An Investigation of the Neurological and Neuropsychiatric Disturbances in Adults with Undiagnosed and/or Untreated Phenylketonuria in Poland

Abstract

Background The aim of the study was to determine neurological and neuropsychiatric manifestations in a group of patients with previously undiagnosed or untreated phenylketonuria (PKU) in the south-eastern part of Poland. Methods The study was conducted among 400 adults with severe intellectual disability who were born prior to neonatal screening and who resided in Social Welfare Homes in south-eastern Poland. Participants were aged between 27 and 89 years (mean 51 years). The screening for PKU was performed by blood test using tandem mass spectrometry method (MS/MS) and analysis of organic acids in urine. Among all new identified untreated individuals, neurological symptoms were recorded and neuropsychiatric disturbances were assessed with The Neuropsychiatric Inventory-Nursing Home Version (NPI-NH). Results We found 10 previously undiagnosed and one previously diagnosed but untreated individuals with PKU (four women and seven men). The most commonly exhibited neurological manifestations included the following: profound speech disturbances, balance disturbances, muscular hypertonicity, muscular tremors and seizures. The most frequent behaviours included the following: aberrant/troublesome motor behaviour, agitation/aggression and euphoria/elation. Conclusion Data from the present study indicate that future treatment of these individuals should combine a dietary intervention with individual behavioural therapy and neurorehabilitation to improve general health and quality of life.