nerve palsy and highlight the challenging nature of neurosarcoidosis in a patient without a prior diagnosis of the disease.

Bilateral, vertical supranuclear gaze palsy following unilateral midbrain infarct.

A 60-year-old man recently admitted for bipedal oedema, endocarditis and a persistently positive COVID-19 swab with a history of anticoagulation on rivaroxaban for atrial fibrillation, transitional cell carcinoma, cerebral amyloid angiopathy, diabetes and hypertension presented with sudden onset diplopia and vertical gaze palsy. Vestibulo-ocular reflex was preserved. Simultaneously, he developed a scotoma and sudden visual loss, and was found to have a right branch retinal artery occlusion. MRI head demonstrated a unilateral midbrain infarct. This case demonstrates a rare unilateral cause of bilateral supranuclear palsy which spares the posterior commisure. The case also raises a question about the contribution of COVID-19 to the procoagulant status of the patient which already includes atrial fibrillation and endocarditis, and presents a complex treatment dilemma regarding anticoagulation.