Vital Vitamins
This water-soluble vitamin's deficiency causes a triad of ophthalmoplegia, ataxia, and encephalopathy - classically seen in chronic alcohol misuse.
What is vitamin B1 (thiamine) deficiency / Wernicke's encephalopathy?
This antibody is found in small cell lung cancer patients with a subacute sensory neuronopathy.
What is anti-Hu (ANNA-1)?
The encephalitis classically presenting in young women with psychiatric symptoms, seizures, orofacial dyskinesias and autonomic instability, often with an ovarian teratoma.
What is anti-NMDA receptor encephalitis?
A 67-year-old man with a 50-pack-year smoking history presents with pseudoathetosis of the hands, sensory ataxia, absent reflexes, and absent SNAPs but normal motor responses.
What is paraneoplastic sensory neuronopathy / anti-Hu syndrome (SCLC)?
First-line treatment for Wernicke's encephalopathy in any at-risk patient - and the rule about when to give it relative to glucose.
What is IV Pabrinex / thiamine BEFORE any IV glucose?
Best biochemical markers for functional B12 deficiency when serum B12 is borderline - both are elevated.
What are methylmalonic acid (MMA) and homocysteine?
Antibodies against this presynaptic ion channel cause Lambert-Eaton myasthenic syndrome.
What is the P/Q-type voltage-gated calcium channel (VGCC)?
This specific EEG pattern is highly suggestive of anti-NMDA receptor encephalitis.
What is the 'extreme delta brush' pattern?
A 60-year-old man with PROXIMAL leg weakness whose power BRIEFLY IMPROVES after exercise; reflexes are absent but reappear after a brief contraction.
What is Lambert-Eaton myasthenic syndrome (LEMS)?
For B12 deficiency WITH neurological involvement, this is the recommended replacement regimen.
What is hydroxocobalamin 1 mg IM on alternate days until no further improvement, then 1 mg IM every 2 months?
This nutritional deficiency is associated with a photosensitive dermatitis distributed across the neck - Casal's necklace - plus diarrhoea and dementia.
What is pellagra (vitamin B3 / niacin deficiency)?
This antibody-mediated paraneoplastic cerebellar degeneration is most strongly associated with ovarian and breast cancer.
What is anti-Yo (PCA-1)?
Up to 60% of patients with this autoimmune encephalitis are initially admitted under psychiatry.
What is anti-NMDA receptor encephalitis?
A patient with chronic diarrhoea and arthralgia develops dementia, ophthalmoplegia, and PENDULAR CONVERGENCE NYSTAGMUS synchronous with jaw movements - even during sleep.
What is Whipple's disease (oculomasticatory myorhythmia)?
The two key first-line immunotherapies, in addition to corticosteroids, for anti-NMDA receptor encephalitis.
What are IV immunoglobulin (IVIG) and plasma exchange (PLEX)?
This vitamin's deficiency mimics Friedreich's ataxia - gait ataxia, areflexia, loss of proprioception - and arises in fat malabsorption such as cystic fibrosis or abetalipoproteinaemia.
What is vitamin E (tocopherol) deficiency?
Limbic encephalitis with this antibody is characteristically associated with hyponatraemia (SIADH) and faciobrachial dystonic seizures.
What is the LGI1 (leucine-rich glioma-inactivated 1) antibody?
These brief (less than 3 seconds) unilateral dystonic jerks of the arm and ipsilateral face, occurring up to 100 times per day, are pathognomonic for LGI1 antibody syndrome.
What are faciobrachial dystonic seizures (FBDS)?
A 26-year-old woman at 14 weeks gestation, treated with IV dextrose for hyperemesis, develops confusion, nystagmus, and gait ataxia.
What is Wernicke's encephalopathy (precipitated by glucose before thiamine)?
The single most important intervention in paraneoplastic syndromes - without it, immunotherapy is usually inadequate.
What is treatment of the underlying tumour (resection / chemo / radiotherapy)?
If you give this nutrient to a patient with undiagnosed B12 deficiency, you may correct their anaemia while accelerating their subacute combined degeneration of the cord.
What is folate (folic acid)?
This antibody, associated with testicular germ cell tumours in young men, causes limbic encephalitis with prominent brainstem and hypothalamic features.
What is anti-Ma2 (anti-Ta)?
On MRI, both autoimmune limbic encephalitis (LGI1) and paraneoplastic limbic encephalitis show T2/FLAIR hyperintensity in this bilateral structure.
What is the mesial temporal lobe (hippocampus / amygdala)?
A 45-year-old woman with dry eyes and dry mouth presents with bilateral facial numbness in V2 and V3 distributions and a slowly progressive sensory ataxia.
What is Sjogren's syndrome with trigeminal sensory neuropathy and sensory neuronopathy?
This potassium-channel blocker is the symptomatic treatment of choice for Lambert-Eaton myasthenic syndrome, as it prolongs depolarisation and increases calcium influx at the presynaptic terminal.
What is 3,4-diaminopyridine (3,4-DAP / amifampridine)?