[A case of rigid spine syndrome associated with severe respiratory failure]

Rigid spine syndrome (RSS) is clinically characterized by progressive limitation of flexion of the spine and contractures of other joints. We herein report a 27-year-old man with RSS, who underwent tracheotomy because of severe restrictive respiratory failure. He had limitation of neck flexion and proximal muscle weakness from early childhood and was diagnosed as having muscular dystrophy at 16 years old. He was suffered from dyspnea and his first tracheotomy was performed at 24 years old. Two years later, the second tracheotomy was done because his respiratory failure was aggravated. He had limitation of spine flexion, scoliosis, but no limited range of elbow and wrist joints movement except mild contracture of ankle joints. Serum CK level was elevated to 590 IU/L. Repeated ECG examinations showed negative T wave but no conduction block. In his family, his parents and brother had neither similar clinical symptoms nor heart block. Chest X-ray study showed elevated diaphragm and enlarged heart shadow (CTR = 65%). Percent VC and FEV1 in sitting position were 14.6% and 100%, respectively. Arterial blood gas analysis showed PaO2 of 34.2 mmHg and PaCO2 of 77.2 mmHg. The density of paraspinal muscle in CT scan was severely decreased. Needle EMG showed myogenic change. Muscle biopsy from left biceps brachii showed myopathic change with mild type 2 fiber grouping. After the second tracheotomy, he was on a respiratory during sleep but mostly off in the daytime. His clinical features are different from Emery-Dreifuss muscular dystrophy because he had no heart conduction block and no family history, but progressive respiratory failure.(ABSTRACT TRUNCATED AT 250 WORDS)