Early infarction detected by diffusion-weighted imaging in patients with subarachnoid hemorrhage.
OBJECTIVE
Early infarction that occurs at the time of initial subarachnoid hemorrhage (SAH) due to rupture of an aneurysm is a poorly understood phenomenon. We investigate the frequency of early infarction using diffusion-weighted images (DWI) at the time of admission. We then discuss the pathogenesis of infarction.


METHODS
This study included 85 SAH patients who underwent serial DWI on admission. Early infarction detected by DWI and clinical features were investigated retrospectively.


RESULTS
The overall incidence of DWI-detected early infarction at the time of SAH onset was 8% (7 of 85 cases). In all seven patients, early infarctions were asymptomatic on admission. Types of early infarction seen on DWI included infarcts occurring in the territory of the vessel harboring a ruptured aneurysm (solitary, three cases) and infarcts occurring outside the territory of the vessel (multiple, two cases; solitary, two cases). Six of seven patients eventually developed delayed ischemic neurological deficit (DIND) and computed tomography (CT)-detected and DWI-detected delayed extensive infarction. Four of seven patients with early infarction had an unfavorable outcome. The occurrence of DWI-detected early infarction on admission was significantly correlated with delayed angiographic vasospasm, DIND, CT-detected delayed infarction, DWI-detected delayed infarction, and unfavorable outcome.


CONCLUSIONS
In the present study, DWI-detected early infarction at the time of SAH onset was correlated with the occurrence of delayed extensive ischemic lesions. We believe that performing DWI at the time of admission is useful for evaluating the primary ischemic insult, which might play an important role in the pathogenesis of early brain injury and delayed vasospasm-related complications.
Shimoda
Masami
M
Department of Neurosurgery, Tokai University Hachioji Hospital, 1838 Ishikawa-machi, Hachioji, Tokyo, 192-0032, Japan. mashimoda-nsu@umin.ac.jp
Hoshikawa
Kaori
K
Shiramizu
Hideki
H
Oda
Shinri
S
Yoshiyama
Michitsura
M
Osada
Takahiro
T
Matsumae
Mitsunori
M
D000368:Aged; D000369:Aged, 80 and over; D002544:Cerebral Infarction / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000175:diagnosis / Q000473:pathology*; D013997:Time Factors