H YPERTROPHIC cervical pachymeningirls is a clinical syndrome characterized by compression of the spinal roots and spinal cord caused by a marked inf lammatory hyper t rophy of the cervical dura mater. The pathological process can spread to the leptomeninges and give rise, because of the progressive compression, to areas of softening of the spinal cord, where it is also possible to find cavities similar to those in syringomyelia. 26,29,4~ The cause of the disease is still unknown26,3~ T he clinical picture is still tha t first described by Charcot in 18696 and Joffroy in 1873, TM who divided the evolution of the disease into three stages. The first stage is character ized by intermit tent radicular pains in the neck, shoulders, and arms, which gradually become continuous. In the second stage, muscular weakness and a t rophy develop in the arms. Finally, spastic paralysis of the legs, loss of various modalities of sensation, paresis of bowel and bladder, and respira tory disturbances characterize a third stage. The disease has been described in the cervico_thoraeic,S,2s,29.3t ,37 thoracic,~4 z~,25.3s.~9 and lumbar 1,11 regions, or along the entire extension of the spinal column, 6,24,27 with symptoms vary ing according to the level of the lesion. We are reporting five cases of hyper t rophic spinal pachymeningitis operated upon during 1955 to 1965. We have excluded from this series 14 cases of chronic epidural inf l ammatory processes and 30 cases of spinal arachnoidit is operated on in the same period, even though some of these showed a modera te thickening of the spinal dura mater.