Zastosowanie spektroskopii magnetycznego rezonansu jądrowego w celu oceny mózgowego stężenia fenyloalaniny u chorych na fenyloketonurię

Abstract

AimThe aim of the study was to assess the usefulness of magnetic resonance spectroscopy for measurement of brain phenylalanine concentrations in adolescents and adults with phenylketonuria. Material and methodsA total of 80 patients with phenylketonuria aged 12–31 years participated in the study. Assessment of brain phenylalanine concentration was done with use of spectroscopic PRESS technique and blood phenylalanine concentration was measured with colorimetric method. Correlation of brain and blood phenylalanine concentrations was analyzed. ResultsIn the studied group of patients brain phenylalanine concentration correlated with hyperphenylalaninemia extend. The spectroscopic signal of the brain phenylalanine was clearly visible in all patients, in whom blood phenylalanine concentration was >1,2 mmol/l (20 mg/dl). Interestingly, the brain phenylalanine signal was not detectable in some patients with blood phenylalanine <1,2mmol/l (20mg/dl). However, the signal was clearly detectable in all remaining patients, even in case of moderate hyperphenylalaninemia 0,72–1,2mmol/l (12–20mg/dl). ConclusionsBrain magnetic resonance spectroscopy allows for reliable assessment of brain phenylalanine concentration, particularly in case of severe hyperphenylalaninemia. The method can be also useful to detect patients with moderate hyperphenylalaninemia and high brain phenylalanine concentration, what can allow for treatment modification.