title: Nonaneurysmal nonperimesencephalic subarachnoid hemorrhage: is it a benign entity?
abstract: BACKGROUND
  Although the clinical profile of patients with PMN SAH is well documented, there are scarce data available for patients with nonaneurysmal n-PMN SAH. In the present study, the clinical characteristics of patients with n-PMN SAH were analyzed and compared with those of PMN SAH and aneurysmal SAH.
  
  
  METHODS
  Patients with spontaneous SAH, in whom the initial DSA or 3-dimensional CTA result was normal, underwent another investigation (CTA/DSA). If the results of both of these were negative, a second DSA was done after 4 to 6 weeks. Patients in whom even the second DSA failed to reveal an aneurysm or any other vascular abnormality were labeled as nonaneurysmal SAH. Within this group, 2 different types were identified: PMN SAH and n-PMN SAH.
  
  
  RESULTS
  There were 61 patients in whom the results of the first DSA and CTA were both negative. In 2 of these patients, an aneurysm was demonstrated at a second DSA. Seven patients died before a second DSA could be done. After excluding these, there were 18 patients with PMN SAH and 34 with n-PMN SAH. There was no mortality in these patients; and at a mean follow-up of 1.8 years, all patients with PMN SAH and 94.1% of patients with n-PMN SAH had a good outcome. Associated comorbid illnesses were more frequent in patients with PMN SAH and n-PMN SAH as compared with the aneurysmal SAH patients.
  
  
  CONCLUSIONS
  Once an aneurysm is definitely excluded, patients with n-PMN SAH have a good outcome, and like PMN SAH, have a benign clinical course. However, a second DSA is mandatory to avoid missing an aneurysm or any other vascular lesion.
authors.affiliation: Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh-160012, India. drguptasunil@gmail.com
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Gupta
authors.forename: Rahul
authors.initials: R
authors.lastname: Gupta
authors.forename: Virender K
authors.initials: VK
authors.lastname: Khosla
authors.forename: Sandeep
authors.initials: S
authors.lastname: Mohindra
authors.forename: Rajesh
authors.initials: R
authors.lastname: Chhabra
authors.forename: Niranjan
authors.initials: N
authors.lastname: Khandelwal
authors.forename: Vivek
authors.initials: V
authors.lastname: Gupta
authors.forename: Kanchan K
authors.initials: KK
authors.lastname: Mukherjee
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Tewari
authors.forename: Ashish
authors.initials: A
authors.lastname: Pathak
authors.forename: Suresh N
authors.initials: SN
authors.lastname: Mathuriya
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009026:Mortality; D011182:Postoperative Care / Q000379:methods / Q000592:standards; D019106:Postoperative Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D055502:Secondary Prevention; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology*; D013346:Subarachnoid Space / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D013525:Surgical Instruments; D014057:Tomography, X-Ray Computed; D014656:Vascular Surgical Procedures / Q000295:instrumentation / Q000379:methods
chemical_list: D002121:Calcium Channel Blockers