Spinal intradural arachnoid cysts.

Three patients with indural spinal arachnoid cysts presented with back or neck pain of several months' duration. They gradually developed weakness and difficulty in walking followed by rapid deterioration with signs of spinal cord or nerve root compression. Radiological studies showed a posteriorly located mass in the cervical, dorsal and lumbar region; one cyst filled with contrast medium and the diagnosis of the others was made at operation. Surgery resulted in full recovery of two patients and partial recovery of the third.