Low body temperature associated with severe ischemic stroke within 6 hours of onset: The Bergen NORSTROKE Study.
BACKGROUND
Hypothermia is considered neuroprotective and a potential treatment in cerebral ischemia. Some studies suggest that hyperthermia may promote clot lysis. We hypothesized that low body temperature would prolong time to spontaneous clot lysis resulting in an association between low body temperature and severe neurological deficits in the early phase of ischemic stroke.


METHODS
In this prospective study, patients (n = 516) exhibiting ischemic stroke with symptom onset within 6 hours were included. Body temperature and National Institute of Health Stroke Scale (NIHSS) score were registered on admission. Because low body temperature on admission may be secondary to immobilization due to large stroke, separate analyses were performed on patients with cerebral hemorrhage admitted within 6 hours (n = 85).


RESULTS
Linear regression showed that low body temperature on admission was independently associated with a high NIHSS score within 6 hours of stroke onset in patients with ischemic stroke (P < 0.001). The association persisted when NIHSS was measured at 24 hours after admission. No such associations were found in patients with cerebral hemorrhage admitted within 6 hours of stroke onset.


CONCLUSIONS
Our study suggests that low body temperature within 6 hours of symptom onset is associated with severe ischemic stroke. This is in support of our hypothesis, although other contributing mechanisms cannot be excluded.
Department of Neurology, Haukeland University Hospital, University of Bergen, Bergen, Norway. echr@helse-bergen.no
Christopher E
CE
Kvistad
Lars
L
Thomassen
Ulrike
U
Waje-Andreassen
Halvor
H
Naess
D000368:Aged; D000369:Aged, 80 and over; D001833:Body Temperature Regulation; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D016009:Chi-Square Distribution; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009664:Norway; D010343:Patient Admission; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D015912:Thrombolytic Therapy; D013997:Time Factors