Rivastigmine transdermal patches in the treatment of dementia in Alzheimer's disease in adults with Down syndrome-pilot study

Pharmacotherapy of Down syndrome

Introduction: Comorbid psychiatric disorders are common in Down syndrome (DS). Evidence for pharmacotherapy of psychiatric co-morbidity in DS is limited. Areas covered: This article reviews the literature on the pharmacotherapy of psychiatric conditions co-occurring with DS, including major depressive disorder (MDD), bipolar disorder, anxiety disorders, obsessive-compulsive disorder (OCD), attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), psychosis, and catatonia. A section on the phenomenon of regression is included. Expert opinion: For MDD, we typically begin with selective serotonin reuptake inhibitors (SSRIs). For bipolar disorder, we often use carbamazepine. For psychotic symptoms, we begin with risperidone or aripiprazole. We use buspirone to treat anxiety. For obsessional slowness/OCD, we begin with an SSRI. For stereotypical repetitive behavior, we tend to use buspirone. For ADHD, we begin with guanfacine. For irritability of comorbid ASD, we use risperidone or aripiprazole. For dementia in DS, we refer to a neurologist for medical work-up and medication management. We treat catatonia-like 'regression' with lorazepam. If ineffective, we use memantine or clozapine. Electroconvulsive therapy is considered if pharmacotherapy is ineffective. We treat 'regression' with symptoms of MDD ± psychosis, with an antidepressant and an antipsychotic if needed. Randomized controlled trials of medications for comorbid psychiatric disorders in DS are warranted.

Impact of cholinesterase inhibitors or memantine on survival in adults with Down syndrome and dementia: clinical cohort study

BACKGROUND

There is little evidence to guide pharmacological treatment in adults with Down syndrome and Alzheimer's disease. Aims To investigate the effect of cholinesterase inhibitors or memantine on survival and function in adults with Down syndrome and Alzheimer's disease.

METHOD

This was a naturalistic longitudinal follow-up of a clinical cohort of 310 people with Down syndrome diagnosed with Alzheimer's disease collected from specialist community services in England.

RESULTS

Median survival time (5.59 years, 95% CI 4.67-6.67) for those on medication (n = 145, mainly cholinesterase inhibitors) was significantly greater than for those not prescribed medication (n = 165) (3.45 years, 95% CI 2.91-4.13, log-rank test P<0.001). Sequential assessments demonstrated an early effect in maintaining cognitive function.

CONCLUSIONS

Cholinesterase inhibitors appear to offer benefit for people with Down syndrome and Alzheimer's disease that is comparable with sporadic Alzheimer's disease; a trial to test the effect of earlier treatment (prodromal Alzheimer's disease) in Down syndrome may be indicated. Declaration of interest A.S. has undertaken consulting for Ono Pharmaceuticals, outside the submitted work. Z.W. has received a consultancy fee and grant from GE Healthcare, outside the submitted work.

Challenges faced in managing dementia in Alzheimer's disease in patients with Down syndrome

Dementia in Alzheimer’s disease (DAD) is more common in adults with Down syndrome (DS), with characteristically an earlier onset. The treatment of DAD is not too dissimilar in the general population and in people with intellectual disabilities. However, the underlying intellectual disability can make the management of DAD more challenging in older adults with DS. This literature review aimed to look at the management of DAD in people with DS. The management of dementia is holistic. This includes treating reversible factors, aiming to slow the cognitive decline, psychological therapies, ensuring that the environment is appropriate, and use of psychotropic medication when necessary to manage behavioral problems, psychotic symptoms, depressive symptoms, and sleep difficulty. Antidementia medications have a role to play but remain limited. The management of DAD in the DS population can be at times challenging, but good clinical practice should involve accurate diagnosis of dementia, treating any reversible additional factors, consideration of psychological and behavioral management, use of antidementia medication, and a multidisciplinary team approach.

Dementia in Down's syndrome

Down's syndrome is the most common genetic cause of learning difficulties, and individuals with this condition represent the largest group of people with dementia under the age of 50 years. Genetic drivers result in a high frequency of Alzheimer's pathology in these individuals, evident from neuroimaging, biomarker, and neuropathological findings, and a high incidence of cognitive decline and dementia. However, cognitive assessment is challenging, and diagnostic methods have not been fully validated for use in these patients; hence, early diagnosis remains difficult. Evidence regarding the benefits of cholinesterase inhibitors and other therapeutic options to treat or delay progressive cognitive decline or dementia is very scarce. Despite close similarities with late-onset Alzheimer's disease, individuals with Down's syndrome respond differently to treatment, and a targeted approach to drug development is thus necessary. Genetic and preclinical studies offer opportunities for treatment development, and potential therapies have been identified using these approaches.

Pharmacological management of behavioral and psychiatric symptoms in older adults with intellectual disability

Given medical and social advances, the life expectancy of individuals with intellectual disability (ID) has increased dramatically, leading to a generation of older individuals with such disabilities. This review focuses on the pharmacological treatment of behavioral and psychiatric symptoms and disorders in older adults with ID. Older adults with ID often present with medical co-morbidities and mental health issues. Medication management of behavioral and psychiatric problems is complicated by a higher risk for adverse events, lack of decision-making capacity, and complex care networks. Some studies have shown that individuals with ID and co-morbid mental disorders are undertreated in comparison with those with similar disorders in the general population, resulting in poorer outcomes. However, older adults with ID are also at risk of polypharmacy, and older age is a risk factor for development of side effects. A general principle is that medication treatment for psychiatric disorders in older individuals with ID should be started at low dosages and increased cautiously while monitoring response and side effects. The use of psychotropic drugs for older individuals with ID and behavioral problems remains controversial, particularly in those with dementia.

Care considerations for dementia in people with Down's syndrome: a management perspective

Dementia is common in people with Down's syndrome as they age. Having dementia raises huge care considerations for carers and staff. Excellence in care requires attention to a wide variety of interrelated issues. Carers and staff need to have a good understanding of what it means to have dementia to deliver person-centered care. In addition, they need to be clear at all stages of the disease about the outcomes they want to achieve for the person. This will necessitate taking into account both health and social care issues, as well as looking at the physical environment. Staffing and staff training are crucial in providing the right support at the right time. Finally, a vignette of excellence in care is presented.

Neurotransmitter-based strategies for the treatment of cognitive dysfunction in Down syndrome

Down syndrome (DS) is a multisystem disorder affecting the cardiovascular, respiratory, gastrointestinal, neurological, hematopoietic, and musculoskeletal systems and is characterized by significant cognitive disability and a possible common pathogenic mechanism with Alzheimer's disease. During the last decade, numerous studies have supported the notion that the triplication of specific genes on human chromosome 21 plays a significant role in cognitive dysfunction in DS. Here we reviewed studies in trisomic mouse models and humans, including children and adults with DS. In order to identify groups of genes that contribute to cognitive disability in DS, multiple mouse models of DS with segmental trisomy have been generated. Over-expression of these particular genes in DS can lead to dysfunction of several neurotransmitter systems. Therapeutic strategies for DS have either focused on normalizing the expression of triplicated genes with important roles in DS or restoring the function of these systems. Indeed, our extensive review of studies on the pathogenesis of DS suggests that one plausible strategy for the treatment of cognitive dysfunction is to target the cholinergic, serotonergic, GABA-ergic, glutamatergic, and norepinephrinergic system. However, a fundamental strategy for treatment of cognitive dysfunction in DS would include reducing to normal levels the expression of specific triplicated genes in affected systems before the onset of neurodegeneration.

Prenatal treatment of Down syndrome: a reality?

PURPOSE OF REVIEW

Down syndrome affects more than 5 million people globally. During the last 10 years, there has been a dramatic increase in the research efforts focused on therapeutic interventions to improve learning and memory in Down syndrome.

RECENT FINDINGS

This review summarizes the different functional abnormalities targeted by researchers in mouse models of Down syndrome. Three main strategies have been used: neural stem cell implantation; environmental enrichment and physical exercise; and pharmacotherapy. Pharmacological targets include the choline pathway, GABA and NMDA receptors, DYRK1A protein, oxidative stress and pathways involved in development and neurogenesis. Many strategies have improved learning and memory as well as electrophysiological and molecular alterations in affected animals. To date, eight molecules have been tested in human adult clinical trials. No studies have yet been performed on infants. However, compelling studies reveal that permanent brain alterations originate during fetal life in Down syndrome. Early prenatal diagnosis offers a 28 weeks window to positively impact brain development and improve postnatal cognitive outcome in affected individuals. Only a few approaches (Epigallocatechine gallate, NAP/SAL, fluoxetine, and apigenin) have been used to treat mice in utero; these showed therapeutic effects that persisted to adulthood.

SUMMARY

In this article, we discuss the challenges, recent progress, and lessons learned that pave the way for new therapeutic approaches in Down syndrome.

Dementia in intellectual disability

PURPOSE OF REVIEW

Dementia is emerging as a significant condition in the population with intellectual disability. This review is aimed at clinicians working in the field. We revisit what is known on the subject and expand on this with results from recent research. The emphasis of this review is on the clinical research rather than laboratory or molecular research.

RECENT FINDINGS

Research has encompassed all aspects of dementia in intellectual disability, from epidemiology, assessment and diagnosis, through to management. There remains a lack of evidence concerning both pharmacological and nonpharmacological treatment of dementia in people with intellectual disability. Recent research has tended to focus on dementia in Down syndrome.

SUMMARY

More research is necessary in order to translate improvements in the understanding of the neuropathology of intellectual disability and dementia into effective treatments. There is also a need to investigate the optimum environment in which to provide holistic care for individuals affected.

The National Task Group on Intellectual Disabilities and Dementia Practices consensus recommendations for the evaluation and management of dementia in adults with intellectual disabilities

Adults with intellectual and developmental disabilities (I/DD) are increasingly presenting to their health care professionals with concerns related to growing older. One particularly challenging clinical question is related to the evaluation of suspected cognitive decline or dementia in older adults with I/DD, a question that most physicians feel ill-prepared to answer. The National Task Group on Intellectual Disabilities and Dementia Practices was convened to help formally address this topic, which remains largely underrepresented in the medical literature. The task group, comprising specialists who work extensively with adults with I/DD, has promulgated the following Consensus Recommendations for the Evaluation and Management of Dementia in Adults With Intellectual Disabilities as a framework for the practicing physician who seeks to approach this clinical question practically, thoughtfully, and comprehensively.