A study of bone densitometry in patients with complex regional pain syndrome after stroke

This study was undertaken to evaluate the bone mineral density (BMD) in patients with complex regional pain syndrome type-I (CRPS-I) after stroke, and to correlate it with various clinical and neurophysiological parameters.

Twenty patients with CRPS-I after stroke were included and a detailed neurological evaluation was carried out. The severity of CRPS-I was graded on the basis of shoulder hand syndrome score. All the patients underwent bone mineral densitometry of paralysed and non-paralysed forearm by dual energy x ray absorptiometry. The BMD of paralysed forearm was also compared with that of age matched healthy controls. Neurophysiological tests included sympathetic skin response in both upper and lower limbs and median somatosensory evoked potentials.

The mean age of patients was 57.2 (45-75) years and eight were females. Eight patients had severe weakness and 12 had moderate weakness of grade 2 on the hemiplegic side. There was significant reduction in BMD in the patients compared with controls (p<0.01). The bone density reduction correlated well with duration of illness (r = -0.673, p<0.01), shoulder hand syndrome score (r = -0.804, p<0.01), and Canadian neurological scale score (r = -0.738 p<0.01). Sympathetic skin response was not recordable bilaterally in all patients. Median somatosensory evoked potentials were not recordable in seven out of 20 patients who also had higher grade of CRPS-I.

Our results show significant reduction of BMD in patients with CRPS-I after stroke. The reduction in BMD correlates with the severity of shoulder hand syndrome score, degree of weakness, duration of hemiplegia, and the severity of stroke.