Alcohol Withdrawal and Wernicke's Encephalopathy

The stages of alcohol withdrawal are:

• 6-12 hours – Tremor, Sweating, Headache, Craving, Anxiety

• 12-24 hours – Hallucinations

• 24-72 hours – Delirium Tremens (Confusion, Seizures, Tachycardia, HTN)

N.B. Commonly tactile hallucinations, where they feel spiders crawling on their skin.

The 2 main medications given to manage this are:

• Chlordiazepoxide – Benzo given as a reducing regime, titrated to the required dose based on hospital protocol

• Pabrinex (High-dose B vitamins) – Followed by regular, low-dose oral Thiamine

  • These are given to prevent Wernicke-Korsakoff Syndrome (WKS)

Delirium Tremens

Symptoms usually peak around day 4-5.

The effects of alcohol on the brain:

• Stimulates GABA receptors in the brain, which have a relaxing effect on the rest of the brain

• Inhibits Glutamate/NMDA rec

  eptors, therefore having an inhibitory effect on brain electrical activity

• With chronic alcohol use, there's downregulation of the GABA system, and upregulation of the Glutamate/NMDA system to balance the long-term effects of alcohol. These dysfunctions cause extreme brain excitability.

Clinical features:

• Confusion

• Hallucinations

  • Particularly visual and tactile hallucinations (such as formication – feeling crawling insects on/under skin)

• Agitation

• Sweating

• Tremor

• Tachycardia

• HTN

Management:

• Lorazepam

• Maintenance management of alcohol withdrawal i.e. Chlordiazepoxide, Pabrinex

Wernicke’s Encephalopathy

This is due to Thiamine (Vit B1) deficiency.

N.B. It’s associated with lesions in the mammillary bodies.

It's more common in alcoholics as thiamine is poorly absorbed in the presence of alcohol, and alcoholics tend to have a poor dietary intake.

It presents with a triad of Confusion, Ataxia, and Ophthalmoplegia (nystagmus, lateral rectus, conjugate gaze palsies etc.).

N.B. Ocular abnormality (particularly nystagmus) is the hallmark sign of Wernicke's encephalopathy.

It's treated with Urgent IV Pabrinex to prevent the progression to Korsakoff’s syndrome. Glucose has to be checked before giving this.

• If hypoglycaemic, Thiamine should be given first to prevent the precipitation/worsening of the Wernicke’s.

N.B. Glucose metabolism requires Thiamine, therefore giving it first will deplete the thiamine levels even more.

Korsakoff’s Syndrome

Hypothalamic damage and Cerebral atrophy due to Thiamine deficiency.

Clinical features:

• Memory impairment

  • Anterograde – Reduced ability to make new memories

  • Retrograde – Patients confabulate (fabricate memories to mask the memory deficit)

• Behavioural changes – Lack of insight, Apathy

N.B. Often irreversible and results in patients being in full-time institutional care.