title: Cerebrospinal fluid shunting and hearing loss in patients treated for medulloblastoma.
abstract: OBJECTIVE
  Cerebrospinal fluid shunting has previously been associated with hearing loss. Although the mechanism for this is unclear, it is thought that changes in CSF pressure can affect cochlear physiology via endolymph expansion in the setting of a patent cochlear aqueduct. Patients undergoing radiation and cisplatin chemotherapy are at risk for hearing loss. The authors hypothesized that the incidence and severity of hearing loss in patients undergoing radiation and chemotherapy for medulloblastoma would be greater in those with shunts than in those without shunts.
  
  
  METHODS
  Baseline and longitudinal audiology data were collected in 33 patients with medulloblastoma who were receiving radiation and cisplatin chemotherapy. Additional data included age, sex, details of shunt placement and revision, and details of chemotherapy and radiation. Hearing sensitivity and peripheral auditory function measures included pure tone audiometry, immittance audiometry, and distortion product evoked otoacoustic emissions. Ototoxicity was determined according to the American Speech-Language-Hearing Association criteria. Severity of hearing loss was determined using the Brock hearing loss grades. Incidence of hearing loss and association with shunting was determined.
  
  
  RESULTS
  Thirteen (39.4%) of the 33 patients evaluated had undergone shunt placement. Hearing loss occurred in 14 (70%) of 20 patients without shunts and in 13 (100%) of 13 patients with shunts. The difference between the rates of hearing loss in patients with shunts versus those without the devices was highly significant (p = 0.0008). The odds ratio for hearing loss in patients with a CSF shunt compared with those without a shunt was 23.49 (95% CI 4.21-131.15). Age, side of shunt, evidence of dissemination, diameter of cochlear aqueduct, and treatment protocol did not have a significant effect on shunt-related ototoxicity.
  
  
  CONCLUSIONS
  This study suggests an independent association between CSF shunting and hearing loss in children undergoing treatment for medulloblastoma, laying the foundation for a prospective study evaluating hearing loss in children with shunts who are not treated with ototoxic therapy.
authors.affiliation: Department of Neurological Surgery, Oregon Health & Science University, Portland, OR 97239, USA. dguillau@umn.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Guillaume
authors.forename: Kristin
authors.initials: K
authors.lastname: Knight
authors.forename: Carol
authors.initials: C
authors.lastname: Marquez
authors.forename: Dale F
authors.initials: DF
authors.lastname: Kraemer
authors.forename: Dianna M E
authors.initials: DM
authors.lastname: Bardo
authors.forename: Edward A
authors.initials: EA
authors.lastname: Neuwelt
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects; D001309:Auditory Threshold; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D059186:Chemoradiotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects; D005072:Evoked Potentials, Auditory; D005260:Female; D006309:Hearing / Q000187:drug effects / Q000528:radiation effects; D034381:Hearing Loss / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy* / Q000532:radiotherapy*; D016017:Odds Ratio; D017084:Otoacoustic Emissions, Spontaneous; D012720:Severity of Illness Index
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin