hydroxocobalamin and Demyelinating-Diseases

Topics: Age of Onset; Anemia, Hemolytic; Anemia, Megaloblastic; Blood Transfusion; Child; Child, Preschool; Dementia; Demyelinating Diseases; Diagnostic Errors; Family Health; Female; Gas Chromatography-Mass Spectrometry; Humans; Hydroxocobalamin; Metabolism, Inborn Errors; Methylation; Nuclear Family; Paralysis; Vitamin B 12 Deficiency

A series of 21 patients admitted to St Thomas' Hospital, Medical Ophthalmology Unit, with a diagnosis of West Indian or West African amblyopia is reported. Patients were investigated for haematological, biochemical, serological, and radiological abnormalities and particular attention was paid to dietary history. Patients admitted in recent years also underwent neurophysiological investigations. No definite correlation between visual loss and dietary or family history was found, and there was no evidence that the improvement in vision which occurred in just under half the patients on follow-up was related to treatment with hydroxocobalamin or multivitamins. Visual-evoked responses in 4 patients showed a prolonged latency suggesting optic nerve demyelination, while in only one case was the electro-oculogram definitely subnormal. These findings contrast with those in 'toxic' amblyopias and suggest that the syndrome of West Indian amblyopoa may be due to bilateral optic nerve demyelination of unknown aetiology rather than the effect of toxic substances or nutritional deficiency on the retina.

Topics: Adolescent; Africa, Western; Amblyopia; Child; Demyelinating Diseases; Diet; Female; Humans; Hydroxocobalamin; London; Male; Middle Aged; Nutrition Disorders; Syndrome; West Indies

Five patients presenting clinically with a form B12-deficiency neuromyelopathy, with cord involvement in all and proximal muscle weakness in two of them, were investigated for their neurologic, hematologic and vitamin status. Megaloblastosis and achlorhydria were present in all, and impaired absorption of 57Co vitamin B12 and of D-xylose was detected in four. Total cyanide extracted vitamin B12 (A) was lowered in all cases and noncyanide extractable (B) in four of the five, being zero in three. All five responded to injections of hydroxocobalamin. In two patients sequential estimations showed that both A and B, especially the latter, rose steeply initially, normalizing at 50% of A after some weeks. Moiety B is suggested to be physiologically the more active and dissociable form of vitamin B12. Markedly elevated initial serum folate levels, and their subsequent fall under treatment with B12, indicated the operation of the "methyltetrahydrofolate trap". Blood levels of thiamin, nicotinic acid and pantothenic acid were within normal limits. However, serum riboflavin (B2) total vitamin B6 and pyridoxal were reduced in all where tested. Vitamin B6 deficiency could have resulted from its own malabsorption and have contributed to be B12 deficiency. Vitamin B2 and B6 levels also corrected themselves on B12 therapy. The B-vitamin deficiencies in our patients probably resulted from intestinal malabsorption, with a possible factor of malnutrition consequent to their strictly vegetarian diet.

Topics: Achlorhydria; Adolescent; Adult; Animals; Demyelinating Diseases; Diet, Vegetarian; Erythrocyte Count; Humans; Hydroxocobalamin; Malabsorption Syndromes; Male; Megaloblasts; Milk; Spinal Cord Diseases; Vitamin B 12 Deficiency; Vitamin B 6 Deficiency; Vitamin B Complex

Topics: Amblyopia; Animals; Cyanides; Demyelinating Diseases; Humans; Hydroxocobalamin; Male; Rats; Smoking; Vitamin B 12