Subjective hearing impairment after subarachnoid haemorrhage: Prevalence and risk factors

Background Sensorineural hearing impairment is a key symptom in patients with superficial siderosis of the central nervous system, a disease caused by chronic or intermittent haemorrhage into the subarachnoid space. We investigated the prevalence and risk factors of subjective hearing impairment after SAH. Methods We systematically interviewed all SAH patients admitted between June 2011 and December 2014, who were able to visit the SAH outpatient clinic six to eight weeks after hospital discharge. We calculated the proportion of patients with subjective hearing impairment noticed after SAH onset, and adjusted risk ratios (aRR) with 95% confidence intervals (CI) for potential risk factors with Poisson regression. Results We included 277 patients. Subjective hearing impairment was reported by 54/277 (19%) patients (aneurysmal SAH: 42/212 [20%;95%CI:15–26%]; perimesencephalic haemorrhage 8/36 [22%;95%CI:12–38%], non-aneurysmal non-perimesencephalic SAH: 4/29 [14%;95%CI:6–31%]). Hearing impairment was associated with a poor clinical condition on admission (defined as PAASH score 4–5) (aRR3.00;95%CI:1.43–6.28), aneurysm rupture at the middle cerebral artery (aRR2.72;95%CI:1.38–5.39), and moderate/severe disability 3 months after ictus (aRR2.25;95%CI:1.28–3.97), but not with large amounts of extravasated blood (highest vs. lowest tertile of Hijdra score) (aRR0.77;95%CI:0.33–1.81) or endovascular treatment (aRR1.19;95%CI:0.61–2.33). Conclusion Subjective hearing impairment occurs in 1 of every 5 SAH patients. It is related to the clinical condition on admission, aneurysm rupture at the middle cerebral artery, and functional outcome, but not to the amount of subarachnoid blood or the method of aneurysm occlusion. Audiometric tests, auditory cognitive assessments, and follow-up studies are needed to determine the cause and prognosis of hearing impairment after SAH.