Brian Weisinger

Tolerability of transcranial direct current stimulation in childhood-onset schizophrenia

BACKGROUND In recent years, transcranial direct current stimulation (tDCS) has been used to study and treat many neuropsychiatric conditions. However, information regarding its tolerability in the pediatric population is lacking. OBJECTIVE This study aims to investigate the tolerability aspects of tDCS in the childhood-onset schizophrenia (COS) population. METHODS Twelve participants with COS completed this inpatient study. Participants were assigned to one of two groups: bilateral anodal dorsolateral prefrontal cortex (DLPFC) stimulation (n = 8) or bilateral cathodal superior temporal gyrus (STG) stimulation (n = 5). Patients received either 2 mA of active treatment or sham treatment (with possibility of open active treatment) for 20 minutes, for a total of 10 sessions (2 weeks). RESULTS tDCS was well tolerated in the COS population with no serious adverse events occurring during the study. CONCLUSIONS This is the first study to demonstrate that a 20-minute duration of 2 mA of bilateral anodal and bilateral cathodal DC polarization to the DLPFC and STG was well tolerated in a pediatric population.

Using multivariate machine learning methods and structural MRI to classify childhood onset schizophrenia and healthy controls

Introduction: Multivariate machine learning methods can be used to classify groups of schizophrenia patients and controls using structural magnetic resonance imaging (MRI). However, machine learning methods to date have not been extended beyond classification and contemporaneously applied in a meaningful way to clinical measures. We hypothesized that brain measures would classify groups, and that increased likelihood of being classified as a patient using regional brain measures would be positively related to illness severity, developmental delays, and genetic risk. Methods: Using 74 anatomic brain MRI sub regions and Random Forest (RF), a machine learning method, we classified 98 childhood onset schizophrenia (COS) patients and 99 age, sex, and ethnicity-matched healthy controls. We also used RF to estimate the probability of being classified as a schizophrenia patient based on MRI measures. We then explored relationships between brain-based probability of illness and symptoms, premorbid development, and presence of copy number variation (CNV) associated with schizophrenia. Results: Brain regions jointly classified COS and control groups with 73.7% accuracy. Greater brain-based probability of illness was associated with worse functioning (p = 0.0004) and fewer developmental delays (p = 0.02). Presence of CNV was associated with lower probability of being classified as schizophrenia (p = 0.001). The regions that were most important in classifying groups included left temporal lobes, bilateral dorsolateral prefrontal regions, and left medial parietal lobes. Conclusion: Schizophrenia and control groups can be well classified using RF and anatomic brain measures, and brain-based probability of illness has a positive relationship with illness severity and a negative relationship with developmental delays/problems and CNV-based risk.

Delayed White Matter Growth Trajectory in Young Nonpsychotic Siblings of Patients With Childhood-Onset Schizophrenia

CONTEXT Nonpsychotic siblings of patients with childhood-onset schizophrenia (COS) share cortical gray matter abnormalities with their probands at an early age; these normalize by the time the siblings are aged 18 years, suggesting that the gray matter abnormalities in schizophrenia could be an age-specific endophenotype. Patients with COS also show significant white matter (WM) growth deficits, which have not yet been explored in nonpsychotic siblings. OBJECTIVE To study WM growth differences in nonpsychotic siblings of patients with COS. DESIGN Longitudinal (5-year) anatomic magnetic resonance imaging study mapping WM growth using a novel tensor-based morphometry analysis. SETTING National Institutes of Health Clinical Center, Bethesda, Maryland. PARTICIPANTS Forty-nine healthy siblings of patients with COS (mean [SD] age, 16.1 [5.3] years; 19 male, 30 female) and 57 healthy persons serving as controls (age, 16.9 [5.3] years; 29 male, 28 female). INTERVENTION Magnetic resonance imaging. MAIN OUTCOME MEASURE White matter growth rates. RESULTS We compared the WM growth rates in 3 age ranges. In the youngest age group (7 to <14 years), we found a significant difference in growth rates, with siblings of patients with COS showing slower WM growth rates in the parietal lobes of the brain than age-matched healthy controls (false discovery rate, q = 0.05; critical P = .001 in the bilateral parietal WM; a post hoc analysis identified growth rate differences only on the left side, critical P = .004). A growth rate difference was not detectable at older ages. In 3-dimensional maps, growth rates in the siblings even appeared to surpass those of healthy individuals at later ages, at least locally in the brain, but this effect did not survive a multiple comparisons correction. CONCLUSIONS In this first longitudinal study of nonpsychotic siblings of patients with COS, the siblings showed early WM growth deficits, which normalized with age. As reported before for gray matter, WM growth may also be an age-specific endophenotype that shows compensatory normalization with age.

At the boundary of the self: the insular cortex in patients with childhood-onset schizophrenia, their healthy siblings, and normal volunteers.

The insular cortex (insula), whose normal function involves delineating the boundary between self and non‐self stimuli, has been implicated in the pathophysiology of the positive symptoms of schizophrenia, including hallucinations and delusions. Childhood‐onset schizophrenia (COS), that includes the onset of psychosis before age 13, is a severe and continuous form of the illness which shows profound and global progressive cortical brain abnormalities during adolescence which merge in the adult pattern with age. Using prospectively acquired anatomic brain magnetic resonance imaging (MRI) scans, a matched sample of COS patients, their nonpsychotic full siblings and healthy volunteers, we measured insular volume using the FreeSurfer automated software. COS patients (n = 98; 234 scans) had significantly lower right (p = 0.003), left (p < 0.001), and total (p < 0.001) insular volumes than healthy volunteers (n = 100; 248 scans). Right insular volume negatively correlated with positive symptoms as measured by the Scale for the Assessment of Positive Symptoms (SAPS) (p = 0.02), while both left (p = 0.01) and right (p = 0.006) insula volumes were positively correlated with overall functioning, as measured by the Childrens Global Assessment Scale (CGAS) scores. COS siblings (n = 71; 153 scans), on the other hand, did not differ significantly from normal volunteers suggesting that the insular deficits are more related to the illness state than a familial endophenotype. These results also highlight the salience of the insula in positive symptoms of schizophrenia perhaps resulting from the inability to discriminate between self from the non‐self in COS. Further work to connect insular deficits to other neurocircuitries is warranted.

Risk factors for neutropenia in clozapine-treated children and adolescents with childhood-onset schizophrenia.

OBJECTIVE The purpose of this study was to retrospectively analyze rates of neutropenia and risk factors for neutropenia in hospitalized children and adolescents treated with clozapine. METHODS A retrospective chart review was conducted for all patients who received clozapine at any time during a hospitalization at the National Institute of Mental Health (NIMH) between 1990 and 2011. All patients satisfied screening criteria for the NIMH childhood-onset schizophrenia study, including onset of psychosis before the age of 13 years. Absolute neutrophil count (ANC) values recorded during inpatient hospitalization were extracted for 87 eligible patients with a mean age of 13.35±2.46 years at hospitalization and a mean length of stay of 117±43 days. RESULTS Mild neutropenia only (lowest ANC<2000/mm3 but>1500/mm3) was observed in 27 (31%) patients and moderate neutropenia (any ANC<1500/mm3) was observed in 17 (20%) patients. There were no cases of agranulocytosis or severe infection. Significant risk factors for mild neutropenia compared with no hematologic adverse effects (HAEs) were male gender (p=0.012) and younger age (p<0.001). Male gender was also a significant risk factor for moderate neutropenia compared with no HAEs (p=0.003). If a child of African American ethnicity developed neutropenia during hospitalization at all that child was significantly more likely to develop moderate neutropenia than mild neutropenia only (p=0.017). African American boys had the highest rate of moderate neutropenia at 47%. Sixteen of the 17 patients exhibiting moderate neutropenia were successfully treated with clozapine by the time of discharge; 8 of these 16 required adjunctive lithium carbonate administration to maintain ANC>2000/mm3. CONCLUSIONS Our study shows that the rates of neutropenia in clozapine-treated children and adolescents are considerably higher than in the adult population. Younger age, African American ethnicity, and male gender were significant risk factors. These are also risk factors for benign neutropenia in healthy children and adolescents. Despite these high rates of neutropenia, all but one of the patients with neutropenia during hospitalization were successfully discharged on clozapine.

Lack of Gender Influence on Cortical and Subcortical Gray Matter Development in Childhood-Onset Schizophrenia

BACKGROUND Progressive cortical gray matter (GM) abnormalities are an established feature of schizophrenia and are more pronounced in rare, severe, and treatment refractory childhood-onset schizophrenia (COS) cases. The effect of sex on brain development in schizophrenia is poorly understood and studies to date have produced inconsistent results. METHODS Using the largest to date longitudinal sample of COS cases (n = 104, scans = 249, Male/Female [M/F] = 57/47), we compared COS sex differences with sex differences in a sample of matched typically developing children (n = 104, scans = 244, M/F = 57/47), to determine whether or not sex had differential effects on cortical and subcortical brain development in COS. RESULTS Our results showed no significant differential sex effects in COS for either GM cortical thickness or subcortical volume development (sex × diagnosis × age interaction; false discovery rate q = 0.05). CONCLUSION Sex appears to play a similar role in cortical and subcortical GM development in COS as it does in normally developing children.