Herbert A. Leeper

A prospective study of cognitive impairment in ALS.

Objective: To characterize prospectively the cognitive profile in ALS. Methods: Clinically definite ALS patients (11 men, 2 women), age 39.9 to 74.0 years (mean age, 54.2 ± 9.6 years; mean disease duration, 21.1 ± 10.5 months) underwent neuropsychologic, language, and speech testing followed by MR 1H spectroscopy (4 T). Five spousal control subjects completed an identical protocol. Eight ALS patients participated in follow-up studies at a 6-month interval. Results: Relative to control subjects, ALS patients showed mild impairment in word generation, recognition memory (faces), and motor-free visual perception. Bulbar-onset patients showed greater impairment in a number of measures (working memory, problem solving/cognitive flexibility, visual perception, and recognition memory for words and faces), and cognitive impairment appeared more progressive over time. ALS patients demonstrated anomia on a confrontation naming test, with no significant problems following commands or repeating. Speech motor performance scores and intelligibility scores were not significantly different. No significant declines in forced vital capacity, forced expiratory volume, or peak expiratory flow rates were observed. Although normal at initial testing (T1), MR 1H spectroscopy demonstrated a reduction of the N-acetylaspartate/creatine (NAA/Cr) ratio in the nondominant precentral motor strip across the two testing intervals. In contrast, the NAA/Cr ratio obtained from the anterior cingulate gyrus at T1 was already reduced in bulbar-onset patients (p < 0.001), whereas no deficits were observed in limb-onset individuals in the same region. Conclusions: Bulbar-onset ALS patients with cognitive impairments and neuronal loss in the anterior cingulate gyrus subsequently developed more profound neuropsychological dysfunction whereas both language and speech capabilities remained relatively preserved. Of note, the absence of bulbar signs did not predict an absence of cognitive decline.

Cognition, Language, and Speech in Amyotrophic Lateral Sclerosis: A Review

Amyotrophic lateral sclerosis (ALS) is a progressive, adult-onset neurodegenerative disorder manifesting as a relentless loss of motor capabilities and, ultimately, death. Traditionally thought to affect solely the lower motor neurons and corticospinal tracts, recent studies suggest that the pathogenic process of ALS is more extensive, involving dysfunction of cortical grey and white matter with clinical correlates of impairment in cognition and language. The impact of speech and motor deficits are discussed in relation to the issues of assessment of cognition and language. Three case studies are presented for illustrative purposes. Finally, direction for future research to investigate cognitive dysfunction in ALS are presented.

Computerized speech recognition: influence of intelligibility and perceptual consistency on recognition accuracy

The effects of intelligibility and consistency on the recognition accuracy of a speaker-adaptable speech recognition system (IBM VoiceType Version 1.0) were evaluated. Six participants who had dysarthria of speech across three severity levels (i.e., mild, moderate, severe) and six age- and gender-matched peers without speech impairments participated in the study. Productions of sentences were evaluated across five assessment sessions. Recognition accuracy was significantly higher for the speakers in the control group than for the speakers with dysarthria across severity levels. High levels of intelligibility correlated significantly with high recognition accuracy scores. Perceptual rankings of speech consistency did not correlate significantly with recognition accuracy scores. Results suggest that for speaker-adaptable systems, the more intelligible a speaker, the greater his or her success with the voice recognition system. Results also suggest that perceived inconsistencies in the speech productions of ...

Aerodynamic, Acoustic, and Perceptual Changes following Adenoidectomy

Fourteen children were seen prior to adenoidectomy and at 1 month, 3 months, and 6 months following surgery. On each visit, nasal airway resistance values, nasal cross-sectional area estimates, nasalance scores, and perceptual ratings of nasality were collected. These data were analyzed to identify changes that were related to the time of the test, and to the primary indication for surgery (nasal airway obstruction or recurrent infection). Results revealed significant reduction in nasal airway resistance and significant changes in nasalance following surgery. Perceptual changes were not significant. Clinical implications of these findings are discussed.

Changes in laryngeal airway resistance in young adult men and women as a function of vocal sound pressure level and syllable context

Summary A noninvasive pressure-flow technique was used to assess laryngeal airway resistance (R law ) in eight young adult women and seven men. Syllable structures used were consonant-vowel (/pi/) and consonant-vowel-consonant (/bip/). The data were obtained from oscillographic records of intraoral air pressure and transglottal airflow over 2 consecutive days. Repetitions of each syllable context were produced at each subjects 25th, 50th, and 75th percentiles of vocal sound pressure level. No significant differences in R law were found across days for the two groups. Women had significantly greater R law than did men for the /pi/ and /bip/ contexts. Men showed a significantly greater average airflow rate than did women for both syllable contexts. Airflow, air pressure, and the ratio R law increased as the sound pressure level of voice increased. The technique appears to be useful for characterizing certain features of laryngeal airway resistance for men and women.

Vocal Fold Diadochokinetic Function of Individuals With Amyotrophic Lateral Sclerosis

This study relates over time the changes in voluntary opening and closing of the vocal folds (vocal fold diadochokinesis, or VFDDK) of patients with amyotrophic lateral sclerosis (ALS). The rate, p...

Young children's preferences for listening rates.

A paired-comparison paradigm was utilized to determine the preferences of 20 young children for listening rate for prose speech. An electronic expansion/compression technique yielded nine rates of speech ranging from 100 wpm to 200 wpm, with intervals of 25 wpm. The results indicated that the children most preferred a listening rate of 200 wpm and least preferred a rate of 100 wpm. Comparisons of the present findings with preference rates of older, post-adolescent children and adults are discussed. Direction for further research with temporal alteration and linguistic constraints on the message are considered.