Makindo Medical Notes.com

Always give Pabrinex to anyone who is malnourished or alcoholic or hyperemesis. It contains ascorbic acid 500 mg, anhydrous glucose 1 g, nicotinamide 160 mg, pyridoxine hydrochloride 50 mg, riboflavin 4 mg, and thiamine hydrochloride 250 mg in a total of 10 ml especially before giving carbohydrates /glucose. If untreated Wernicke-Korsakoff syndrome may lead to an irreversible amnestic state.

About

• Described in 1881 by Carl Wernicke
• Damage to memory - confusion, ataxia, and nystagmus
• Usually due to Thiamine deficiency
• The body stores 18 days worth of Thiamine

Clinical Signs of Acute Wernicke's encephalopathy

• Ophthalmoplegia (diplopia) horizontal and vertical nystagmus,
• Weakness of lateral rectus, weakness of conjugate gaze
• Ataxia : unsteadiness of standing and walking
• Confusion: Confabulation and inattention and confusion
• May have a polyneuropathy or cerebellar signs

If untreated, this condition could develop into a Chronic Korsakoff’s Syndrome, which presents symptoms such as:

• Severe if not permanent memory loss.
• Confabulation – Making up stories of oneself.
• Hallucinations – Seeing things that are not present.
• Inability to form new memories.

Causes

• Precipitants include infection, surgery, trauma, or a carbohydrate load
• Alcoholism: Alcohol prevents uptake of thiamine leads to a decrease of thiamine pyrophosphate from thiamine as well as the liver’s capacity to store thiamine itself.
• Anorexia nervosa
• Hyperemesis gravidarum in pregnancy
• Weight loss / Bariatric surgery
• Any persisting sickness and nausea, starvation etc
• Malabsorption

Differentials

• Hepatic encephalopathy: Ammonia levels
• Encephalitis - consider LP/MRI
• Alcohol induced peripheral neuropathy or cranial neuropathies
• Tumours or lesions involving the hypothalamus
• Syphilis, Carbon monoxide poisoning, Head Injury and SAH

Mamillary body, medial thalamus hypothalamus, Periaqueductal grey matter involved. T2 and FLAIR hyper and restriction of diffusion

Investigations

• Check U&E, Mg, LFTs and general confusion screen
• Reduced red cell transketolase and ? thiamine levels and ? pyruvate levels
• CT brain: exclude bleed or SDH
• Brain MRI might show specific atrophy in diencephalic structures in Korsakoff's syndrome. T2 weighted changes in the thalamus (memory loss) and periaqueductal grey matter (causing eye signs)
• ABG: exclude hypoxemia, hypercarbia, acidosis, or alkalosis, COHb
• Post mortem: punctate haemorrhages affecting the grey matter around the third and fourth ventricles and aqueduct of Sylvius

Management

• Thiamine replacement e.g. Pabrinex contains parenteral vitamin B and C should be used for the first 3 days or IV/IM Thiamine 100 mg for 3-7 day and then orally long term before giving any carbohydrates. Others have suggested larger doses of 500 mg IV TDS for 2-3 days. Anaphylactic reactions to parenteral thiamine do occur.
• Correct any deficiency of electrolytes, particularly magnesium and potassium and review any sedation.
• Manage ongoing alcohol abuse and abstention - community alcohol abuse treatment
• May need psychiatric management for long term cognitive and behavioural issues