Carbamazepine reduces short-interval interhemispheric inhibition in healthy humans

ObjectiveWe sought to elucidate the influence of centrally active drugs on interhemispheric inhibition (IHI) between primary motor cortices in healthy humans.MethodsWe therefore studied IHI before and 2 h after intake of a single oral dose of carbamazepine, dextrometorphane, lorazepam, or placebo and compared it with the well known results for short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). Drugs were tested in separate sessions and in random order.ResultsWhile SICI and ICF were not altered by carbamazepine, IHI was reduced at the interstimulus interval of 8 ms. Dextrometorphane tended to enhance SICI and to reduce ICF and had no effect on IHI. Lorazepam reduced ICF as expected and enhanced IHI at the long intervals of 50 and 80 ms. A moderate trend for interhemispheric facilitation was inconsistently observed at the interval 2 ms and blocked by carbamazepine. In addition, carbamazepine increased the motor threshold.ConclusionsWe conclude that circuits mediating short interstimulus intervals of IHI are susceptible to sodium channel blockade.SignificanceThe results increase our knowledge of interhemispheric transmission.     

Effect of dose and frequency of interferon beta-1a administration on clinical and magnetic resonance imaging parameters in relapsing-remitting multiple sclerosis

There is still debate over the optimal dosage, frequency and route of administration of interferon (IFN) beta in multiple sclerosis (MS). A prospective, non-randomized, comparative study was performed to evaluate differences in magnetic resonance imaging and clinical outcomes of two IFN beta-1a preparations (30mcg intramuscular [im] once-weekly [qw], AVO; and 22 mcg subcutaneous [sc] three-times-weekly [tiw]; R22). Relapsing-remitting MS patients on one of the two IFN preparations (AVO, n=47; R22, n=48) were assessed at baseline and after 6 months of further treatment. There were no significant differences between the two groups at baseline. Both groups showed significantly reduced relapse rates (F=19.5; p<0.001) from baseline (0.6) to 6-month assessment (0.2; p<0.001). Univariate analysis showed a significant difference in favour of R22 on T2 lesion volume (F=14.4; p<0.001) and T1 black hole lesion load (F=8.5; p=0.004), the latter showing a significant increase in the AVO group (p<0.001). The incidence of patients with new T1 black holes was also higher for AVO than R22 (23.5% vs 8.3%; p=0.025). These results from patients receiving AVO or R22 in normal clinical practice are in line with randomized clinical studies that show the benefits of high-dose, high-frequency administration of IFN beta-1a in MS therapy.     

Interaction of CTSD and A2M polymorphisms in the risk for Alzheimer's disease

The proteins cathepsin D, encoded by CTSD gene, and alpha2-macroglobulin, encoded by A2M gene, are involved in the biochemical pathway leading to deposition of beta-amyloid. In these proteins two amino acid polymorphisms (CTSD-Ala/Val C-->T and A2M-Ile/Val A-->G) have been associated with an increased risk for Alzheimer's disease (AD), but conflicting results have been reported. We studied the association and the mutual interactions of the CTSD-C/T and A2M-A/G polymorphisms with sporadic AD in 100 patients with late-onset AD and 136 healthy elderly subjects as controls. The CTSD-T allele and the CTSD-C/T genotype are significantly more frequent in AD than in controls. The odds ratio (OR) for CTSD-T subjects is 1.93 [95% confidence interval (CI)=1.01-3.72], and 2.07 (95% CI=1.01-4.21) after adjustment for age, sex and APOE epsilon4+ status, while no significant association was found for the A2M-A/G polymorphism. The coexistence of the CTSD-T with the A2M-G allele synergistically increased the OR for AD to 2.69 (95% CI=1.13-6.34) [2.82 (95% CI=1.12-7.17) after adjustment], and to 3.29 (95% CI=1.33-8.16) if estimated for the allelic combination. Our data suggest that the CTSD-T allele of the CTSD-C/T polymorphism is associated with an increased relative risk for late-onset AD and, more interestingly, the combination of CTSD-T with the A2M-G allele seems to increase this risk.     

Treatment and adequacy of treatment of mental disorders among respondents to the Mexico National Comorbidity Survey

OBJECTIVE: This study described the rate and adequacy of mental health service use among participants in the Mexico National Comorbidity Survey and the correlates of any 12-month treatment and of adequate treatment. METHOD: The authors conducted face-to-face household surveys of a probability sample of individuals ages 18 to 65 years in the noninstitutionalized population living in urban areas of Mexico from 2001 to 2002. The use of mental health services and 12-month DSM-IV disorders was assessed with the World Mental Health version of the World Health Organization Composite International Diagnostic Interview. The rates and correlates of any service use and the adequacy of treatment were identified in logistic regression analyses, taking into account the complex sample design and weighting process. RESULTS: The data reported here were based on 2,362 interviews. Fewer than one in five respondents with any psychiatric disorder during the last 12 months used any service during the prior year. The rates of service use by those with mood disorders were somewhat higher. About one in every two respondents who used services received minimally adequate care. CONCLUSIONS: The authors found large unmet needs for mental health services among those with psychiatric disorders. Those with mental illness and those who deliver or seek to improve mental health care in Mexico face enormous challenges.     

Anorexia nervosa patients with a prior history of bulimia nervosa

OBJECTIVES: To investigate clinical and psychological features of patients with anorexia nervosa (AN) with a previous history of bulimia nervosa. METHOD: Three hundred thirty-three patients with a full diagnosis of AN were assessed by the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, the Eating Disorders Inventory, and the Hopkins Symptom Checklist. RESULTS: Twenty-four patients (7%) reported a previous diagnosis of bulimia nervosa and were compared with a control group of 48 patients without a history of bulimia, matched for diagnostic subtype. Among the patients with a history of bulimia nervosa, 11 were of the restricting type and 13 of the binge eating/purging type. Among restricting anorexic patients, those with a history of bulimia reported greater age of onset, more psychiatric symptoms, more family psychiatric morbidity, and a higher rate of sexual abuse. On the contrary, among patients with the AN bingeing-purging subtype, the presence of a previous bulimia nervosa was not associated with any of the investigated variables. CONCLUSIONS: Patients with restricting AN who report a history of previous bulimia nervosa are not frequent among those referring to an outpatient eating disorders unit. However, our findings in this small group of subjects confirm that a lifetime history of bingeing and purging in patients with eating disorder, irrespective of when it occurs, is always associated with more psychopathology compared with those restricting patients with AN who have never had a period of bingeing and purging.     

The role of aura in psychopathology and dissociative experiences in epilepsy

Cognitive auras seem to be associated with depression and anxiety, especially in patients with temporal lobe epilepsy (TLE). Dissociative symptoms may occur as an aura or in the context of psychiatric disorders such as depression, anxiety or schizophrenia. This is a cross-sectional study of 62 patients with TLE, using personality and dissociation measures to investigate their relationship with the presence of aura and its different subtypes. Our findings show no difference in psychopathology in patients with different types of aura and reveal that dissociative symptoms correlate with specific measures of anxiety, suggesting a possible link between these experiences and anxiety disorders.     

Newborns discriminate novel from harmonic sounds: a study using magnetoencephalography.

OBJECTIVE: We investigated whether newborns respond differently to novel and deviant sounds during quiet sleep. METHODS: Twelve healthy neonates were presented with a three-stimulus oddball paradigm, consisting of frequent standard (76%), infrequent deviant (12%), and infrequent novel stimuli (12%). The standards and deviants were counterbalanced between the newborns and consisted of 500 and 750 Hz tones with two upper harmonics. The novel stimuli contained animal, human, and mechanical sounds. All stimuli had a duration of 300 ms and the stimulus onset asynchrony was 1s. Evoked magnetic responses during quiet sleep were recorded and averaged offline. RESULTS: Two deflections peaking at 345 and 615 ms after stimulus onset were observed in the evoked responses of most of the newborns. The first deflection was larger to novel and deviant stimuli than to the standard and, furthermore, larger to novel than to deviant stimuli. The second deflection was larger to novel and deviant stimuli than to standards, but did not differ between the novels and deviants. CONCLUSIONS: The two deflections found in the present study reflect different mechanisms of auditory change detection and discriminative processes. SIGNIFICANCE: The early brain indicators of novelty detection may be crucial in assessing the normal and abnormal cortical function in newborns. Further, studying evoked magnetic fields to complex auditory stimulation in healthy newborns is needed for studying the newborns at-risk for cognitive or language problems.     

The relationship between neighborhood-level socioeconomic characteristics and individual mental disorders in five cities in Latin America: multilevel models from the World Mental Health Surveys

Purpose

Our understanding of community-level predictors of individual mental disorders in large urban areas of lower income countries is limited. In particular, the proportion of migrant, unemployed, and poorly educated residents in neighborhoods of these urban areas may characterize group contexts and shape residents’ health.

Methods

Cross-sectional household interviews of 7251 adults were completed across 83 neighborhoods of Buenos Aires, Argentina; Medellín, Colombia; São Paulo, Brazil; Lima, Peru; and Mexico City, Mexico as part of the World Mental Health Survey Initiative. Past-year internalizing and externalizing mental disorders were assessed, and multilevel models were used.

Results

Living in neighborhoods with either an above-average or below-average proportion of migrants and highly educated residents was associated with lower odds of any internalizing disorder (for proportion migrants: OR 0.75, 95% CI 0.62–0.91 for the bottom tertile and OR 0.79, 95% CI 0.67–0.94 for the top tertile compared to the middle tertile; for proportion highly educated: OR 0.76, 95% CI 0.64–0.90 for the bottom tertile and OR 0.58, 95% CI 0.37–0.90 for the top tertile compared to the middle tertile). Living in neighborhoods with an above-average proportion of unemployed individuals was associated with higher odds of having any internalizing disorder (OR 1.49, 95% CI 1.14–1.95 for the top tertile compared to the middle tertile). The proportion of highly educated residents was associated with lower odds of externalizing disorder (OR 0.54, 95% CI 0.31–0.93 for the top tertile compared to the middle tertile).

Conclusions

The associations of neighborhood-level migration, unemployment, and education with individual-level odds of mental disorders highlight the importance of community context for understanding the burden of mental disorders among residents of rapidly urbanizing global settings.

     

Guidelines for single fiber EMG

This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG) and the measurement of neuromuscular jitter with concentric needle electrodes (CNE – CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. Donald Sanders and Erik Stålberg then edited the final document.     

Resting state functional connectivity of the subthalamic nucleus in Parkinson's disease assessed using arterial spin‐labeled perfusion fMRI

Neurophysiological changes within the cortico‐basal ganglia‐thalamocortical circuits appear to be a characteristic of Parkinson's disease (PD) pathophysiology. The subthalamic nucleus (STN) is one of the basal ganglia components showing pathological neural activity patterns in PD. In this study, perfusion imaging data, acquired noninvasively using arterial spin‐labeled (ASL) perfusion MRI, were used to assess the resting state functional connectivity (FC) of the STN in 24 early‐to‐moderate PD patients and 34 age‐matched healthy controls, to determine whether altered FC in the very low frequency range of the perfusion time signal occurs as a result of the disease. Our results showed that the healthy STN was functionally connected with other nuclei of the basal ganglia and the thalamus, as well as with discrete cortical areas including the insular cortex and the hippocampus. In PD patients, connectivity of the STN was increased with two cortical areas involved in motor and cognitive processes. These findings suggest that hyperconnectivity of the STN could underlie some of the motor and cognitive deficits often present even at early stages of the disease. The FC measures provided good discrimination between controls and patients, suggesting that ASL‐derived FC metrics could be a putative PD biomarker. Hum Brain Mapp 36:1937–1950, 2015. © 2015 Wiley Periodicals, Inc .