Hereditary non-syndromic hearing loss: influence of different variables

Non-syndromic hearing loss [NSHL] was studied in twenty-five patients using a clinical, audiological, cytogenetic and neurobiochemical evaluation. The study group was divided into five subgroups according to severity of hearing loss. Positive parental consanguinity was present in 84% of cases and similarly affected family members were present in 76%. All patients had no congenital malformations and were not dysmorphic. Patients possibly exposed to environmental factors were excluded from the study. Abnormal karyotyping was present in three cases, one case showed chromosome 15p 4, another case showed chromosomal del 11q22.1 and in the third case [47,XY] there was marker chromosome 15. Fluorescence in situ Hybridization [FISH] technique was performed on the case which showed marker. The study group showed significant lowering of five plasma amino acid levels [glutamic acid, aspartic acid, histidine, 3-methylhistidine and carnosine]. There was significant correlation between severity of hearing loss and each of the following: patient's age, glutamic acid, aspartic acid, 3-methylhistidine and carnosine. Identification of NSHL early after birth, as well as, amino acid screening is essential, to allow for faster therapeutic intervention and proper genetic counseling

Vestibulo-ocular reflex testing in peripheral vestibular disorders

The present study was conducted to evaluate the vestibulo-ocular reflex [VOR] using rotary chair. A new chair concept generating dynamic stimuli by alternating rotations in the horizontal plane of the chair's seat was recently developed. Twenty-five adult subjects suffering from variable peripheral vestibular lesions, proved by caloric testing, participated in the study. Eleven healthy normal adults served as controls; gender and age matched to the study group. Results of rotational sinusoidal harmonic acceleration [SHA] testing showed gain reduction at lower frequencies of rotation with improvement of gain at higher frequencies. Meanwhile, phase and symmetry parameters remained normal at all frequencies. Findings of SHA testing in the present study suggest the presence of a certain degree of compensation. This reflects remaining vestibular function, which could be utilized in vestibular rehabilitation

Study of P300 cognitive event related potentials in adult stutterers

This study investigated possible differences between adult stutterers and non-stutterers in P300 event- related potential. Twenty-seven adult right-handed stutterers and fifteen normal adult subjects were included. Both groups exhibited right-left asymmetry as regards P300 amplitude. Right ear showed higher P300 amplitude in both groups. In the left ear, stutterers showed prolonged latency and higher amplitude in P300 wave more than non-stutterers. This study supports the opinion of the existing brain changes in stutterers that could be studied by event related potentials. Further cognitive event-related studies are needed to compare between linguistic and non-linguistic stimuli to reveal more knowledge about brain changes occurring in stutterers