Cochlear implant should not be absolute contraindication for electroconvulsive therapy and transcranial magnetic stimulation

Cochlear implants (CI) provide deaf or severely hearingimpaired people with speech perception. A microphone and sound processor behind the ear capture sound and transmit it, via a radiofrequency link and magnets, to an implant below the scalp. The implant delivers the transformed acoustic signal as electric pulses onto the auditory nerve fibres through intracochlear electrodes [1]. Importantly, hearing loss increases the risk of dementia, depression, psychosis, and schizophrenia. Electroconvulsive therapy is a highly effective treatment for severe and psychotic depression and other psychiatric conditions, and ECT is often the last resort in medically treatment-resistant patients. ECT relies on the induction of seizures by electrical stimulation (Fig. 1). Transcranial magnetic stimulation (TMS), on the other hand, uses electromagnetic induction fields in different brain regions to treat neurological and psychiatric disorders [2]. Both methods space a range of doses that determines the strength of the current or the electromagnetic field generated in the body. The dose is defined by parameters that affect the spatial distribution (including properties of the stimulating electrodes or coil) and temporal characteristics (including parameters of the current or voltage waveform of the stimulating electrodes or coil) of the electromagnetic field [3]. The number of CI-users is increasing [1], and so is the number of CI-users that may need psychiatric treatment with ECT or TMS. However, ECT and TMS are not advised by CI manufacturers and contraindicated in ECT and TMS guidelines [2,4]. Thus, CI-patients are prevented from an effective and, in some cases, life-saving treatment [5,6]. Potential problems with electrical or magnetic stimulation in CI patients have been argued to include heating of the device and heat-induced injury to adjacent tissue, induction of current, damage to the implant, and magnetic displacement [2].