Routine use of CANTAB system for detection of neuropsychological deficits in patients with PKU.

Several studies have reported neuropsychological deficits related to hyper phenylalaninemia in patients with phenylketonuria (PKU). As computerized neuropsychological tests seem to be promising in the detection of such abnormalities, we aimed to assess the usefulness of routine use of CANTAB system in PKU clinic. A group of 49 PKU patients aged >16 years were tested by means of computerized CANTAB tests measuring speed of response, response inhibition, sustained attention, and working memory capacity. The scores achieved by study participants were analyzed with respect to their blood phenylalanine concentrations. Proper dietary control was observed in 22 patients, whereas in the remaining 27 persons, blood phenylalanine concentrations exceeded the recommended range. The results of the tests assessing sustained attention, working memory, and inhibitory control achieved by the non-compliant patients were significantly worse in comparison with patients maintaining proper diet. However, the mean scores achieved by treatment-adherent patients were also worse than expected, what could probably be related to problems with early start of treatment during their infancy. Our results confirmed the presence of specific neuropsychological deficits related to hyperphenylalaninemia in adults and adolescents with PKU. In our opinion, routine use of computerized neuropsychological tests should be recommended in PKU clinics.

[1]  J. Sergeant,et al.  Sustained attention and inhibition of cognitive interference in treated phenylketonuria: associations with concurrent and lifetime phenylalanine concentrations , 2002, Neuropsychologia.

[2]  M. Bik-Multanowski,et al.  Use of handheld computers for assessment of prefrontal cortex function in patients with phenylketonuria. , 2005, Molecular genetics and metabolism.

[3]  C. Scriver,et al.  The Metabolic and Molecular Bases of Inherited Disease, 8th Edition 2001 , 2001, Journal of Inherited Metabolic Disease.

[4]  R. Steiner,et al.  Deficits in memory strategy use related to prefrontal dysfunction during early development: evidence from children with phenylketonuria. , 2001, Neuropsychology.

[5]  M. W. van der Molen,et al.  Prefrontal dysfunction in early and continuously treated phenylketonuria , 1999 .

[6]  J. Denecke,et al.  Phenylketonuria: No Specific Frontal Lobe-Dependent Neuropsychological Deficits of Early-Treated Patients in Comparison with Diabetics , 2002, Pediatric Research.

[7]  P. Sly,et al.  High dose pancreatic enzymes in cystic fibrosis. , 1990, Archives of disease in childhood.

[8]  A. Ades,et al.  Effect on intelligence of relaxing the low phenylalanine diet in phenylketonuria. , 1991, Archives of disease in childhood.

[9]  J. Sergeant,et al.  Event-related potential correlates of selective processing in early- and continuously-treated children with phenylketonuria: effects of concurrent phenylalanine level and dietary control. , 2010, Molecular genetics and metabolism.

[10]  S. Christ,et al.  Executive function in early-treated phenylketonuria: profile and underlying mechanisms. , 2010, Molecular genetics and metabolism.

[11]  A. Diamond,et al.  Phenylalanine levels of 6‐10mg/dl may not be as benign as once thought , 1994, Acta paediatrica (Oslo, Norway : 1992). Supplement.

[12]  A. Boneh,et al.  How practical are recommendations for dietary control in phenylketonuria? , 2002, The Lancet.

[13]  P. Griffiths,et al.  Executive function and psychosocial adjustment in children with early treated phenylketonuria: correlation with historical and concurrent phenylalanine levels. , 2007, Journal of intellectual disability research : JIDR.