• A case of convergence nystagmus associated with an Arnold-Chiari type I malformation is presented. The nystagmus appeared in the absence of fixation, was provoked during Valsalva's maneuver and neck flexion and extension, and attenuated on deep inspiration. Sagittal magnetic resonance images showed that the diameter of the cerebral aqueduct increased with the neck in full flexion and in full extension. Surgical foramen magnum decompression considerably reduced the nystagmus and abolished the postural variation of aqueduct diameter. It is postulated that this nystagmus was due to a combination of mechanical distortion and abnormal transmission of cerebrospinal fluid pressure to the aqueductal region.
Mossman SS, Bronstein AM, Gresty MA, Kendall B, Rudge P. Convergence Nystagmus Associated With Arnold-Chiari Malformation. Arch Neurol. 1990;47(3):357–359. doi:10.1001/archneur.1990.00530030139030
Browse and subscribe to JAMA Network podcasts!
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: