The neurology of cobalamin deficiency in an elderly population in Israel

Abstract

Objectives

To evaluate the neurological status in elderly subjects with cobalamin deficiency (CblD) compared with matched non–deficient subjects before and after cobalamin (Cbl) supplementation.

Methods

Participants completed a questionnaire on activities of daily living, level of education, medical history, alcohol, nicotine, caffeine, and medication usage and prior consumption of vitamins. They underwent a detailed programmed neurological evaluation which was repeated after 6–9 months of Cbl therapy.

Results

There were 113 subjects with blood Cbl ≤147 pmol/L, methylmalonic acid ≥0.24 μmol/L, and 212 nondeficient subjects (controls). The mean age of the patients and controls was 79.5 ± 6.9 and 79.5 ± 5.9 years, respectively. Fifty patients (44.4 %) and 56 controls (26.4%) were found to have mild sensory neuropathy (SN).When subjects with diabetes mellitus (DM) were excluded, however, only 30 (26.5%) patients and 23 (10.8 %) controls had SN. A history of confusional state was more common among the patients than among the controls (12.4 % and 3.3%, respectively) as was a low mini–mental state examination (MMSE) score (20.2% and 15.2%, respectively).No patient had clinical signs compatible with subacute combined degeneration (SCD). Supplementation of Cbl for 6–9 months did not alter the neurological findings,while the biochemical deficiency was corrected.

Conclusions

Mild SN rather than SCD is the main neurological impairment in elderly people with CblD. Short–term supplementation of CbL can correct the biochemical deficiency without affecting the neurological impairment.