Citations

MFT has the potential to become the standard of care when dealing with possible middle ear pathologies. By applying those applications appropriate to the individual practice, and with a reasonable marketing effort, the cost of MFT-capable equipment should be readily recoverable. Finally, and most importantly, MFT is being shown in the current literature to be a better diagnostic tool than traditional tympanometry and to improve the level of care being provided to many clients by the audiologist and the physician. In my mind, this alone justifies the expenditure.

Simultaneous four-channel (ipsilateral, contralateral, horizontal, and noncephalic) ABR recordings were reviewed by three audiologists for 187 ears of nontumor patients, and 13 ears of patients having eighth nerve tumors. Waveforms from a subgroup of 63 ears were reexamined by the same audiologists to assess inter- and intra-judge consistency. For nontumor ears, the ipsilateral tracings provided the best identification of Waves I and III; the ipsilateral and noncephalic recordings allowed equal identification of Wave V. Waves I, III, and V generally were more robust from the ipsilateral electrode array than from any of the other electrode montages for the tumor ears. Three-way inter-judge agreement ranged from 82% to 87% for ipsilateral Waves I, III, and V and for noncephalic Wave V. Agreement between pairs of judges ranged from 86% to 100%. Intra-judge agreement ranged from 87% to 94% for ipsilateral Waves I, III, and V, and from 92% to 95% for noncephalic Wave V.

Audiologic test results were reviewed for 30 patients whose hearing was preserved following eighth nerve tumor surgery. Speech reception thresholds, 4,000-Hz thresholds, acoustic reflexes, and ABR wave I absolute latencies were generally unchanged or poorer following surgery; word recognition scores were essentially unchanged. By contrast, ABR waves III and V, and the I–III and I–V interpeak intervals, were generally improved postoperatively, including several patients who had clear waves following surgery despite absent preoperative responses. The improved ABR tracings likely indicate increased neural synchrony due to reduced pressure on the cochlear nerve following surgery, whereas the reduced hearing sensitivity probably reflects cochlear damage coincident to the surgery.

ABR absolute latencies and interpeak intervals were reviewed for 684 non-tumor ears and 75 eighth-nerve tumor ears having various degrees of high frequency hearing loss. For non-tumor ears, the percentage of abnormal absolute latencies for waves I, III, and V increased rather systematically as hearing loss increased, whereas absolute latencies for eighth-nerve tumor ears were largely abnormal regardless of hearing loss. Interpeak intervals were normal for most of the non-tumor ears, but the I–III and I–V intervals were abnormal for most of the tumor ears. The most sensitive index for otoneurologic assessment was a combination of abnormal wave V interaural latency differences or I–V interpeak interval, and the most specific criterion was the I–V interpeak interval. Tumor size influenced sensitivity of most ABR indices.

Multichannel ABR recordings for 30 otoneurologic patients were reviewed independently by three audiologists to assess interjudge consistency in determining absolute latencies and overall interpretation of ABR results. Four months later, the tracings were reviewed a second time to evaluate intrajudge consistency in interpretation of ABR waveforms. Interjudge agreement in marking latencies for waves I, III, and V within 0.2 ms was on the order of 90% or better. Intrajudge consistency was slightly higher. Only rarely did inter- or intrajudge differences in latency measurements exceed 0.3 ms. Agreement in overall interpretation of ABR results as "normal" or "abnormal" was unanimous for 90% of the patients. Across pairs of judges, the agreement for "normal" and "abnormal" classification of the ABR tracings was 97%. Intrajudge consistency for "normal" and "abnormal" categorization of the ABR results was 100% for one judge, 97% for the other two judges.

This article presents retrospective longitudinal perceptual and acoustic analyses of the recovery of motor speech control in a right-handed 5-year-old male in the 46 weeks following acquired brain damage. The primary lesion site involved the left fronto-parietal cortex. Correlative descriptions of some aspects of linguistic recovery up to 29 months post-onset are also presented. A mute period of 8 days followed a 2-day comatose period. Spontaneous undifferentiated central vowel-like utterances emerged at 11 days post-injury. Intelligible purposeful utterances emerged at 26 weeks post-onset with the motor speech impairment resolving almost completely within the first year post-onset. The motor speech deficit following the mute period was more consistent with the diagnosis of apraxia of speech than dysarthria. Further, the seemingly lateralized damage associated with the communication disorder may indicate that lateralized hemispheric control of motor speech occurs in early childhood. Finally, the redevelopment of motor speech abilities indicates that the young child’s brain is able to reestablish parameters of motor control underlying speech following acquired brain damage.