Selective, age-related autobiographical memory deficits in children with severe traumatic brain injury.

OBJECTIVES: Autobiographical memory (AM) is a complex function that involves re-experiencing of past personal events (episodic memory) scaffolded by personal facts (semantic memory). While AM is supported by a brain network and cognitive skills that are vulnerable to disruption by child traumatic brain injury (TBI), AM has not been examined in this patient population. DESIGN: Cross-sectional study. METHODS: Participants included children with severe closed TBI (n = 14) and healthy control (NC) children (n = 20) of comparable age, sex, and socioeconomic status. Participants completed (1) the Child Autobiographical Interview (Willoughby et al., 2012, Front. Psychol., 3, 53), which required recall of autobiographical events and distinguished episodic (internal) from non-episodic (external) details, and self-rating of event phenomenological qualities, and (2) a battery of neuropsychological tests. RESULTS: Children with TBI recalled significantly fewer internal details relative to NCs, but the between-group difference was eliminated when specific probes were provided. The groups did not differ in either recall of external details or in ratings of events' phenomenological qualities. The gap between the groups in recall of internal details increased with age, as the greater number of internal details was associated with older age in the NC group, but not in the TBI group. Poorer verbal memory and lower IQ were related to recall of fewer internal details in the TBI group. CONCLUSIONS: This study unveils, to our knowledge for the first time, that severe child TBI is associated with a selective deficit in autobiographical memory that involves episodic, but spares semantic details, and identifies the risk factors for this impairment.

Accelerated Long-Term Forgetting Is Not Epilepsy Specific: Evidence from Childhood Traumatic Brain Injury.

Accelerated long-term forgetting (ALF) is characterized by adequate recall after short, but not long delays. ALF is not detected by standardized neuropsychological memory tests. Currently, the prevailing conceptualization of ALF is of a temporal lobe seizure-related phenomenon. Nevertheless, Mayes and colleagues (2003) proposed that ALF may occur when any of the components of the brain network involved in long-term memory formation, or their interaction, is disrupted. This disruption does not have to be caused by temporal lobe seizures for ALF to occur. Here, we investigate this possibility in a group of school-age children who have sustained traumatic brain injury (TBI) (n = 28), as TBI typically disrupts the brain network that is important for long-term memory formation and recall. Healthy control children (n = 62) also participated. Contrary to the dominant conceptualization of ALF being a seizure-related phenomenon, children with TBI showed ALF. Sustaining a severe TBI and diffuse subcortical damage was related to ALF. Individually, 8 of the 13 children with severe TBI presented with ALF. ALF would remain undetected on standardized testing in six of these eight children. One child had the opposite pattern of dissociation, an impaired score on standardized testing, but an average long-term memory score. This is the first study, to our knowledge, to show ALF in patients with TBI, which has remained undiagnosed and untreated in this patient population. Our study also challenges the dominant hypothesis of ALF being a temporal lobe seizure-related phenomenon, and raises a possibility that short-term and long-term memory systems may be independent.

Neuropsychological functioning in children with medium chain acyl coenzyme a dehydrogenase deficiency (MCADD): the impact of early diagnosis and screening on outcome.

Children with medium chain acyl coenzyme A dehydrogenase deficiency (MCADD) have been reported to be at high risk for neurocognitive deficits. However this has not been systematically studied and little is known about the exact nature of neuropsychological sequelae or of the impact of early diagnosis and screening on outcome. We examined cognitive and adaptive outcome in children with MCADD (N = 38, age range: 2 years, 2 months - 10 years, 3 months) diagnosed either through a newborn screening program(tandem mass spectrometry/MSMS) or upon clinical presentation. There was no evidence of overall intellectual impairment in either groups but there was some suggestion of poorer verbal and specific executive functioning (i.e., planning) abilities in the unscreened cohorts. Adaptive functioning was relatively intact with the exception of reduced Daily Living Skills in both our screened and unscreened groups. Early diagnosis and greater number of hospitalizations were related to higher verbal, communication, and socialization skills. Overall, our results highlight the importance of early diagnosis and management for children with MCADD.

Healthcare use and costs of medium-chain acyl-CoA dehydrogenase deficiency in Australia: screening versus no screening.

OBJECTIVE: To describe and analyze the use and costs of hospital services for children diagnosed with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency either with newborn screening or clinical diagnosis in Australia between 1994 and 2002. MCAD deficiency is a potentially lethal disorder of fatty-acid oxidation. STUDY DESIGN: We conducted a retrospective audit of medical records supplemented by a parental survey. RESULTS: A total of 59 children with MCAD deficiency were identified, 24 by using newborn screening. In the first 4 years of life, screening children cost an average of A$1676 (US$1297) per year for inpatient, emergency department, and outpatient visits, compared with A$1796 (US$1390) for children in whom a clinical diagnosis was made. Forty-two percent of the children who underwent screening were admitted to the hospital, compared with 71% of children who did not undergo screening. Children who did not undergo screening used significantly more inpatient services and cost significantly more in emergency services. There were also some significant differences in use on a year-by-year basis. CONCLUSIONS: Children who do not undergo screening may be more likely to be admitted to the hospital and to incur higher emergency department costs than children who underwent screening, and children seem more likely to attend hospital outpatient clinics. Screening does not result in higher costs from a hospital perspective.

Outcome of neonatal screening for medium-chain acyl-CoA dehydrogenase deficiency in Australia: a cohort study.

BACKGROUND: Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the disorder thought most to justify neonatal screening by tandem-mass spectrometry because, without screening, there seems to be substantial morbidity and mortality. Our aim was to assess the overall effectiveness of neonatal screening for MCAD deficiency in Australia. METHODS: We identified MCAD-deficient patients from a total population of 2,495,000 Australian neonates (810,000 screened) born between April 1, 1994, and March 31, 2004. Those from a cohort of 1,995,000 (460,000 screened) were followed up for at least 4 years, and we recorded number of deaths and severe episodes, medical and neuropsychological outcome, and hospital admissions within the screened and unscreened groups. FINDINGS: In cohorts aged at least 4 years there were 35 MCAD-deficient patients in those not screened (2.28 per 100,000 total population) and 24 in the screened population (5.2 per 100,000). We estimated that patients with this disorder in the unscreened cohort remained undiagnosed. Before 4 years of age, three screened patients had an episode of severe decompensation (including one neonatal death) versus 23 unscreened patients (including five deaths). At the most conservative estimate, relative risk of an adverse event was 0.44 (95% CI 0.13-1.45). In the larger cohort the relative risk (screened vs unscreened) of an adverse event by age 2 years was 0.26 (95% CI 0.07-0.97), also a conservative estimate. 38 of 52 living patients had neuropsychological testing, with no suggestions of significant differences in general cognitive outcome between the groups. INTERPRETATION: Screening is effective in patients with MCAD deficiency since early diagnosis reduces deaths and severe adverse events in children up to the age of 4 years.