title: Preoperative predictive factors for surgical and functional outcomes in chronic subdural hematoma.
abstract: BACKGROUND
  Chronic subdural hematoma (CSDH) is a frequently encountered neurosurgical condition, especially in the elderly. We investigated predictive factors for surgical and functional outcomes after burr-hole drainage (BHD) surgery.
  
  
  METHODS
  All patients with CSDH treated by BHD between January 2012 and December 2014 were included in this study. All patients were classified by symptom, clinical grade, time, location, hematoma density, midline shift, and other characteristics. Pre- and postoperative CT evaluation was performed at 0, 3, and 6 months. Clinical grades were classified as described in Markwalder et al. Surgical and clinical outcomes were evaluated with the brain expansion rate and modified Rankin Scale (mRS). Brain expansion rate was calculated as the ratio between post- and pre-operative hematoma thickness. Recurrence was defined as the occurrence of symptoms and hematoma on CT within 6 months.
  
  
  RESULTS
  This study included 130 patients over 2 years. Among the variable parameters, young age (<75), iso-density of hematoma on CT, and short duration from symptom to surgery were correlated with good brain expansion. Patients with good brain expansion had fewer recurrences. In terms of mRS, young age, iso-density, and good clinical grade were correlated with good functional outcomes.
  
  
  CONCLUSIONS
  Clinicians should be more aware of general conditions and medical problems, especially in elderly patients. Membranectomy should be considered in patients with a long duration of symptoms or hypo-dense hematomas to promote good brain expansion and good mRS scores.
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
authors.forename: Hyeong Woo
authors.initials: HW
authors.lastname: Ro
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea. skparkns@gmail.com.
authors.forename: Sang Kyu
authors.initials: SK
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
authors.forename: Dong Kyu
authors.initials: DK
authors.lastname: Jang
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
authors.forename: Wan Soo
authors.initials: WS
authors.lastname: Yoon
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
authors.forename: Kyeong Sool
authors.initials: KS
authors.lastname: Jang
authors.affiliation: Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003399:Craniotomy; D005260:Female; D005500:Follow-Up Studies; D020200:Hematoma, Subdural, Chronic / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D012008:Recurrence
keywords: Burr-hole drainage; Chronic subdural hematoma; Functional outcome; Predictive factors; Surgical outcome