Sleep Disorders and Circadian Disruption in Huntington's Disease

Melatonin for Huntington's Disease (HD) gene carriers with HD-related sleep disturbance - A pilot study

BACKGROUND

Sleep disorders are common in people with Huntington's Disease (HD). Possible causes include disruptions to the body's internal clock and changes in melatonin levels. Although melatonin is known to treat sleep disruptions related to circadian rhythm disorders, its effects on HD patients have not been thoroughly explored.

OBJECTIVE

to assess the effectiveness of melatonin in improving the sleep quality of individuals with HD.

METHODS

double-blind, randomized, placebo-controlled, crossover trial with individuals with HD experiencing sleep disturbances, defined as Pittsburgh Sleep Quality Index (PSQI) > 5. Participants received 4-week treatments with 5 mg immediate-release melatonin/placebo, separated by a one-week wash-out (NCT04421339). Clinical assessments were conducted at baseline, week 5 (crossover visit), and week 9 (final visit) and included the PSQI, HD Sleep Questionnaire (HD-SQ), Epworth Sleepiness Scale (ESS), Montreal Cognitive Assessment (MoCA), Neuro-QoL™ v2.0 Cognitive Function, Neuropsychiatric Inventory Questionnaire (NPI-Q), Hospital Anxiety and Depression Scale (HADS), Unified Huntington Disease Rating Scale (UHDRS), and Clinical Global Impression (CGI).

RESULTS

Fifteen patients (46.53 ± 13.92 years old, seven females) completed the study procedures. We found no significant differences between melatonin and placebo treatments in the primary outcome (PSQI), other sleep measures (ESS and HD-SQ), neuropsychiatric symptoms (NPI-Q, HADS, Neuro-QoL, MoCA), and motor/functional measures.

CONCLUSIONS

We found that melatonin did not significantly differ from placebo in improving sleep quality in individuals with HD. Given the conflicting findings from previous research, it may be beneficial to explore alternative dosages of melatonin, increase the sample size, and consider different stages of HD in future studies.

The role of mitochondrial dysfunction in Huntington's disease: Implications for therapeutic targeting

Huntington's disease (HD) is a progressive, autosomal dominant neurodegenerative disorder characterized by cognitive decline, motor dysfunction, and psychiatric disturbances. A common feature of neurodegenerative disorders is mitochondrial dysfunction, which affects the brain's sensitivity to oxidative damage and its high oxygen demand. This dysfunction may plays a significant role in the pathogenesis of Huntington's disease. HD is caused by a CAG repeat expansion in the huntingtin gene, which leads to the production of a toxic mutant huntingtin (mHTT) protein. This disruption in mitochondrial function compromises energy metabolism and increases oxidative stress, resulting in mitochondrial DNA abnormalities, impaired calcium homeostasis, and altered mitochondrial dynamics. These effects ultimately may contribute to neuronal dysfunction and cell death, underscoring the importance of targeting mitochondrial function in developing therapeutic strategies for HD. This review discusses the mechanistic role of mitochondrial dysfunction in Huntington's disease. Mitochondrial dysfunction is a crucial factor in HD, making mitochondrial-targeted therapies a promising approach for treatment. We explore therapies that address bioenergy deficits, antioxidants that reduce reactive oxygen species, calcium modulators that restore calcium homeostasis, and treatments that enhance mitochondrial dynamics to rejuvenate mitochondrial function. We also highlight innovative treatment approaches such as gene editing and stem cell therapy, which offer hope for more personalized strategies. In conclusion, understanding mitochondrial dysfunction in Huntington's disease may guide potential treatment strategies. Targeting this dysfunction may help to slow disease progression and enhance the quality of life for individuals affected by Huntington's disease.

Sleep-wake cycle and 24-h motor activity in early-mid Huntington's disease patients: An actigraphy-based study

Background: Disrupted 24-h sleep-wake and rest-activity cycles are known common features in Huntington's disease (HD) patients; however, critical periods during the 24-h cycle have been less studied. Objective: To analyze the differences between early-mid stage HD patients and healthy controls (HC) in sleep patterns and 24-h motor activity by using actigraphic monitoring. Methods: Twenty HD patients (13 females; mean age ± SD 56.45 ± 16.94) at early-mid stage of the disease and 20 HC were actigraphically monitored for a week. We applied the Functional Linear Modeling (FLM) to analyze motor activity from the actigraphic data. We analyzed parameters regarding both the time spent in bed and out of bed; get-up time (GUT); time in bed (TIB); midpoint of sleep (MS); sleep motor activity (SMA); sleep onset latency (SOL); total sleep time (TST); wake after sleep onset (WASO); sleep efficiency (SE); number and duration of awakenings (AWK); diurnal motor activity (DMA) and diurnal total sleep time (DTST). Results: Ten patients were in Stage I, 6 in Stage II and 4 in Stage III. HD patients presented lower SE and higher TIB, SOL, WASO, AWK and AWK > 5 min in comparison to HC. Moreover, higher motor activity was observed in patients with HD, in particular between 2:15 and 4:00 am, from around 40 min prior to bedtime until 20 min after bedtime, and from around 20 min prior to get-up time until 50 min after get-up time. Conclusions: Actigraphy documented a specific 24-h motor pattern in HD, potentially constituting a disease signature.

The Abnormal N-Acetylaspartate to Creatine Ratio of the Right Putamen is Linked to Wakefulness in Patients with Insomnia Disorder

Purpose

Converging evidence implicates the putamen in sleep-wake regulation. However, its role remains unclear. We hypothesized that metabolic abnormalities in the putamen are linked to insomnia disorder, which has not been previously addressed, and investigated putaminal N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) in patients with insomnia disorder compared to healthy controls.

Participants and Methods

In the present study, the concentrations of NAA, Cho, and Cr in the putamen of 23 patients with insomnia disorder and 18 healthy controls were determined using proton magnetic resonance spectroscopy. Sociodemographic, psychometric, and polysomnography data were obtained from all participants.

Results

We found that the mean NAA/Cr ratio of the right putamen was significantly greater in the insomnia group compared to the control group and also greater than the left putamen within the insomnia group. The NAA/Cr ratio of the right putamen distinguished insomnia disorder from normal sleep with 78.3% sensitivity and 61.1% specificity. Furthermore, this ratio positively correlated with both objective and subjective insomnia severity and sleep quality.

Conclusion

Our findings provide critical evidence for the dysfunctional putaminal metabolism of NAA/Cr in insomnia disorder, suggesting that the abnormal NAA/Cr ratio of the right putamen is linked to wakefulness in patients with insomnia disorder and may serve as a potential biomarker of insomnia disorder.

Sleep and circadian rhythm dysfunctions in movement disorders beyond Parkinson's disease and atypical parkinsonisms

PURPOSE OF REVIEW

This review aimed to comprehensively outline sleep and circadian rhythm abnormalities in hyperkinetic movement disorders beyond Parkinson's disease and atypical parkinsonisms, including tremor, dystonia, choreiform movements, tics, and ataxia disorders.

RECENT FINDINGS

Insomnia, poor sleep quality, and excessive daytime sleepiness (EDS) are commonly reported in essential tremor, Wilson's disease, tics or Tourette's syndrome, and spinocerebellar ataxia (SCA). REM sleep behavior disorder (RBD) have been observed in Wilson's disease and SCA. A combination of REM and non-REM parasomnias, along with nocturnal stridor with the initiation of sleep and re-entering after awakening, are characterized by undifferentiated Non-REM and poorly structured N2 in anti-IgLON5 disease. Restless legs syndrome (RLS) has been reported commonly in SCAs. Sleep-related dyskinesia has been reported in ADCY5-related disease and GNAO1-related movement disorder.

SUMMARY

Sleep problems can manifest as a result of movement disorders, either through direct motor disturbances or secondary nonmotor symptoms. Medication effects must be considered, as certain medications for movement disorders can exacerbate or alleviate sleep disturbances. Distinguishing sleep problems in some diseases might involve pathognomonic symptoms and signs, aiding in the diagnosis of movement disorders.

Sleep and Circadian Rhythm Dysfunction in Animal Models of Huntington's Disease

Sleep and circadian disruption affects most individuals with Huntington's disease (HD) at some stage in their lives. Sleep and circadian dysregulation are also present in many mouse and the sheep models of HD. Here I review evidence for sleep and/or circadian dysfunction in HD transgenic animal models and discuss two key questions: 1) How relevant are such findings to people with HD, and 2) Whether or not therapeutic interventions that ameliorate deficits in animal models of HD might translate to meaningful therapies for people with HD.