Morbidities in rapid eye movement sleep behavior disorder

Electroencephalography of rapid eye movement sleep behavior disorder in a dog with generalized tetanus

CASE SUMMARY

A 3-month-old Airedale dog with clinically diagnosed generalized tetanus was investigated for the occurrence of excessive paddling and chewing movements when sleeping. Electroencephalogram (EEG) with time-locked video over 31 hours determined occurrence of the abnormal movements to be within 20 to 180 seconds of the onset of rapid eye movement (REM) sleep, but not at any other stage of wakefulness or sleep. No epileptiform activity was noted. Clinical signs of generalized tetanus resolved over 8 weeks with antimicrobial and symptomatic treatment, and sleep-associated movements resolved 6 weeks after presentation.

CLINICAL RELEVANCE

Rapid eye movement sleep behavior disorder (RBD) has been suspected in dogs with generalized tetanus but not confirmed by correlation of repeated episodes of vocalization or motor behaviors or both with REM sleep defined by an EEG. The case further defines RBD in dogs with tetanus, and highlights the value of EEG to differentiate among different parasomnias and epileptiform activity.

Activation of Dopamine Signals in the Olfactory Tubercle Facilitates Emergence from Isoflurane Anesthesia in Mice

Activation of dopamine (DA) neurons is essential for the transition from sleep to wakefulness and maintenance of awakening, and sufficient to accelerate the emergence from general anesthesia in animals. Dopamine receptors (DR) are involve in arousal mediation. In the present study, we showed that the olfactory tubercle (OT) was active during emergence from isoflurane anesthesia, local injection of dopamine D1 receptor (D1R) agonist chloro-APB (1 mg/mL) and D2 receptor (D2R) agonist quinpirole (1 mg/mL) into OT enhanced behavioural and cortical arousal from isoflurane anesthesia, while D1R antagonist SCH-23390 (1 mg/mL) and D2R antagonist raclopride (2.5 mg/mL) prolonged recovery time. Optogenetic activation of DAergic terminals in OT also promoted behavioural and cortical arousal from isoflurane anesthesia. However, neither D1R/D2R agonists nor D1R/D2R antagonists microinjection had influences on the induction of isoflurane anesthesia. Optogenetic stimulation on DAergic terminals in OT also had no impact on the anesthesia induction. Our results indicated that DA signals in OT accelerated emergence from isoflurane anesthesia. Furthermore, the induction of general anesthesia, different from the emergence process, was not mediated by the OT DAergic pathways.

Activation of adenosine A2A receptors in the olfactory tubercle promotes sleep in rodents

The olfactory tubercle (OT), an important nucleus in processing sensory information, has been reported to change cortical activity under odor. However, little is known about the physiological role and mechanism of the OT in sleep-wake regulation. The OT expresses abundant adenosine A_2A receptors (A_2ARs), which are important in sleep regulation. Therefore, we hypothesized that the OT regulates sleep via A_2ARs. This study examined sleep-wake profiles through electroencephalography and electromyography recordings with pharmacological and chemogenetic manipulations in freely moving rodents. Compared with their controls, activation of OT A_2ARs pharmacologically and OT A_2AR neurons via chemogenetics increased non-rapid eye movement sleep for 5 and 3 h, respectively, while blockade of A_2ARs decreased non-rapid eye movement sleep. Tracing and electrophysiological studies showed OT A_2AR neurons projected to the ventral pallidum and lateral hypothalamus, forming inhibitory innervations. Together, these findings indicate that A_2ARs in the OT play an important role in sleep regulation.

Narcolepsy

Narcolepsy is a chronic sleep disorder that has a typical onset in adolescence and is characterized by excessive daytime sleepiness, which can have severe consequences for the patient. Problems faced by patients with narcolepsy include social stigma associated with this disease, difficulties in obtaining an education and keeping a job, a reduced quality of life and socioeconomic consequences. Two subtypes of narcolepsy have been described (narcolepsy type 1 and narcolepsy type 2), both of which have similar clinical profiles, except for the presence of cataplexy, which occurs only in patients with narcolepsy type 1. The pathogenesis of narcolepsy type 1 is hypothesized to be the autoimmune destruction of the hypocretin-producing neurons in the hypothalamus; this hypothesis is supported by immune-related genetic and environmental factors associated with the disease. However, direct evidence in support of the autoimmune hypothesis is currently unavailable. Diagnosis of narcolepsy encompasses clinical, electrophysiological and biological evaluations, but simpler and faster procedures are needed. Several medications are available for the symptomatic treatment of narcolepsy, all of which have quite good efficacy and safety profiles. However, to date, no treatment hinders or slows disease development. Improved diagnostic tools and increased understanding of the pathogenesis of narcolepsy type 1 are needed and might lead to therapeutic or even preventative interventions.

Premotor Symptoms as Predictors of Outcome in Parkinsons Disease: A Case-Control Study

Background

To evaluate the association between the premotor symptoms and the prognosis of PD.

Methods

A total of 1213 patients who were diagnosed of PD from January 2001 to December 2008 were selected from the Taiwan’s National Health Insurance Research Database. Patients were traced back to determine the presence of premotor symptoms, including rapid eye movement sleep behavior disorder (RBD), depression, and constipation. Cox’s regression analysis was used to detect the risks between the occurrence of premotor symptoms and the outcome (including death, psychosis, accidental injury, dementia and aspiration pneumonia). In addition, the association between premotor symptoms and levodopa equivalent dosage (LED) was examined.

Results

Higher occurrence of death, dementia and aspiration pneumonia were identified in PD patients with premotor symptoms than without premotor symptoms (HR 1·69, 95% CI 1·34–2·14, p <0·001 for death; HR 1·63, 95% CI 1·20–2·22, p = 0·002 for dementia; HR 2·45, 95% CI 1·42–4·21, p = 0·001 for aspiration pneumonia). In a comorbidities-stratified analysis, PD patients with premotor symptoms showed significantly high risks of mortality and morbidity (dementia and aspiration pneumonia), especially in the absence of comorbidities. Independent predictors of mortality in PD were found to be higher age, male sex, constipation, RBD, RBD with constipation and depression, and diabetes. Furthermore, no significant differences of LED and subsequent accidental injury were noted between PD patient with or without premotor symptoms.

Conclusion

Premotor symptoms seem to be not merely risk factors, but also prognostic factors of PD.

Clinical presentation and differential diagnosis of dementia with Lewy bodies: a review

BACKGROUND

Dementia with Lewy bodies is one of the most prevalent dementia diagnoses. However, differential diagnosis between dementia with Lewy bodies, Alzheimer's disease, and Parkinson's disease with dementia can still be very difficult given the overlap in neuropathology, clinical presentation, cognitive, and neuroanatomical changes.

METHOD

A literature review of dementia with Lewy bodies, Alzheimer's disease, and Parkinson's disease with dementia was conducted using PubMed.

RESULTS AND IMPLICATIONS

Accurate diagnosis of dementia with Lewy bodies is crucial in order to more accurately predict the progression of the disease and negative side effects from pharmacological treatment. The differences and similarities between dementia with Lewy bodies, Alzheimer's disease, and Parkinson's disease with dementia are highlighted in order to aid clinicians in differential diagnosis.

Autonomic symptoms in idiopathic REM behavior disorder: a multicentre case-control study

Patients with idiopathic REM sleep behavior disorder (iRBD) are at very high risk of developing neurodegenerative synucleinopathies, which are disorders with prominent autonomic dysfunction. Several studies have documented autonomic dysfunction in iRBD, but large-scale assessment of autonomic symptoms has never been systematically performed. Patients with polysomnography-confirmed iRBD (318 cases) and controls (137 healthy volunteers and 181 sleep center controls with sleep diagnoses other than RBD) were recruited from 13 neurological centers in 10 countries from 2008 to 2011. A validated scale to study the disorders of the autonomic nervous system in Parkinson's disease (PD) patients, the SCOPA-AUT, was administered to all the patients and controls. The SCOPA-AUT consists of 25 items assessing the following domains: gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, and sexual dysfunction. Our results show that compared to control subjects with a similar overall age and sex distribution, patients with iRBD experience significantly more problems with gastrointestinal, urinary, and cardiovascular functioning. The most prominent differences in severity of autonomic symptoms between our iRBD patients and controls emerged in the gastrointestinal domain. Interestingly, it has been reported that an altered gastrointestinal motility can predate the motor phase of PD. The cardiovascular domain SCOPA-AUT score in our study in iRBD patients was intermediate with respect to the scores reported in PD patients by other authors. Our findings underline the importance of collecting data on autonomic symptoms in iRBD. These data may be used in prospective studies for evaluating the risk of developing neurodegenerative disorders.