SPINAL-CORD COMPRESSION BY HETEROTOPIC OSSIFICATION ASSOCIATED WITH PSEUDOHYPOPARATHYROIDISM

This report describes a 37-year-old man presenting with a gait disturb ance due to spastic paraparesis. Physical findings showed typical feat ures of albright's hereditary osteodystrophy, including short stature, obesity, brachydactyly and dental hypoplasia. He was diagnosed as hav ing pseudohypoparathyroidism type Ia, on the basis of his hypocalcaemi a, hyperphosphataemia, increased plasma level of parathyroid hormone ( PTH), and the unresponsiveness to exogenous PTH loading of his urinary excretion of both nephrogenous cyclic adenosine monophosphate and pho sphate. Magnetic resonance imaging and myelographic computed tomograph ic scans clearly demonstrated severe compression of the spinal cord at T 9/10 by tumour-like ossifications of the paravertebral ligaments. N eurosurgical decompression therapy was, therefore, performed to allevi ate his spastic paraparesis. This was a rare case of pseudohypoparathy roidism complicated with spinal cord compression caused by ectopic oss ification of the ligaments.