Cognitive outcomes in early-treated adults with phenylketonuria (PKU): a comprehensive picture across domains

Liana Palermo; Tarekegn Geberhiwot; Anita MacDonald; Ellie Limback; S. Kate Hall; Cristina Romani

doi:10.1037/neu0000337

Cognitive outcomes in early-treated adults with phenylketonuria (PKU): a comprehensive picture across domains

Liana Palermo, Tarekegn Geberhiwot, Anita MacDonald, Ellie Limback, S. Kate Hall, Cristina Romani

Research output: Contribution to journal › Article › peer-review

Abstract

OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature.

METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education.

RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment.

CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Record

Original language	English
Pages (from-to)	255–267
Number of pages	13
Journal	Neuropsychology
Volume	31
Issue number	3
DOIs	https://doi.org/10.1037/neu0000337
Publication status	Published - 12 Jan 2017

Bibliographical note

This article has been published under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright for this article is retained by the author(s). Author(s) grant(s) the American Psychological Association the exclusive right to publish the article and identify itself as the original publisher.

Supplemental materials: http://dx.doi.org/10.1037/neu0000337.supp

Keywords

adult PKU
metabolic diseases
cognitive impairments
executive functions and speed of processing
memory and learning

Access to Document

10.1037/neu0000337Licence: CC BY 3.0

Cognitive outcomes in early-treated adults with phenylketonuria
This article has been published under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright for this article is retained by the author(s). Author(s) grant(s) the American Psychological Association the exclusive right to publish the article and identify itself as the original publisher.
Final published version, 647 KBLicence: CC BY 3.0

Cite this

@article{d5fd86fed17c4728af721b128d11011c,

title = "Cognitive outcomes in early-treated adults with phenylketonuria (PKU): a comprehensive picture across domains",

abstract = "OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature.METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education.RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment.CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Record",

keywords = "adult PKU, metabolic diseases, cognitive impairments, executive functions and speed of processing, memory and learning",

author = "Liana Palermo and Tarekegn Geberhiwot and Anita MacDonald and Ellie Limback and Hall, {S. Kate} and Cristina Romani",

note = "This article has been published under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright for this article is retained by the author(s). Author(s) grant(s) the American Psychological Association the exclusive right to publish the article and identify itself as the original publisher. Supplemental materials: http://dx.doi.org/10.1037/neu0000337.supp",

year = "2017",

month = jan,

day = "12",

doi = "10.1037/neu0000337",

language = "English",

volume = "31",

pages = "255–267",

journal = "Neuropsychology",

issn = "0894-4105",

publisher = "American Psychological Association Inc.",

number = "3",

}

TY - JOUR

T1 - Cognitive outcomes in early-treated adults with phenylketonuria (PKU)

T2 - a comprehensive picture across domains

AU - Palermo, Liana

AU - Geberhiwot, Tarekegn

AU - MacDonald, Anita

AU - Limback, Ellie

AU - Hall, S. Kate

AU - Romani, Cristina

N1 - This article has been published under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright for this article is retained by the author(s). Author(s) grant(s) the American Psychological Association the exclusive right to publish the article and identify itself as the original publisher. Supplemental materials: http://dx.doi.org/10.1037/neu0000337.supp

PY - 2017/1/12

Y1 - 2017/1/12

N2 - OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature.METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education.RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment.CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Record

AB - OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature.METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education.RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment.CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Record

KW - adult PKU

KW - metabolic diseases

KW - cognitive impairments

KW - executive functions and speed of processing

KW - memory and learning

UR - http://psycnet.apa.org/journals/neu/31/3/255

U2 - 10.1037/neu0000337

DO - 10.1037/neu0000337

M3 - Article

C2 - 28080075

SN - 0894-4105

VL - 31

SP - 255

EP - 267

JO - Neuropsychology

JF - Neuropsychology

IS - 3

ER -

Cognitive outcomes in early-treated adults with phenylketonuria (PKU): a comprehensive picture across domains

Abstract

Bibliographical note

Keywords

Access to Document

Other files and links

Fingerprint

Cite this