Browsing by Subject "Myotonic dystrophy"

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    Cognitive Deficits, Apathy, and Hypersomnolence Represent the Core Brain Symptoms of Adult-Onset Myotonic Dystrophy Type 1
    (Frontiers Media, 2021-07) Miller, Jacob N.; Kruger, Alison; Moser, David J.; Gutmann, Laurie; van der Plas, Ellen; Koscik, Timothy R.; Cumming, Sarah A.; Monckton, Darren G.; Nopoulos, Peggy C.; Neurology, School of Medicine
    Myotonic dystrophy type 1 is the most common form of muscular dystrophy in adults, and is primarily characterized by muscle weakness and myotonia, yet some of the most disabling symptoms of the disease are cognitive and behavioral. Here we evaluated several of these non-motor symptoms from a cross-sectional time-point in one of the largest longitudinal studies to date, including full-scale intelligence quotient, depression, anxiety, apathy, sleep, and cerebral white matter fractional anisotropy in a group of 39 adult-onset myotonic dystrophy type 1 participants (27 female) compared to 79 unaffected control participants (46 female). We show that intelligence quotient was significantly associated with depression (P < 0.0001) and anxiety (P = 0.018), but not apathy (P < 0.058) or hypersomnolence (P = 0.266) in the DM1 group. When controlling for intelligence quotient, cerebral white matter fractional anisotropy was significantly associated with apathy (P = 0.042) and hypersomnolence (P = 0.034), but not depression (P = 0.679) or anxiety (P = 0.731) in the myotonic dystrophy type 1 group. Finally, we found that disease duration was significantly associated with apathy (P < 0.0001), hypersomnolence (P < 0.001), IQ (P = 0.038), and cerebral white matter fractional anisotropy (P < 0.001), but not depression (P = 0.271) or anxiety (P = 0.508). Our results support the hypothesis that cognitive deficits, hypersomnolence, and apathy, are due to the underlying neuropathology of myotonic dystrophy type 1, as measured by cerebral white matter fractional anisotropy and disease duration. Whereas elevated symptoms of depression and anxiety in myotonic dystrophy type 1 are secondary to the physical symptoms and the emotional stress of coping with a chronic and debilitating disease. Results from this work contribute to a better understanding of disease neuropathology and represent important therapeutic targets for clinical trials.
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    Heart Rate Variability Declines with Increasing Age and CTG Repeat Length in Patients with Myotonic Dystrophy Type 1
    (Wiley, 2003-07) Hardin, Bradley A.; Lowe, Miriam R.; Bhakta, Deepak; Groh, William J.; Medicine, School of Medicine
    Background: Cardiac myopathy manifesting as arrhythmias is common in the neurological disease, myotonic dystrophy type 1 (DM1). The purpose of the present study was to evaluate heart rate variability (HRV) in patients with DM1. Methods: In a multicenter study, history, ECG, and genetic testing were performed in DM1 patients. Results: In 289 patients in whom the diagnosis of DM1 was confirmed by a prolonged cytosine-thymine-guanine (CTG) repeat length the most common ambulatory ECG abnormality was frequent ventricular ectopy (16.3%). The 24-hour time domain parameters of SDNN (SD of the NN interval) and SDANN (SD of the mean NN, 5-minute interval) declined as age and CTG repeat length increased (SDNN: −8.5 ms per decade, 95% confidence intervals [CI]−12.9, −4.2, −8.7 ms per 500 CTG repeats, CI −15.7, −1.8, r = 0.24, P < 0.001; SDANN: −8.1 ms per decade, CI −12.4, −3.8, −8.8 ms per 500 CTG repeats, CI −15.7, −1.9, r = 0.23, P < 0.001). Short-term frequency domain parameters declined with age only (total power: −658 ms2 per decade, CI: −984, −331, r = 0.23, P < 0.001; low frequency (LF) power −287 ms2 per decade, CI: −397, −178, r = 0.30, P < 0.001; high frequency (HF) power: −267 ms2 per decade, CI: −386, −144, r = 0.25, P < 0.001). The LF/HF ratio increased as the patient aged (0.5 per decade, CI: 0.1, 0.9, r = 0.13, P = 0.03). Conclusions: In DM1 patients a decline in HRV is observed as the patient ages and CTG repeat length increases.