What are the signs and symptoms of top-of-the-basilar syndrome in vertebrobasilar stroke?

Updated: Aug 09, 2021
  • Author: Vladimir Kaye, MD; Chief Editor: Stephen Kishner, MD, MHA  more...
  • Print


This syndrome is the manifestation of upper brainstem and diencephalic ischemia caused by occlusion of the rostral basilar artery; the occlusion usually results from an embolism. [16] Varying degrees of involvement of the midbrain, thalamus, and portions of the temporal and occipital lobes may occur and can produce severe disability.

Patients present with sudden changes in the level of consciousness, confusion, amnesia, and visual symptoms (eg, hemianopia, cortical blindness, abnormal color vision/color dysnomia). These patients can also demonstrate oculomotor abnormalities, most commonly of the vertical gaze, such as gaze palsy, skew deviation, convergence spasm resulting in pseudoabducens palsy, or convergence-retraction nystagmus.

CN III palsy and pupillary abnormalities, including small pupils with decreased light reactivity (diencephalic), large/mid-position and fixed pupils (midbrain), and ectopic or oval pupils, also are frequent.

Other abnormalities include varying degrees of weakness, sensory deficits, or posturing.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!