ALCOHOL AND THE NERVOUS SYSTEM

1. ALCOHOL AND THE NERVOUS SYSTEM DR M KAKAZA

2. COMMON COMPLICATIONS • Nutritional deficiency • Diseases partly nutritional in origin • Direct effects of alcohol • Abnormalities of electrolytes and osmolality • Diseases of uncertain pathogenesis

3. A. Nutritional Complications • Wernicke’s Encephalopathy • Korsakoff’s syndrome • Pellagra

4. 1. Wernicke’s Encephalopathy • Clinical features include: • Confusion • Opthalmoplegia • Ataxia • MRI features: ( T2, Diffusion-weighted and FLAIR) Signal changes in periaqueductal gray matter, medial thalami and mamillary bodies

5. Wernicke’s Encephalopathy…. • Treatment: • Thiamine 100mg ivi stat then daily throughout the acute stage NB alcoholics may have poor intestinal absorption

6. Wernicke’s Encephalopathy…. • Other causes: • Hyperemesis of pregnancy • Systemic malignancy • GIT surgery • Prolonged iv feeding • Re-feeding after prolonged fast • Anorexia nervosa • Dieting and gastric plication • AIDS

7. 2. Korsakoff’s Syndrome • Russian Psychiatrist • Wernicke and Korsakoff’s syndrome are different stages of the same disease process. • Korsakoff’s follows Wernicke’s and tends to appear as ocular symptoms and encephalopathy improve

8. Korsakoff’s syndrome…. • Memory is impaired out of proportion to other cognitive functions – Amnestic syndrome • Have inability to form new memory

9. Korsakoff’s Syndrome…. • Clinical features: • Memory loss • Confabulation • Alertness, attention, social behavior intact • Localization of the lesion • Diencephalon • Temporal lobes

10. 3. Pellagra • Due to Nicotinic acid deficiency • From Italian ‘pelle agra’ which means ‘dry skin’ • Nicotinic acid is converted to NAD and NADP • NAD and NADP are coenzymes required in the metabolism of carbohydrates

11. Pellagra….. • Clinical triad: • Dementia • Dermatitis • Diarrhea

12. Pellagra…. • Communities that depend on corn for their diet can suffer from pellagra. • Corn lacks tryptophan, a precursor that can be converted to nicotinic acid in the body.

13. Pellagra…. • Bread is now enriched with niacin • Treatment: • Nicotinic acid ivi 25mg bd or tds

14. B. Direct Effects of Alcohol • Acute intoxication • Fetal alcohol syndrome • Alcohol withdrawal seizures • Delirium tremens

15. Stages of acute alcohol intoxication BLOOD LEVEL • 0.01 – 0.05 • 0.03-0.12 • 0.09-0.25 • 0.18-0.30 • 0.25-0.40 • 0.35-0.50 • 0.45+ STAGE Subclinical Euphoria Excitement Confusion Stupor Coma Death

17. C. Abnormalities of Serum Electrolytes and osmolality • Hyponatremia • Hypocalcemia • Hypomagnesemia • Hypophosphatemia

18. Central pontine myelinolysis

20. D. Diseases at least partly nutritional in origin • Alcoholic neuropathy • Amblyopia

21. 1 Alcoholic Neuropathy • Most common complication • Distal symmetrical polyneuropathy • Mixed sensory motor disorder • Pathology – Axonal loss • Pathogenesis: • Direct alcohol neurotoxicity • Thiamine deficiency

22. 2. Amblyopia • Vision loss caused by a selective lesion of the optic nerves • History – chronic alcoholic, poor dietary intake, loss of weight • Most likely due to nutritional deficiency • Treatment – Good nutrition , B vitamins • Prognosis – Improves on treatment (despite continued drinking)

23. E. Diseases of uncertain pathogenesis • Alcoholic myopathy • Alcoholic dementia • Cerebellar degeneration • Marchiafava-Bignami Syndrome

24. 1. Cerebellar Degeneration • Associated with long-standing use of alcohol • Patients often have neuropathy as well • Presentation • Progressive unsteadiness of gait • Trunkal ataxia

25. Cerebellar Degeneration…. • Pathological changes: • Selective atrophy of the anterior and superior parts of the vermis • Histological changes: • Purkinje’s cells most severely affected

26. 4. Marchiafava-Bignami Syndrome • Italian pathologists • Described in 1903 • Clinical picture difficult Mental slowing, Motor slowing, Personality or behaviour changes, Incontinence, Seizures, Dysarthria and hemiparesis

27. Marchiafava-Bignami Syndrome…. • Patholological changes: • Selective demyelination of the corpus callosum