Much is Known about Caregiver Burden in Dementia - What is Next? The Role of Comorb idities and Future Perspectives

Introduction and background: Care for family members suffering from neurological disorders is often demanding and increases with disease progression. Numerous patientand caregiver-related factors underlying caregiver burden have been identified. Some potential factors need to be clarified. Little is known about the effects of comorbidities and dementia complications on the burden of care for persons living with dementia. Objectives: We hypothesized that burdens of care for family members living with dementia increase with the number and severity of comorbidities and dementia complications. Methods: Multi-center prospective registry study (PRODEM) on caregiver burden in family caregivers (median age 61, 66% female) of 556 persons living with mild to moderate dementia, mainly Alzheimer’s disease (median age 77, 58% female). Results: Caregiver burden (Zarit Burden Interview) did not correlate with arterial hypertension, diabetes, hypercholesterolemia, cardioembolic/thromboembolic diagnoses, heart failure, severe arrhythmia or heart valve disease, but was worse in care recipients with symptoms of anxiety, psychotic episodes, depression and emotional, psychotic, behavioral and somatic symptom clusters (Neuropsychiatric Inventory, Geriatric Depression Scale-15 items). Moreover, caregiver burden correlated with the number of drugs taken daily. MRI evidence of cerebrovascular pathology (total volume of white matter hyperintensities on axial T2w-FLAIR sequences related to intracranial volume, measured in 301 patients) did not correlate with caregiver burden. Gerhard R, Defrancesco M, Damulina A, Hermann P, Benke T, Dal-Bianco P, et al. Much is Known about Caregiver Burden in Dementia What is Next? The Role of Comorbidities and Future Perspectives. J Exp Neurol. 2021;2(3):101-111. J Exp Neurol. 2021 Volume 2, Issue 3 102 Introduction and Background Care for patients with chronic debilitating neurological diseases is often demanding and can result in a variety of negative consequences including mental and physical morbidity. Numerous studies have been published on the burden of care for persons caring for spouses, parents, siblings or children with chronic neurological disorders, particularly for those who live with the care recipient and are directly responsible for care. Most studies address the care for dementia and stroke patients, persons with epilepsy, Parkinson’s disease and atypical parkinsonism, multiple sclerosis, motor neuron disease, Huntington’s disease, brain tumours, chronic pain syndromes, traumatic central nervous system injury, ataxias, and muscular dystrophy [1]. Little is known about caregiver burden in advanced stages of myasthenia gravis, adultonset myopathies, amyloidosis or other debilitating polyneuropathies or other rare neurological diseases. Most studies were performed in highor middle-income countries. The literature from low-income countries on family care for persons with chronic neurological diseases including dementia is sparse [2-4]. Little is known about burdens for formal caregivers caring for persons in the clients’ homes, in nursing homes or in palliative care [5-8]. Considerable differences have been found between countries concerning burdens and health-related quality of life of informal caregivers of family members living with dementia. The differences were explained by variable support, traditions and social norms, and occupational duties and other competing responsibilities [2-4]. A pattern was found with caregivers in eastern and southern European countries expressing more severe caregiver burdens than caregivers in central and western European countries. Differences in caregiver burden have been found between neurological diseases [1,9,10]. The risk of severe caregiver burden is high in persons caring for individuals with dementia [8-10]. Caregiver burden depends on objective, patient-related parameters, such as age, disease duration, disease severity, physical and mental morbidity including behavioural and neuropsychiatric impairments, daily hours and total duration of care, impairment of activities of daily living, dependency, and proximity between care recipients and caregiver. On the other hand, caregiver-related objective parameters contribute to caregiver burden, such as age, health state, incompatibility of care and occupational and family responsibilities and lack of personal, psychological and financial support. Moreover, subjective factors influence caregiver burden, such as emotional relationship between the caregiver and the care recipient, personality traits, missing agreement between involved persons, strict social norms, high expectations of the care recipient and other family members, negative social reactions, lack of choice in taking on the caregiving role, feeling of insecurity, loneliness, lack of self-esteem, self-efficacy and resilience, and poor coping strategies [2,4,7,8,11,22-28]. The Zarit Burden Interview (ZBI) is the most frequently applied inventory to estimate subjective caregiver burden [2,4,11]. Subjective caregiver burden has also been assessed in the literature using the Caregiver Strain Index (CSI) [12], the Burden Scale for Family Caregivers [13], the Multidimensional Index and the Modified Caregiver Strain Index [14,15], and other individually designed scales. The Caregiver Burden Scale [16] assesses both subjective and objective caregiver burden. In individual studies caregiver burden and caregiver strain are distinguished [14]. Different quality of life and health scales have been applied, such as the SF-36, EuroQL, Health Utility Index-3 [17-20]. Assessment tools for clinical characterisation of care recipients living with dementia depend on the type of dementia, disease severity and stage (early, advanced, late stage of dementia) and palliative care [1,2,4,6, 7,9,10,2026]. Acknowledged, objective patient-related factors underlying caregiver burden reported in the literature are summarized in Table 1. Table 2 shows objective caregiverrelated factors of caregiver burden [2,3,10,19,22-28]. However, the effect of a variety of parameters on caregiver burden is uncertain or considered controversial. The influence of caregiver age on caregiver burden is complex. In several studies an inverse relationship was found between caregiver age and caregiver burden. Caregiving children reported more severe caregiver burden than caregiving spouses [2,10,24] because of difficulties integrating caregiving into busy daily routine that include work, family life, social activities, leisure, and sports. Spousal caregivers living with a sick family member, Discussion and conclusions: Neuropsychiatric complications and the number of drugs taken daily, but not internal medicine diseases and cerebral white matter hyperintensities increased the burden of care for caregivers of family members suffering from dementia, which is in partial agreement with the literature. However, severe internal medicine comorbidities were rare in the study. Standardized and harmonized longitudinal assessment of the scope of care and caregiver burden is required including algorhythms for ageand life situation-adjusted assessment of caregiver burden. Further studies on caregiver burden and stronger male involvement in family care are needed.