[Clinical study of spinal intradural arachnoid cyst]

Spinal intradural arachnoid cysts (S-IAC) are rarely found and only 80 cases have been reported since 1915. We report two of them. A 68-year-old male had slowly progressive dull pain in both thighs for about 6 years prior to admission. Neurological examination and plain x-ray on admission showed no abnormality. Myodil myelography showed a S-IAC at T4 vertebral level. Surgical treatment of cyst wall excision resulted in success. The other case, a 39-year-old male suddenly noticed monoparesis and sensory disturbance of left leg in the morning. On admission were observed spastic monoparesis of the left leg, analgesia at right T2-3 cord segment and sensory disturbance (hypesthesia, dysesthesia, paresthesia) below T3-4 cord segment on the left side. Plain X-ray showed no abnormality. Myodil myelography revealed a S-IAC at T3-4 vertebral level. This patient was treated not surgically but conservatively because all neurological deficits but numbness in the left leg almost subsided after bed rest. The patient has experienced no neurological deterioration for five years since then. We also discuss the clinical feature, treatment and etiology of the S-IAC, by analyzing these 82 cases. There is a slight male preponderance. The age ranges between 3 and 66 years (mean 38 years). The duration from onset to admission is 2 days to 30 years. Sixty percent (48/80) of the cases were ill far longer than a year (mean 6.7 years). Of 82 cases, 83% suffered from motor disturbance, 70% had sensery disturbance, 62% local pain and 24% urinary with/without fecal disturbance.(ABSTRACT TRUNCATED AT 250 WORDS)