SUBACUTE COMBINED DEGENERATION OF THE SPINAL CORD
(Posterolateral Sclerosis)
DEFINITION
SUBACUTE COMBINED DEGENERATION OF THE SPINAL CORD is a disease characterised by degeneration of posterior and lateral columns of the spinal cord due to Vitamin B12 deficiency. This disease may be associated with pernicious anemia, gastric carcinoma, partial or complete gastrectomy, idiopathic steatorrhoea, regional ileitis, diverticulitis, etc. Pyramidal tract and tracts of Goll and Burdach are affected.
CLINICAL FEATURES
Onset is gradual, rarely acute.
Age : 40 to 60 years.
Sex Both.
Sensory changes
Tingling and numbness of the toes followed by fingers and then coldness or tightness of the fingers and toes may develop. Lower limbs are more affected than the upper limbs. Light touch, pin prick, hot and cold sensations in hands and feet may be lost, Joint sense and vibration senses are also affected.
Motor changes
Weakness and ataxia in all four limbs mainly in the lower limbs along with spasticity may be present in some cases. Jerks are lost but may be brisk, plantar reflexes at first become flexor but later on become extensor in type.
Sphincteric changes
At fist there may be little difficulty in micturition or precipitate micturition but later on retention or incontinence may develop.
Cranial nerves
Visual disturbances may develop due to optic atrophy.
Mental changes
Impaired memory, confusion, Korsakow’s psychosis, mild dementia, irritability or depression may sometimes be present.
INVESTIGATIONS
1. Augmented Histamine test will show achylia gastrica.
2. Bone marrow examination and blood picture may point towards pernicious anemia.
3. Vitamin B12 level in serum may be low, even less than 50 ugm/cc.
4. Vitamin B12 absorption and excretion test using radioactive cobalt will show minimal or no absorption and practically 100 per cent elimination.
TREATMENT
When pernicious anemia is present Vitamin B12 100 mg IM daily for 7 days may be given and then weekly for 1 month and then monthly for the rest of the patient’s life.