SACD of spinal cord Flashcards
What causes subacute combined degeneration of the spinal cord?
vitamin B12 deficiency
Which columns are affected in subacute combined degeneration fo the spinal cord?
dorsal and lateral columns
What are 3 key symptoms of subacute combined degeneration of the spinal cord?
- Joint position and vibration sense lost first (carried in dorsal column)
- Distal paraesthesia occurs next
- Upper motor neuron signs typically develop in the legs, classically extensor plantars, brisk knees reflexes, absent ankle jerks
What are the 3 classic upper motor neuron signs that typically develop in the legs in SACD of the spinal cord?
- extensor plantars
- brisk knee reflexes
- absent ankle jerks
If untreated what can be the lasting effects of SACD of the spinal cord?
stiffness and weakness
What is the management of SACD of the SC?
- hydroxocobalamin - form of vitamin B12 of choice
- IM injection initially 1mg 3x a week for 2 weeks, then 1mg every 3 months
What must you not give in vitamin B12 deficiency and why?
don’t give folic acid instead as this may result in fulminant neurological deficit
What is the key investigation for diagnosis of vitamin B12 deficiency?
serum vitamin B12 levels (may give galse normal level)
(can also measure plasma total homocysteine, raised in deficiency)
What are 4 investigations to help determine the aetiology of vitamin B12 deficiency?
- Autoantibody screen - pernicious anaemia one of many autoimmune diseases which can coexist
- intrinsic factor antibody - low false positive rate but low sensitivity
- gastric anti-parietal cell antibodies - 80% of pernicious anaemia subjects but low specificity
- Bone marrow aspiration - myelodsplasi, aplastic anaemia, myeloma . megaloblasts and giant metamyelocytes seen in B12 and folate deficiency
- gastric secretions
- gastroscopy
