title: Impedance testing on cochlear implants after electroconvulsive therapy.
abstract: OBJECTIVE
  Cochlear implants (CI) are neural prostheses that restore hearing to individuals with profound sensorineural hearing loss. The surgically implanted component consists of an electrode array, which is threaded into the cochlea, and an electronic processor, which is buried under the skin behind the ear. The Food and Drug Administration and CI manufacturers contend that electroconvulsive therapy (ECT) is contraindicated in CI recipients owing to risk of damage to the implant and/or the patient. We hypothesized that ECT does no electrical damage to CIs.
  
  
  METHODS
  Ten functional CIs were implanted in 5 fresh cadaveric human heads. Each head then received a consecutive series of 12 unilateral ECT sessions applying maximum full pulse-width energy settings. Electroconvulsive therapy was delivered contralaterally to 5 CIs and ipsilaterally to 5 CIs. Electrical integrity testing (impedance testing) of the electrode array was performed before and after CI insertion, and after the first, third, fifth, seventh, ninth, and 12th ECT sessions. Electroconvulsive therapy was performed by a staff psychiatrist experienced with the technique. Explanted CIs were sent back to the manufacturer for further integrity testing.
  
  
  RESULTS
  No electrical damage was identified during impedance testing. Overall, there were statistically significant decreases in impedances (consistent with no electrical damage) when comparing pre-ECT impedance values to those after 12 sessions. There was no statistically significant difference (P > 0.05) in impedance values comparing ipsilateral to contralateral ECT. Manufacturer testing revealed no other electrical damage to the CIs.
  
  
  CONCLUSIONS
  Electroconvulsive therapy does not seem to cause any detectable electrical injury to CIs.
authors.affiliation: From the *Department of Otolaryngology-Head Neck Surgery, †Department of Psychiatry and ‡Department of Biostatistics, Schools of Medicine and Nursing, Vanderbilt University, Nashville, TN.
authors.forename: Theodore R
authors.initials: TR
authors.lastname: McRackan
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rivas
authors.forename: Andrea
authors.initials: A
authors.lastname: Hedley-Williams
authors.forename: Vidya
authors.initials: V
authors.lastname: Raj
authors.forename: Mary S
authors.initials: MS
authors.lastname: Dietrich
authors.forename: Nathaniel K
authors.initials: NK
authors.lastname: Clark
authors.forename: Robert F
authors.initials: RF
authors.lastname: Labadie
mesh_terms: D002102:Cadaver; D003054:Cochlear Implants / Q000592:standards*; D017097:Electric Impedance; D004565:Electroconvulsive Therapy; D004567:Electrodes, Implanted; D007839:Functional Laterality; D006801:Humans