Upper extremity motor improvement after carotid endarterectomy associated with postoperative recovery in cerebral
Yasukazu Katakura1, Yosuke Akamatsu1, Shunrou Fujiwara2
1Department of Neurosurgery, Iwate Medical University School of Medicine, Iwate, Japan.
Abstract:
The present prospective study aimed to elucidate improvements in affected upper extremity motor function after carotid endarterectomy (CEA) for symptomatic patients without obvious cognitive decline and to clarify associations between this post-CEA improvement and postoperative recovery of cerebral perfusion and/or cerebral neurotransmitter receptor function. Fifty-three symptomatic patients undergoing CEA were subjected to the Action Research Arm Test (ARAT) and early (within 30 min after 123I-iomazenil administration) and late (at 180 min after 123I-iomazenil administration) single-photon emission computed tomography (SPECT) before and after surgery. Based on the difference in time taken to complete the ARAT before and after surgery for the affected upper extremity, improvement in motor function was classified into three categories. Relative mean radioactive counts for each Brodmann's area on SPECT images were calculated before and after surgery, and the difference between pre- and postoperative relative counts Δ was calculated on early (ΔRCearly) and late (ΔRClate) images. Motor function in the affected upper extremity was definitely improved in 9 patients (17%), probably improved in 9 patients (17%), and not improved in 35 patients (66%). Both ΔRCearly and ΔRClate for Brodmann's areas 4, 6, and 7 were significantly higher in the definitely improved motor function group than in the probably or not improved motor function group. Area under the receiver operating characteristic curve for detecting patients with definitely improved motor function was greater for ΔRClate than for ΔRCearly on Brodmann's areas 4 (0.995 versus 0.947), 6 (0.992 versus 0.965), and 7 (0.992 versus 0.917). Motor function in the affected upper extremity infrequently (17%) improves after CEA for symptomatic patients without obvious cognitive decline, and this post-CEA improvement is associated with recovery of neurotransmitter receptor function resulting from post-CEA restoration of cerebral perfusion in the motor and somatosensory association cortices.
