Maternally inherited nonsyndromic hearing loss.

In this study we characterized clinically and evaluated molecularly a large family with maternally inherited hearing impairment. Relatives were evaluated audiologically and clinically, the most likely pattern of inheritance was deduced, and molecular DNA analysis for the known mitochondrial mutations associated with hearing impairment was performed. Clinical examination of several relatives showed a normal general state of health, but in 14 of the members tested variable degrees of sensorineural hearing loss were noted. The pedigree was established and demonstrated a clear pattern of maternal inheritance, with 34 of 38 offspring of deaf mothers being hearing impaired, but none of 22 offspring of deaf fathers having any hearing impairment. Since by far the most likely explanation of such a maternal inheritance pattern is a mitochondrial mutation, molecular testing for the three known mitochondrial mutations, A1555G, A7445G, and Cins7472, was performed on 27 of the relatives. All of the individuals tested had the normal sequence at the sites tested. This family with nonsyndromic sensorineural hearing loss has an inheritance pattern strongly suggestive of a mitochondrial mutation. However, molecular testing for the three known mitochondrial mutations associated with nonsyndromic hearing impairment was negative, implying that additional molecular defects can lead to the same phenotype. The search for this novel molecular defect is underway.

Central auditory processing in a patient with bilateral temporal lobe tumors: case report.

The purpose of this article is to report the audiologic and central auditory processing abilities of a 34-year-old male with a right temporal lobe tumor and a history of bilateral tumors of the temporal lobes. The patient was evaluated presurgical re-exploration and again at 2.5 months and 4 months postoperatively. Test results demonstrated little change in peripheral hearing abilities; however, marked fluctuations were recorded on several tests administered postoperatively. Overall, this patient demonstrated a wide range of performance on tests of central auditory function, notably scores that decreased postoperatively and returned to better than baseline on the SCAN-A and repeated abnormal scores on the Pitch Pattern Sequence Test and the Symbol Digit Modality Test. Auditory Fusion Test-Revised results were initially normal, were markedly abnormal immediately postoperative, and returned to normal during the second postoperative visit. Our purpose in conducting this case study was to demonstrate, with central auditory processing test findings as well as magnetic resonance images, functional disorders of communication in a pre- and postoperative patient with a temporal lobe tumor.