Eating behavior in frontotemporal dementia

Abstract

Objective: To contrast the relationships of hormonal eating peptides and hypothalamic volumes to eating behavior and metabolic changes (body mass index [BMI]) in behavioral variant frontotemporal dementia (bvFTD) and semantic variant primary progressive aphasia (svPPA).Methods: Seventy-five patients with dementia (19 bvFTD, 26 svPPA, and 30 Alzheimer disease dementia) and 23 controls underwent fasting blood analyses of leptin, ghrelin, cholecystokinin, peptide tyrosine tyrosine (PYY), and agouti-related peptide (AgRP) levels. On brain MRI anterior, posterior, and total hypothalamic volumes were measured. Relationships between endocrine measures, hypothalamic volumes, eating behaviors, and BMI were investigated.Results: Levels of AgRP were higher in patients with bvFTD (69 6 89 pg/mL) and svPPA (62 6 81 pg/mL) compared with controls (23 6 19 pg/mL, p , 0.01). No differences were found for leptin, oxytocin, cholecystokinin, ghrelin, and PYY levels. Patients with bvFTD and svPPA had higher scores on questionnaires measuring eating behaviors. Atrophy of the posterior and total hypothalamus was observed in the bvFTD group only. Linear regression modeling revealed that leptin and AgRP levels predicted BMI. Conclusion:Eating abnormalities are multifactorial in FTD. In bvFTD, they are in part related to hypothalamic degeneration, with potential disintegration of the network connections between the hypothalamus and orbitofrontal cortex/reward pathways. In svPPA, although hypothalamic volumes are preserved, this group experiences elevated AgRP levels similar to bvFTD, which predicts BMI in both groups. This finding highlights the potential key role of AgRP in eating and metabolic changes and provides a potential target for treatment to modify disease progression. Alterations in eating behavior are one of the diagnostic criteria for behavioral variant frontotemporal dementia (bvFTD).

A Review: Mealtime Difficulties following Frontotemporal Lobar Degeneration

“…Appetite-regulating peptide levels in subjects with bvFTD are found to be consistent with an expected satiated state between meals [18, 32, 33]. Appetite-regulating peptide levels differ between subjects with bvFTD and healthy controls.…”

“…The restriction of food by the caregiver can lead to tension between carer and individual, including aggression [17]. Health risks associated with aberrant eating behaviors include an increased BMI and the risk of aspiration [4, 10, 17, 18]. Risky behaviors, such as rapidly eating large quantities of food, can induce aspiration and asphyxiation, even when swallow function is intact [4, 19, 20].…”

“…One study suggested that peptide levels change to compensate for hyperphagia which occurs secondary to neural atrophy [32]. Alternatively, it has been suggested that changes in appetite-regulating peptide levels are a direct consequence of neural atrophy and contribute to the multifactorial nature of hyperphagia [18]. …”

“…Atrophy of the right ventral insular cortex, striatum, rostral orbitofrontal cortex [34], and posterior hypothalamus [18, 35] has been associated with the onset and progression of hyperphagia. The hypothalamus is thought to be a key area involved in feeding behavior [7, 18, 36, 37].…”

Prosocial deficits in behavioral variant frontotemporal dementia relate to reward network atrophy

“…These studies suggest that social relationships have reduced reward value in bvFTD and that patients are less motivated to partake in selfless acts that prioritize the feelings and needs of others. Although alterations in reward‐seeking (e.g., changes in eating, drug and alcohol use, and sexual behavior) are common in bvFTD and are associated with atrophy in reward network structures including the ventral striatum (Ahmed et al., 2015; Bocchetta et al., 2015; Perry & Kramer, 2015; Perry et al., 2014), whether alterations in reward processing also underlie patients’ waning social engagement is not well understood.…”