Learning disabilities in children with neurofibromatosis type 1: subtypes, cognitive profile, and attention-deficit–hyperactivity disorder

Neurofibromatosis type 1 is a common, autosomal dominant, monogenetic neurocutaneous disorder. It is characterized by café au lait spots, axillary and inguinal freckling, Lisch nodules, optic pathway gliomas, neurofibromas, and distinctive bony abnormalities. Also associated with this condition are other central nervous system tumors, scoliosis, hypertension, vascular abnormalities, and cognitive issues such as learning disabilities and attention deficit-hyperactivity disorder.

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Feedback-Based Learning of Timing in Attention-Deficit/Hyperactivity Disorder and Neurofibromatosis Type 1

Journal of the International Neuropsychological Society ◽

10.1017/s1355617721000072 ◽

2021 ◽

pp. 1-10

Author(s):

Astrid Prochnow ◽

Annet Bluschke ◽

Barbara Novotna ◽

Maja von der Hagen ◽

Christian Beste

Keyword(s):

Attention Deficit Hyperactivity Disorder ◽

Attention Deficit ◽

Dopaminergic System ◽

Time Estimation ◽

Neurofibromatosis Type ◽

Children With Adhd ◽

Hyperactivity Disorder ◽

Feedback Learning ◽

Patient Groups

Abstract Objective: Patients with Neurofibromatosis Type 1 (NF1) frequently display symptoms resembling those of Attention Deficit/Hyperactivity Disorder (ADHD). Importantly, these disorders are characterised by distinct changes in the dopaminergic system, which plays an important role in timing performance and feedback-based adjustments in timing performance. In a transdiagnostic approach, we examine how far NF1 and ADHD show distinct or comparable profiles of timing performance and feedback-based adjustments in timing. Method: We examined time estimation and learning processes in healthy control children (HC), children with ADHD with predominantly inattentive symptoms and those with NF1 using a feedback-based time estimation paradigm. Results: Healthy controls consistently responded closer to the correct time window than both patient groups, were less variable in their reaction times and displayed intact learning-based adjustments across time. The patient groups did not differ from each other regarding the number of in-time responses. In ADHD patients, the performance was rather unstable across time. No performance changes could be observed in patients with NF1 across the entire task. Conclusions: Children with ADHD and NF1 differ in feedback learning-based adjustments of time estimation processes. ADHD is characterised by behavioural fluctuations during the learning process. These are likely to be associated with inefficiencies in the dopaminergic system. NF1 is characterised by impairments of feedback learning which could be due to various neurotransmitter alterations occurring in addition to deficits in dopamine synthesis. Results show that despite the strong overlap in clinical phenotype and neuropsychological deficits between NF1 and ADHD, the underlying cognitive mechanisms are different.

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