Cognitive impairment and neurovascular function in patients with severe steno-occlusive disease of a main cerebral artery.

OBJECTIVE: Patients with severe steno-occlusive disease of a main cerebral artery may demonstrate cognitive impairment without identification of causative lesions on magnetic resonance imaging. We investigated whether cognitive impairment in these patients is associated with regional cerebral blood flow (rCBF), leukoaraiosis, risk factors of atherosclerosis and cerebrovascular reserve (CVR), which shows so-called clinical neurovascular function. METHODS: In 65 patients with severe steno-occlusive disease of an internal carotid artery or a middle cerebral artery (MCA) and no cerebral infarction (CI), we examined cognitive function with COGNISTAT, grades of leukoaraiosis, and CBF and CVR as calculated by iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography and blood data. We compared such values of the left and right sided diseases. rCBF and CVR on the affected side were compared to other side. RESULTS: Logistic regression analysis revealed that CVR correlated with cognitive impairment. There was no significant difference in rCBF, CVR, or COGNISTAT score when comparing the left and right sided diseases. There were good correlations between CBF or CVR of the ipsilateral MCA area and ipsilateral and contralateral other areas. CONCLUSION: Cognitive impairment is associated with CVR in the whole brain. Nonselective widespread neurovascular mild dysfunction can be a reason for cognitive impairment in patients with severe steno-occlusive disease of a main cerebral artery and no CI.

Early diagnosis of cerebral ischemia in cerebral vasospasm by oxygen-pulse near-infrared optical topography.

PURPOSE: Early diagnosis of vasospasm is a key factor in the choice of treatment after subarachnoid hemorrhage (SAH). However, a noninvasive method of diagnosing delayed ischemic neurological deficit (DIND) has not been established. We therefore propose a new method of diagnosing cerebral ischemia using near-infrared optical topography (OT) with oxygen inhalation. MATERIALS AND METHODS: We used a 44-channel OT system that covers the bilateral front otemporoparietal areas to assess 29 patients who underwent surgery within 72 h of the onset of SAH. The patients inhaled room air followed by oxygen for 2 min, and then peripheral oxygen saturation (SpO2) was continuously monitored at the index fingertip. The patients were assessed by N-isopropyl-p-[¹²³I]iodoamphetamine (IMP)-SPECT and OT on the same day. Ischemic findings were confirmed using principal component analysis with reference to the systemic SpO2value. RESULTS: Seven of 29 patients developed DIND. Evidence of ischemia was identified by OT in all seven of these patients before the onset of DIND. The OT and SPECT findings agreed in 27 (93 %) of the 29 patients. DISCUSSION AND CONCLUSIONS: Our method might detect cerebral ischemia before the onset of DIND and thus be clinically useful for assessing cerebral ischemia with vasospasm.