Impaired inhibitory control is associated with higher-order repetitive behaviors in autism spectrum disorders.

BACKGROUND: Impairments in executive cognitive control, including a reduced ability to inhibit prepotent responses, have been reported in autism spectrum disorders (ASD). These deficits may underlie patterns of repetitive behaviors associated with the disorder. METHOD: Eighteen individuals with ASD and 15 age- and IQ-matched healthy individuals performed an antisaccade task and a visually guided saccade control task, each with gap and overlap conditions. Measures of repetitive behaviors were obtained using the Autism Diagnostic Inventory-Revised (ADI-R) and examined in relation to neurocognitive task performance. RESULTS: Individuals with an ASD showed increased rates of prosaccade errors (failures to inhibit prepotent responses) on the antisaccade task regardless of task condition (gap/overlap). Prosaccade error rates were associated with the level of higher-order (e.g. compulsions, preoccupations) but not sensorimotor repetitive behaviors in ASD. CONCLUSIONS: Neurocognitive disturbances in voluntary behavioral control suggest that alterations in frontostriatal systems contribute to higher-order repetitive behaviors in ASD.

Epilepsy surgery in children with pervasive developmental disorder.

Pervasive developmental disorder (PDD) is occasionally associated with medically intractable complex partial seizures. The outcome of PDD was explored in three males and two females who underwent epilepsy surgery at 32 months to 8 years of age (mean = 4 years) after onset of epilepsy at 1 week to 21 months of age (mean = 11 months). Four children had temporal lobe resections (three right, one left; two for focal cortical dysplasia, and two for tumors), and one had a right temporoparieto-occipital resection (for focal cortical dysplasia). Each child underwent repeated evaluations by a pediatric neuropsychologist and psychiatrist. Fourteen to 47 months (mean = 23 months) after operation, one child with persistent seizures had moderate developmental and behavioral improvement, three children (two seizure free, one with rare staring spells) had mild developmental and behavioral improvement, and the remaining child (seizure free) experienced a worsening of her PDD. The four children with mild-to-moderate improvement in postoperative cognitive and behavioral development still demonstrated persistent delay. Cognitive gains were confirmed by neuropsychologic testing in the oldest patient but were not reflected in test results from the three younger children, who had more modest improvement. The child with worsening of her PDD had cognitive and emotional deterioration to babbling, echolalia, aggressiveness, decreased social interaction, and increased mouthing of objects beginning several months postoperatively. These results suggest that families should be counseled that PDD symptoms in children with focal epileptogenic lesions may or may not improve after epilepsy surgery, even if the surgery is successful with respect to seizure control.

Neuropsychological effect of temporal lobe resection in preadolescent children with epilepsy.

PURPOSE: Numerous studies have demonstrated changes in cognitive, memory, and language functioning in adults and adolescents after temporal lobectomy, yet little information is available regarding neuropsychological outcome in preadolescent children. METHODS: We studied pre- and postoperative neuropsychological test results from 14 children who underwent temporal lobe resection for intractable epilepsy at age 7-12 years (mean 9.4 years). RESULTS: Thirteen patients (93%) had no seizures or less than one seizure a year at follow-up 23-48 months (mean 34 months) after operation. Postoperative neuropsychological testing was performed 6-9 months (mean 7 months) after surgery in 13 patients and 36 months after the first operation in 1 patient who underwent two-stage resection of a tumor. Verbal, Performance, and Full Scale IQ were initially in the low-average range, with no significant change across the pre- and postoperative evaluations. Immediate verbal memory performance decreased significantly in children who initially performed above the median preoperatively and tended to decrease in children who had left rather than right temporal lobe resection. Significant postoperative decreases in delayed memory scores were independent of preoperative ability or side of resection. CONCLUSIONS: Our small study suggests vulnerability to postoperative decline in immediate verbal memory scores in preadolescent children who have higher baseline immediate memory function or undergo left rather than right temporal lobe resection, similar to that observed in adolescents in adults. The entire group exhibited a statistically significant decrease in delayed verbal memory. Study of larger series of patients will be important to clarify further the short- and long-term risks and benefits of temporal lobe resection in childhood.

Congruence of behavioral symptomatology in children with ADD/H, ADD/WO, and learning disabilities.

Although evidence generally supports the behavioral differentiation of attention deficit disorder with hyperactivity (ADD/H) and attention deficit disorder without hyperactivity (ADD/WO), a growing body of literature suggests that children with learning disabilities (LD) share behavioral symptomatology with children diagnosed as having ADD/WO. The present study examined this issue by comparing parent and teacher behavioral ratings among groups of children diagnosed as having ADD/H, ADD/WO, and LD on symptoms of impulsivity, inattention, and social withdrawal. The subjects were 77 outpatients in a diagnostic and referral-service clinic who were divided into three groups. Group 1 included children with a primary diagnosis of ADD/H (n = 35), Group 2 included children with a primary diagnosis of ADD/WO (n = 25), and Group 3 included children with a primary diagnosis of learning disabilities (n = 17). The results indicated that parents and teachers view children with ADD/H as more disruptive than children with ADD/WO or LD. Children with ADD/WO or LD were described as more underactive and shy and as daydreaming more often than children with ADD/H. Teachers rated children with ADD/WO and LD as being similar to each other on symptoms of withdrawal and impulsivity, but both parents and teachers endorsed different symptoms of inattention for children with ADD/WO or LD. Issues related to comorbidity and differentiation of behavioral symptomatology are discussed.