Sudden hearing loss is a rare but real potential complication in multiple sclerosis.
Sudden sensorineural hearing loss (SSHL) is a rare symptom of multiple sclerosis (MS), however people with MS experience SSHL far more often than the general population, according to the findings of a recent study.
Published in the Multiple Sclerosis Journal -- Experimental, Translational and Clinical, the study was conducted by Sari Atula of the Department of Clinical Sciences, Neurology, at the University of Helsinki and Helsinki University Hospital in Finland, and colleagues.
The researchers describe their objective, saying, “We aimed to assess the incidence of SSHL among MS patients, its frequency as an initial symptom of MS, and magnetic resonance imaging (MRI) findings associated with SSHL in MS.” In order to complete that assessment, they examined patient records from an 11-year period.
The researchers found a total of 2736 patient records for patients diagnosed with MS or demyelinating disease from the Helsinki University Hospital. During the same period, 1,581 patients were treated for SSHL. The researchers report, “Of the 18 patients (0.7% of all MS patients) with both diagnoses, 17 patients were diagnosed with MS, and on patients with neuromyelitis optica with features of MS.” However, they say, “MS was present in 1.1% of all SSHL cases.”
Two of the patients had SSHL as the first symptom of MS and for one of those it was the only symptom. The authors note that several studies with smaller sample sizes showed higher frequency of SSHL among MS patients, and say that “the incidence of SSHL among MS patients is two to 12 times higher than the normal population.”
The MRI scans the researchers considered, “failed to reveal signs of demyelination of the vestibulocochlear nerve, possibly because in most sequences the changes in the vestibulocochlear nerve would fall below the resolution level of MRI,” they say. Additionally, they say, “The causes of SSHL in our patients remained unclear, as MRI verification in the form of a definite new demyelinating lesion along the vestibulocochlear nerve tract was unobtainable.”
“In conclusion, this study shows that MS associates with SSHL, but that SSHL is rarely an initial symptom of MS,” say the authors.