M. De Lima Oliveira, K. Andrade Norremose, A. Negrao Esteves, B. Magalhaes Barbosa Leite, M. Ferreira Machado, M. Jacobsen Teixeira, E. Bor-Seng-Shu
Department of Neurology, University Hospital, University of São Paulo – São Paulo, Brazil

Objective: Bow Hunter´s syndrome (BHS) reflects a perturbation of blood flow provoked by changes in the position of head. Symptoms include syncope, dizziness, vertigo, visual blurriness, drop attacks, tinnitus, hypoacusis, and sensory or motor deficits. Here we describe the application of Transcranial Doppler (TCD) in diagnosis of BHS.

Case Report: The subject is a 86-year old female presenting with sudden loss of consciousness lasting few seconds after flexing neck. After the episode the patient remained with dizziness and vertigo. Her previous medical history displayed hypertension. At admission, she presented with right apendicular ataxia and left homonymous hemyanopsia. She performed skull computadorized tomography (CT), which revealed a large ischemic zone in right cerebellar hemisphere and ipsilateral occipital lobe. TCD was then performed before and during mechanical maneuvers. The vessel chosen was the posterior cerebral artery. There was an important amplitude in mean flow velocity: 38 cm/s before maneuver, 20 cm/s during cervical flexion and rotation maneuver (reduction of 48%); 50 cm/s after assuming neutral position (increase in 24% – reactive hyperemia). It was also noted the passage of an arterial embolus during examination in neutral position. A vertebrobasilar vascular insufficiency was diagnosed and an angiogram was performed which revealed a dominant right vertebral artery associated with a hypoplasic left vertebral artery also characterized by critical stenosis in V2 segment. Discussion: TCD may be very useful as an initial diagnostic tool because of low costs, reproducibility, ease of use, and the possibility of performing a real-time correlation between the PCA velocities and symptoms.

Key words: Bow Hunter, dizziness, transcranial Doppler, stroke.

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