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Biomedical subjects

C L Ludlow

Publications and source records attributed to C L Ludlow.

70 records · Page 4Linked to original sources

Procedures for the selection of spastic dysphonia patients for recurrent laryngeal nerve section.

Patients with spastic dysphonia were studied to identify the characteristics of patients benefiting from recurrent laryngeal nerve (RLN) surgery. Studies included laryngeal video recordings made during speech, measures of frequency and amplitude variations during extended phonation, the effects of altered auditory feedback on dysfluencies, and temporary unilateral RLN block. Two patients had vocal fold adductor spasms during connected speech, had increased acoustic phonatory tremor in frequency, were not benefited by altered auditory feedback, and responded favorably to nerve block. Subsequent RLN section improved the speech of both patients. Other patients had speech blocks, repetitions and prolongations, vocal fold tremors during phonation, reduced dysfluencies during altered auditory feedback, and were not benefited by temporary nerve block. Two subtypes of spastic dysphonic patients are proposed.

Adult↗

Qualitative analysis of scopolamine-induced amnesia.

The neurochemistry of memory remains to be determined. Acetylcholine may be one of the neuotransmitters which mediates memory function, since the anticholinergic drug scopolamine produces amnesia in man. This study of scopolamine-induced memory deficits further defines those cognitive processes which are disrupted. The drug does not diminish attention, as assessed with an auditory vigilance task, or initial signal detection. More complex auditory decoding is affected, however. Scopolamine impairs aspects of initial memory acquisition (e. g., encoding and consolidation) and spontaneous memory retrieval. Retention is unaffected. Precise delineation of the neurochemistry of human memory will require comparative studies of amnesia-producing compounds, systematically examining the neuropsychological processes impaired by each.

Adult↗

Children's language disorders: recent research advances.

Between 3 and 8% of preschool children in Britain and the United States are delayed in their language development by more than a year below the normal range. Evidence suggests that such children are particularly impaired in acquiring syntactic and morphological rules, although well-defined syndromes of impaired language development have not yet been determined. The effects of preschool impairments in language development on subsequent school achievement are significant: 60% of these children are in special classes for the learning impaired at 9 years of age. Auditory processing deficits have been demonstrated in language-impaired children, but the contributions of such deficits to language development difficulties have yet to be determined. While autistic children have severe cognitive disorders and visual and auditory perceptual disturbances, the difficulties of nonautistic language-impaired children seem confined more to language expression and comprehension. Recent neuropsychological evidence concerning brain organization for language behavior suggests that these children have deficiencies in language functions which normally depend on left hemisphere functioning.

Achievement↗

Cerebral activation during speech discrimination in temporal lobe epilepsy.

Eight patients with uncontrolled complex partial seizures underwent positron emission tomography with 18-fluoro-2-deoxyglucose both at rest and during an auditory order discrimination task using speech syllables. Eight age-matched controls were scanned under identical conditions; an additional 18 normal subjects were scanned only at rest. No consistent task-related changes were seen in control subjects. For the 3 patients with left temporal epileptogenic foci, left inferior temporal lobe hypometabolism was more evident during the activated than during the resting scan. Activation procedures may augment the diagnostic yield of metabolic scanning in epilepsy.

Adult↗

Identification of symptoms for spasmodic dysphonia and vocal tremor: a comparison of expert and nonexpert judges.

UNLABELLED: Spasmodic dysphonia is a rare voice disorder that is most successfully treated by injection of botulinum toxin (i.e., BOTOX) into the affected laryngeal muscles. BOTOX is currently available for use by professionals outside of metropolitan voice centers who may be unfamiliar with this rare disorder. Patients may seek assessment and treatment locally from clinicians who are unfamiliar with the speech symptoms for adductor-type (ADSD) or abductor-type (ABSD) spasmodic dysphonia. Although these disorders have been described in the literature, the symptoms have not been well defined and may appear similar to those of vocal tremor or muscle tension dysphonia (MTD). Thus, patients with spasmodic dysphonia might not be easily identified by local clinicians for treatment. The purpose of the current study was to determine whether voice clinicians with infrequent exposure to patients with spasmodic dysphonia could learn to identify speech symptoms for ADSD and ABSD comparable to voice clinicians with extensive experience with these disorders. The ratings of five nonexpert judges were compared to the ratings obtained from three expert judges. The results of this study demonstrated that nonexpert judges could be trained to identify the speech symptoms associated with ADSD, ABSD, and vocal tremor. While the nonexpert judges tended towards false positive judgements for the speech symptoms of interest, the overall speech symptom profiles for each type of voice disorder appeared comparable to those obtained from the expert judges. The symptom identificationscales used, therefore, have potential for use by clinicians unfamiliar with these disorders for correctly identifying persons with symptoms of ADSD and ABSD. EDUCATIONAL OBJECTIVES: Readers will be able to (1) define the predominant speech symptoms reflective of the voice disorder categories of ABSD, ADSD, and vocal tremor; and (2) describe the methods utilized in a new perceptual training protocol for teaching clinicians how to identify predominant speech symptoms associated with the voice disorder categories of ABSD, ADSD, and vocal tremor.

Humans↗

The effects of fluency-evoking conditions on voicing onset types in persons who do and do not stutter.

Voicing onset changes between control conditions and three fluency-evoking conditions (choral reading [CHORAL], delayed auditory feedback [DAF], and noise [NOISE]) were studied in 12 persons who do not stutter and 10 who do stutter. Voicing onsets were distinguished physiologically using airflow prior to voicing, with zero airflow prevoicing categorized as hard and the rest as breathy. Persons who stutter were more fluent under all fluency-evoking conditions than control conditions. Speaking under fluency-evoking conditions did not significantly increase the overall proportion of breathy onsets from control conditions for either group. However, looking only at hard onsets in the control condition, we found that both groups changed significantly more to breathy (p = 0.001) under CHORAL and NOISE. In persons who stutter, onset type was not associated with whether a word was produced fluently or dysfluently in the control condition. Also, no relationship was found between onsets changing to breathy under fluency-evoking conditions and onsets changing to fluent. The results suggest that although fluency-evoking conditions can modify some voicing onset behaviors, these modifications do not relate to improvements in fluency.

Adult↗

Vocal fold paresis in Shy-Drager syndrome.

Twelve patients with Shy-Drager syndrome (SDS) presenting symptoms of multiple nervous system atrophy and orthostatic hypotension were examined for laryngeal movement disorders and vocal impairment in speech. Vocal fold abductor paresis was found in 11 patients and was bilateral in 10. Speech task performance was recorded in SDS patients, Parkinson patients and age- and sex-matched controls. Trained listeners with inter-rated reliability greater than or equal to .85 judged each recording on 20 attributes while blind to speaker identity. SDS patients had a breathy and strained voice quality, reduced loudness, monopitch and monoloudness, imprecise consonants, variations in rate and rate-slowing, suggesting a flaccid type of dysarthria. In comparison with Parkinson patients, SDS patients had excess vocal hoarseness, intermittent glottal fry and a slow and deliberate speaking rate. Orthostatic hypotension, laryngeal stridor, hoarseness, intermittent glottal fry and slow speech rate were found to be discriminating symptoms of SDS.

Aged↗

Emerging clinical applications of electrical stimulation: opportunities for restoration of function.

Emerging clinical application of electrical stimulation in three systems is reviewed. In the bladder, stimulation of sacral posterior roots reduces reflex incontinence and significantly improves bladder capacity. With the combination of anterior and posterior root stimulation, bladder control can be achieved without the need for rhizotomy. Preliminary research demonstrates that bladder contractions may also be generated by stimulation of the urethral sensory branch of the pudendal nerve, even after acute spinal cord transection, while inhibition of the bladder and control of urge incontinence can be achieved by stimulation of the whole pudendal nerve. Spinal cord stimulation can modulate the activity of the intrinsic cardiac nervous system involved in the regulation of regional cardiac function and significantly reduce the pain associated with angina pectoris. Finally in the area of upper airway disorders, functional electrical stimulation has great potential for increasing life support as well as for quality of life in chronic ailments, particularly obstructive sleep apnea and dysphagia.

Angina Pectoris↗