Effects of donepezil on sleep disturbances in patients with dementia with Lewy bodies: An open-label study with actigraphy

REM Sleep Behavior Disorder and Other REM Parasomnias

OBJECTIVE

This article reviews rapid eye movement (REM) sleep behavior disorder (RBD) and other REM sleep parasomnias, particularly recurrent isolated sleep paralysis and nightmare disorder.

LATEST DEVELOPMENTS

People with RBD have dream enactment behaviors that can be distressing and cause injuries to themselves or a bed partner. Diagnosis of RBD still requires video polysomnography but new evaluative techniques are emerging. Automatic scoring of REM sleep without atonia, the polysomnographic RBD feature, has led to clearer diagnostic cutoff values. Isolated RBD is strongly linked with neurodegenerative disorders, particularly α-synucleinopathies, with a median latency to neurodegenerative disease diagnosis of 8 years. Mounting imaging, electrophysiologic, and pathologic evidence supports neurodegenerative changes in patients with isolated RBD. Safety precautions should be reviewed with patients to reduce the risk of injury. Clonazepam and melatonin are first-line agents for RBD symptoms, and rivastigmine appears to be beneficial for RBD in people with mild cognitive impairment. For nightmare disorder, image rehearsal therapy is effective and can be delivered through online platforms.

ESSENTIAL POINTS

While RBD symptoms can often be managed, patients with isolated RBD should be monitored for signs and symptoms of impending neurodegenerative disease. Individuals who wish to know about the associated risk should be counseled accordingly to allow planning and involvement in research if they choose. Exercise may have some neuroprotective effects, although no treatment has been shown to modify the neurodegenerative risk.

Management of REM sleep behavior disorder: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

This systematic review provides supporting evidence for a clinical practice guideline for the management of rapid eye movement (REM) sleep behavior disorder in adults and children. The American Academy of Sleep Medicine commissioned a task force of 7 experts in sleep medicine. A systematic review was conducted to identify randomized controlled trials and observational studies that addressed interventions for the management of REM sleep behavior disorder in adults and children. Statistical analyses were performed to determine the clinical significance of critical and important outcomes. Finally, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations. The literature search identified 4,690 studies; 148 studies provided data suitable for statistical analyses; evidence for 45 interventions is presented. The task force provided a detailed summary of the evidence assessing the certainty of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Howell M, Avidan AY, Foldvary-Schaefer N, et al. Management of REM sleep behavior disorder: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2023;19(4):769-810.

Donepezil Beyond Alzheimer's Disease? A Narrative Review of Therapeutic Potentials of Donepezil in Different Diseases

Donepezil hydrochloride is an acetylcholine esterase inhibitor studied and approved to treat Alzheimer's disease (AD). However, this drug can have positive therapeutic potential in treating different conditions, including various neurodegenerative disorders such as other types of dementia, multiple sclerosis, Parkinson's disease, psychiatric and mood disorders, and even infectious diseases. Hence, this study reviewed the therapeutic potential of this drug in treating Alzheimer's and other diseases by reviewing the articles from databases including Web of Science, Scopus, PubMed, Cochrane, and Science Direct. It was shown that donepezil could affect the pathophysiology of these diseases via mechanisms such as increasing the concentration of acetylcholine, modulating local and systemic inflammatory processes, affecting acetylcholine receptors like nicotinic and muscarinic receptors, and activating various cellular signaling via receptors like sigma-1 receptors. Despite many therapeutic potentials, this drug has not yet been approved for treating non-Alzheimer's diseases, and more comprehensive studies are needed.

Sleep disturbances in Lewy body dementia: A systematic review

BACKGROUND

Lewy body dementia (LBD) refers to both dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD). Sleep disturbances are common in LBD, and can include poor sleep quality, excessive daytime sleepiness (EDS), and rapid eye movement behaviour disorder (RBD). Despite the high clinical prevalence of sleep disturbances in LBD, they are under-studied relative to other dementias. The aim of the present systematic review was to examine the nature of sleep disturbances in LBD, summarise the effect of treatment studies upon sleep, and highlight specific and necessary directions for future research.

METHODS

Published studies in English were located by searching PubMED and PSYCArticles databases (until 10 June 2022). The search protocol was pre-registered in PROSPERO (CRD42021293490) and performed in accordance with PRISMA guidelines.

RESULTS

Following full-text review, a final total of 70 articles were included. These included 20 studies focussing on subjective sleep, 14 on RBD, 8 on EDS, 7 on objective sleep, and 1 on circadian rhythms. The majority of the 18 treatment studies used pharmacological interventions (n = 12), had an open-label design (n = 8), and were of low-to-moderate quality. Most studies (n = 55) included only patients with DLB. Due to the heterogeneity of the studies, we reported a narrative synthesis without meta-analysis.

CONCLUSIONS

At least one form of sleep disturbance may be present in as many as 90% of people with LBD. Subjectively poor sleep quality, excessive daytime sleepiness, and RBD are more common and severe in LBD relative to other dementias.

Using a Non-Wearable Actigraphy in Nursing Care for Dementia With Lewy Bodies

People who have dementia with Lewy bodies often have sleep disorders. We used non-wearable devices to record and categorize the sleep patterns of patients with Lewy body dementia. Individual sleep data at a dementia-care unit in Japan were recorded using non-wearables. One week's worth of data from 18 patients was analyzed. Median metrics for all participants were the following: sleep efficiency, 68% (23-89); sleep duration at night, 6.8 hours (1.6-11.1); times getting out of bed at night, 3.5 (0-13). We identified three types of abnormal sleep: extremely short sleep duration, excessive sleep duration at night, and excessive number of times getting out of bed at night. Sleep disturbances in Lewy body dementia patients are treated using various practices; staff must choose the most effective plan for each patient's situation. Monitoring patient sleep using non-wearable provides more objective data that can help staff better personalize nursing care.

The association of changes of sleep architecture related to donepezil: A systematic review and meta-analysis

BACKGROUND

Donepezil had been recognized to have impact on sleep quality in demented patients. However, there was insufficient evidences about the actual effect of donepezil in the sleep architectures. Our meta-analysis aimed to evaluate the changes of sleep architectures related to donepezil use.

METHODS

Followed the PRISMA2020 and AMSTAR2 guidelines, electronic search had been performed on the databases of PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane CENTRAL, ProQuest, Web of Science, and ClinicalTrials.gov. The outcome measurement was changes of sleep parameters detected by polysomnography. A random-effects meta-analysis was conducted.

RESULTS

Total twelve studies had been involved. The percentage of REM sleep would significantly increase after donepezil treatment (Hedges' g = 0.694, p < 0.001). Compared to placebo/controls, subjects with donepezil would had significantly increased percentage of REM sleep stage (Hedges' g = 0.556, p = 0.018). Furthermore, donepezil was also associated with the decreased stage 2 sleep percentage, sleep efficiency, or total sleep time in different analysis conditions.

CONCLUSION

Our meta-analysis provided detailed changes of sleep architectures related to donepezil treatment. Further larger sample size studies with stricter control of potential moderators are needed to clarify these issues.

Treatment Efficacy and Acceptabilityof Pharmacotherapies for Dementia with Lewy Bodies: A Systematic Review and Network Meta-Analysis

INTRODUCTION

We investigated the efficacy and acceptability of pharmacotherapy for dementia with Lewy bodies (DLB) while simultaneously considering the neuropsychiatric symptoms (NPS), cognitive function, motor symptoms, and acceptability.

METHODS

Electronic databases were searched from inception through June 5, 2019, for randomized controlled trials (RCTs) and open-label trials (OLTs) in patients with DLB. We performed a pairwise conventional meta-analysis (PWMA) and network meta-analysis (NMA) within a frequentist framework. The main outcomes were mean change scores in NPS, general cognition, motor symptoms and acceptability. The effect sizes and odds ratios with 95% confidence intervals (CIs) were calculated. This study was registered with PROSPERO (CRD42018096996).

RESULTS

In total, we included 29 studies (9 RCTs and 20 OLTs). In the NMA with 9 RCTs, both high- (mean difference [MD] 2.00, 95% CIs, 0.69 to 3.31) and low-dose (1.86, 0.58 to 3.15) donepezil were associated with a greater cognitive improvement than placebo. High-dose zonisamide was associated with greater motor symptom improvement ( -4.10, -7.03 to -1.17]). No medications reached statistical significance regarding improving neuropsychiatric symptoms or developing intolerable adverse effects as compared to placebo. In the second NMA, with 29 studies as an exploratory analysis, aripiprazole and yokukansan may be effective for neuropsychiatric symptoms, while levodopa may be associated with cognitive impairment.

CONCLUSIONS

We report the most comprehensive evidence for the selection of pharmacotherapy for treating different clusters of DLB-related symptoms. Due to the limited availability of RCTs on DLB, more well-conducted RCTs are needed for MMA to warrant clinical efficacy in the future.

Sleep disturbance in movement disorders: insights, treatments and challenges

Sleep and circadian rhythm disturbances are central features of many movement disorders, exacerbating motor and non-motor symptoms and impairing quality of life. Understanding these disturbances to sleep is clinically important and may further our understanding of the underlying movement disorder. This review evaluates the current anatomical and neurochemical understanding of normal sleep and the recognised primary sleep disorders. In addition, we undertook a systematic review of the evidence for disruption to sleep across multiple movement disorders. Rapid eye movement sleep behaviour disorder has emerged as the most reliable prodromal biomarker for the alpha synucleinopathies, including Parkinson's disease and multiple system atrophy, often preceding motor symptom onset by several years. Abnormal sleep has also been described for many other movement disorders, but further evidence is needed to determine whether this is a primary or secondary phenotypic component of the underlying condition. Medication used in the treatment of motor symptoms also affects sleep and can aggravate or cause certain sleep disorders. Within the context of movement disorders, there is also some suggestion of a shared underlying mechanism for motor and sleep pathophysiology, with evidence implicating thalamic and brainstem structures and monoaminergic neurotransmission. This review highlights the need for an understanding of normal and abnormal sleep within the movement disorder clinic, an ability to screen for specific causes of poor sleep and to treat sleep disturbance to improve quality of life. Key sleep disorders also act as important biomarkers and have implications in diagnosis, prognosis and the development of future therapies.

The Treatment of Sleep Dysfunction in Neurodegenerative Disorders

Sleep dysfunction is highly prevalent across the spectrum of neurodegenerative conditions and is a key determinant of quality of life for both patients and their families. Mounting recent evidence also suggests that such dysfunction exacerbates cognitive and affective clinical features of neurodegeneration, as well as disease progression through acceleration of pathogenic processes. Effective assessment and treatment of sleep dysfunction in neurodegeneration is therefore of paramount importance; yet robust therapeutic guidelines are lacking, owing in part to a historical paucity of effective treatments and trials. Here, we review the common sleep abnormalities evident in neurodegenerative disease states and evaluate the latest evidence for traditional and emerging interventions, both pharmacological and nonpharmacological. Interventions considered include conservative measures, targeted treatments of specific clinical sleep pathologies, established sedating and alerting agents, melatonin, and orexin antagonists, as well as bright light therapy, behavioral measures, and slow-wave sleep augmentation techniques. We conclude by providing a suggested framework for treatment based on contemporary evidence and highlight areas that may emerge as major therapeutic advances in the near future.

[Fluctuation of cognitive functions in dementia with Lewy bodies]

Fluctuations of cognitive function (FCF) is one of the core diagnostic features of dementia with Lewy bodies (DLB). However, identification, pathophysiology, management of this unusual phenomena remain poor understood. The review presents modern ideas about phenomenology, causes, systematization, clinical significance and current methods of diagnosis and treatment of FCF in patients with DLB.

Thalamic pulvinar metabolism, sleep disturbances, and hallucinations in dementia with Lewy bodies: Positron emission tomography and actigraphy study

OBJECTIVES

Although sleep disturbances are prevalent among patients with dementia with Lewy bodies (DLB), their neural substrates remain unclear. We aimed to clarify the neural substrates of sleep disturbances in patients with DLB.

METHODS

We evaluated sleep disturbances, neuropsychiatric symptoms, and brain glucose metabolism in 22 patients with probable DLB using actigraphy, the Neuropsychiatric Inventory (NPI), and ¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography, respectively. Total sleep time (TST) and average activity count per minute (AAC) during sleep were calculated for seven consecutive days via actigraphy. We investigated associations between FDG uptake and the actigraphy parameters using Statistical Parametric Mapping version 12b. Spearman's rank correlation coefficients were used to investigate associations among TST, AAC, and clinical symptoms. The level of statistical significance was set at P < .05. P values were adjusted using the Benjamini-Hochberg method for multiple comparisons. This study was registered with ClinicalTrials.gov (NCT00776347).

RESULTS

TST exhibited a significant positive association with FDG uptake in the bilateral orbitofrontal cortex and left thalamus, while AAC exhibited a significant negative association with FDG uptake in the left thalamus and the left parieto-occipital region. FDG uptake in the left pulvinar was associated with both TST and AAC. In addition, TST exhibited a significant negative association with the NPI hallucinations score (r = -0.66, P = .001), while AAC exhibited significant positive associations with the NPI delusions (r = 0.70, P < .001) and hallucinations (r = 0.63, P = .002) scores.

CONCLUSIONS

TST and bodily activity during sleep are associated with dysfunction of the left pulvinar and the severity of hallucinations in patients with DLB.

Fluctuating cognition in the Lewy body dementias

Fluctuating cognition is a core diagnostic feature of dementia with Lewy bodies and is also a key clinical feature of Parkinson's disease dementia. These dementias share common pathological features and are referred to as Lewy body dementias. Whilst highly prevalent in Lewy body dementia, with up to 90% of patients experiencing the symptom at some point in the disease trajectory, clinical identification of fluctuating cognition is often challenging. Furthermore, its underlying pathophysiological processes remain unclear. However, neuroimaging and neurophysiological techniques have recently provided insight into potential drivers of the phenomenon. In this update, we review data pertaining to clinical features and underlying mechanisms of fluctuating cognition in Lewy body dementia. We collate evidence for different proposed aetiologies: fluctuating cognition as an attentional disorder, as a consequence of loss of cholinergic drive, as a manifestation of failure in neuronal efficiency and synchrony, and as a disorder of sleep/arousal. We also review data relating to putative mechanisms that have received less attention to date. Increased understanding of fluctuating cognition may help to illuminate pathophysiological mechanisms in cognitive processing in Lewy body dementia, guide future research, and facilitate the design of targeted therapeutic approaches.

Use of Cholinesterase Inhibitors in Non-Alzheimer's Dementias

Non-Alzheimer's dementias constitute 30% of all dementias and present with major cognitive and behavioral disturbances. Cholinesterase inhibitors improve memory by increasing brain acetylcholine levels and are approved symptomatic therapies for Alzheimer's disease (AD). They have also been investigated in other types of dementias with potential cholinergic dysfunction. There is compelling evidence for a profound cholinergic deficit in Lewy Body dementia (LBD) and Parkinson's disease dementia (PDD), even to a greater extent than AD. However, this deficit is difficult to objectivize in vascular dementia (VaD) given the increased comorbidity with AD. Furthermore, there is minimal to no evidence for cholinergic loss in frontotemporal dementia (FTD). Although cholinesterase inhibitors showed significant improvement in cognitive, behavioral, and functional measures in both LBD and PDD clinical trials, only rivastigmine is approved for PDD, due to the heterogeneity of the scales used, the duration of trials, and the limited sample sizes impacting data interpretation. Similarly, the interpretation of findings in VaD trials are limited by the lack of pre-defined inclusion criteria for 'pure VaD' and the wide heterogeneity of patients enrolled with respect to location and extent of cerebrovascular disease. In FTD patients, cholinesterase inhibitors were mostly associated with worsening of cognitive and behavioral symptoms. In non-AD dementias, cholinesterase inhibitors were well tolerated, with increased reports of mild to moderate cholinergic side effects and a non-significant trend for increased cardio and cerebrovascular events with rivastigmine in VaD, justifying their cautious use on a case-by-case basis, especially when there is evidence for cholinergic deficit.

Changes in brain morphology in patients in the preclinical stage of idiopathic normal pressure hydrocephalus

BACKGROUND

Specific ventriculomegaly features, including tight high-convexity and medial subarachnoid spaces, are found on magnetic resonance images in patients with idiopathic normal pressure hydrocephalus (iNPH). However, some healthy elderly individuals with no typical triad symptoms of iNPH also exhibit specific magnetic resonance image features of iNPH. Therefore, this study quantitatively clarified the brain morphology of suspected iNPH patients with no objective triad symptoms (iNPH-NOS).

METHODS

We recruited patients with suspected iNPH and divided them into two groups based on their iNPH grading scale scores: the iNPH-NOS group and the iNPH with apparent objective triad symptoms (iNPH-AOS) group. Data for normal controls (NC) were taken from the database used in our previous study. We compared the relative volumes of ventricle systems (VS), Sylvian fissures (SF), and sulci at high convexity and the midline (SHM), adjusted by the intracranial volume, of the iNPH-NOS, iNPH-AOS, and NC groups. Additionally, we compared the relative volumes of VS, SF, and SHM in iNPH-NOS patients between their first visit and follow-up 1 year later.

RESULTS

Fifteen iNPH-NOS patients and 45 iNPH-AOS patients were recruited, and 24 NCs were found in the database. The relative volumes of VS and SF were significantly smaller than in NCs than in the iNPH-NOS and iNPH-AOS groups, and the relative volume of SHM was significantly larger in NCs. The relative volume of SHM was significantly larger in the iNPH-NOS group than in the iNPH-AOS group, but there were no significant differences in the relative volumes of VS and SF between these groups. In the iNPH-NOS group, the relative volumes of VS and SF were significantly smaller at the first visit than 1 year later, whereas the relative volume of SHM was significantly larger. In 6 of 15 iNPH-NOS patients, objective symptoms appeared during the observation period.

CONCLUSIONS

Our results indicate that iNPH-NOS patients were in the transitional stage between normal and iNPH-AOS, both morphologically and clinically.

A manual-based intervention for carers of people with dementia and sleep disturbances: an acceptability and feasibility RCT

BACKGROUND

It has been estimated that between 25% and 40% of people living with dementia suffer from sleep disturbances, and there are currently no known effective treatments. Sleep disturbances may be the direct result of dementia or due to other comorbidities, such as pain and limited mobility. If carers' sleep is also disturbed, carers too can become tired and stressed, and this sometimes results in the breakdown of care in the home.

OBJECTIVES

To design an evidence-based manualised non-pharmacological therapy for sleep disturbances and test it for feasibility and acceptability.

DESIGN

A single-blind, randomised, parallel-group feasibility trial, with participants randomised 2 : 1 to intervention or treatment as usual (TAU).

SETTING

Five memory services in two London NHS trusts and Join Dementia Research (JDR).

PARTICIPANTS

The study recruited people with dementia and sleep disturbances (who scored ≥ 4 on at least one question on the Sleep Disorders Inventory) and their primary family carers.

INTERVENTION

All participants were given an Actiwatch (CamNtech Ltd, Cambridge, UK) to wear to record their sleep patterns for 2 weeks before randomisation. The intervention group received Dementia RElAted Manual for Sleep; STrAtegies for RelaTives (DREAMS START). This was designed as a six-session, manual-based intervention for carers of people with dementia, delivered by trained and clinically supervised psychology graduates, based on evidence about managing sleep disturbance in people with dementia. It uses the structure of a previous manual-based treatment, STrAtegies for RelaTives (START). Family carers were consulted about structure, content and design. Sessions were interactive, and each involved techniques, tasks to practise between sessions, relaxation and a recapitulation on the previous session. The sessions covered understanding sleep and dementia, making a plan (incorporating information from Actiwatch read-outs and a light box to increase light), daytime activity and routine, difficult night-time behaviours, taking care of your own (carer's) sleep and using the strategies in the future. Carers kept their own manual, light box and relaxation recordings post intervention.

RANDOMISATION AND BLINDING

A statistician created an electronic randomisation list, stratified by site, using random permuted blocks. Those assessing the outcome were blinded to allocation; participants were not blinded.

MAIN OUTCOME MEASURES

Outcomes were assessed at 3 months. (1) Feasibility, defined as the percentage of eligible people who consented to the study recruitment, with an expected value of 50% [95% confidence interval (CI) 41% to 59%]. (2) Acceptability, defined as the percentage of intervention group participants attending ≥ 4 intervention sessions, with an expected value of 75% (95% CI 59% to 87%). The predetermined criterion for progression to the main trial was acceptability of ≥ 70%.

RESULTS

Of 95 eligible patients referred, 63 (66%, 95% CI 56% to 76%) consented between 4 August 2016 and 24 March 2017: 61 from memory clinics and two from JDR. Of these, 62 participants (65%, 95% CI 55% to 75%) were randomised: 42 to the intervention arm and 20 to the TAU arm. Thirty-seven out of 42 participants (88%, 95% CI 75% to 96%) adhered to the intervention.

CONCLUSIONS

The results show that the randomised controlled trial is feasible and that the intervention is acceptable. A higher than expected proportion of eligible patients referred consented to the study and adhered to the intervention.

LIMITATIONS

Participants were not blinded and were recruited only in London.

FUTURE WORK

The results of this trial indicate that a future efficacy trial is warranted.

TRIAL REGISTRATION

Current Controlled Trials ISCTRN36983298.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 71. See the NIHR Journals Library website for further project information. Funding was also provided by Camden and Islington NHS Foundation Trust and Barnet, Enfield and Haringey Mental Health NHS Trust to pay for excess treatment costs from therapist training and supervision and intervention delivery.

The management of sleep disorders in dementia: an update

PURPOSE OF REVIEW

Sleep disorders in dementia cause distress and may lead to families being unable to care for someone with dementia at home. Recent Cochrane reviews found no interventions of proven effectiveness. There was no effect of light therapy and moderate evidence that melatonin was ineffective both given without knowledge of the patient's circadian rhythm. The current article updates this review by considering newer publications on interventions for sleep disorders or abnormalities of the sleep-wake cycle in people with dementia living in the community.

RECENT FINDINGS

We searched electronically for new primary research, reviews and meta-analyses and identified 258 articles published between 15/12/2015 and 14/06/2017 on sleep and dementia; 43 of them on nonpharmacological or pharmacological treatments. Fifteen articles reported on the management of sleep disturbances in people with dementia, living at home. Those using pharmacological treatments (melatonin, psychotropic medications, donepezil, memantine) encompassed a meta-analysis, two double-blind RCTs, two uncontrolled trials, two population-based studies, and one case report. The studies of behavioural interventions comprised five uncontrolled trials, one case series, and one qualitative study. We also included three recent reviews on the management of sleep disturbances in Alzheimer's disease; pharmacotherapies for sleep disturbances in dementia, and dementia prevention, intervention and care. None of these found a treatment that showed definitive effectiveness, although there is preliminary work about nonpharmacological interventions, which can be built on.

SUMMARY

Clinically effective, safe treatment of sleep disturbances in dementia remains an unresolved challenge. Given the importance of sleep and the many consequences of its disruption, well designed controlled trials are needed to determine acceptable and cost-effective treatment strategies that work for sleep disturbances.

Diagnosis and Management of Cognitive and Behavioral Changes in Dementia With Lewy Bodies

OPINION STATEMENT

Proper diagnosis of dementia with Lewy bodies (DLB) in clinical practice remains suboptimal as many cases are misdiagnosed, usually as Alzheimer disease (AD) or Parkinson's disease (PD) and, in rare cases, psychosis. Therefore, it is important for patients with dementia to be thoroughly evaluated by a specialist who is familiar with current diagnostic tests and treatment options. New diagnostic criteria from the Dementia with Lewy Bodies Consortium have been developed to increase diagnostic sensitivity for DLB (Diagnosis and management of dementia with Lewy bodies: fourth consensus report of the DLB Consortium; McKeith et al.; Neurology, 89(1): 88-100). REM sleep behavior disorder (RBD) has been studied more thoroughly in correlation with DLB and is now considered a core feature. D2 receptor blocking antipsychotics, which can cause severe antipsychotic sensitivity, are now rarely prescribed for treatment. Therefore, severe antipsychotic sensitivity, which was a suggestive criterion for DLB diagnosis, is now listed as a supportive feature. Reduced DAT uptake in basal ganglia demonstrated by SPECT or PET imaging has high specificity (90%) for distinguishing DLB from AD. Reduced uptake on metaiodobenzylguanidine myocardial scintigraphy correlates with reduced postganglionic sympathetic cardiac innervation in Lewy body diseases, which can increase specificity for discriminating probable DLB from probable AD in milder cases of dementia. However, the latter is more commonly used in Japan and is not used in the USA. The evidence supporting the benefit of other therapeutic modalities is limited in DLB due to lack of extensive studies. There are no FDA-approved medications for the treatment of DLB, although some effective drugs have been used off label to treat various symptoms.