Regional cerebral blood flow in developmental stutterers.

Stuttering is a poorly understood communication disorder with a 1% global prevalence. Recently, there has been a resurgence of interest in a neurogenic origin for the disorder, although no research has established clear neurological differences between "developmental" (stuttering onset in childhood) stutterers and nonstutterers. We have used xenon 133 single-photon emission computed tomography to study regional cerebral blood flow (rCBF) in 20 stutterers. Analysis revealed global, absolute flow reductions. Relative flow asymmetries (left less than right) were identified in three hemispheric regions: anterior cingulate and superior and middle temporal gyri. Milder changes were found in the left inferior frontal gyrus. Stutterers had rCBF values below median for either anterior cingulate or middle temporal gyri. With one exception, severe stutterers had rCBF values below median for the anterior cingulate gyrus. All stutterers with rCBF values above median in the cingulate gyrus had rCBF values below median in the middle temporal gyrus, and severity of their disorder was either mild or moderate. Our findings suggest that stuttering is a neurogenic disorder involving recognized cortical regions of speech-motor control.

Heterogeneity in spasmodic dysphonia. Neurologic and voice findings.

Spasmodic dysphonia is a disturbance of phonation with laryngeal spasms. We report voice and neurologic examination findings in 45 subjects. Neurologic abnormalities were found in 32 subjects (71.1%). Rapid alternating movement abnormalities, weakness, and tremor were common. Incoordination and spasticity were rare. Lower extremity findings were frequent. Abnormalities were bilateral. Spasmodic dysphonia severity was related to age. Type, severity, and duration of vocal symptoms were not different for subjects with or without neurologic abnormalities. Vocal tremor was more frequent in neurologically abnormal subjects. Involvement of a pallidothalamic-supplementary motor area system could account for neurologic findings, brain imaging findings, and clinical heterogeneity. The view emerging is that spasmodic dysphonia is a manifestation of disordered motor control involving systems of neurons rather than single anatomical sites.

Quantitative electroencephalography and anatomoclinical principles of aphasia. A validation study.

No single technology in isolation can provide a full view of the anatomoclinical principles evident in the clinical populations we study. The dynamic nature of quantitative electrophysiology makes it an ideal complement to anatomic and metabolic imaging. The statistical conundrum it has presented may be resolved by the approach incorporated in CART. The intent of this study was to examine QEEG and CART in the evaluation of the neurologic bases of a well-defined behavioral disorder like aphasia. The combined power of QEEG and CART yielded objective electrophysiologic methods to predict aphasia that rival the reliability of the language examination. Such success is unprecedented. This success allows us to incorporate QEEG and CART into our technological armamentarium and to return to the evaluation of less well-understood disorders with confidence in both our findings and anatomoclinical principles we derive from them.

Spasmodic dysphonia subsequent to head trauma.

Spasmodic dysphonia (SD) is a low-incidence voice disorder of unknown origin. A subgroup of seven patients with SD from our larger pool of 70 report vocal symptoms subsequent to head injury. This article is a case report of the neurodiagnostic findings, including computed tomography, magnetic resonance imaging, auditory brain-stem response, brain electrical activity mapping, and single photon emission computed tomography for three such patients. For each patient, two or more tests revealed positive neurologic findings. Each test, except computed tomography, demonstrated abnormalities in one or more patients. Two principles of clinical management are derived: (1) information regarding head trauma sustained before SD symptom onset is significant; (2) the absence of neuropathology on a single measure of central nervous system function should not be considered conclusive evidence that no neurologic lesions exist.

Otitis media. Incidence, duration, and hearing status.

The middle ear status and hearing sensitivity in 483 normal infants have been closely monitored as part of the Dallas Cooperative Project, University of Texas at Dallas, effort to assess the effect of early otitis media with effusion on speech and language development. At least one episode of otitis media with effusion occurred in 73.5% of the children between the ages of 6 and 18 months. Almost a quarter of these were discovered at "well-baby" checkups and were appropriately classified as "silent." The hearing levels, the methods of hearing assessment, and the implications of these data are described.

The role of the pediatrician in hearing loss. From detection to connection.

The advocacy by pediatricians is imperative if early hearing detection and intervention (EHDI) programs are to be effective, efficient, and successful over the long term. Some pediatricians remain unfamiliar with the rationale for universal screening of all newborns prior to hospital discharge. Pediatricians' questions regarding universal screening are data- and quality-driven. Discussion of the components of the EHDI program, answers to pediatricians' most frequently asked questions, supported by data, and the quality indicators used to monitor EHDI programs in Texas are provided.

Evidence for cortical dysfunction in spasmodic dysphonia: regional cerebral blood flow and quantitative electrophysiology.

Cortical function was evaluated in 26 subjects with spasmodic dysphonia. Quantitative topographic electrophysiologic mapping (QTE) was employed to provide quantitative analyses of EEG spectra and auditory and visual long-latency evoked potentials. Single-photon emission computed tomography (SPECT) of the cerebral transit of Xenon-133 was used to evaluate regional cerebral blood flow. Left hemispheric abnormalities in cortical function were found by both techniques in 10 subjects and by at least one technique in 18 subjects. Right hemispheric abnormalities were observed by both techniques in 8 subjects and by at least one technique in 18 subjects. Most patients with cortical dysfunction in one hemisphere had cortical dysfunction in the other, while only 4 subjects had unilateral lesions as found by one of the two techniques. Eight subjects were normal by all measurements. Underlying structural abnormalities were detected by magnetic resonance imaging in 5/24 subjects. However, functional abnormalities (SPECT or QTE) were not observed at sites of structural abnormalities. SPECT and QTE were significantly related in identification of left hemispheric dysfunction (p = .037) with a trend in the right hemisphere (p = .070), and a significant congruence of SPECT and QTE findings occurred in the left anterior cortical quadrant (p = .011). These findings indicate that dysfunction of cortical perfusion and/or cortical electrophysiology is associated with spasmodic dysphonia in the majority of subjects studied.

Magnetic resonance imaging findings and correlations in spasmodic dysphonia patients.

A sample of 19 spasmodic dysphonia (SD) patients was selected from a larger population of such patients to undergo magnetic resonance imaging (MRI), auditory brain stem response (ABR) testing, speech analysis, and extensive physical examination. Six patients had abnormal spin-echo MRI findings, ranging from infarcts within the basal ganglia to demyelinating lesions within the supralateral angles of the lateral ventricles. A weakly positive correlation was noted between the abnormal MRI findings and an abnormal ABR. The lack of a significant correlation between the MRI findings and other predictors of brain stem and midbrain disease, and the current spatial resolution limitations of MRI, suggest that we are visualizing the associated lesions rather than the actual foci of SD. The range of MRI findings is consistent with the concept that SD is a voice disorder in a heterogeneous patient population.

Hearing loss in children with congenital heart disease: a preliminary report.

Life expectancy for children with serious congenital heart defects has dramatically increased in recent years due to advances in medical and surgical care. Anatomic studies of temporal bones in patients with non-syndromic congenital heart disease have demonstrated a high incidence of middle and inner ear anomalies. Systematic study of auditory function in these patients has not been reported. Fifty children with serious congenital heart disease have been evaluated with otologic examination and auditory brainstem-evoked response (ABR) testing. The patients ranged in age from 3 days to 17 years-8 months. Eight patients had hearing loss and normal otologic examinations, 14 patients had hearing loss and associated otitis media with effusion, and 28 patients had normal hearing by ABR testing. These results show a high incidence (16%) of hearing loss not associated with otitis media with effusion in the study population. We suggest that children with serious congenital heart disease are at high risk for hearing loss. This patient group will benefit from early identification, and appropriate medical and audiologic management.

Tympanometry and otoscopy prior to myringotomy: issues in diagnosis of otitis media.

Tympanometry and pneumatic otoscopy were compared to findings at myringotomy in 86 children (163 ears). Seventy percent of the ears (115) had effusion, as revealed by myringotomy. Sensitivity and specificity for tympanometry were 90% and 86%, respectively. Sensitivity and specificity for pneumatic otoscopy were 93% and 58%, respectively. A chi-square was performed to compare the sensitivity and specificity to tympanometry to otoscopy, revealing tympanometry significantly better at determining non-effusion states. Additionally, a combined otoscopy and tympanometry sensitivity and specificity were calculated for those otoscopy and tympanometry determinations in agreement, revealing both sensitivity and specificity above 90%. A Fisher's exact probability test revealed no significant differences for the accuracy of tympanometry over otoscopy when the determinations of each were not in agreement. Implications of these results are discussed.

Episodic reactive dysphonia: a case study.

This case study exemplifies successful diagnosis through stroboscopic fiberoptic examination, illustrates the critical importance of a careful case history, and demonstrates potential hazards of supposedly benign environmental substances for hypersensitive individuals.

Spasmodic dysphonia, whether and where: results of seven years of research.

Two questions are addressed in this presentation and integration of experimental data from seven years of research. They are (a) is spasmodic dysphonia (SD) a neurologic disorder; and (b) if so, where in the nervous system does the dysfunction have its locus? The conclusion is that SD is a supranuclear movement disorder primarily, but not exclusively, affecting the larynx. For over 50% of the subjects, isolated, multifocal, cortical lesions can be identified, specifically in left frontal/temporal cortex (perisylvian region), medial frontal cortex, and right posterior temporal/parietal cortex. Twenty-five percent have mixed subcortical and cortical pathology. Seven percent manifest subcortical lesions alone. For 16%, neither cortical nor subcortical structural or functional lesions are identified. Three etiologic processes that could produce mild multiple cortical and subcortical lesions are closed head injury, multi-infarct microvascular disease, and exposure to neurotoxins. These processes are discussed with reference to the population studied.

Conductive hearing loss during infancy: effects on later auditory brain stem electrophysiology.

Long-term effects on auditory electrophysiology from early fluctuating hearing loss were studied in 27 children, aged 5 to 7 years, who had been evaluated originally in infancy. For controls (Group A), infant auditory brain stem responses (ABRs) were normal from birth to age 2 years. A second group (Group B) had intermittent conductive hearing loss. A third group (Group C) had more abnormal ABRs during infancy than Group B and more severe and frequent conductive hearing loss. For this follow-up study, all children had normal peripheral hearing at test. ABRs were obtained to monaural and binaural stimuli. Binaural interaction (BI) in the ABR was assessed in difference traces, derived by subtracting summed binaural from summed monaural waveforms. Controls differed from both groups with early hearing loss for wave III and wave V latencies and interpeak I-III and I-V latencies. There was a significant difference in the presence of BI. Eight of 9 A subjects and 8 of 9 B subjects, but only 4 of 9 C subjects, had demonstrable BI. Findings suggest that early fluctuating hearing loss disrupts later auditory brain stem electrophysiology.

Evaluation of a computer-automated program for clinical assessment of the auditory brain stem response.

An evaluation of an automatic auditory brain stem evaluation (AABE) for waves I, III, and V, of the auditory brain stem response (ABR) is presented. The on-line procedure performs a mathematical analysis of ABR waveforms using principles similar to those used by experienced clinicians to make threshold and latency decisions. It has been tested and applied to normal and pathologic traces at stimulus levels from 20 to 100 dB HL. Subject ages ranged from 6 months through adulthood. Latencies and thresholds determined by the analytic technique were examined and found to be indistinguishable from decisions of two "expert" observers and four practicing clinical audiologists experienced in ABR. Speed, practicality, and limitations of the software for routine ABR assessments are discussed.

Language learning in a prospective study of otitis media with effusion in the first two years of life.

We report cross-sectional findings on children's early experience with otitis media with effusion (OME) related to hearing over time and emerging receptive and expressive language skills on the Sequenced Inventory of Communication Development Scale (SICD). Tympanometry and otoscopy on the same day are combined to diagnose OME. Hearing from 6 to 12 months is significantly related to scores on the SICD beginning with receptive language at 12 months. At 18 and 24 months, both receptive and expressive language are significantly related to average hearing from 6 to 18 months. Better language is associated with better average hearing levels. These findings suggest that the relationship between OME and language is mediated by hearing. It remains to be seen whether these relationships persist as the children continue to develop language.

The newborn with hearing loss: detection in the nursery.

BACKGROUND: Early detection of hearing loss coupled with appropriate early intervention is critical to speech, language, and cognitive development. These competencies serve as the foundation for later academic skills. For these reasons, many states are undertaking aggressive efforts to screen all newborns before hospital discharge. Universal detection of hearing loss in newborns is a three-stage process composed of 1) the birth admission screen, 2) follow-up and diagnosis, and 3) intervention services. Breakdown at any stage jeopardizes the entire effort. The goals of this research are to examine the birth admission screen by reviewing outcome measurements for 54 228 Texas newborns and to evaluate factors that impact outcomes positively or negatively. METHODOLOGY: All newborns were screened for hearing loss using a physiologic test of auditory function; either screening auditory brainstem responses or transient evoked otoacoustic emissions. Screening occurred in the newborn and intensive care nurseries, before hospital discharge in 9 sites as part of the nursery protocol. Patients. A total of 54 228 newborns were available for screening. OUTCOME MEASURES: Four measures were evaluated and are reported: the number of births screened, the number of newborns who passed the screen before discharge, the number of infants who returned for follow-up, and the number of infants identified with hearing loss. A Birth Screening Performance Index is also calculated. RESULTS: Results are reported for calendar years 1994, 1995, 1996, and through June 1997. A total of 54 228 newborns were available for screening; 52 508 were screened before hospital discharge during their birth admission and 50 721 passed this screen. Infants returning for follow-up screen as outpatients numbered 1224. Over this 31/2-year span, 113 infants who failed the birth admission screening had hearing loss that was sensorineural in nature. From these data, the estimated incidence of hearing loss is 3.14/1000 infants. CONCLUSIONS: Screening in the nursery with low false-positive rates can be achieved when three elements are present: audiology involvement, hospital support, and automated data and information management. Follow-up measures need improvement. Better tracking methods may help assure that at-risk newborns are connected to services.

Quantitative topographic electrophysiology and functional neurologic status in right middle cerebral artery infarction.

Thirteen patients with clinically and radiographically defined right middle cerebral artery infarction were studied using EEG, quantitative electroencephalographic (QEEG) spectra, and multi-channel evoked potentials. The purpose of this effort was to develop QEEG rules that related to the patient's neurologic status. Three QEEG relative delta spectral patterns were identified in the right hemisphere which related to neurologic residua. These include limited perisylvian involvement, mixed involvement of perisylvian and extrasylvian regions, and extrasylvian involvement only. While there were parallels between QEEG spectral patterns and auditory, visual and somatosensory evoked potentials, there were modality specific features consistent with functional differences.

Localization of multiple dipoles: mathematical programming approaches.

Although there has been progress in EEG and evoked potential analysis, the identification of underlying neural activity has eluded researchers despite its importance. This paper introduces the application of mathematical programming techniques to the "inverse" problem of three-dimensional localization of brain activity from scalp potentials. Preliminary computer experience with these optimization methods reported herein, yields encouraging results on simulated data and points new directions for research.

Infarction of the superior temporal gyrus: a description of auditory evoked potential latency and amplitude topology.

P1 and N1 of the cortical auditory evoked potential (AEP) were studied with multiple electrodes in 10 normal subjects and 6 patients with left middle cerebral artery infarction. Patients were selected based on neurological examination and on CT scans showing both (1) infarction limited to the vascular territory and (2) involvement of posterior portion of superior temporal gyrus. Waveforms recorded from C3, Cz, and C4 were examined for peak latency and amplitude of P1 and N1 on all subjects. Topographic displays of amplitude over P1 and N1 latency ranges were also examined. In normals, P1 was identified in 9 of the 10 subjects at all three electrode sites. In patients, P1 was identified at C3 in only 1 of the 6. N1 was present at all three electrodes in the 10 normal subjects and in 5 of the 6 patients. The remaining patient had N1 at C4 and Cz only. Examination of amplitude topology showed as asymmetric evolution of P1 and N1 in the patients. This asymmetry was not present in normals. The results of this study are consistent with theory that P1 arises from primary auditory cortex. Results further suggest multiple generators for N1. Additional study correlating topographic display from multichannel recordings with CT or MRI in brain-injured patients may bring more insight into N1 generators.

Brain blood flow related to acoustic laryngeal reaction time in adult developmental stutterers.

The 1980s witnessed renewed interest in the relation between developmental stuttering and central nervous system (CNS) abnormalities. We have reported differences between nonstutterers and developmental stutterers on electrophysiologic (QTE) and metabolic (rCBF) measures of brain function. A critical step in the interpretation of results of functional brain imaging studies is to determine the relation, if any, of identified CNS abnormalities to speech motor control in persons who stutter. In this study we addressed the interpretation of rCBF findings by asking whether we could identify patterns of impaired acoustic laryngeal reaction time (LRT) as a function of response complexity parallel to rCBF findings. Stutterer subgroups determined by clinical severity ratings were not differentiated by LRT values as a function of response complexity. Stutterers with relative blood flow asymmetry below the normal median value involving both left superior and middle temporal regions of interest (ROIs) showed significantly longer LRT for the complex response than did normal speakers and stutterers with above-normal median relative flow values to at least one of these temporal ROIs. Stutterer subgroups based on reduced cingulate flow alone were not differentiated by LRT values. Findings are consistent with Goldberg's (1985) model of CNS premotor processing. Findings also suggest that stutterer subgroups might be distinguished by the presence, loci, and relative magnitude of cortical and/or subcortical rCBF abnormality in regions that subserve a fluency-generating system.