8. Metabolic and toxic diseases

Question 1

Types of metabolic and toxic diseases

Answer 1

1. Deficiencies
   - Vitamin B1 (thiamine) → Wernicke encephalopathy
   - Vitamin B12 → subacute combined degeneration spinal cord
2. Storage disease
   - Niemann Pick disease
   - Tay-Sachs disease
3. Hepatic encephalopathy
4. Carbon monoxide poisoning
   - Necrosis of globus pallidus
   - Diffuse cortical necrosis
5. Alcohol-related diseases

Question 2

How can alcohol affect the brain

Answer 2

1. Fetal alcohol syndrome
2. Acute intoxication → respiratory depression → death
3. Chronic alcoholism
   - Cerebral cortical atrophy
   - Cerebellar atrophy
   - Wernicke encephalopathy (thiamine deficiency)
   - Korsakoff’s psychosis

Question 3

Thiamine (vitamine B1) deficiency

Answer 3

Damage to the medial thalamus and mammillary bodies, and generalised cerebral atrophy

Question 4

Wernicke encephalopathy

Answer 4

1. Acute development of psychotic symptoms or ophthalmoplegia
2. Morphology:
   - Haemorrhage and necrosis in mammillary bodies, walls of 3rd and 4th ventricles

Question 5

Chronic alcohol abuse or severe malnutrition leads to

Answer 5

Korsakoff’s syndrome

Question 6

Morphology of Korsakoff’s syndrome

Answer 6

Cystic spaces with haemosiderin-laden macrophages

Question 7

Wernicke encephalopathy + Korsakoff’s syndrome =

Answer 7

Wernicke-Korsakoff syndrome

Question 8

6 major symptoms of Korsakoff’s syndrome

Answer 8

1. Anterograde amnesia
2. Retrograde amnesia
3. Confabulation - invented memories which are then taken as true due to gaps in memory sometimes associated with blackouts
4. Meager content in conversation
5. Lack of insight
6. Apathy - patients lose interest in things quickly and generally appear indifferent to change

Question 9

Morphology of alcohol damage in the CNS

Answer 9

1. Atrophy of cerebellar vermis

2. Haemorrhage in mammillary bodies