Physiological diagnosis and surgical treatment of recurrent limb shaking: Case report

OBJECTIVE AND IMPORTANCE: Although recurrent limb shaking has been observed in patients with carotid occlusion, its cause, method of diagnosis, and definitive treatment have yet to be fully elucidated. This report examines the cerebrovascular physiology of a patient with recurrent limb shaking by means of xenon-enhanced computed tomographic (XeCT) scanning. By measuring cerebral blood flow (CBF) and cerebrovascular reserve capacity, we were able to confirm both the clinical diagnosis and the response to treatment on physiological grounds. CLINICAL PRESENTATION: The patient is a 49-year-old man who presented with frequent brief attacks of left arm and leg shaking that occurred at standing or coughing. After cervical radiation therapy fora laryngeal carcinoma, he was found to have bilateral carotid occlusion with minimal collateral development. XeCT scans revealed borderline ischemic perfusion and lack of cerebrovascular reserve in response to an acetazolamide vasodilatory challenge. INTERVENTION: The patient underwent a right superficial temporal artery to middle cerebral artery bypass to augment cerebral perfusion. CONCLUSION: After the procedure, the patient's limb shaking attacks ceased. The postoperative XeCT scan showed improved CBF and a return of cerebrovascular reserve capacity. Recurrent limb shaking is a manifestation of decreased CBF. Quantitative XeCT CBF studies coupled with vasodilatory challenge is an important way to assess patients with cerebrovascular disorders and thus identify individuals who will benefit from cerebral revascularization.