B12 DEFICIENCY

Question 0

Sx of b12 deficiency?

Answer 0

General
- anaemia, jaundice (haemolysis) , glossitis, angular cheilosis
Neuropsychiatric 
- irritability, depression, psychosis
Neurological
- peripheral neuropathy 
SACD

Question 1

Causes of B12 deficiency?

Answer 1

Dietary
Malabsorption
- STOMACH: lack of intrinsic factor, pernicious anemia, post gastrectomy
- TERMINAL ILLEUM: Crohn’s disease, Ileal resection
Congenital metabolic errors

Question 2

What is pernicious anaemia?

Answer 2

Atrophic gastritis with autoimmune destruction of gastric parietal cells -> lack of intrinsic factor.

Question 3

What is subacute degeneration of the spinal cord (SACD)?

Answer 3

Degeneration of the posterior (sensory) and lateral columns (motor) of SC dt B12 deficiency or Vit E/copper.

Insidious onset with peripheral neuropathy, ataxia. Spinothalamic tracts preserved.

Classic triad

1. Babinskis positive (UMN)
2. Absent knee jerks (LMN)
3. Absent ankle jerks (LMN)

Question 4

Importance of B12?

Answer 4

Binds to intrinsic factor in stomach.
Absorbed in the terminal ILLEUM.

If deficient -> DNA impairment -> RBC production is slow