Neurological Monitoring during Carotid Artery Stenting: The Duck Squeezing Test

Abstract

Purpose:

To examine the usefulness of a novel method for neurological monitoring during carotid artery stenting (CAS).

Methods:

The records of patients who underwent elective CAS between June 1996 and October 1998 were reviewed to identify those who had neurological changes during the procedure. We examined whether the neurological change had been detected by a change in the ability of the patient to respond to predetermined commands involving a small rubber duck placed in the contralateral hand.

Results:

Two hundred seventy patients (320 vessels) underwent monitoring using the Duck Squeezing Test; 10 suffered neurological events during the procedure. Four of these were transient and temporally related to balloon inflation. Another 6 were tentatively ascribed to distal embolism. All instances were accompanied by a change in the patient's ability to perform the Duck Squeezing Test, which allowed the identification of the abnormal clinical situation. In addition, there were 4 false-positive tests secondary to the patient accidentally dropping the rubber duck.

Conclusions:

The Duck Squeezing Test is a sensitive and specific method for monitoring patients during elective CAS. Its practical applicability is based on sound neurophysiological concepts, which underscore the clinical importance of the test.