Influence of lipoproteins and fibrinogen on pathogenesis of sudden sensorineural hearing loss.

AIM: To evaluate the relationship between lipoproteins, fibrinogen and sudden sensorineural hearing loss in a Croatian population. Since pathological derangement of lipoproteins and fibrinogen could be one of the causes of sudden sensorineural hearing loss, we hypothesised that patients with sudden sensorineural hearing loss would have more abnormal fibrinogen and lipoprotein concentrations, compared with subjects with normal hearing. METHODS: Plasma concentrations of cholesterol, fibrinogen and triglycerides in patients with sudden sensorineural hearing loss were compared with those in a control group (i.e. subjects with normal hearing function). RESULTS: Patients with sudden sensorineural hearing loss had significantly higher plasma concentrations of cholesterol and low density lipoprotein cholesterol, compared with controls. CONCLUSION: Higher cholesterol and low density lipoprotein cholesterol concentrations were found in patients with sudden sensorineural hearing loss, within a Croatian population. Cholesterol and low density lipoprotein cholesterol concentrations may be important factors in the pathogenesis of sudden sensorineural hearing loss, and should be assessed during the investigation of patients with this condition.

First Croatian auditory brainstem implantation.

A deaf female patient was diagnosed with bilateral acoustic neurinomas. Diagnosis incorporated the standard audiological battery for sensorineural hearing loss, computed tomography and magnetic resonance imaging. The left side had been operated on four years previously in another clinic using the suboccipital approach. The auditory brainstem implant surgery was performed on the 'second side' using the same approach. It was an uneventful operation with good anatomy and no serious post-operative complications. Post-operatively, the patient performed exceptionally well, with up to 50 per cent of words recognized in the opened set and 85 per cent in the closed set, both without lip-reading.

On the capability of the vestibular apparatus to perceive sound stimuli.

This paper discusses the capacity of sound perception in 5 profoundly deaf subjects in whom a "fenestra" was previously formated on the lateral semicircular canal. The ability of sound and vibration perception after fenestra formation in profoundly deaf subjects with normal function of the vestibular apparatus has been described previously. The experiments for this procedure were done on pigeons by Wit & Bleeker. The subjects aged from 22 to 34 years. Causes of deafness varied. Their hearing threshold was bilaterally higher than 95 dB HL and their vestibular apparatus was of normal excitability bilaterally when tested with a caloric test. In all 5 patients the ear conduction hearing threshold remained the same, but the ability of vibration perception improved significantly, and ranged postoperatively between 30 and 45 dB HL. The frequency dynamic range was from 125 to 2,000 Hz in 4 subjects, and from 125 to 4,000 Hz in 1 subject. The patients claimed to have perceived higher intensities, but with a variable dynamic range from frequency to frequency. The intensity range amounted to between 15 and 40 dB. The obtained data of vibration perception ability are discussed.