Definition: Thiamine deficiency with a classical triad of confusion, ataxia, and ophthalmoplegia.
Aetiology/ risk factors:
-inadequate dietary intake
-reduced GI absorption
= focal areas of brain damage, including periaqueductal punctate haemorrhages
-Often seen in chronic alcoholism
–Also: eating disorders, malnutrition, prolonged vomiting e.g. with chemo, GI malignancy, extreme morning sickness (Hyperemesis gravidarum)
-12.5% prevalence in patients with alcohol dependence
-confusion/delirium, disorientation, apathy
-diplopia (double vision)
–ophthalmoplegia = nystagmus, lateral rectus (inability to abduct eye) or conjugate gaze palsies (inability to move both eyes in a single direction), internuclear ophthalmoplegia
-gait ataxia = wide-based gait
-hypotension, hypothermia, reduced consciousness
-Diagnosis primarily clinical and based on response to thiamine
–Red cell transketolase activity decreased (rarely done)
-IV Pabrinex- high potency vitamins C (ascorbic acid), B1 (thiamine), B2 (riboflavin), B3 (nicotinamide) and B6 (pyridoxine).
-2 pairs of high potency ampoules (IV/IM/8h) over 30 min for 2 days, then 1 pair daily for a further 5 days.
-oral supplementation until no longer at risk (100mg/d)
-If there is also hypoglycaemia, make sure that thiamine is given before glucose.
-Correct any magnesium deficiency (co-factor for thiamine)
-Advice and support for alcohol cessation
-Irreversible Korsakoff’s syndrome (a.k.a Korsakoff’s psychosis) if not treated urgently
= reduced ability to acquire new memories (anterograde amnesia)
= confabulation (invented memory owing to retrograde amnesia)
= lack of insight, apathy
-reversible with prompt treatment
-untreated = 20% death, 85% Korsakoff’s psychosis (1/4 of these will need institutional care)
References: Cheese & Onion, Rapid Medicine, BMJ Best Practice