title: Clinical characteristics of ruptured distal middle cerebral artery aneurysms: Review of the literature.
abstract: Middle cerebral artery (MCA) aneurysms usually arise at the primary MCA bifurcation or trifurcation. Distal MCA aneurysms are rarely considered as sources of aneurysmal subarachnoid hemorrhage (SAH). It has been reported that ruptured distal MCA aneurysms are associated with head trauma, neoplastic emboli, arterial dissection, or bacterial infection. We experienced five cases of ruptured distal MCA aneurysms and evaluated their clinical characteristics. Retrospective analysis of aneurysmal SAH at Kobayashi Neurosurgical Neurological Hospital was performed from January, 2004 to December, 2014. Clinical characteristics of ruptured distal MCA aneurysms were analyzed using our database. Among 191 aneurysmal SAH patients, there were five ruptured distal MCA aneurysms. All patients did not have any specific medical problems such as infectious disease, head trauma, or cardiac disorders. The incidence of ruptured distal MCA aneurysm was higher than expected and was equivalent to 9.4% of the total ruptured MCA aneurysms. Strong male predominance (80%) and M2-3 junction aneurysm preponderance (80%) were observed. In addition, there were only two patients (40%) with intracerebral hematoma in our study. We reported five cases of ruptured distal MCA aneurysms. Although ruptured distal MCA aneurysms are thought to be rare as sources of aneurysmal SAH, the incidence of ruptured distal MCA aneurysm was 9.4% of all ruptured MCA aneurysms in our study. Ruptured distal MCA aneurysms should be considered as sources of aneurysmal SAH without intracerebral hematoma.
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan; Kobayashi Neurosurgical Neurological Hospital, Ueda, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Tsutsumi
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan. Electronic address: tetuyosi@shinshu-u.ac.jp.
authors.forename: Tetsuyoshi
authors.initials: T
authors.lastname: Horiuchi
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan; Department of Neurosurgery, Al-Azhar University, Faculty of Medicine-Nasr City, Cairo, Egypt.
authors.forename: Alhusain
authors.initials: A
authors.lastname: Nagm
authors.affiliation: Kobayashi Neurosurgical Neurological Hospital, Ueda, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Toba
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hongo
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery; D008297:Male; D008875:Middle Aged
keywords: Clinical characteristics; Distal middle cerebral artery aneurysm; Intracerebral hematoma; Subarachnoid hemorrhage