Functional neuroimaging in anorexia nervosa: A clinical approach

Aims

To provide a review of the available literature about the functional neuroimaging of anorexia nervosa, and to summarize the possible role of neurobiological factors in its pathogenesis.

Methods

A systematic review of the literature was performed using PubMed and Medline electronic database (1950-September 2009). Eligible studies were restricted to those involving the main parameters of cerebral activity and functional neuroimaging techniques. Findings of the reviewed studies have been grouped on a diagnostic subtype basis, and their comparison has been interpreted in terms of concordance.

Results

We found a high level of concordance among available studies with regard to the presence of frontal, parietal and cingulate functional disturbances in both anorexia nervosa restricting and binge/purging subtypes. Concordance among studies conducted regardless of the anorexia nervosa subtypes suggests an alteration in temporal and parietal functions and striatal metabolism.

Conclusions

The most consistent alterations in anorexia nervosa cerebral activity seem to involve the dorsolateral prefrontal cortex, the inferior parietal lobule, the anterior cingulate cortex and the caudate nucleus. They may affect different neural systems such as the frontal visual system, the attention network, the arousal and emotional processing systems, the reward processing network, and the network for the body schema.     

Gustatory and olfactory sensitivity in patients with anorexia and bulimia in the course of treatment

Background

The majority of studies on taste and smell in eating disorders have revealed several alterations of olfactory or gustatory functions. Aim of this prospective study was to employ detailed olfactory and gustatory testing in female subjects of three homogenous groups - anorexia nervosa, bulimia nervosa and healthy controls - and to look at the effects of treatment on these measures.

Methods

Sixteen hospitalized female patients with anorexia (restricting type, mean age [M] = 24.5 years), 24 female patients with bulimia (purging type, M = 24.3 years) as well as 23 healthy controls (M = 24.5 years) received olfactory (“Sniffin’ Sticks”) and gustatory testing (“Taste Strips”). Group differences in olfactory and gustatory sensitivity, body mass index (BMI), the Beck depression inventory, the eating attitudes test (EAT), and the influence of therapy on gustatory and olfactory function were investigated.

Results

(1) Group differences were present for odor discrimination and overall olfactory function with anorexic patients having the lowest scores. (2) Regarding taste function, controls scored higher than patients with anorexia. (3) At admission small but significant correlations were found between overall olfactory function and body weight (r₆₃ = 0.35), BMI (r₆₃ = 0.37), and EAT score (r₆₃ = −0.27). Similarly, (4) the taste test score correlated significantly with body weight (r₆₃ = 0.48), and BMI (r₆₃ = 0.45). Finally, (5) at discharge overall olfactory and gustatory function were significantly higher compared to admission in anorexic patients.

Conclusions

As compared to healthy controls and bulimic patients our results show lowered olfactory and gustatory sensitivities in anorexic patients that improved with increasing BMI and decreasing eating pathology in the course of treatment.     

Aggressiveness, anger, and hostility in eating disorders

Objective

Despite evidence of a link between the behavioral and cognitive dimensions of aggressiveness and eating disorders, only few studies have tested this relation empirically.

Methods

A total of 112 female patients with anorexia nervosa (n = 61) or bulimia nervosa (n = 51) and 631 young girls attending 7 high schools in the same health district as the patients (northeast Italy) were invited to fill in a set of self-report instruments including the Eating Attitudes Test, the Bulimic Investigatory Test of Edinburgh, the Body Attitudes Test, and the Buss-Perry Aggression Questionnaire (AQ).

Results

In both healthy controls and patients, scores on the measures of eating disorder symptoms were positively related to the scores on the AQ: the strength of the association did not differ between healthy controls and patients. However, patients diagnosed with eating disorders were not more likely to disclose a propensity to aggression than the healthy controls drawn from the community: patients with anorexia nervosa scored lower than controls on the physical aggression and on the verbal aggression subscales of the AQ (P < .05). On the other hand, patients with bulimia nervosa scored higher than controls on the anger subscale of the AQ (P < .05) but did not differ from them on the other subscales of the questionnaire.

Conclusions

The results confirm the higher propensity to anger in patients with bulimia nervosa; in patients with anorexia nervosa, difficulties in expressing anger and outward-directed aggressiveness can be a prevailing feature. The younger age of controls and exclusive reliance on self-report measures might have concealed some differences between patients and community subjects.     

In adults with Prader-Willi syndrome, elevated ghrelin levels are more consistent with hyperphagia than high PYY and GLP-1 levels

Objective

Prader-Willi syndrome (PWS) is a leading genetic cause of obesity, characterized by hyperphagia, endocrine and developmental disorders. It is suggested that the intense hyperphagia could stem, in part, from impaired gut hormone signaling. Previous studies produced conflicting results, being confounded by differences in body composition between PWS and control subjects.

Design

Fasting and postprandial gut hormone responses were investigated in a cross-sectional cohort study including 10 adult PWS, 12 obese subjects matched for percentage body fat and central abdominal fat, and 10 healthy normal weight subjects.

Methods

PYY[total], PYY[3-36], GLP-1[active] and ghrelin[total] were measured by ELISA or radioimmunoassay. Body composition was assessed by dual energy X-ray absorptiometry. Visual analog scales were used to assess hunger and satiety.

Results

In contrast to lean subjects (p < 0.05), PWS and obese subjects were similarly insulin resistant and had similar insulin levels. Ghrelin[total] levels were significantly higher in PWS compared to obese subjects before and during the meal (p < 0.05). PYY[3-36] meal responses were higher in PWS than in lean subjects (p = 0.01), but not significantly different to obese (p = 0.08), with an additional non-significant trend in PYY[total] levels. There were no significant differences in self-reported satiety between groups, however PWS subjects reported more hunger throughout (p = 0.003), and exhibited a markedly reduced meal-induced suppression of hunger (p = 0.01) compared to lean or obese subjects.

Conclusions

Compared to adiposity-matched control subjects, hyperphagia in PWS is not related to a lower postprandial GLP-1 or PYY response. Elevated ghrelin levels in PWS are consistent with increased hunger and are unrelated to insulin levels.     

A personality classification system for eating disorders: a longitudinal study

Background

Studies of eating disorders (EDs) suggest that empirically derived personality subtypes may explain heterogeneity in ED samples that is not captured by the current diagnostic system. Longitudinal outcomes for personality subtypes have not been examined.

Method

In this study, personality pathology was assessed by clinical interview in 213 individuals with anorexia nervosa and bulimia nervosa at baseline. Interview data on EDs, comorbid diagnoses, global functioning, and treatment utilization were collected at baseline and at 6-month follow-up intervals over a median of 9 years.

Results

Q-factor analysis of the participants based on personality items produced a 5-prototype system, including high-functioning, behaviorally dysregulated, emotionally dysregulated, avoidant-insecure, and obsessional-sensitive types. Dimensional prototype scores were associated with baseline functioning and longitudinal outcome. Avoidant-Insecure scores showed consistent associations with poor functioning and outcome, including failure to show ED improvement, poor global functioning after 5 years, and high treatment utilization after 5 years. Behavioral dysregulation was associated with poor baseline functioning but did not show strong associations with ED or global outcome when histories of major depression and substance use disorder were covaried. Emotional dysregulation and obsessional-sensitivity were not associated with negative outcomes. High-functioning prototype scores were consistently associated with positive outcomes.

Conclusions

Longitudinal results support the importance of personality subtypes to ED classification.     

Predictors of excessive exercise in anorexia nervosa

Objective

The aim of the present study was to replicate and amalgamate findings from previous research into a comprehensive regression model predicting excessive exercise in individuals with anorexia nervosa (AN).

Method

Participants were 153 patients admitted to an inpatient treatment program for AN. Excessive exercise status was defined as a minimum of 1 hour of obligatory exercise aimed at controlling shape and weight, 6 days per week in the month before admission.

Results

Thirty-four percent (n = 52) of participants met criteria for excessive exercise. A logistic regression was conducted with excessive exercise status as the dependent variable and a number of variables previously found to be predictors of excessive exercise entered as independent variables on the same step. The overall regression model was statistically significant (P < .0005) and explained 31% of the variance in exercise status. Higher levels of dietary restraint (P = .03), depression (P = .04), and self-esteem (P = .02); lower levels of obsessive-compulsive symptomatology (P = .04); and the restricting subtype of AN (P = .03) were significantly associated with excessive exercise.

Conclusions

Excessive exercise is associated with a number of independent psychologic and behavioral variables, some that suggest a negative impact and others that suggest positive effects.     

Personality dimensions in bulimia nervosa, binge eating disorder, and obesity

Objective

The purpose of this investigation was to examine differences in personality dimensions among individuals with bulimia nervosa, binge eating disorder, non-binge eating obesity, and a normal-weight comparison group as well as to determine the extent to which these differences were independent of self-reported depressive symptoms.

Method

Personality dimensions were assessed using the Multidimensional Personality Questionnaire in 36 patients with bulimia nervosa, 54 patients with binge eating disorder, 30 obese individuals who did not binge eat, and 77 normal-weight comparison participants.

Results

Participants with bulimia nervosa reported higher scores on measures of stress reaction and negative emotionality compared to the other 3 groups and lower well-being scores compared to the normal-weight comparison and the obese samples. Patients with binge eating disorder scored lower on well-being and higher on harm avoidance than the normal-weight comparison group. In addition, the bulimia nervosa and binge eating disorder groups scored lower than the normal-weight group on positive emotionality. When personality dimensions were reanalyzed using depression as a covariate, only stress reaction remained higher in the bulimia nervosa group compared to the other 3 groups and harm avoidance remained higher in the binge eating disorder than the normal-weight comparison group.

Conclusions

The higher levels of stress reaction in the bulimia nervosa sample and harm avoidance in the binge eating disorder sample after controlling for depression indicate that these personality dimensions are potentially important in the etiology, maintenance, and treatment of these eating disorders. Although the extent to which observed group differences in well-being, positive emotionality, and negative emotionality reflect personality traits, mood disorders, or both, is unclear, these features clearly warrant further examination in understanding and treating bulimia nervosa and binge eating disorder.     

Amours et neurologie

Introduction

Love is a complex emotional state which is difficult to define. Considering anthropological studies, this feeling can now be divided into three distinct behaviors: lust, attraction for a specific partner and conjugal or filial attachment.

State of art

For each, recent findings have contributed to identify specific neuronal networks which are interconnected as shown by common activation of limbic and paralimbic systems. A major role of arginine/vasopressin and oxytocin has also been pointed out for mate choice and attachment promotion. In the field of neurology, studies about pathologies of love are sparse and mainly focused on sexual disorders. Pathologies of attachment like autism and borderline personality are beginning to be identified.

Perspectives

Future investigations would yield a better understanding of this complex emotional state and a better detection of new pathologies related to a major affective disability.

Conclusion

Neurosciences have contributed to highlight mechanisms involved in love.     

Voice acoustic changes during bilateral subthalamic stimulation in patients with Parkinson's disease

Objectives

The purpose of this study was to investigate the effects of bilateral subthalamic nucleus deep brain stimulation on the phonation of patients with Parkinson's disease in three drug-free conditions: (1) stimulation off, (2) with clinically optimised stimulation parameters, and (3) subthreshold overstimulation, in order to detect differences following voice analysis.

Patients and methods

Conversational speech and sustained vowel sounds /a/, /i/, /o/, /u/ and high /i/ were recorded from 22 PD patients. Perceptual analysis, perturbation jitter, shimmer, noise-to-harmonics ratio, and nonlinear dynamic analysis (NDA) with detrended fluctuation analysis and recurrence period density entropy were measured and compared to the above conditions. Quadratic discriminant analysis (QDA) was used to investigate stimulation conditions for given acoustic data.

Results

The changes of perturbation measurements for the above conditions were not significant. With differences between vowels, NDA showed more significant changes and more powerful correlation with perceptual scores than perturbation measurements. NDA was significantly more sensitive during the QDA of the conditions.

Conclusions

Acoustic voice analysis of sustained vowels can help with recognizing the overstimulated condition, and, with an appropriate test battery and software package including nonlinear dynamic analysis, it can be a valuable tool for fine adjustments of stimulation parameters.     

Stimulation cérébrale profonde et troubles de la marche dans la maladie de Parkinson

Introduction

Gait disorders and freezing of gait (FOG) are seen in most patients with advanced Parkinson disease. Response to levodopa and deep brain stimulation is variable across patients.

State of art

Thalamic stimulation is ineffective on gait and can even worsen balance when bilaterally applied. Pallidal stimulation moderately improves gait disorders and FOG although this effect tends to wane after three to five years. Stimulation of the subthalamic nucleus (STN) improves levodopa-responsive gait disorders and FOG. However, some patients worsen after STN stimulation and others are better improved under levodopa than under STN stimulation. Synergistic effects of the two treatments have been reported. As for pallidal stimulation, there is a failure of long-term STN stimulation to improve gait, probably due to the involvement of non-dopaminergic pathways as the disease progresses. Levodopa-resistant gait disorders and FOG do not usually benefit from STN stimulation. In the rare cases of levodopa-induced FOG, STN stimulation may be indirectly effective, as it enables reduction or arrest of the levodopa treatment.

Perspectives

Pedunculopontine nucleus stimulation has recently been performed in small groups of patients with disabling gait disorders and FOG. Although encouraging, the first results need to be confirmed by controlled studies involving larger series of patients.

Conclusions

Overall, gait disorders remain a motor PD symptom that is little improved, or only temporarily, by current pharmacological and surgical treatments. Patient management is complex.     

Cortical visual evoked potentials recorded after optic tract near field stimulation during GPi-DBS in non-cooperative patients

Object

Neurophysiologic monitoring during deep brain stimulation (DBS) interventions in the globus pallidus internum (Gpi) for the treatment of Parkinson's disease or primary dystonia is generally based upon microelectrode recordings (MER); moreover, MER request sophisticated technology and high level trained personnel for a reliable monitoring. Recordings of cortical visual evoked potentials (CVEPs) obtained after stimulation of the optic tract may be a potential option to MER; since optic tract lies just beneath the best target for Gpi DBS, changes in CVEPs during intraoperative exploration may drive a correct electrode positioning.

Patients and methods

Cortical VEPs from optic tract stimulation (OT C-CEPs) have been recorded in seven patients during GPi-DBS for the treatment of Parkinson's disease and primary dystonia under general sedation. OT C-VEPs were obtained after near-field monopolar stimulation of the optic tract; recording electrodes were at the scalp. Cortical responses after optic tract versus standard visual stimulation were compared.

Results

After intraoperative near-field OT stimulation a biphasic wave, named N40-P70, was detected in all cases. N40-P70 neither change in morphology nor in latency at different depths, but increased in amplitude approaching the optic tract. The electrode tip was positioned just 1 mm above the point where OT-CVEPs showed the larger amplitude. No MERs were obtained in these patients; OT CVEPs were the only method to detect the Gpi before positioning the electrodes.

Conclusions

OT CVEPs seem to be as reliable as MER to detail the optimal target in Gpi surgery: in addition they are less expensive, faster to perform and easier to decode.     

Safety of nerve conduction studies in patients with implantable cardioverter-defibrillators

Objective

A patient with an implantable cardioverter-defibrillator (ICD) may suffer from neuromuscular disorders and may need to undergo a nerve conduction study (NCS). However, a NCS may be a source of electromagnetic interference (EMI).The aim of the present study was to investigate whether the interference from NCS used in a standardised test protocol affects ICD function.

Methods

Twenty patients (19 males; mean age of 59.8 ± 9.9 years) with implantable ICDs (eight with integrated and 12 with true bipolar leads), treated with amiodarone and with symptoms suggesting neuropathy were included. NCS were conducted using repetitive stimulation with frequency of 2 Hz and single, rectangular pulses of intensity up to 100 mA. Stimulation was performed in standard sites including proximal sites in the arm.

Results

The impulses generated NCS were not detected by the ICD, irrespective of the site, rate or stimulus intensity.

Conclusions

Standardised test protocol for an NCS is safe in patients with an ICD regardless of the leads type.

Significance

Current guidelines which limitate the NCS in patients with ICD may be the subject of revision.     

Spontaneous K-complexes in chronic psychophysiological insomnia

Objective

Spontaneous K-complexes are electroencephalographic features unique to non-rapid eye movement sleep. It has been suggested that this phasic event is a sleep-protective mechanism. Because insomnia sufferers report poor sleep quantity and quality, the objective of this study was to document the occurrence of spontaneous K-complexes in Stage 2 sleep of individuals with chronic insomnia. Specifically, the number and density of spontaneous K-complexes were studied in psychophysiological insomnia sufferers.

Setting

This study took place in a sleep and event-related potentials laboratory.

Design

Spontaneous K-complexes were scored during Stage 2 sleep on the second and third nights of a four-consecutive-nights protocol of polysomnographic recordings.

Participants

The sample included 14 participants suffering from psychophysiological insomnia (INS group; mean age=44.1 years) and 14 good sleepers (mean age=38.1 years). Participants underwent sleep and psychological evaluations. INS group participants met the diagnostic criteria for primary psychophysiological insomnia (mean duration of insomnia=9.6 years).

Intervention

Not applicable.

Results

The total number of spontaneous K-complexes and the density according to the total time spent in Stage 2 sleep (spontaneous K-complexes per minute) were compiled. Repeated-measures analyses of variance showed no significant difference in the number and density of spontaneous K-complexes between the INS group (313.98 and 2.66) and the GS group (361.10 and 2.88), respectively.

Conclusion

These results suggest no deficiency in the sleep-protective mechanism of psychophysiological insomnia sufferers in comparison with good sleepers, as measured by the spontaneous K-complexes' number and density.     

Parental eating disorder symptoms and observations of mealtime interactions with children

Objective

To examine relationships between parental eating disorder symptomatology and observed feeding interactions with children.

Method

Twenty-three mother-father pairs of children between 18 months and 5 years completed a self-report measure of eating disorders and were observed during a family mealtime.

Results

Parental reports of eating disorder symptoms were related to observations of greater pressurizing by both parents, maternal restriction of children's food intake and use of incentives to eat, more mouthfuls of food eaten by the child, and less food refusal.

Discussion

Observed controlling feeding practices are related to symptoms of eating disorders in nonclinical groups of mothers and fathers, highlighting one mechanism by which eating distress may be transmitted within families.     

Compulsive exercise to control shape or weight in eating disorders: prevalence, associated features, and treatment outcome

Objective

The study was aimed at assessing the prevalence of compulsive exercising to control shape and weight in eating disorders (EDs) and its relationship with treatment outcome.

Method

Compulsive exercising to control shape and weight, defined according to a modified version of the Intense Exercising to Control Shape or Weight section of the Eating Disorder Examination (EDE), was assessed in 165 consecutive ED inpatients entering a protocol based on the transdiagnostic cognitive behavior theory and treatment of EDs. Baseline assessment also included anthropometry, the global EDE interview, the Beck Depression Inventory, the State-Trait Anxiety Inventory (STAI), the Eating Disorders Inventory-Perfectionism Scale, and the Temperament and Character Inventory.

Results

Of the patients, 45.5% were classified as compulsive exercisers, the prevalence being highest (80%) in restricting-type anorexia nervosa (AN), lowest in EDs not otherwise specified (31.9%), and intermediate in binge/purging AN (43.3%) and in purging-type bulimia nervosa (39.3%). Compulsive exercising to control shape and weight was independently predicted by the EDE restraint score (odds ratio, 1.32; 95% confidence interval, 1.06-1.64; P = .014) after adjustment for ED; the total amount of exercise was associated with EDE restraint, as well as with the Temperament and Character Inventory reward dependence. At follow-up, an improved EDE global score was predicted by lower baseline values, higher baseline STAI and STAI improvement, and lower amount of exercise in the last 4 weeks. Voluntary treatment discontinuation was not predicted by baseline exercise.

Discussion

Compulsive exercising to control shape and weight is a behavioral feature of restricting-type AN, associated with restraint and temperament dimensions, with influence on treatment outcome.     

Prevalence and functioning of children with cerebral palsy in four areas of the United States in 2006: a report from the Autism and Developmental Disabilities Monitoring Network

Aim

To estimate the prevalence of cerebral palsy (CP) and the frequency of co-occurring developmental disabilities (DDs), gross motor function (GMF), and walking ability using the largest surveillance DD database in the US.

Methods

We conducted population-based surveillance of 8-year-old children in 2006 (N = 142,338), in areas of Alabama, Georgia, Wisconsin, and Missouri. This multi-site collaboration involved retrospective record review at multiple sources. We reported CP subtype, co-occurring DDs, Gross Motor Function Classification System (GMFCS) level, and walking ability as well as CP period prevalence by race/ethnicity and sex.

Results

CP prevalence was 3.3 (95% confidence interval [CI]: 3.1-3.7) per 1000 and varied by site, ranging from 2.9 (Wisconsin) to 3.8 (Georgia) per 1000, 8-year olds (p < 0.02). Approximately 81% had spastic CP. Among children with CP, 8% had an autism spectrum disorder and 35% had epilepsy. Using the GMFCS, 38.1% functioned at the highest level (I), with 17.1% at the lowest level (V). Fifty-six percent were able to walk independently and 33% had limited or no walking ability.

Interpretation

Surveillance data are enhanced when factors such as functioning and co-occurring conditions known to affect clinical service needs, quality of life, and health care are also considered.     

A new scale for assessing the quality of randomized clinical trials of psychotherapy

Context

In 2004, the American Psychiatric Association's Committee on Research on Psychiatric Treatments appointed a subcommittee to investigate the status of empirical evidence with regard to psychodynamic psychotherapy.

Objective

As a part of this effort, the committee developed a rating scale designed to assess the quality of randomized controlled trials (RCTs) of psychotherapy.

Data Sources

A 25-item RCT of Psychotherapy Quality Rating Scale was generated by expert consensus. Interrater reliability, internal consistency, and validity testing were undertaken using 7 trained raters.

Study Selection

A PubMed search was conducted to locate all RCTs of psychotherapies identified by their authors as being “psychodynamic” or “psychoanalytic” in origin and implementation.

Data Extraction

A total of 69 RCTs were independently rated by 2 raters.

Data Synthesis

The scale was found to have good interrater reliability (total score intraclass correlation = 0.76), internal consistency (Cronbach α = .87), and external validity.

Conclusions

This scale establishes a new standard for the design and execution of psychotherapy RCTs and provides a systematic empirical method for evaluating the quality of published RCTs.     

Symptoms of disordered eating, body shape, and mood concerns in male and female Chinese medical students

Objective

This cross-sectional study explored the prevalence of disordered eating attitudes, body shape concerns, and social anxiety and depressive symptoms in male and female medical students in China.

Method

Four hundred eighty-seven students from Central South University (Hunan Province, Changsha City, China) completed the following self-report measures: Eating Attitudes Test-26, Eating Disorders Assessment Questionnaire, Body Shape Questionnaire, Swansea Muscularity Attitudes Questionnaire, Social Interaction Anxiety Scale, and the Self-Rating Depression Scale.

Results

A comparatively lower rate of at-risk eating attitudes (2.5%) and eating disorders (0.90%) were found compared to those reported in other studies. Significantly more female (3.2%) than male (1.2%) students had abnormal eating attitudes with 4 female students meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for bulimia nervosa. Significant relationships were observed between eating attitudes, body shape concern, social anxiety, depression, and body mass index. For females, the most significant correlate of distorted eating attitudes was body shape concern, whereas for male students, social anxiety and concern with muscle size and shape were most strongly correlated with distorted eating attitudes.     

Reduced salience and default mode network activity in women with anorexia nervosa

Background

The neurobiology of anorexia nervosa is poorly understood. Neuronal networks contributing to action selection, self-regulation and interoception could contribute to pathologic eating and body perception in people with anorexia nervosa. We tested the hypothesis that the salience network (SN) and default mode network (DMN) would show decreased intrinsic activity in women with anorexia nervosa and those who had recovered from the disease compared to controls. The basal ganglia (BGN) and sensorimotor networks (SMN) were also investigated.

Methods

Between January 2008 and January 2012, women with restricting-type anorexia nervosa, women who recovered from the disease and healthy control women completed functional magnetic resonance imaging during a conditioned stimulus task. Network activity was studied using independent component analysis.

Results

We studied 20 women with anorexia nervosa, 24 recovered women and 24 controls. Salience network activity in the anterior cingulate cortex was reduced in women with anorexia nervosa (p = 0.030; all results false-discovery rate–corrected) and recovered women (p = 0.039) compared to controls. Default mode network activity in the precuneus was reduced in women with anorexia compared to controls (p = 0.023). Sensorimotor network activity in the supplementary motor area (SMA; p = 0.008), and the left (p = 0.028) and right (p = 0.002) postcentral gyrus was reduced in women with anorexia compared to controls; SMN activity in the SMA (p = 0.019) and the right postcentral gyrus (p = 0.008) was reduced in women with anorexia compared to recovered women. There were no group differences in the BGN.

Limitations

Differences between patient and control populations (e.g., depression, anxiety, medication) are potential confounds, but were included as covariates.

Conclusion

Reduced SN activity in women with anorexia nervosa and recovered women could be a trait-related biomarker or illness remnant, altering the drive to approach food. The alterations in the DMN and SMN observed only in women with anorexia nervosa suggest state-dependent abnormalities that could be related to altered interoception and body image in these women when they are underweight but that remit following recovery.     

Contributions to singing ability by the posterior portion of the superior temporal gyrus of the non-language-dominant hemisphere: First evidence from subdural cortical stimulation, Wada testing, and fMRI

Introduction

Although the substrates that mediate singing abilities in the human brain are not well understood, invasive brain mapping techniques used for clinical decision making such as intracranial electro-cortical testing and Wada testing offer a rare opportunity to examine music-related function in a select group of subjects, affording exceptional spatial and temporal specificity.

Methods

We studied eight patients with medically refractory epilepsy undergoing indwelling subdural electrode seizure focus localization. All patients underwent Wada testing for language lateralization. Functional assessment of language and music tasks was done by electrode grid cortical stimulation. One patient was also tested non-invasively with functional magnetic resonance imaging (fMRI). Functional organization of singing ability compared to language ability was determined based on four regions-of-interest (ROIs): left and right inferior frontal gyrus (IFG), and left and right posterior superior temporal gyrus (pSTG).

Results

In some subjects, electrical stimulation of dominant pSTG can interfere with speech and not singing, whereas stimulation of non-dominant pSTG area can interfere with singing and not speech. Stimulation of the dominant IFG tends to interfere with both musical and language expression, while non-dominant IFG stimulation was often observed to cause no interference with either task; and finally, that stimulation of areas adjacent to but not within non-dominant pSTG typically does not affect either ability. Functional fMRI mappings of one subject revealed similar music/language dissociation with respect to activation asymmetry within the ROIs.

Conclusion

Despite inherent limitations with respect to strictly research objectives, invasive clinical techniques offer a rare opportunity to probe musical and language cognitive processes of the brain in a select group of patients.