[The determinants of bone mineral density in hemiplegic patients. Preliminary data]

We studied a group of hemiplegic patients to determine the amount of bone loss of the paretic versus the normal limb and to evaluate the importance of several variables in determining this difference. Thirty consecutive subjects with hemiplegia caused by a cerebral vascular accident were studied: 15 postmenopausal women (average age 65.1 years) and 15 men (average age 58.3 years) (average age of entire group, 63.2 years; age range of entire group, 27-84 years). The mean duration of immobilization was 7.7 months for women (range 1-40 months) and 10.5 months for men (range 1-48 months). All subjects had a complete physical examination, underwent bilateral femoral neck DEXA, and filled out a questionnaire. The percent difference (delta) between the paretic and normal limb was 6.1% in the women and 3.8% in the men. Logistic regression analysis, after control for age and sex, indicated that the degree of demineralization depended significantly and directly on the duration of immobilization and depended inversely on the time elapsed since menopause. Our data evidence the importance of immobilization osteoporosis and point to the role of hormonal factors in its pathogenesis.