title: A cross-sectional controlled developmental study of neuropsychological functions in patients with glutaric aciduria type I.
abstract: BACKGROUND
  Glutaric aciduria type I (GA-I) is an inherited metabolic disease due to deficiency of glutaryl-CoA dehydrogenase (GCDH). Cognitive functions are generally thought to be spared, but have not yet been studied in detail.
  
  
  METHODS
  Thirty patients detected by newborn screening (n = 13), high-risk screening (n = 3) or targeted metabolic testing (n = 14) were studied for simple reaction time (SRT), continuous performance (CP), visual working memory (VWM), visual-motor coordination (Tracking) and visual search (VS). Dystonia (n = 13 patients) was categorized using the Barry-Albright-Dystonia Scale (BADS). Patients were compared with 196 healthy controls. Developmental functions of cognitive performances were analysed using a negative exponential function model.
  
  
  RESULTS
  BADS scores correlated with speed tests but not with tests measuring stability or higher cognitive functions without time constraints. Developmental functions of GA-I patients significantly differed from controls for SRT and VS but not for VWM and showed obvious trends for CP and Tracking. Dystonic patients were slower in SRT and CP but reached their asymptote of performance similar to asymptomatic patients and controls in all tests. Asymptomatic patients did not differ from controls, except showing significantly better results in Tracking and a trend for slower reactions in visual search. Data across all age groups of patients and controls fitted well to a model of negative exponential development.
  
  
  CONCLUSIONS
  Dystonic patients predominantly showed motor speed impairment, whereas performance improved with higher cognitive load. Patients without motor symptoms did not differ from controls. Developmental functions of cognitive performances were similar in patients and controls. Performance in tests with higher cognitive demand might be preserved in GA-I, even in patients with striatal degeneration.
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. nikolas.boy@med.uni-heidelberg.de.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Boy
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. jana.heringer@med.uni-heidelberg.de.
authors.forename: Jana
authors.initials: J
authors.lastname: Heringer
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. gisela.haege@med.uni-heidelberg.de.
authors.forename: Gisela
authors.initials: G
authors.lastname: Haege
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. esthermariaglahn@gmx.de.
authors.forename: Esther M
authors.initials: EM
authors.lastname: Glahn
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. georg.hoffmann@med.uni-heidelberg.de.
authors.forename: Georg F
authors.initials: GF
authors.lastname: Hoffmann
authors.affiliation: Faculty of Applied Psychology, SRH University of Applied Sciences, D-69123, Heidelberg, Germany. sven.garbade@hochschule-heidelberg.de.
authors.forename: Sven F
authors.initials: SF
authors.lastname: Garbade
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. stefan.koelker@med.uni-heidelberg.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kölker
authors.affiliation: Department of General Paediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany. peter.burgard@med.uni-heidelberg.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Burgard
mesh_terms: D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000523:psychology*; D001928:Brain Diseases, Metabolic / Q000523:psychology*; D002648:Child; D002652:Child Behavior; D002675:Child, Preschool; D003072:Cognition Disorders / Q000523:psychology*; D003430:Cross-Sectional Studies; D004421:Dystonia / Q000523:psychology*; D001330:Electronic Data Processing; D005260:Female; D050770:Glutaryl-CoA Dehydrogenase / Q000172:deficiency*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D009483:Neuropsychological Tests; D055815:Young Adult
chemical_list: D050770:Glutaryl-CoA Dehydrogenase