Biomedical subjects

Antonio Y Hardan

Publications and source records attributed to Antonio Y Hardan.

18 recordsLinked to original sources

PubMed2006

Abnormal brain size effect on the thalamus in autism.

This study was conducted to examine the volume of the thalamus in autism and to investigate the effect of brain size on this structure in an attempt to replicate, in a larger sample, findings from a previous study reporting the existence of a relationship between brain volume and thalamus in healthy controls but not in individuals with autism. Additionally, the relationships between thalamic volumes and clinical features were examined. Volumetric measurements of the right and left thalamic nuclei were performed on MRI scans obtained from 40 high-functioning individuals with autism (age range: 8-45 years) and 41 healthy controls (age range: 9-43 years). No differences were observed between the two groups for unadjusted thalamic volumes. However, the expected linear relationship between TBV and thalamic volume was not observed in individuals with autism. Furthermore, no correlations were observed between thalamic volumes and clinical features. Findings from this larger study are consistent with the previous report of an abnormal brain size effect on the thalamus in autism and support the possibility of abnormal connections between cortical and subcortical structures in this disorder.

Adolescent↗

PubMed2006

Volumetric alterations of the orbitofrontal cortex in autism.

Recent evidence has implicated the orbitofrontal cortex (OFC) in the pathophysiology of social deficits in autism. An MRI-based morphometric study of the OFC was conducted involving 11 children with autism (age range 8.1-12.7 years) and 18 healthy, age-matched controls (age range 8.9-12.8 years). Decreased grey matter volume in the right lateral OFC in the patient group was found, and correlations were observed between social deficits and white, but not grey, matter structures of the OFC. These findings support the role of OFC in autism and warrant further investigations of this structure using structural and functional methodologies.

Autistic Disorder↗

PubMed2006

Risperidone in first-episode psychosis: a longitudinal, exploratory voxel-based morphometric study.

Previous studies have provided evidence supporting a neuroplastic effect of atypical antipsychotics. The present investigation explores the short-term effects of risperidone on brain parenchyma by performing voxel-based morphometry on baseline and 6-week follow-up MRI scans obtained from 15 neuroleptic-naïve individuals with first-episode psychosis treated with risperidone and 15 healthy controls. The risperidone-treated subjects demonstrated changes in grey matter and white matter in several brain regions, including superior temporal gyrus. No areas of change were found in controls. The results of this exploratory investigation support the possibility that risperidone has short-term effects on brain parenchyma in individuals with first-episode psychosis.

Adolescent↗

PubMed2006

An MRI study of minor physical anomalies in autism.

The objective of this investigation was to examine the existence of minor physical anomalies (MPA) in autism. The interorbital and interlens distances were measured on MRI scans obtained from a sample of 40 non-mentally retarded individuals with autism and 41 healthy controls. No differences were observed between the two groups on any measurements. However, when the analysis was conducted using a split median procedure, individuals with autism and either low FSIQ, PIQ, or VIQ had shorter interorbital distances when compared to controls. Hypotelorism is a MPA that may be present in a subgroup of individuals with autism. Additional research is warranted using large sample sizes with a wide range of intellectual functioning.

Adolescent↗

PubMed2006

Open-label, prospective trial of olanzapine in adolescents with subaverage intelligence and disruptive behavioral disorders.

OBJECTIVE: Olanzapine, an atypical antipsychotic, has been shown to be efficacious for treatment of psychotic and mood disorders in adults. This prospective, open-label study was conducted to examine the safety and usefulness of olanzapine in treating disruptive behavior disorders in adolescents with subaverage intelligence. METHOD: Sixteen adolescents (ages 13-17 years) with borderline to moderate mental retardation and disruptive behavior were enrolled in an 8-week olanzapine trial (5-20 mg/day). Dependent measures included the Aberrant Behavior Checklist, Conners Parent Rating Scale, Clinical Global Impressions, and two side effects scales. RESULTS: Statistically significant improvement (p <.002) was found on the Irritability and Hyperactivity subscales of the Aberrant Behavior Checklist and the Conners Parent Rating Scale Hyperactivity Index. No subjects developed extrapyramidal side effects. However, four were terminated prematurely from the trial because of either worsening of symptoms (requiring psychiatric inpatient hospitalization in two subjects) or side effects. The most common side effect for the sample was weight gain (averaging 12.7 lb), with 67% of subjects gaining > or =10 lb. Although there was also a statistically significant increase in prolactin levels, no subjects reported prolactin-related side effects (e.g., gynecomastia, galactorhea, amenorrhea). CONCLUSION: Olanzapine may be useful in treating disruptive behavior in adolescents with subaverage intelligence. However, side effects, especially weight gain, are a significant issue. Future double-blind, placebo-controlled studies need to confirm these findings and assess long-term safety and outcome of olanzapine treatment.

Adolescent↗

PubMed2006

An MRI study of increased cortical thickness in autism.

OBJECTIVE: The purpose of this study was to examine cortical thickness in autism in light of the postmortem evidence of cortical abnormalities of the disorder. METHOD: Magnetic resonance imaging (MRI) scans were acquired from 17 children with autism and 14 healthy comparison subjects, and sulcal and gyral thickness were measured for the total brain and for all lobes. RESULTS: Increases in total cerebral sulcal and gyral thickness were observed in children with autism relative to comparison subjects. Similar findings were noted in the temporal and parietal lobes but not in the frontal and occipital lobes. CONCLUSIONS: These preliminary findings indicate that increased cortical thickness may contribute to the increased gray matter volume and total brain size that have been observed in autism and may also be related to anomalies in cortical connectivity.

Autistic Disorder↗

PubMed2006

Magnetic resonance imaging study of the orbitofrontal cortex in autism.

The orbitofrontal cortex is involved in multiple psychologic functions, such as emotional and cognitive processing, learning, and social behavior. These functions are variably impaired in individuals with autism. The present study examined the size of the orbitofrontal cortex, and its medial and lateral subdivisions, using magnetic resonance imaging (MRI) scans obtained from 40 non-mentally retarded individuals with autism and 41 healthy controls. No differences were observed between the two groups on any of the orbitofrontal cortex measurements. However, when compared with controls, a smaller right lateral orbitofrontal cortex was observed in children and adolescents with autism, whereas a larger right lateral orbitofrontal cortex was found in adult patients. Interestingly, a positive relationship was found in the patient group between circumscribed interests and all orbitofrontal cortex structures. The present study suggests the absence of global volumetric abnormalities in the orbitofrontal cortex in autism and indicates that the functional disturbances in this structure might not be related to anatomic alterations.

Adolescent↗

PubMed2005

Retrospective study of quetiapine in children and adolescents with pervasive developmental disorders.

A retrospective study was conducted in a clinic specialized in treating individuals with developmental disabilities to examine the effectiveness and tolerability of quetiapine in children and adolescents with pervasive developmental disorders. Ten consecutive outpatients (age = 12.0 +/- 5.1 years) treated with quetiapine (dose = 477 +/- 212 mg, duration = 22.0 +/- 10.1 weeks) were identified and six were judged to be responders based on impressions from chart review and Conners Parent Scale (CPS). Improvements were observed in the conduct, inattention, and hyperactivity subscales of the CPS. Adverse events were mild with sedation being the most common, and no patient required treatment termination. Quetiapine may be beneficial in children and adolescents with pervasive developmental disorders, however open-label and double-blind, placebo-controlled studies are warranted.

Adolescent↗

PubMed2005

Retrospective assessment of atomoxetine in children and adolescents with pervasive developmental disorders.

A retrospective study was conducted to assess the effectiveness and tolerability of atomoxetine in children and adolescents with pervasive developmental disorders (PDD). An outpatient clinic registry of individuals with PDD was used to identify all children and adolescents who received atomoxetine over a period of 12 months. Patients were included if concomitant medications remained unchanged. Treatment response was assessed using the Global Improvement item of the Clinical Global Impressions scale (CGI-GI) based on the Conners Parent Rating Scale (CPRS) routinely completed by primary caretakers and other clinical information available in the registry. Twenty patients were identified, including 16 males and 4 females (age, 11.5 years; standard deviation, 3.5). Most patients (80%) were taking at least 1 concomitant medication. Treatment dose was 43.3 mg (standard deviation, 18.1) and duration was 19.5 weeks (standard deviation, 10.5). Twelve patients were judged to be responders, as defined by a score of 1 or 2 on the CGI-GI. Differences between baseline and the end of the trial period were observed in the following CPRS subscales: Conduct, hyperactivity, inattention, and learning. No differences were noted in the anxiety and psychosomatic subscales. One patient discontinued atomoxetine because of severe mood swings. Atomoxetine may be beneficial for treating secondary symptoms of PDD, and prospective open-label or double-blind, placebo-controlled studies are needed to assess its efficacy and safety.

Adolescent↗

PubMed2004

Reduced cortical folding in individuals at high risk for schizophrenia: a pilot study.

While cortical gyrification anomalies have been reported in schizophrenia, it is unknown if individuals at high risk for schizophrenia (HR) might also exhibit abnormal cortical folding. Using MRI scans, the gyrification index (GI) was calculated for 9 adolescent HR males and 12 healthy male controls. Using the first coronal slice anterior to the corpus callosum, cortical contours were manually traced to calculate the GI. The left GI was lower in HR when compared to controls, but no difference in the right GI was observed. These results are consistent with studies of affected individuals, supporting genetic and neurodevelopmental models of schizophrenia.

Adolescent↗

PubMed2004

Increased frontal cortical folding in autism: a preliminary MRI study.

The gyrification index (GI), the ratio of total to outer cortical contour, was applied to measure the cerebral folding patterns in autism. GI was examined on a frontal coronal slice obtained from MRI scans of 30 nonmentally retarded individuals with autism and 32 matched healthy controls. In the autistic group, left frontal GI was higher in children and adolescents but not in adults. Cortical folding was decreased bilaterally with age in the total autistic sample but not in controls. These preliminary findings suggest that the gyrification patterns in autism may be abnormal, which could be related to the various cortical anomalies observed in this disorder.

Adolescent↗

PubMed2004

Anatomic evaluation of the orbitofrontal cortex in major depressive disorder.

BACKGROUND: The orbitofrontal cortex (OFC) plays a major role in neuropsychologic functioning including exteroceptive and interoceptive information coding, reward-guided behavior, impulse control, and mood regulation. This study examined the OFC and its subdivisions in patients with MDD and matched healthy control subjects. METHODS: Magnetic resonance imaging (MRI) was performed on 31 unmedicated MDD and 34 control subjects matched for age, gender, and race. Gray matter volumes of the OFC and its lateral and medial subdivisions were measured blindly. RESULTS: The MDD patients had smaller gray matter volumes in right medial [two-way analysis of covariance F(1,60) = 4.285; p =.043] and left lateral OFC [F(1,60) = 4.252; p =.044]. Left lateral OFC volume correlated negatively with age in patients but not in control subjects. Male, but not female patients exhibited smaller left and right medial OFC volumes compared with healthy control subjects of the same gender. CONCLUSIONS: These findings suggest that patients with MDD have reduced OFC gray matter volumes. Although this reduction might be important in understanding the pathophysiology of MDD, its functional and psychopathologic consequences are as yet unclear. Future studies examining the relationship between specific symptomatic dimensions of MDD and OFC volumes could be especially informative.

Adult↗

PubMed2004

A retrospective assessment of topiramate in children and adolescents with pervasive developmental disorders.

An open-label retrospective study was conducted to assess the effectiveness and tolerability of topiramate in children and adolescents with pervasive developmental disorders (PDD). Topiramate is a novel antiepileptic drug approved as an adjunctive treatment for seizure disorders. A retrospective chart review was conducted in an outpatient clinic specialized in treating individuals with developmental disabilities, to identify all children and adolescents with PDD who received topiramate. Patients were included if concomitant medications remained unchanged. Treatment response was assessed using the Global Improvement item of the Clinical Global Impressions scale (CGI-GI), based on a review of medical records and the Conners Parent Scale (CPS), as completed by parents. Fifteen patients were identified (12 male, 3 female; age = 14.7 +/- 3.3 years), including 11 patients with autistic disorder, 2 patients with Asperger's disorder, and 2 patients with PDD not otherwise specified (PDD, NOS). Eight patients (4 patients with autistic disorder, 2 patients with Asperger's disorder, and 2 patients with PDD, NOS) were judged to be responders, as defined by a score of 1 or 2 on the CGI-GI. Treatment duration was 25 +/- 16 weeks, and the mean dose was 235 +/- 88 mg. Differences between baseline and the end-of-trial period were observed in the following CPS subscales: conduct, hyperactivity, and inattention. No differences were noted in the psychosomatic, learning, and anxiety subscales. Three patients discontinued topiramate because of side effects, with 2 patients experiencing cognitive difficulties and 1 patient a skin rash. Topiramate may be beneficial for treating secondary symptoms of PDD, and prospective openlabel studies and double-blind, placebo-controlled studies to assess its efficacy and safety are needed.

Adolescent↗

PubMed2004

Neuropsychiatric problems in tuberous sclerosis complex.

Tuberous sclerosis complex is an autosomal dominant disorder characterized by abnormal cellular differentiation and proliferation, as well as abnormal neuronal migration. It is a disease affecting multiple organ systems and typically has brain involvement, causing severe disabilities. This article reviews the literature of the commonly associated neuropsychiatric complications, including mental retardation, autism-like features, and other behavior problems, which are discussed in the context of the neuropathology and epilepsy observed in tuberous sclerosis complex. The potential pathogenesis of neuropsychiatric problems is explored, including links to the genetics, neuropathology, neurotrophins, and epilepsy factors associated with tuberous sclerosis complex. Treatment of neuropsychiatric symptoms, including autism-like features, attention deficits, and sleep disorders, is also discussed.

Autistic Disorder↗

PubMed2003

Measurement of the orbitofrontal cortex: a validation study of a new method.

The orbital frontal cortex (OFC) plays a critical role in the pathophysiology of several neuropsychiatric disorders. Few morphometric neuroimaging studies have examined the OFC using different methodologies and have reported discrepant values. Substantial variability in gyri and sulci across individuals as well as unclear landmarks underline the difficulties in obtaining accurate and reliable measurements. We propose a new geometrical method for measuring the OFC taking into account individual brain variability. The OFC was defined by using the intercommissural line and the inferior edge of the frontal lobe as the main landmarks. The medial and lateral subdivisions of OFC were also separately measured using the olfactory sulcus as the boundary to distinguish between them. After resampling and refitting, 10 scans were independently traced by two trained researchers using BRAINS software. Talairach coordinates were identified on each scan from the OFC and surrounding adjacent brain regions to assess the validity of this method. Brain regions were assigned using Talairach Daemon system. OFC volumes were comparable with those previously reported. Sensitivity and specificity for OFC gray matter were 87.6 and 84.8%, respectively. Intraclass coefficients (ICCs) for gray, white, and total OFC were 0.995, 0.994, and 0.997, respectively. ICCs for OFC medial and lateral subdivisions ranged between 0.996 and 0.998. This method appears to be a valid method for measuring the OFC with excellent reliability. This uncomplicated approach is easy to apply and has the potential to be a valuable alternative to the previously published methods.

Adult↗

PubMed2003

Motor performance and anatomic magnetic resonance imaging (MRI) of the basal ganglia in autism.

This study was conducted to examine the volume of the basal ganglia in individuals with autism and to evaluate whether performance on specific motor tasks correlated with the volume of these structures. Volumetric measurements of the caudate nucleus and putamen were obtained from magnetic resonance images (MRI) of 40 non-mentally retarded individuals with autism and 41 healthy controls. Motor performance was assessed in these subjects by using the Finger Tapping Test, the Grooved Pegboard Test, and the measurement of Grip Strength. No volumetric differences of the basal ganglia were found between the two groups after adjusting for brain volume. The autistic subjects' performance was slower on the Grooved Pegboard Test and weaker on Grip Strength. Our findings suggest that the motor deficits observed in autism may not be related to structural abnormalities of the basal ganglia, and other brain regions, such as the cerebellum and the frontal lobe, may be involved in the pathophysiology of motor disturbances in autism.

Adolescent↗

PubMed2002

A retrospective open trial of adjunctive donepezil in children and adolescents with autistic disorder.

In light of the recently reported neuropathologic and neurochemical abnormalities of the cholinergic pathways in autism, donepezil, a cholinesterase inhibitor, is a potentially useful agent in the treatment of cognitive and behavioral symptoms observed in this disorder. A retrospective pilot study was conducted to determine whether donepezil is effective in the treatment of children and adolescents with autism. Eight patients (mean age = 11.0 +/- 4.1 years; range 7-19 years) who met Diagnostic and Statistical Manual of Mental Disorders (4th edition) criteria for autistic disorder were openly treated with donepezil. All patients were on concomitant psychoactive medications. Four of these patients (50%) demonstrated significant improvement as assessed by the Aberrant Behavior Checklist and the Clinical Global Impression Scale. Decreases in the Irritability and Hyperactivity subscales were observed, but no changes in the Inappropriate Speech, Lethargy, and Stereotypies subscales were noted. Limited and transient side effects were reported, with one patient experiencing gastrointestinal disturbances and another reporting mild irritability. Double-blind, placebo-controlled investigations are needed to provide further evidence of the potential benefits of donepezil to patients with autistic disorder.

Adolescent↗

PubMedDate not supplied

The functional neuroanatomy of autism.

Autism is a neurodevelopmental syndrome characterized by impaired social and executive functions. Functional magnetic resonance imaging (fMRI) is a non-invasive technique that allows investigation of the neural networks underlying cognitive impairments in autism. In this article, brain imaging studies investigating the functional brain anatomy of autism are reviewed. Face recognition, theory of mind and executive functions have all been explored in functional neuroimaging studies involving autistic patients. The available literature suggests an involvement of abnormal functional mechanisms in face recognition, mentalization and executive functions in adults with high-functioning autism or Asperger's syndrome, possibly due to brain maturation abnormalities, and resulting in dysfunctional reciprocal cortico-subcortical connections. Future functional neuroimaging research should investigate subgroups of autistic children and adolescents longitudinally and attempt to integrate genetic, cognitive and empirical approaches. Such studies will be instrumental in furthering understanding of the pathophysiology of autism and in exploring the importance of dimensional measures of the broader phenotype currently defined as autism.

Adolescent↗