Neurofibromatosis Type 1
Neuropsychological profile in adults with neurofibromatosis type 1 compared to a control group.[Descheemaeker et al. (2013). Journal of Intellectual Disability Research, 57(9): 874-886.]
Neurofibromatosis type 1 (NF1) is a common inherited autosomal dominant condition, characterised by multiple café-au-lait macules, axillary and/or inguinal freckling, iris Lisch nodules and tumours of the nervous system such as neurofibromas and optic pathway gliomas. At the same time, NF1 is frequently associated with intellectual disabilities across several neuropsychological domains. Existing neuropsychological data in NF1 adults are limited and sometimes contradictory. Moreover, most studies use a non-IQ-controlled norm group for comparison. This study sought to investigate specific neuropsychological characteristics in intellectual abilities unrelated to the global intellectual capacity.
METHOD: Twenty NF1 adults and an IQ-, age- and gender-matched control group completed a comprehensive neuropsychological test battery composed of specific cognitive tests investigating visual-spatial abilities and memory, auditory memory, selective and sustained attention and executive functioning. A short version of the Wechsler Adult Intelligence Scale - III was also administered to both groups.
RESULTS: Norm comparison showed that both groups perform poorly on most neuropsychological functions, except for sustained attention. However, comparison with the IQ-matched control group showed significantly lower scores on visual-spatial abilities and memory, on auditory working memory and on tests for cognitive flexibility in NF1 adults. Nevertheless, as the significant difference in average estimated IQ score between the NF1 group and the selected control group almost reaches the 5% significance level, further analysis is needed to include IQ as a covariate. Eventually, problems in visual-spatial skills and auditory long-term memory seem to be specific NF1-related deficits, while problems in attention and executive functioning are particularly related to their general lowered intellectual abilities.
CONCLUSION: Taking into account that primary visual perception problems could be part of a more general central coherence deficit while interpreting auditory memory problems as possibly related to deficits in language use and comprehension, this idea also fits with the observation of several problems in social information processing and functioning of NF1 persons.
Longitudinal assessment of cognition and T2-hyperintensities in NF1: an 18-year study.[Payne et al. (2014). American Journal of Medical Genetics Part A, 164A(3): 661-665.]
The developmental course of cognitive deficits in individuals with neurofibromatosis type 1 (NF1) is unclear. The objectives of this study were to determine the natural history of cognitive function and MRI T2-hyperintesities (T2H) from childhood to adulthood and to examine whether the presence of discrete T2H in childhood can predict cognitive performance in adulthood. We present cognitive and structural neuroimaging data from 18 patients with NF1 and five sibling controls assessed prospectively across an 18-year period. Longitudinal analyses revealed a significant increase in general cognitive function in patients with NF1 over the study period. Improvements were limited to individuals with discrete T2H in childhood. Patients without lesions in childhood exhibited a stable profile. The number of T2H decreased over time, particularly discrete lesions. Lesions located within the cerebral hemispheres and deep white matter were primarily stable, whereas those located in the basal ganglia, thalamus and brainstem tended to resolve. Our results support the hypothesis that resolution of T2H is accompanied by an improvement in general cognitive performance, possibly as a result of increased efficiency within white matter tracts.
May 4, 2008 Neurofibromatosis: A 21st Century Perspective
A. David Rothner, MD
Neurofibromatosis: An Overview
Learn about this disorder of the nervous system and its causes, symptoms, and treatment.
B. Bruce H. Cohen, MD
Neurofibromatosis: Understanding the Science
Although neurofibromatosis is genetic, nearly half of those affected have no family history of it. Find out more about the relationship between genes and this disorder.
C. Francis Papay, MD
NF-1 The Cosmetic Issues
Plastic surgery may be an option to treat some physical abnormalities caused by this disorder. But do the benefits outweigh the risks?
Social functioning in adults with neurofibromatosis type 1. [Pride et al. (2013). Research in Developmental Disabilities, 34(10): 3393-3399.]
Neuropsychological impairments in elderly Neurofibromatosis type 1 patients. [de Souza Costa et al. (2014). European Journal of Medical Genetics, 57(5): 216-219.]
Relationship between cognitive dysfunction, gait, and motor impairment in children and adolescents with neurofibromatosis type 1. [Champion et al. (2014). Developmental Medicine & Child Neurology, 56(5): 468-474.]
Behaviour in children with neurofibromatosis type 1: cognition, executive function, attention, emotion, and social competence. [Lehtonen et al. (2013). Developmental Medicine & Child Neurology, 55(2): 111-125.]
Neurofibromatosis type 1. [North, K. (2000). American Journal of Medical Genetics, 97(2): 119-127.]