The myotonic dystrophy health index: Japanese adaption and validity testing.

INTRODUCTION: The Myotonic Dystrophy Health Index (MDHI) is a disease-specific, patient-reported outcome measure. The objective of this study was to translate, evaluate, and validate a Japanese version of the MDHI (MDHI-J). METHODS: We utilized forward and backward translations and qualitative interviews with 11 myotonic dystrophy type 1 (DM1) participants. We subsequently tested the internal consistency, test-retest reliability, concurrent validity against muscle strength, and 3 quality-of-life measures, and the known-groups validity of the MDHI-J with 60 adult patients. RESULTS: The MDHI-J was found to be culturally appropriate, comprehensive, and clinically relevant. The MDHI-J and its subscales had high internal consistency (mean Cronbach's α = 0.91), test-retest reliability (intraclass coefficient 0.678-0.915), and concurrent validity (Spearman's ρ - 0.869 to 0.904). MDHI-J scores were strongly associated with employment, duration of symptoms, and modified Rankin Scale. DISCUSSION: The MDHI-J is suitable and valid to measure patient-reported disease burden in adult Japanese patients with DM1. Muscle Nerve 59:577-577, 2019.

Cognitive impairment and quality of life in patients with myotonic dystrophy type 1.

INTRODUCTION: This study sought to clarify whether specific cognitive abilities are impaired in patients with myotonic dystrophy type 1 (DM1) as well as to investigate the relationships among quality of life (QoL), cognitive function, and psychological factors. METHODS: Sixty patients with DM1 were evaluated on cognitive functioning (abstract reasoning, attention/working memory, executive function, processing speed, and visuoconstructive ability), apathy, depression, excessive daytime sleepiness, fatigue, and QoL. QoL was assessed by 2 domains of the Muscular Dystrophy Quality of Life Scale (Psychosocial Relationships and Physical Functioning and Health). RESULTS: More than half of the patients exhibited cognitive impairment in attention/working memory, executive function, processing speed, and visuoconstructive ability. The Psychosocial Relationships factor was associated with processing speed, attention/working memory, and apathy, whereas depression and fatigue were associated with 2 QoL domains. DISCUSSION: Our study identified specific cognitive impairments in DM1. Specific cognitive functions and psychological factors may be potential contributors to QoL. Muscle Nerve 57: 742-748, 2018.

Disturbance of time orientation, attention, and verbal memory in amnesic patients with confabulation.

Confabulation is often observed in amnesic patients after brain damage. However, evidence regarding the relationship between confabulation and other neuropsychological functions is scarce. In addition, previous studies have proposed two possibilities of the relationship between confabulation and false memory, in which patients with confabulation are likely to retrieve false memories, or confabulations are relatively independent of false memories. The present study investigated how confabulation is related to various cognitive functions, including orientation, attention, frontal lobe function, memory, and mental status, and to false memories, as assessed by the Deese-Roediger-Mcdermott (DRM) paradigm. Patients with organic amnesia participated, and confabulations were evaluated using the Confabulation Battery. Amnestic patients were classified into two groups: confabulating (CP) and nonconfabulating patients (NCP). The CP group was significantly impaired in time orientation, attention, and verbal memory, compared to the NCP group and age-matched healthy controls (HC). Results of the DRM paradigm revealed no significant difference in false memory retrieval induced by critical lures across CP, NCP, and HC groups. Confabulating responses in organic amnesia could be in part induced by disturbance of time consciousness and attention control in severe impairment of verbal memories, and confabulation and false memory could be modulated by different cognitive systems.