This month’s case courtesy of Ali Chahlavi M.D. and Peter Rasmussen M.D., from the Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, OH.
History of Present Illness: A 63 year-old right handed Caucasian male with a history of hyperlipidemia, emphysema, and borderline hypertension presents with sudden onset of right hemiparesis, right facial droop, and global aphasia. After about 30 minutes, the patient’s symptoms improved to full motor strength in all 4 extremities, although the right hemiparesis and the aphasia re-occurred intermittently, depending on his blood pressure. The aphasia consisted of fluent speech, poor comprehension, poor naming and normal repetition. The patient had a fluctuating neurologic exam that was extremely dependent on the systolic blood pressure. IV fluids and pressor agents were required to maintain his blood pressure greater than 160 systolic. If the systolic blood pressure dipped below 140, he would develop global aphasia and right-sided hemiparesis.
Studies: A Doppler ultrasound of his cervical carotid arteries showed a 60-70% right internal carotid artery (ICA) stenosis and an occlusion of left ICA at its origin. The MRI demonstrated a watershed infarct within the left anterior cerebral artery (ACA) and middle cerebral artery (MCA) distribution (Figure 1). The MRA confirmed this with no flow signal in the left ICA with collateral filling of left ACA and left MCA, and moderate to severe stenosis within the proximal right ICA.
Figure 1. MRI
The following day, a three-vessel angiogram was performed (Figure 2). It showed occlusion of the left internal carotid artery at its origin (2a) and 50-55% stenosis of the proximal right ICA (2b). The left internal carotid artery was supplied by the left ophthalmic artery and, from the right ICA via the anterior communicating artery (2c). There was no significant supply from the posterior circulation (2d).
Figure 2. Angiogram
(a) (b) (c) (d)
A Diamox SPECT (single photon emission computed tomography) scan showed decreased perfusion in the left MCA distribution with a 20% reduction in perfusion after the administration of Diamox (acetazolamide) (Figure 3)
Figure 3. Diamox SPECT
HOSPITAL COURSE: To improve perfusion, the patient underwent angioplasty with stenting of the right ICA, with residual stenosis of 30% [Figure 4A (Pre-stent) & B(Post-Stent)]. A repeat Diamox SPECT scan showed improved perfusion in the left MCA distribution, but there was still reduced cerebral vascular reserve (20% reduction with Diamox challenge). Furthermore, the patient continued to have recurrent symptoms when the systolic blood pressure was less than 140 mmHg.
Figure 4. Angioplasty
OUTCOME: The patient underwent a left superficial temporal artery to middle cerebral artery (STA-MCA) bypass without complication. Postoperatively, a head CT showed mild edema in the left MCA territory that resolved with follow-up imaging but no new infarcts. There was no recurrence of ischemic symptoms when his blood pressure was normalized. On the day of discharge, the patient had fluent speech, good repetition and comprehension, and mild word finding difficulty; his motor strength was 5-/5 on the right side, and sensory function was normal. At 6 week follow-up, the patient had full motor power, good fine motor control of his right hand and very subtle word-finding difficulty. The arterial graft was clinically patent.