Brain MRI diffusion-weighted imaging in patients with classical phenylketonuria

Abstract

Among the different MR sequences, DWI seems to be the most sensitive and reliable in detecting and grading the typical WMAs of cPKU patients.

Neurocognitive and neuroimaging outcome of early treated young adult PKU patients: A longitudinal study

“…There is some evidence from the literature that no WM alterations are detected in patients with Phe level b 600 μM [31][32][33][34]. This was not confirmed from the MRI findings of our young adult patients.…”

The outcome of white matter abnormalities in early treated phenylketonuric patients: A retrospective longitudinal long-term study

“…No quantitative methods to measure the severity of white matter lesions could be applicable because the very long time lag we analyzed included both digital and non digital recording of the MRI images and DTI studies were not routinary realized in our centre before 2010. Even if previously reported studies demonstrated that scoring scales based on conventional semiquantitative assessment and DWI values of white matter are strictly correlated [24] a quantitative approach is mandatory for future prospective studies. -the retrospective nature of the study and the very long time lag we analyzed impeded a deep longitudinal systematic evaluation of some cognitive domains possibly most sensitive to PKU (e.g., working memory, processing speed) with tools other than IQ assessment.…”

“…In the lack of neuropathological data from early treated PKU patients, the information on the brains of these patients comes from MRI studies performed in the last 20 years [1], which showed that white matter changes: a) usually appear during the second decade of life in virtually all PKU patients [11]; b) are related to the increase of blood phenylalanine, as supported by the fact that they recede 3 to 6 months after the restoration of a strict metabolic control [18,19]; c) are not found in subjects with blood phenylalanine level lower than 500-600 μmol/l. [20][21][22][23][24]; c) are affected by the levels of blood phenylalanine and the duration of the exposure to high phenylalanine levels [10,[25][26][27][28][29].…”

Resonancia magnética nuclear de encéfalo en pacientes con fenilcetonuria diagnosticada tardíamente

“…La neuropatología de los pacientes con fenilcetonuria clásica no tratados ha sido previamente analizada con resonancia magnética por diversos investigadores (Cuadro 1); 23,[25][26][27] sin embargo, en este artículo presentamos por primera vez los hallazgos de neuroimagen en pacientes mexicanos con esta enfermedad (Figuras 1-4). Este grupo corresponde a la forma más grave de la enfermedad (fenilcetonuria clásica) y todos fueron diagnosticados tardíamente, por lo que el tiempo de exposición a la toxicidad de la fenilalanina fue muy prolongado.…”

“…26 Kono y sus colaboradores encontraron que los pacientes con pobre control metabólico tienen coeficientes de difusión aparente significativamente menores que los pacientes bien controlados. 25 Se sabe que las concentraciones elevadas de sustancias peptídicas aumentan la viscosidad y restringen la difusión (disminución del coeficiente de difusión aparente).…”