Helen Maroulis, M.B., B.S.1, G. Michael Halmagyi, F.R.A.C.P.2, Robert Heard, F.R.A.C.P.3, and Raymond J. Cook, F.R.A.C.S.1
1Department of Neurosurgery, Royal North Shore Hospital; 2Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia; and 3Department of Neurology, Gosford Hospital, Gosford, Australia
Abbreviations used in this paper: ICP = intracranial pressure; SAS = sylvian aqueduct syndrome; VP = ventriculoperitoneal.
Address correspondence to: G. Michael Halmagyi, M.D., Neurology Department, Royal Prince Alfred Hospital, Camperdown, NSW-2050, Sydney, Australia. email:
Michael@icn.usyd.edu.au.
DOI: 10.3171/JNS/2008/109/11/0939
The authors report on 3 patients who developed sylvian aqueduct syndrome (SAS) in the context of shunt dysfunction and slit ventricles. All 3 patients had received shunts for adult onset hydrocephalus due to aqueduct stenosis and were stable for years before presenting with loss of upward gaze, convergence-retraction nystagmus, and slit ventricles, all due to shunt overdrainage. All 3 improved after either shunt revision or a third ventriculostomy procedure. Although it is well known that SAS can be caused by shunt blockage producing a transtentorial pressure gradient, these cases emphasize that an identical clinical pattern can occur with a reverse transtentorial pressure gradient and slit ventricles due to shunt overdrainage. The authors propose a simple management plan for patients with shunted hydrocephalus who develop SAS.
