rTMS as a treatment for neurogenic communication and swallowing disorders.

Recent years have seen the introduction of non-invasive brain stimulation techniques (e.g. transcranial direct current stimulation and transcranial magnetic stimulation) utilized to target neural-based pathologies, for therapeutic gain. The direct manipulation of cortical brain activity by repetitive transcranial magnetic stimulation (rTMS) could potentially serve as an efficacious complimentary rehabilitatory treatment for speech, language and swallowing disorders of a neurological origin. The high prevalence of positive reports on communication and swallowing outcomes support these premises. Nonetheless, experimental evidence to date in some areas is considered rudimentary and is deficient in providing placebo-controlled substantiation of longitudinal neuroplastic change subsequent to stimulation. The most affirmative therapeutic responses have arisen from small placebo-controlled trials using low-frequency rTMS for patients with non-fluent aphasia and high-frequency rTMS applied to individuals with Parkinson's disease to improve motor speech performance and outcomes. Preliminary studies applying rTMS to ameliorate dysphagic symptoms post-stroke provide positive swallowing outcomes for patients. Further research into the optimization of rTMS protocols, including dosage, stimulation targets for maximal efficacy and placebo techniques, is critically needed to provide a fundamental basis for clinical interventions using this technique. rTMS represents a highly promising and clinically relevant technique, warranting the future development of clinical trials across a spectrum of communication and swallowing pathologies, to substantiate and expand on the methods outlined in published reports.

Treatment of articulatory dysfunction in Parkinson's disease using repetitive transcranial magnetic stimulation.

BACKGROUND AND PURPOSE: Neuroimaging has demonstrated that improved speech outcomes in Parkinson's Disease (PD) subsequent to behavioural treatment approaches are associated with increased activity in the motor and pre-motor cortex. High-frequency repetitive transcranial magnetic stimulation (rTMS) is capable of modulating cortical activity and has been reported to have significant benefit to general motor function in PD. It is possible that high-frequency rTMS may also have beneficial outcomes on speech production in PD. METHODS: High-frequency (5 Hz) rTMS was applied to 10 active stimulation and 10 sham placebo patients for 10 min/day (3000 pulses), for 10 days and speech outcome measures and lingual kinematic parameters recorded at baseline and 1 week, 2 and 12 months post-stimulation. RESULTS: The findings demonstrated positive treatment-related changes observed in the active rTMS group when compared to the sham placebo control group at 2 and 12 months post-stimulation in speech intelligibility, communication efficiency ratio, maximum velocity of tongue movements and distance of tongue movements. CONCLUSION: The results support the use of high-frequency rTMS as a therapeutic tool for the treatment of articulatory dysfunction in PD.

Improved language performance subsequent to low-frequency rTMS in patients with chronic non-fluent aphasia post-stroke.

BACKGROUND: Low-frequency repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential tool for neurorehabilitation and remediation of language in chronic non-fluent aphasia post-stroke. Inhibitory (1 Hz) rTMS has been applied to homologous language sites to facilitate behavioural language changes. Improvements in picture-naming performance and speech output over time have been reported. METHODS: Low-frequency (1 Hz) rTMS was applied to six real stimulation and six sham placebo patients for 20 min per day, for 10 days, and behavioural language outcome measures were taken at baseline (pre-stimulation) and 2 months post-stimulation. RESULTS: The findings demonstrate treatment-related changes observed in the stimulation group when compared to the placebo control group at 2 months post-stimulation on naming performance as well as other aspects of expressive language and auditory comprehension. CONCLUSIONS: These findings provide considerable evidence to support the theory of rTMS modulating mechanisms of transcallosal disinhibition in the aphasic brain and highlight the potential clinical applications for language rehabilitation post-stroke.

Processing lexical ambiguities in word triplets: evidence of lexical-semantic deficits following dominant nonthalamic subcortical lesions.

Lexical-semantic function was investigated in 10 participants with lesions of the dominant nonthalamic subcortical (NS) region and a matched normal control group. Participants performed speeded lexical decisions on the 3rd member of auditorily presented word triplets. The 4 critical triplet conditions were concordant (coin-bank-money), discordant (river-bank-money), neutral (day-bank-money), and unrelated (river-day-money). When the interstimulus interval (ISI) between the words in the triplets was 100 ms, patients with NS lesions obtained priming that indicated nonselective lexical access; at 1,250-ms ISI, however, there was no significant priming effect. This pattern of results is consistent with the view that patients with NS lesions can automatically access lexical-semantic information but may be unable to sustain lexical activation through controlled or attentional forms of processing.

Understanding ambiguous words in biased sentences: evidence of transient contextual effects in individuals with nonthalamic subcortical lesions and Parkinson's disease.

A cross-modal priming experiment was used to investigate lexical ambiguity resolution during sentence processing in individuals with nonthalamic subcortical lesions (NSL) (n = 10), compared to matched normal controls (n = 10), and individuals with cortical lesions (CL) (n = 10) and Parkinson's disease (PD) (n = 10). Critical sentences biased towards the dominant or subordinate meaning of a sentence-final lexical ambiguity were presented auditorily, followed after a short interstimulus-interval (ISI) (0 msec) or a long ISI (1000 msec), by the presentation of a visual target which was related to the dominant or subordinate meaning, or was an unrelated control word. Subjects made speeded lexical decisions on the targets. At the short ISI, lexical activation for the neurological patient groups appeared influenced by contextual information to a greater extent than in normal controls, which may indicate delayed lexical decision making or disturbed automatic lexical activation. At the long ISI, only the PD and NSL individuals failed to selectively activate the contextually appropriate meaning, suggesting a breakdown in the attention-based control of semantic activation through contextual integration. This finding may implicate disruptions to proposed frontal-striatal mechanisms which mediate attentional allocation and strategy formation.

Chronic aphasia subsequent to striato-capsular and thalamic lesions in the left hemisphere.

The language abilities of a group of seven chronic aphasics with vascular lesions centered on the striato-capsular region and thalamus of the left hemisphere were described. A range of severity and types of chronic language disorder were documented through assessment using a battery of standardized language tests. The most common language disorder documented was a naming impairment of varying degrees of severity, exhibited by six of the seven cases. The majority of subjects made predominantly semantic errors in the naming task; however, each subject produced a variety of error types and there was no pattern of errors characteristic of the group. The language data obtained were used to evaluate previously developed models of the role of the subcortical structures in naming functions.

Semantic abilities in dementia of the Alzheimer type. 1. Lexical semantics.

The lexical semantic abilities of 18 Alzheimer patients were investigated using confrontation naming tasks (including both visual and tactile naming tests) and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients produced a greater number of naming errors than the control subjects. The errors made by subjects during the naming tasks were analyzed according to a set of 16 error response types. The Alzheimer patients' response patterns suggest that they do recognize objects which they are unable to name and are able to identify the semantic class to which the target belongs, but cannot provide the lexeme corresponding to the correct individual class member. The results support a semantic network disruption rather than a visual perceptual deficit as the basis of the naming disturbance observed in Alzheimer patients.

Automatic and volitional semantic processing in aphasia.

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that object's semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.

Semantic abilities in dementia of the Alzheimer type. II. Grammatical semantics.

The grammatical semantic abilities of 18 Alzheimer patients were investigated using picture description tasks and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. During picture description, Alzheimer patients showed that they were able to provide as much information about the target picture as control subjects, but were less concise in their verbal representation of the information. The lack of conciseness was reflected in the DAT patients requiring more time and more syllables to communicate a similar quantity of information than the control subjects. The appropriateness of using a picture description task which involves a perceptual step-by-step account of unrelated events to assess sentential semantics and the conveying of information at a conceptual level is discussed.

Language disorders in dementia of the Alzheimer type.

The language profile of a group of 18 Alzheimer patients is documented and their performance on a standard aphasia test battery compared to a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients scored significantly lower than the controls in the areas of verbal expression, auditory comprehension, repetition, reading, and writing. Articulation abilities were the same in each group. A language deficit was evident in all Alzheimer patients. The language disorder exhibited resembled a transcortical sensory aphasia. Syntax and phonology remained relatively intact but semantic abilities were impaired. The results support the inclusion of a language deficit as a diagnostic criterion of Alzheimer's disease.

Speech and language skills in children with early treated phenylketonuria.

The speech and language skills of 29 children with early treated phenylketonuria (PKU) were reported. The performances of two experimental groups that differed in language development level on standardized speech/language tests were compared with the performances of appropriate control groups matched for age, sex, and socioeconomic level. No significant differences were found on speech and/or language measures between either of the two experimental groups and their respective controls. Examination of individual scores, however, did reveal linguistic impairment in a small number of persons with PKU. No pattern of linguistic deficit was found nor were there any consistent relations between individual speech/language scores, cognitive abilities, or dietary control ratings.

Acute lymphoblastic leukaemia: language deficits in children post-treatment.

The language abilities of a group of 22 children (aged between 5 years and 17 years, 9 months) treated for acute lymphoblastic leukaemia (ALL) were investigated and compared with those of a group of non-neurologically impaired, age- and sex-matched controls. The language test battery included an age-appropriate measure from the Test of Language Development (TOLD) series, consisting of either the Test of Adolescent Language (TOAL--2), or the Test of Language Development--Intermediate or --Primary (TOLD--I or --P); the timed subtests of the Clinical Evaluation of Language Function (CELF); the Boston Naming Test; and one of either the Token Test or the Token Test for Children, depending on the age of the subject. As a group, the leukaemia subjects performed significantly worse than the controls on the TOAL--2, TOLD--I, TOLD--P, Token Test, and Boston Naming Test. The need for post-treatment monitoring of the language abilities of children treated for ALL to enable early remediation of areas of deficit is highlighted.

Which one of these is not like the others? An inter-hospital study of the viscosity of thickened fluids.

This investigation examined the rheological (viscosity and yield stress) and material property (density) characteristics of the thickened meal-time and videofluorscopy fluids provided by 10 major metropolitan hospitals. Differences in the thickness of thickened fluids were considered as a source of variability and potential hazard for inter-hospital transfers of dysphagic patients. The results indicated considerable differences in the viscosity, density, and yield stress of both meal-time and videofluoroscopy fluids. In theory, the results suggest that dysphagic patients transferred between hospitals could be placed on inappropriate levels of fluid thickness because of inherent differences in the rheology and material property characteristics of the fluids provided by different hospitals. Slowed improvement or medical complications are potential worst-case scenarios for dysphagic patients if the difference between the thick fluids offered by 2 hospitals are extreme. The investigation outlines the most appropriate way to assess the rheological and material property characteristics of thickened fluids. In addition, it suggests a plan of quality improvement to reduce the variability of the thickness of fluids offered at different hospitals.

Voice changes in women treated for endometriosis and related conditions: the need for comprehensive vocal assessment.

Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documented subjective vocal changes or documented single cases without detailed, baseline voice assessments. The impact on laryngeal function of women taking these androgenic treatments requires further detailed, objective assessment. The need for increased awareness of the actions of androgenic hormones on womens' voices, and the benefits of a thorough voice assessment are discussed.

Aphasia following right thalamic hemorrhage in a dextral.

A 74-year-old, right-handed woman with a right thalamic hemorrhage and aphasia is described. Sequential neurologic examinations and aphasia testing were carried out during a 1-year period and the results are reported. The patient exhibited a language deficit resembling a transcortical aphasia in the acute stage. Reduced spontaneous speech, fading voice volume, fluent verbal output with paraphasia, anomia, and a mild comprehension difficulty were present. Repetition was good. At 1 year postonset, the primary language problem exhibited by the patient was in object naming, all other components of the original language deficit having shown good recovery. This is the first reported case of right thalamic involvement in speech/language in the absence of personal and familial sinistrality.

Disorders of nasality in subjects with upper motor neuron type dysarthria following cerebrovascular accident.

The nasality of 19 subjects with upper motor neuron (UMN) damage following cerebrovascular accident (CVA), and 19 control subjects matched for age and sex, was investigated using both perceptual judgements of nasality and a modified version of the nasal accelerometric procedure described by Horii (1980). Nasality indices were calculated for each subject during the production of a series of nasal and non-nasal sounds, words, and sentences. Statistical comparison of the two groups revealed that the CVA subjects had significantly higher nasality indices on the production of nonnasal speech tasks than the controls. No significant difference was noted between the two groups on nasal tasks. Individual case by case examination of the accelerometer data confirmed the presence of hypernasality in 7 of the 19 CVA subjects. In contrast to the instrumental findings, the results of the perceptual judgements of nasality identified the presence of hypernasality, hyponasality, and normal nasal resonance within the CVA group.

Acute computerized tomographic scans: their value in the localization of lesions and as prognostic indicators in aphasia.

Twenty three patients with past or present evidence of aphasia following either stroke (n = 19) or head trauma (n = 4) were given the Boston Diagnostic Aphasia Examination in order to classify their aphasia type and determine their language deficit at least three months postonset of their neurological disorder. The location and extent of brain lesions identified from computerized tomographic (C.T.) scans taken in the acute stage and, wherever possible, in the chronic stage (n = 7) were correlated with the type of aphasia. Lesions associated with global, Wernicke's, Broca's, conduction, and anomic aphasia are described and discussed in relation to the findings of previously reported clinico-C.T. scan correlation studies. The value of the acute stage C.T. scan as a predictor of long-term language deficits is discussed.

Tongue-to-palate contact patterns and variability of four English consonants in an /i/ vowel environment.

Minimal data exist describing tongue-to-palate contact patterns and their variability in normal speakers of English. Consequently, the aims of the present study were to examine, using a comprehensive profile of data analysis, tongue-to-palate contact patterns and their variability in a group of ten normal speakers of English using the Reading Electropalatography3 (EPG3) system. Each speaker produced ten repetitions of the target words tea, leap, sea, and key following the carrier phrase 'I saw a ...'. Results revealed that the contact patterns produced exhibited similar characteristics to those described in earlier research. Additionally, the lateral approximant /i/ exhibited the highest degree of intra-subject variability with the alveolar fricative /s/ exhibiting the least. The results of this study are discussed in relation to existing normative data.

Physiological assessment of tongue function in dysarthria following traumatic brain injury.

A tongue pressure transducer system was used to assess tongue strength, endurance, fine pressure control and rate of repetitive movement in a group of 20 individuals, aged 17 to 60 years, with dysarthria following severe traumatic brain injury (TBI). Comparison of the TBI group's results against data obtained from a group of 20 age and sex matched control subjects revealed reductions in tongue endurance and rate of repetitive movement. Tongue strength and fine pressure control, however, were found not to differ significantly from the control group. Pearson's product-moment correlations indicated there to be only weak correlations between the physiological nonspeech tongue parameters and the deviant perceptual articulatory features exhibited by the TBI group. Further analysis of the results on an individual subject basis revealed no clear relationships between the physiological and perceptual parameters suggesting that the TBI subjects may have been compensating in different ways for the physiological impairments.

Reduced N400 semantic priming effects in adult survivors of paediatric and adolescent traumatic brain injury.

The immediate and long-term neural correlates of linguistic processing deficits reported following paediatric and adolescent traumatic brain injury (TBI) are poorly understood. Therefore, the current research investigated event-related potentials (ERPs) elicited during a semantic picture-word priming experiment in two groups of highly functioning individuals matched for various demographic variables and behavioural language performance. Participants in the TBI group had a recorded history of paediatric or adolescent TBI involving injury mechanisms associated with diffuse white matter pathology, while participants in the control group never sustained any insult to the brain. A comparison of N400 Mean Amplitudes elicited during three experimental conditions with varying semantic relatedness between the prime and target stimuli (congruent, semantically related, unrelated) revealed a significantly smaller N400 response in the unrelated condition in the TBI group, indicating residual linguistic processing deviations when processing demands required the quick detection of a between-category (unrelated) violation of semantic expectancy.