Last Updated: 2008-06-26 16:09:19 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Sudden sensorineural hearing loss can be an early warning of impending stroke, according to results of a case-control study reported in the October issue of Stroke, posted online on June 26.

Using information retrieved from Taiwan's National Health Insurance Research Database, Dr. Herng-Ching Lin and colleagues at Taipei Medical University identified 1423 patients hospitalized in 1998 with a first episode of sudden sensorineural hearing loss. For each of these patients, Dr. Lin's team selected four appendectomy patients (total 5692) as control subjects, matched by age category. Thirty-nine percent were below 45 years of age, 40% were ages 45-64, 16% were 65-74, and 5% were older than 74.

Patients in the hearing loss group were significantly more likely to have hypertension, diabetes, and hyperlipidemia, the authors note.

Over the next 5 years, 180 hearing-loss patients (12.7%) and 441 appendectomy patients (7.8%) were diagnosed with stroke. After adjusting for gender, income, level of urbanization, and comorbidities, the hazard of stroke was 1.64 times greater (p < 0.001) in the hearing-loss patients.

Among patients with hearing loss, 12% of strokes occurred within 3 months, 31% occurred in the first year, and 51% by the end of the second year.

Dr. Lin and associates recommend that patients with sudden sensorineural hearing loss, "particularly those with other vascular conditions or elderly patients, should undergo a comprehensive hematologic and neurological examination to help clinicians identify those who are potentially at risk for stroke in the near future."

Because half of the strokes did not occur until after 2 years, they further advise routine follow-up examinations for several years after the index episode of hearing loss.

Stroke 2008.