Postoperative changes in the superficial temporal artery and the external carotid artery duplex sonography after extra-intracranial bypass surgery in European Moyamoya disease.

INTRODUCTION: Despite Duplex ultrasonography being a noninvasive, easily repeatable, readily available and economical tool, this examination and its normal ranges are rarely described in Moyamoya disease (MMD). METHODS: Duplex ultrasonography examinations of the superficial temporal artery (STA) and external carotid artery (ECA) were performed preoperatively, postoperatively (within 30 days) and as follow-up exams (6 months postoperatively) after 32 cerebral revascularization procedures in 20 European patients with MMD. RESULTS: A significant higher mean diastolic flow of STA compared to preoperative values was found in postoperative (p<.000) and follow-up exams (p<.001) in Duplex ultrasonography. Postoperative and follow-up Duplex sonography of STA also showed a significantly higher mean systolic flow compared to preoperative values (p<.05 and p<.05). Also ECA showed significantly changes after bypass surgery (p<.05). CONCLUSION: Duplex ultrasonography of STA is a reliable and non-invasive tool to investigate hemodynamic changes after bypass surgery and to detect bypass patency in European patients with MMD.

Cross-modal plasticity in the human thalamus: evidence from intraoperative macrostimulations.

During stereotactic functional neurosurgery, stimulation procedure to control for proper target localization provides a unique opportunity to investigate pathophysiological phenomena that cannot be addressed in experimental setups. Here we report on the distribution of response modalities to 487 intraoperative thalamic stimulations performed in 24 neurogenic pain (NP), 17 parkinsonian (PD) and 10 neuropsychiatric (Npsy) patients. Threshold responses were subdivided into somatosensory, motor and affective, and compared between medial (central lateral nucleus) and lateral (ventral anterior, ventral lateral and ventral medial) thalamic nuclei and between patients groups. Major findings were as follows: in the medial thalamus, evoked responses were for a large majority (95%) somatosensory in NP patients, 47% were motor in PD patients, and 54% affective in Npsy patients. In the lateral thalamus, a much higher proportion of somatosensory (83%) than motor responses (5%) was evoked in NP patients, while the proportion was reversed in PD patients (69% motor vs. 21% somatosensory). These results provide the first evidence for functional cross-modal changes in lateral and medial thalamic nuclei in response to intraoperative stimulations in different functional disorders. This extensive functional reorganization sheds new light on wide-range plasticity in the adult human thalamocortical system.