CHANGES IN BONE-MINERAL CONTENT AND DENSITY AFTER STROKE

The purpose of this study was to determine whether there are differenc es in bone mineral content and density between paralyzed and nonparaly zed sides of patients who had sustained strokes associated with unilat eral muscle weakness, to determine the relationship between duration o f stroke and degree of demineralization and to compare the degree of d emineralization in upper and lower limbs. The bone mineral content and density were measured by dual photon absorptiometry (high resolution scanning mode, Lunar DP4) in ambulant patients with a history of singl e completed strokes associated with unilateral weakness. The bone mine ral content and density of each limb was determined by the region of i nterest analysis program. In the 30 patients included in this study, t he bone mineral content and density were significantly less on the par alyzed than on the nonparalyzed side. The degree of demineralization w as more pronounced in the upper than in the lower limbs. The mean perc entage differences in bone mineral content and density between paralyz ed and nonparalyzed arms were 13.8% (P < 0.00001) and 7.95% (P = 0.000 3), respectively, and between paralyzed and nonparalyzed legs the diff erences were 4.5% (P = 0.0012) and 3.42% (P = 0.0028), respectively. A better correlation was noted between the time elapsed since the strok e and the degree of demineralization in the upper limbs (r = 0.75, P < 0.0001), than in the lower limbs (r = 0.60, P = 0.0004). In conclusio n, patients who have strokes associated with muscle weakness are at an increased risk of developing osteoporosis on the paralyzed side and p articularly in the upper limbs.