Cognitive impairment is related to cerebral lactate in patients with carotid artery occlusion and ipsilateral transient ischemic attacks.
OBJECTIVE
Patients with carotid artery occlusion (CAO) and ipsilateral transient ischemic attack (TIA) can have lasting cognitive impairment, despite the recovery of focal neurological deficits. We sought to assess whether cognitive impairment in these patients is associated with hemodynamic compromise and/or impaired cerebral metabolism.


METHODS
In 39 consecutive patients with a TIA associated with an angiographically proven occlusion of the carotid artery, we examined (1) cognitive functioning, (2) cerebrovascular reserve capacity of the middle cerebral artery ipsilateral to the CAO as measured by transcranial Doppler ultrasound, and (3) metabolic ratios as measured by 1H-MR spectroscopy in the centrum semiovale ipsilateral to the symptomatic CAO. Findings were compared with those in healthy control subjects.


RESULTS
As a group, patients were cognitively impaired. Mean CO2 reactivity and the mean ratio of N-acetyl aspartate to creatine were decreased. In approximately one third of patients, lactate was present in noninfarcted regions. The presence of lactate proved to be a stronger correlate of cognitive impairment than MRI-detected lesions (beta=0.41 versus beta=0.15). Cognitive impairment did not correlate with CO2 reactivity or the ratio of N-acetyl aspartate to creatine.


CONCLUSIONS
This exploratory study in patients with CAO and ipsilateral TIA showed that 1H-MR spectroscopy-detected lactate in noninfarcted regions is a better indicator of cognitive impairment than MRI-detected lesions. Cognitive impairment did not correlate with CO2 reactivity.
Bakker
Floor C
FC
Department of Neurology, University Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, The Netherlands. F.Bakker@rng.nl
Klijn
Catharina J M
CJ
Jennekens-Schinkel
Aagje
A
van der Tweel
Ingeborg
I
van der Grond
Jeroen
J
van Huffelen
Alexander C
AC
Tulleken
Cornelis A F
CA
Kappelle
L Jaap
LJ
D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D002245:Carbon Dioxide / Q000378:metabolism; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D019344:Lactic Acid / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D017585:Ultrasonography, Doppler, Transcranial
D002245:Carbon Dioxide; D001224:Aspartic Acid; D019344:Lactic Acid; C000179:N-acetylaspartate; D003401:Creatine