The mismatch negativity (MMN) response to complex tones and spoken words in individuals with aphasia

Background: The mismatch negativity (MMN) is a fronto-centrally distributed event-related potential (ERP) that is elicited by any discriminable auditory change. It is an ideal neurophysiological tool for measuring the auditory processing skills of individuals with aphasia because it can be elicited even in the absence of attention. Previous MMN studies have shown that acoustic processing of tone or pitch deviance is relatively preserved in aphasia, whereas the basic acoustic processing of speech stimuli can be impaired (e.g., auditory discrimination). However, no MMN study has yet investigated the higher levels of auditory processing, such as language-specific phonological and/or lexical processing, in individuals with aphasia. Aims: The aim of the current study was to investigate the MMN responses of normal and language-disordered subjects to tone stimuli and speech stimuli that incorporate the basic auditory processing (acoustic, acoustic-phonetic) levels of non-speech and speech sound processing, and also the language-specific phonological and lexical levels of spoken word processing. Furthermore, this study aimed to correlate the aphasic MMN data with language performance on a variety of tasks specifically targeted at the different levels of spoken word processing. Methods & Procedures: Six adults with aphasia (71.7 years ±3.0) and six healthy age-, gender-, and education-matched controls (72.2 years ±5.4) participated in the study. All subjects were right-handed and native speakers of English. Each subject was presented with complex harmonic tone stimuli, differing in pitch or duration, and consonant-vowel (CV) speech stimuli (non-word /de:/ versus real word /deI/). The probability of the deviant for each tone or speech contrast was 10%. The subjects were also presented with the same stimuli in behavioural discrimination tasks, and were administered a language assessment battery to measure their auditory comprehension skills. Outcomes & Results: The aphasic subjects demonstrated attenuated MMN responses to complex tone duration deviance and to speech stimuli (words and non-words), and their responses to the frequency, duration, and real word deviant stimuli were found to strongly correlate with performance on the auditory comprehension section of the Western Aphasia Battery (WAB). Furthermore, deficits in attentional lexical decision skills demonstrated by the aphasic subjects correlated with a word-related enhancement demonstrated during the automatic MMN paradigm, providing evidence to support the “word advantage effect”, thought to reflect the activation of language-specific memory traces in the brain for words. Conclusions: These results indicate that the MMN may be used as a technique for investigating general and more specific auditory comprehension skills of individuals with aphasia, using speech and/or non-speech stimuli, independent of the individual's attention. The combined use of the objective MMN technique and current clinical language assessments may result in improved rehabilitative management of aphasic individuals.     

Topography of dyskinesias and torticollis evoked by inhibition of substantia nigra pars reticulata

GABAergic neurons of the substantia nigra pars reticulata (SNpr) and globus pallidus pars interna (GPi) constitute the output pathways of the basal ganglia. In monkeys, choreiform limb dyskinesias have been described after inhibition of the GPi, but not the SNpr. Given the anatomical and functional similarities between these structures, we hypothesized that choreiform dyskinesias could be evoked by inhibition of an appropriate region within the SNpr. The GABAA receptor agonist, muscimol, was infused into various sites within the SNpr and the adjacent STN of freely moving macaques. The effect of the GABAA antagonist, bicuculline (BIC), was also examined. Muscimol (MUS) in SNpr evoked the following: (1) choreiform dyskinesias of the contralateral arm and/or leg from central and lateral sites; (2) contralaterally directed torticollis from central and posterior sites; and (3) contraversive quadrupedal rotation from anterior and lateral sites. MUS infusions into the adjacent SN pars compacta or STN were without effect, ruling out a contribution of drug spread to adjacent structures. BIC in SNpr induced ipsiversive postures without choreiform dyskinesia or torticollis, whereas in the STN, it evoked ballistic movements. This is the first report of choreiform dyskinesia evoked by inhibition of the SNpr. This highly site‐specific effect was obtained from a restricted region within the SNpr distinct from that responsible for inducing torticollis. These results suggest that overactivity of different SNpr outputs mediates choreiform dyskinesia and torticollis. These abnormalities are symptoms of dystonia, Huntington's disease, and iatrogenic dyskinesias, suggesting that these conditions may result, in part, from a loss of function in SNpr efferent projections. © 2012 Movement Disorder Society     

Influence of maternal and paternal IQ on offspring health and health behaviours: Evidence for some trans-generational associations using the 1958 British birth cohort study

PurposeIndividuals scoring poorly on tests of intelligence (IQ) have been reported as having increased risk of morbidity, premature mortality, and risk factors such as obesity, high blood pressure, poor diet, alcohol and cigarette consumption. Very little is known about the impact of parental IQ on the health and health behaviours of their offspring.MethodsWe explored associations of maternal and paternal IQ scores with offspring television viewing, injuries, hospitalisations, long standing illness, height and BMI at ages 4 to 18 using data from the National Child Development Study (1958 birth cohort).ResultsData were available for 1446 mother-offspring and 822 father-offspring pairs. After adjusting for potential confounding/mediating factors, the children of higher IQ parents were less likely to watch TV (odds ratio (95% confidence interval) for watching 3+ vs. less than 3 hours per week associated with a standard deviation increase in maternal or paternal IQ: 0.75 (0.64, 0.88) or 0.78 (0.64, 0.95) respectively) and less likely to have one or more injuries requiring hospitalisation (0.77 (0.66, 0.90) or 0.72 (0.56, 0.91) respectively for maternal or paternal IQ).ConclusionsChildren whose parents have low IQ scores may have poorer selected health and health behaviours. Health education might usefully be targeted at these families.     

Determinants of time to antiretroviral treatment initiation and subsequent mortality on treatment in a cohort in rural northern Malawi

Background

To optimise care HIV patients need to be promptly initiated on antiretroviral therapy (ART) and subsequently retained on treatment. In this study we report on the interval between enrolment and treatment initiation, and investigate subsequent attrition and mortality of patients on ART at a rural clinic in Malawi.

Methods

HIV-positive individuals were recruited to a cohort study between January 2008 and August 2011 at Chilumba Rural Hospital (CRH). Outcomes were ascertained, up to 7 years after enrolment, through follow-up and by linkage to ART registers and the Karonga Health and Demographic Surveillance System (KHDSS). Kaplan–Meier methods and Cox regression were used to examine ART initiation after enrolment, mortality after ART initiation, and attrition after ART initiation.

Results

Of the 617 individuals recruited, 523 initiated ART between January 2008 and January 2015. Median time from HIV testing to commencement of ART was 59 days (IQR: 10–330). By a year after enrolment 74.2 % (95 % CI 70.6–77.7 %) had initiated ART. Baseline clinical data at ART initiation and data on attrition was only available for the 438 individuals who initiated ART during active follow-up, between January 2008 and August 2011. Of these individuals, 6 were missing Ministry of Health numbers, leaving 432 included in analyses of attrition and mortality. At 4 years after ART initiation 71.3 % (95 % CI 65.7–76.2 %) of these patients were retained on treatment at the CRH and 17.2 % (95 % CI 13.8–21.4 %) had died. Participants who had a lower CD4 count at enrolment (≤350 cells/μl), enrolled in 2008, or tested for HIV at the CRH rather than through serosurveys, initiated treatment faster. Once on treatment, mortality rates were higher in patients who were HIV tested at the CRH, male, older (≥35 years), missing a CD4 count, or underweight (BMI < 18.5) at ART initiation.

Conclusions

Through linkage to the KHDSS and ART registers it was possible to continue follow-up beyond the end of the initial cohort study. Annual mortality after ART initiation remained considerable over a period of 4 years. Greater access to HIV and CD4 testing alongside initiation at higher CD4 counts, as planned in the test and treat strategy, could reduce this mortality.

     

Ending the isolation

In the UK, an estimated 95,000 families are homeless. Nurses who work with these people need a wide range of skills and stand to benefit from a new UK-wide network that has received lottery funding.     

Treatment efficacy of social communication skills training after traumatic brain injury: a randomized treatment and deferred treatment controlled trial

Dahlberg CA, Cusick CP, Hawley LA, Newman JK, Morey CE. Harrison-Felix CL, Whiteneck GG. Treatment efficacy of social communication skills training after traumatic brain injury: a randomized treatment and deferred treatment controlled trial.

Objective

To evaluate the efficacy of a replicable group treatment program to improve social communication skills after traumatic brain injury (TBI).

Design

Randomized treatment and deferred treatment controlled trial, with follow-up at 3, 6, and 9 months post-treatment.

Setting

Community.

Participants

Volunteer sample of 52 people with TBI who were at least 1 year postinjury, who received rehabilitation, and who had identified social communication deficits.

Intervention

Twelve weekly group sessions (1.5h each) to improve social communication.

Main Outcome Measures

The Profile of Functional Impairment in Communication (PFIC), Social Communication Skills Questionnaire–Adapted (SCSQ-A), Goal Attainment Scale (GAS), Craig Handicap Assessment and Reporting Technique–Short Form social integration and occupation subscales, Community Integration Questionnaire social integration and productivity subscales, and Satisfaction With Life Scale (SWLS).

Results

Independent samples t test analysis showed significant treatment effect compared with no treatment on 7 of 10 of the PFIC subscales (P range, .024 to <.001) and the SCSQ-A (P=.005) after the first 12 weeks of the study. After 12 weeks of treatment for all participants, repeated-measures analysis showed significant improvements from baseline on 9 of 10 PFIC subscales (P range, .01−.001), SCSQ-A (P≤.001), GAS (P≤.001), and SWLS (P=.011). At 6-month follow-up, scores were significantly better than baseline on 6 of 10 PFIC scales (P range, .01−.001), the SCSQ-A (P≤.001), GAS (P≤.001), and SWLS (P≤.001).

Conclusions

TBI subjects who received social communication skills training had improved communication skills that were maintained on follow-up. Overall life satisfaction for participants was improved.     

The lateral edge and sourcil acetabular indices for surgical decision-making in developmental dysplasia of the hip

PurposeThe acetabular index (AI) is a radiographic measure that guides surgical decision-making in developmental dysplasia of the hip (DDH). Two AI measurement methods are described; to the lateral edge of the acetabulum (AI-L) and to the lateral edge of the sourcil (AI-S). The purpose of this study was to determine the level of agreement between AI-L and AI-S on the diagnosis and degree of acetabular dysplasia in DDH.MethodsA total of 35 patients treated for DDH with Pavlik harness were identified. The AI-L and AI-S were measured on radiographs (70 hips) at two and five years of age. AI-L and AI-S were then transformed relative to published normative data (tAI-L and tAI-S). Bland-Altman plots, linear regression and heat mapping were used to evaluate the agreement between tAI-L and tAI-S.ResultsThere was poor agreement between tAI-S and tAI-L on the Bland-Altman plots with wide limits of agreement and no proportional bias. The two AI measurements were in agreement as to the presence and severity of dysplasia in only 63% of hips at two years of age and 81% at five years of age, leaving the remaining hips classified as various combinations of normal, mildly and severely dysplastic.ConclusionAI-L and AI-S have poor agreement on the presence or degree of acetabular dysplasia in DDH and cannot be used interchangeably. Clinicians are cautioned to prudently evaluate both measures of AI in surgical decision-making.Level of evidenceI