Neural correlates of changes in sexual function in frontotemporal dementia: implications for reward and physiological functioning

Prevalence of and Factors Associated with Hypersexuality in Patients with Dementia: A Retrospective Cross-Sectional Study

INTRODUCTION

The psychological and behavioral symptoms of dementia are frequently observed in clinical practice, and those related to sexuality are particularly challenging. However, few studies have evaluated the prevalence or factors associated with hypersexuality in patients with dementia.

OBJECTIVES

This study aims to determine the prevalence of hypersexuality in patients with dementia, describe associated factors, and qualitatively report the most common presentations and treatments.

METHODS

This retrospective cross-sectional study collected data from semi-structured charts of dementia patients who were followed up at a secondary care reference center between 2015 and 2019. Results: Of 552 total patients, 52 (9.3%) were hypersexual, which was associated with male sex (P < .000; OR 2.95, 95% CI 1.73-5.01), frontotemporal dementia (P < .007), alcohol use (P < .015; OR 2.35, 95% CI 1.16-4.73) and tobacco use (P < .000; OR 2.88, 95% CI 1.61-5.13).

CONCLUSIONS

Although our findings were similar to the literature, their significant variability reflects the limited and low quality of the available evidence and a lack of standardization regarding terminology, definitions, and diagnostic criteria for hypersexuality.

Cognitive inflexibility and heightened error monitoring are related to lower sexual functioning

Sexual functioning is an important predictor of well-being and relationship satisfaction. Previous research indicates that several aspects of cognitive function are related to sex-related behaviors and functioning among individuals with sex-related disorders, neurological disorders, and in older adults; however, this has been relatively underexamined in younger populations. To examine this, the present study assessed whether behavioral and/or neurophysiological measures of cognitive function are associated with sexual functioning in a community sample of young 489 adults (64 % female) ages 18-30. Cognitive flexibility (n = 460) and inhibition (n = 466) were measured using neuropsychological assessment (D-KEFS), and conflict monitoring and error monitoring were measured by event-related potentials (conflict N2: n = 394; error-related negativity: n = 389). After separately testing relations between the different measures of cognitive function and sexual functioning, we assessed whether results (1) remained after covarying for externalizing and internalizing dimensions (PID-5; n = 489) or (2) varied by gender. Finally, we tested whether any aspects of cognitive function were unique predictors of sexual functioning. Cognitive flexibility and error monitoring (i.e., error-related negativity) were both significantly related to sexual functioning among males and females, such that poorer cognitive flexibility and heightened error monitoring were related to lower sexual functioning. No significant effects emerged for inhibition or conflict monitoring. In a multiple regression model, cognitive flexibility and error monitoring each accounted for a unique portion of variance in sexual functioning beyond other aspects of cognitive function and psychopathology-related traits. Results suggest that cognitive function is a meaningful correlate of sexual functioning in young adulthood, which should be considered further in future research.

Psychological Problem Diagnosis and Management in the Geriatric Age Group

The definition of geriatrics is very complex to explain though it can be written as the treatment and care provided by healthcare and medical systems primarily to more venerable and senior citizens group of the population. The age group considered to be entering the old group is believed to be those who have reached their sixth decade of life. However, most of the global geriatric population doesn't need treatment until their seventh decade. Bodily impairment, both physical and mental, due to various reasons, for example, financial or personal reasons or feeling ignored, is reasonable for clinicians to anticipate caring for a growing proportion of older patients with complicated medical and psychosocial concerns. Complex ethical quandaries could develop as a result of these difficulties and problems. Who should anticipate ethical challenges faced by doctors early during management? We offer practical recommendations for improving communication because ineffective patient-clinician communication might result in moral dilemmas. Physical impairment, hopelessness, and cognitive decline are all more prevalent as people age. Politicians and healthcare providers of nations should step in to search for a measure to reduce the uprising of the condition; otherwise, it will lead to an uprising of the cases in an exponential manner. It is necessary to increase the financial challenges faced by the elderly. In addition, awareness should be increased, as well as programs aimed at enhancing their standard of living.

Addition of the FTD Module to the Neuropsychiatric Inventory improves classification of frontotemporal dementia spectrum disorders

Most neuropsychiatric symptoms (NPS) common in frontotemporal dementia (FTD) are currently not part of the Neuropsychiatric Inventory (NPI). We piloted an FTD Module that included eight extra items to be used in conjunction with the NPI. Caregivers of patients with behavioural variant FTD (n = 49), primary progressive aphasia (PPA; n = 52), Alzheimer's dementia (AD; n = 41), psychiatric disorders (n = 18), presymptomatic mutation carriers (n = 58) and controls (n = 58) completed the NPI and FTD Module. We investigated (concurrent and construct) validity, factor structure and internal consistency of the NPI and FTD Module. We performed group comparisons on item prevalence, mean item and total NPI and NPI with FTD Module scores, and multinomial logistic regression to determine its classification abilities. We extracted four components, together explaining 64.1% of the total variance, of which the largest indicated the underlying dimension 'frontal-behavioural symptoms'. Whilst apathy (original NPI) occurred most frequently in AD, logopenic and non-fluent variant PPA, the most common NPS in behavioural variant FTD and semantic variant PPA were loss of sympathy/empathy and poor response to social/emotional cues (part of FTD Module). Patients with primary psychiatric disorders and behavioural variant FTD showed the most severe behavioural problems on both the NPI as well as the NPI with FTD Module. The NPI with FTD Module correctly classified more FTD patients than the NPI alone. By quantifying common NPS in FTD the NPI with FTD Module has large diagnostic potential. Future studies should investigate whether it can also prove a useful addition to the NPI in therapeutic trials.

The architecture of abnormal reward behaviour in dementia: multimodal hedonic phenotypes and brain substrate

Abnormal reward processing is a hallmark of neurodegenerative diseases, most strikingly in frontotemporal dementia. However, the phenotypic repertoire and neuroanatomical substrates of abnormal reward behaviour in these diseases remain incompletely characterized and poorly understood. Here we addressed these issues in a large, intensively phenotyped patient cohort representing all major syndromes of sporadic frontotemporal dementia and Alzheimer's disease. We studied 27 patients with behavioural variant frontotemporal dementia, 58 with primary progressive aphasia (22 semantic variant, 24 non-fluent/agrammatic variant and 12 logopenic) and 34 with typical amnestic Alzheimer's disease, in relation to 42 healthy older individuals. Changes in behavioural responsiveness were assessed for canonical primary rewards (appetite, sweet tooth, sexual activity) and non-primary rewards (music, religion, art, colours), using a semi-structured survey completed by patients' primary caregivers. Changes in more general socio-emotional behaviours were also recorded. We applied multiple correspondence analysis and k-means clustering to map relationships between hedonic domains and extract core factors defining aberrant hedonic phenotypes. Neuroanatomical associations were assessed using voxel-based morphometry of brain MRI images across the combined patient cohort. Altered (increased and/or decreased) reward responsiveness was exhibited by most patients in the behavioural and semantic variants of frontotemporal dementia and around two-thirds of patients in other dementia groups, significantly (P < 0.05) more frequently than in healthy controls. While food-directed changes were most prevalent across the patient cohort, behavioural changes directed toward non-primary rewards occurred significantly more frequently (P < 0.05) in the behavioural and semantic variants of frontotemporal dementia than in other patient groups. Hedonic behavioural changes across the patient cohort were underpinned by two principal factors: a 'gating' factor determining the emergence of altered reward behaviour and a 'modulatory' factor determining how that behaviour is directed. These factors were expressed jointly in a set of four core, trans-diagnostic and multimodal hedonic phenotypes: 'reward-seeking', 'reward-restricted', 'eating-predominant' and 'control-like'-variably represented across the cohort and associated with more pervasive socio-emotional behavioural abnormalities. The principal gating factor was associated (P < 0.05 after correction for multiple voxel-wise comparisons over the whole brain) with a common profile of grey matter atrophy in anterior cingulate, bilateral temporal poles, right middle frontal and fusiform gyri: the cortical circuitry that mediates behavioural salience and semantic and affective appraisal of sensory stimuli. Our findings define a multi-domain phenotypic architecture for aberrant reward behaviours in major dementias, with novel implications for the neurobiological understanding and clinical management of these diseases.

Treatment and Management of Sexual Disinhibition in Elderly Patients With Neurocognitive Disorders

Sexual disinhibition is uncommon but challenging symptom to address in elderly patients with neurocognitive disorders. Due to the lack of large-scale studies, there is no gold standard treatment for sexual disinhibition, and treatment is largely left up to the discretion of the provider based on the severity and onset of the patient's symptoms. A review was conducted to investigate the non-pharmacological and pharmacological interventions for treating this condition. Articles that discussed treatments were screened for the type of treatment and possible side effects of medication if applicable. Thorough patient history should be taken prior to starting any drug therapy to rule out possible behavioral changes due to an existing medication side effect, delirium, or past mental or sexual health history. Non-pharmacological treatment has been generally recommended as first-line therapy over pharmacological treatment. Distraction/diversion of the patient when inappropriate sexual behaviors occur was the most common non-pharmacological intervention. Antidepressants were generally recommended as the first line of pharmacological treatment after attempting all possible non-pharmacological interventions. Several other categories of interventions are discussed as well in addition to the ethical implications of treating a patient for this condition.

Frontal Pole Hypometabolism Linked to Reduced Prosocial Sexual Behaviors in Frontotemporal Dementia and Corticobasal Syndrome

BACKGROUND

Changes in sexual behaviors in frontotemporal dementia (FTD) are common and multifaceted, but not well characterized.

OBJECTIVE

To characterize changes in sexual behaviors and intimacy in FTD compared to corticobasal syndrome (CBS) and normal controls (NC), and to evaluate the neuroanatomical associations of these changes.

METHODS

Spouses of 30 FTD patients, 20 CBS patients, and 35 NC completed the Sexual Symptoms in Neurological Illness and Injury Questionnaire (SNIQ), which captures changes in sexual interest, inappropriate sexual behaviors, and prosocial sexual behaviors. 25 patients with FTD and 14 patients with CBS also received 18-flouorodeoxyglucose positron-emission topography (18FDG-PET) scans to determine the metabolic changes associated with these symptoms.

RESULTS

FTD patients showed a greater increase in inappropriate sexual behaviors than CBS patients [p = 0.009] and NC [p < 0.001] and a greater decrease in prosocial sexual behaviors than CBS patients [p = 0.026] and NC [p < 0.001]. Groups did not differ in change in sexual interest. Among both patient groups, the most common change was decreased prosocial sexual behaviors p < 0.01. Hypometabolism in Brodmann's Area 10 (BA10), within the right frontal pole, correlated with decreased prosocial sexual behaviors [p(FWE-corr) <0.05, k = 44]. No anatomical associations were found with other sexual changes.

CONCLUSION

Decreased prosocial sexual behavior was associated with hypometabolism in BA 10, an area tied to social knowledge and theory of mind, supporting the idea that changes reflect social-cognitive deficits due to frontal dysfunction.

Beyond language impairment: Profiles of apathy in primary progressive aphasia

Primary progressive aphasia (PPA) is characterised by predominant language and communication impairment. However, behavioural changes, such as apathy, are increasingly recognised. Apathy is defined as a reduction in motivation and goal-directed behaviour. Recent theoretical models have suggested that apathy can be delineated into multiple dimensions: executive apathy (i.e., deficits in maintaining goals and organisation), emotional apathy (i.e., emotional blunting and indifference) and initiation apathy (i.e., reduced self-initiation). Whether the nature of apathy differs between clinical variants of PPA, and across early and late disease stages, remains to be established. Here, carers/informants of 20 semantic variant PPA (svPPA), 15 non-fluent variant PPA (nfvPPA), 16 logopenic variant PPA (lvPPA) and 25 healthy older controls completed the Dimensional Apathy Scale to quantify executive, emotional and initiation apathy. Voxel-based morphometry was used to identify associations between dimensions of apathy and regions of grey matter intensity decrease. Our behavioural results showed greater executive and initiation apathy in late svPPA than in late nfvPPA patients, while late svPPA had greater emotional apathy than both late nfvPPA and late lvPPA groups. Executive and initiation apathy were significantly higher than premorbid levels in all PPA subtypes, while elevated emotional apathy was only seen in early and late svPPA. Distinct neural correlates were identified across apathy dimensions. Executive apathy correlated with grey matter intensity of the left dorsolateral prefrontal and inferior parietal cortices; emotional apathy with the left medial prefrontal, insular and cerebellar regions; and initiation apathy with right parietal areas. Our findings are the first to reveal evidence of the dimensional nature of apathy in PPA, with different clinical signatures observed for each subtype. From a clinical standpoint, these results will inform the development of targeted interventions for specific aspects of apathy which emerge in PPA.

Hypothalamic symptoms of frontotemporal dementia disorders

Frontotemporal dementia (FTD) has traditionally been regarded as a disease of cognition and behavior, but emerging evidence suggests that the disease also affects body functions including changes in eating behavior and metabolism, autonomic function, sleep behavior, and sexual function. Central to these changes are potentially complex neural networks involving the hypothalamus, with hypothalamic atrophy shown in behavioral variant FTD. The physiological changes found in FTD are reviewed and the key neural networks and neuroendocrine changes mediating these changes in function discussed, including the ability to use these changes as biomarkers to aid in disease diagnosis, monitoring disease progression, and as potential treatment targets.

Cognitive and behavioural inhibition deficits in neurodegenerative dementias

Disinhibition, mainly caused by damage in frontotemporal brain regions, is one of the major causes of caregiver distress in neurodegenerative dementias. Behavioural inhibition deficits are usually described as a loss of social conduct and impulsivity, whereas cognitive inhibition deficits refer to impairments in the suppression of prepotent verbal responses and resistance to distractor interference. In this review, we aim to discuss inhibition deficits in neurodegenerative dementias through behavioural, cognitive, neuroanatomical and neurophysiological exploration. We also discuss impulsivity and compulsivity behaviours as related to disinhibition. We will therefore describe different tests available to assess both behavioural and cognitive disinhibition and summarise different manifestations of disinhibition across several neurodegenerative diseases (behavioural variant of frontotemporal dementia, Alzheimer's disease, Parkinson's disease, progressive supranuclear palsy, Huntington's disease). Finally, we will present the latest findings about structural, metabolic, functional, neurophysiological and also neuropathological correlates of inhibition impairments. We will briefly conclude by mentioning some of the latest pharmacological and non pharmacological treatment options available for disinhibition. Within this framework, we aim to highlight i) the current interests and limits of tests and questionnaires available to assess behavioural and cognitive inhibition in clinical practice and in clinical research; ii) the interpretation of impulsivity and compulsivity within the spectrum of inhibition deficits; and iii) the brain regions and networks involved in such behaviours.

Neural networks associated with body composition in frontotemporal dementia

Background

Frontotemporal dementia (FTD) is associated with complex changes in eating behavior and metabolism, which potentially affect disease pathogenesis and survival. It is currently not known if body composition changes and changes in fat deposition also exist in FTD, the relationship of these changes in eating behavior and appetite, and whether these changes are centrally mediated.

Methods

Body composition was measured in 28 people with behavioral‐variant frontotemporal dementia (bvFTD), 16 with Alzheimer’s disease (AD), and 19 healthy controls, using dual energy x‐ray absorptiometry. Changes in body composition were correlated to brain grey matter atrophy using voxel‐based morphometry on high‐resolution magnetic resonance imaging.

Results

Behavioral‐variant FTD was characterized by changes in body composition, with increased total fat mass, visceral adipose tissue area (VAT area), and android: gynoid ratio compared to control and AD participants (all P values < 0.05). Changes in body composition correlated to abnormal eating behavior and behavioral change (P < 0.01) and functional decline (P < 0.01). Changes in body composition also correlated to grey matter atrophy involving a distributed neural network that included the hippocampus, amygdala, nucleus accumbens, insula, cingulate, and cerebellum – structures known to be central to autonomic control – as well as the thalamus, putamen, accumbens, and caudate, which are involved in reward processing.

Conclusions

Changes in body composition and fat deposition extend the clinical phenomenology in bvFTD beyond cognition and behavior, with changes associated with changes in reward and autonomic processing suggesting that these deficits may be central in FTD

FTD spectrum: Neuroimaging across the FTD spectrum

Frontotemporal dementia is a complex and heterogeneous neurodegenerative disease that encompasses many clinical syndromes, pathological diseases, and genetic mutations. Neuroimaging has played a critical role in our understanding of the underlying pathophysiology of frontotemporal dementia and provided biomarkers to aid diagnosis. Early studies defined patterns of neurodegeneration and hypometabolism associated with the clinical, pathological and genetic aspects of frontotemporal dementia, with more recent studies highlighting how the breakdown of structural and functional brain networks define frontotemporal dementia. Molecular positron emission tomography ligands allowing the in vivo imaging of tau proteins have also provided important insights, although more work is needed to understand the biology of the currently available ligands.

Psychological and Cognitive Markers of Behavioral Variant Frontotemporal Dementia-A Clinical Neuropsychologist's View on Diagnostic Criteria and Beyond

Behavioral variant frontotemporal dementia (bvFTD) is the second leading cognitive disorder caused by neurodegeneration in patients under 65 years of age. Characterized by frontal, insular, and/or temporal brain atrophy, patients present with heterogeneous constellations of behavioral and psychological symptoms among which progressive changes in social conduct, lack of empathy, apathy, disinhibited behaviors, and cognitive impairments are frequently observed. Since the histopathology of the disease is heterogeneous and identified genetic mutations only account for ~30% of cases, there are no reliable biomarkers for the diagnosis of bvFTD available in clinical routine as yet. Early detection of bvFTD thus relies on correct application of clinical diagnostic criteria. Their evaluation however, requires expertise and in-depth assessments of cognitive functions, history taking, clinical observations as well as caregiver reports on behavioral and psychological symptoms and their respective changes. With this review, we aim for a critical appraisal of common methods to access the behavioral and psychological symptoms as well as the cognitive alterations presented in the diagnostic criteria for bvFTD. We highlight both, practical difficulties as well as current controversies regarding an overlap of symptoms and particularly cognitive impairments with other neurodegenerative and primary psychiatric diseases. We then review more recent developments and evidence on cognitive, behavioral and psychological symptoms of bvFTD beyond the diagnostic criteria which may prospectively enhance the early detection and differential diagnosis in clinical routine. In particular, evidence on specific impairments in social and emotional processing, praxis abilities as well as interoceptive processing in bvFTD is summarized and potential links with behavior and classic cognitive domains are discussed. We finally outline both, future opportunities and major challenges with regard to the role of clinical neuropsychology in detecting bvFTD and related neurocognitive disorders.