Toward Understanding Cognitive Impairment in Patients with Myotonic Dystrophy Type 1

• Published in: Archives of clinical neuropsychology Vol. 25; no. 4; pp. 303 - 313
• Main Authors: Zalonis, Ioannis, Bonakis, Anastasios, Christidi, Fotini, Vagiakis, Emmanouil, Papageorgiou, Sokratis G., Kalfakis, Nikolaos, Manta, Panagiota, Vassilopoulos, Dimitrios
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-06-2010
• Subjects: Adult; Adult and adolescent clinical studies; Aged; Bias; Biological and medical sciences; Cognition; Cognition Disorders - diagnosis; Cognition Disorders - psychology; Disability Evaluation; Diseases of striated muscles. Neuromuscular diseases; Disorders of Excessive Somnolence - diagnosis; Disorders of Excessive Somnolence - psychology; Female; Humans; Male; Medical sciences; Middle Aged; Myotonic dystrophy; Myotonic Dystrophy - diagnosis; Myotonic Dystrophy - psychology; Neurology; Neuropsychological dysfunctions; Neuropsychological Tests - statistics & numerical data; Organic mental disorders. Neuropsychology; Pneumology; Polysomnography; Psychology. Psychoanalysis. Psychiatry; Psychometrics; Psychopathology. Psychiatry; Reproducibility of Results; Respiratory system : syndromes and miscellaneous diseases; Sleep breathing disorders; Sleep Wake Disorders - diagnosis; Sleep Wake Disorders - psychology; Young Adult; Human; Nervous system diseases; Neuromuscular diseases; Sleep apnea syndrome; Cognitive disorder; Neuropsychological dysfunctions; Myotonia; Respiratory disease; Cognition; Genetic disease; Myotonic dystrophy; Dysfunction; Sleep breathing disorders
• ISSN: 0887-6177; 1873-5843
• DOI: 10.1093/arclin/acq016

Cognitive dysfunction and sleep disruption are two frequent but underestimated features of adult onset myotonic dystrophy type 1 (MD1). In order to investigate the MD1 cognitive profile and its relationship with sleep disruption, 23 patients with genetically proved MD1 (mild–moderate in severity) underwent neuropsychological (nps) and polysomnography assessment. Patients scored lower than controls on almost all nps tests but cognitive impairments were mostly observed in executive functions (z-score = −2.14), with complex attention (z-score = −1.04), memory (z-score = −0.65), constructions (z-score = −1.29), and reasoning (z-score = −0.75) being slightly affected. Moderate–severe sleep apnea (apnea–hypopnea index [AHI] ≥15) was very frequent with most of the apneas being of the obstructive type. However, we found hardly any evidence of association between subjective, objective sleep parameters, and nps performance (p > .001). Thus, in our cohort of 23 adult MD1 patients, mild cognitive dysfunction, which is mostly related to the dysfunction of frontal association cortex and its underlying neural networks, does not seem to be significantly influenced by sleep disruption, which is mainly caused by obstructive apnea events.