Marcello Cherchi M.D. Ph.D., Chicago IL. Timothy C. Hain, MD Page last modified: December 9, 2016
A 10 year old boy with a history of congenital bilateral deafness (for which he had undergone right sided cochlear implantation around age 1 year) was sent to us for a consult us regarding episodes of dizziness, nausea and vomiting that had begun six months previously when he had been in his usual state of health. The episodes were more likely to occur after physical exertion (such as during gym class) or after visual stimulation (such as video games), but could also occur without obvious provocation. The episodes ranged in duration from two to five hours, and were occurring every two to fourteen days. Sleep sometimes blunted the episodes. Meclizine would diminish the intensity of an episode. He also commented that during these episodes he would turn off the cochlear implant transmitter because the “sounds” would be”irritating.”
Aside from the bilateral congenital hearing loss, past medical history included vitamin D deficiency. There was no history of renal disease.
Family history was significant for one sister with normal hearing, and another sister with bilateral congenital deafness. The parents had elected not to pursue genetic testing regarding the congenital hearing loss.
The patient attended a regular school.
Physical examination was remarkable only for hearing loss, but was otherwise normal.
CT scan reported only streak artifact from the right sided cochlear implant. Rotatory chair testing was unremarkable, as was VEMP testing (see bottom).
To boil this case down to the essentials, this is a child with congenital deafness, and a long-standing CI, with recent onset of dizziness triggered by movement and visual stimulation. There is also phonophobia during spells, which is a typical migraine accompaniment.
In children, the main 3 causes of dizziness are migraine, labyrinthitis, and psychological issues (Gruber et al, 2012). In children, migraine may manifest as a syndrome called "benign paroxysmal vertigo" (Mierzwinski et al, 2007), which is thought to be a migraine variant (Krams et al, 2010).
Cochlear implants are also a common source of dizziness (Krause et al, 2009), although the dizziness is generally ignored because of the large benefits to hearing. Dizziness from cochlear implants would be unlikely to be provoked by visual stimulation such as video games, and also be unlikely to cause hyperacusis. We have encountered other patients with cochlear implants with similar symptoms, that they call "loud attacks".
Our conclusion regarding this case is that the episodes of dizziness, nausea and vomiting sometimes provoked by physical exertion or by visual stimuli were likely attributable to migraine associated vertigo, even in the absence of headaches meeting criteria for migraine.
We further suspect that the patient's description of “sound” being ”irritating” during these episodes was likely migrainous hyperacusis, even in the absence of cochlear function.
The other possibility we considered was an episodic ataxia. However, against this idea was the absence of a supportive family history. Moreover, an episodic ataxia would not explain the hyperacusis.
This is a normal VEMP test in a patient with cochlear implantation.
This is a normal rotatory chair in this patient with a cochlear implantation.