title: Bilateral chronic subdural hematoma: what is the clinical significance?
abstract: BACKGROUND
  Bilateral chronic subdural hematoma (CSDH) is not uncommon, although information on this condition is limited.
  
  
  OBJECTIVE
  We aim to identify the differences in clinical characteristics between patients with bilateral or unilateral CSDH.
  
  
  METHODS
  Ninety-eight patients with CSDH were enrolled in the two-year retrospective study. We investigated neurological outcome, morbidity, mortality, and recurrences after burr hole craniostomy for CSDH.
  
  
  RESULTS
  Bilateral convexity hematomas were identified in 25 of 98 CSDH (25.51%). The patients with bilateral lesions had a lower incidence of hemiparesis than those having unilateral lesions (p = 0.004). Analysis of the neuro-images revealed significant differences in the presence of a midline shift (p = 0.001) and thickness of the hematoma (p < 0.001). The mean Markwalder subdural hematoma grade at admission was 1.89 ± 0.66 and 1.64 ± 0.49 in the unilateral and bilateral hematoma groups, respectively (p = 0.010). After a minimum follow-up period of 6 months, the mean Glasgow Outcome Scale was not significantly different (p = 0.060). The recurrence rate of up to 28.00% observed for the bilateral disease was found to be higher than 9.59% observed for the unilateral disease (p = 0.042).
  
  
  CONCLUSIONS
  The frequency of focal neurological deficits was found to be lesser in patients with bilateral CSDH, and it may confound the diagnosis and delay treatment. To prevent neurological deterioration resulting from the thicker hematomas, early surgical decompression for bilateral CSDH should be implemented. Additionally, clinicians must be aware of the higher recurrent rate of bilateral CSDH after burr hole craniostomy.
authors.affiliation: Department of Neurosurgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. newlupin2001@yahoo.com.tw
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Huang
authors.forename: Ka-Yen
authors.initials: KY
authors.lastname: Yang
authors.forename: Tao-Chen
authors.initials: TC
authors.lastname: Lee
authors.forename: Chen-Chieh
authors.initials: CC
authors.lastname: Liao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Bilateral; Burr hole; Chronic subdural hematoma; Prognosis; Recurrence