Which Cortical Area Is Related to the Development of Dysphagia after Stroke? A Single Photon Emission Computed Tomography Study Using Novel Analytic Methods

Abstract

Purpose: The purpose of this study is to clarify cortical areas related to the development of dysphagia in poststroke patients using novel analytic methods for single photon emission computed tomography (SPECT) imaging. Subjects and Methods: Twenty poststroke patients (age: 66.1 ± 5.1 years) with a left hemispheric lesion were studied. According to clinical evaluation, patients were divided into a dysphagia group (n = 10) and a control group (n = 10). In each patient, measurement of regional cerebral blood flow (rCBF) was performed by SPECT imaging with a 99mTc-ethylcysteinate dimer. For the analysis, an easy Z-score imaging system and voxel-based stereotactic extraction estimation were applied, with placing regions of interest segmented into the Brodmann area level. We compared rCBF in each area between the two groups, and receiver operating characteristic analysis to calculate the area under the curve was also performed. Results: The rCBF in Brodmann areas 4 and 24 was significantly lower in the dysphagia group. The highest area under the curve was found in Brodmann area 4. In this area, 80% sensitivity and 60% specificity for discriminating dysphagia were achieved with an optimal cutoff value. Conclusions: When analyzed with novel methods, SPECT imaging can be useful for predicting the risk of dysphagia and subsequent aspiration in poststroke patients.