Mild behavioral impairment as a potential marker of predementia risk states in motor neuron diseases

Identifying Mild Behavioral and Neurocognitive Impairment in Amyotrophic Lateral Sclerosis (MBNI-ALS) Provides Key Prognostic Insights

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a multisystem neurodegenerative disease encompassing cognitive and behavioral impairments. The Revised Diagnostic Criteria for ALS-frontotemporal spectrum disorder (ALS-FTDS), while widely adopted, may overlook subtle impairments such as memory and visuospatial deficits, limiting their prognostic value.

OBJECTIVES

This study aimed to apply the Mild Behavioral and Neurocognitive Impairment (MBNI) approach, adapted from other neurodegenerative diseases, to ALS patients and assess its prognostic utility for survival and disease progression.

METHODS

A prospective cohort of 201 ALS patients was evaluated between January 2018 and July 2024. Participants underwent comprehensive cognitive and behavioral assessments. The MBNI approach identified patients with mild cognitive impairment (MCI), mild behavioral impairment (MBI), or combined cognitive-behavioral impairment (MCBI). Prognostic value was analyzed using Kaplan-Meier survival curves, Cox proportional hazards models, and logistic regression for disease progression.

RESULTS

Mild cognitive and/or behavioral impairments were detected in 67% of patients classified as cognitively normal by ALS-FTDS criteria. At a median follow-up of 15 months, these patients showed shorter tracheostomy-free survival (all p < 0.005). MCI (HR5.3; CI 1.10-25.41; p = 0.038) and frontotemporal dementia (HR6.2; Confidence Interval: 1.34-28.40; p = 0.019) independently predicted poor outcomes. Logistic regression confirmed that MCBI and frontotemporal dementia were associated with rapid progression (both p < 0.019).

CONCLUSION

The MBNI approach enhances the detection of mild cognitive and behavioral impairments in ALS, providing prognostic insights and improving stratification over the Revised Diagnostic Criteria for ALS-FTDS. This framework supports personalized care and the design of clinical trials targeting early disease stages.

Mild behavioral impairment and its relation to amyloid load in isolated REM sleep behavior disorder

INTRODUCTION

In isolated REM sleep behavior disorder (iRBD), the evidence of cognitive impairment and co-existing amyloid pathology suggests that mild behavioral impairment (MBI) may be associated with disease progression. In this study, we investigated MBI and its association with cognitive function, brain amyloid load and glucose metabolism in iRBD patients to evaluate the utility of MBI as a predictive marker of disease progression.

METHODS

Patients with iRBD underwent a neuropsychological evaluation, 18F-florbetaben (FBB) PET, and 18F-fluorodeoxyglucose (FDG) PET. MBI was evaluated using the MBI-checklist (MBI-C). Comparisons between MBI-positive and MBI-negative groups and correlations with MBI-C total scores were examined on neuropsychological performances and PET regional standardized uptake value ratios (SUVRs). Additionally, associations between regional amyloid burden and glucose metabolism and mediating role of MBI status on these associations were evaluated in all iRBD patients.

RESULTS

Of 36 iRBD patients, about one-third were classified as MBI-positive. Although we did not find the differences between the MBI groups and correlations with MBI-C total scores in neuropsychological performances and brain glucose metabolism, the MBI-positive group revealed higher FBB SUVRs in the anterior cingulate cortex, prefrontal cortex, caudate nucleus, and putamen than the MBI-negative group. The FBB SUVR of caudate nucleus was negatively correlated with glucose metabolism in the precuneus, which was not directly mediated by the MBI.

CONCLUSION

Characteristic amyloid accumulation in prefrontal and subcortical structures in MBI-positive iRBD patients suggests that MBI may be associated with early amyloid pathology that can be an integral role in disease progression.

Psychometric properties and clinical correlates of the Frontal Behaviour Inventory in progressive supranuclear palsy: data from the PSP-NET

OBJECTIVES

Neuropsychiatric symptoms, such as apathy, disinhibition and irritability, are common in Progressive Supranuclear Palsy (PSP). The Frontal Behaviour Inventory (FBI) is a useful instrument for the evaluation of behavioural disorders in neurodegenerative diseases. The main goal of the present study was to explore the psychometric properties of the FBI in PSP.

DESIGN, SETTING AND PARTICIPANTS

FBI was administered to the PSP-NET cohort including Italian patients diagnosed according to the Movement Disorder Society criteria. Patients underwent a clinical interview, a motor evaluation, extensive cognitive and behavioural testing.

RESULTS

Two hundred and eight subjects were included in this study. The internal consistency was high (Cronbach's alpha = 0.868) and no improvement of this value was noted upon removal of any item. FBI showed also good acceptability, reliability and validity. The standard error of measurement (SEM) value for FBI total score was 0.169 [SEM = SD √ (1 - Cronbach's alpha)]. Factor analysis indicated a five-factor structure: Apathy, Behavioural disorders, Impulsivity, Motor and speech frontal behaviour and Executive disorders that explained the 54.92% of the total variance. Linear regression analysis showed that global cognitive impairment significantly affects both Apathy and Motor and speech frontal behaviour factors.

CONCLUSIONS

In conclusion, FBI is a reliable and valid tool for the assessment of neuropsychiatric symptoms in PSP, despite some constructs, such as euphoria and irritability, are better measured by the NPI. Two third of the cohort was represented by Richardson's syndrome, thus our data are mainly applicable to such common phenotype. Such data are useful in both clinical and research settings to plan adequate therapeutic interventions and to improve the quality of life of PSP patients and their caregivers.

The spectrum of behavioral disorders in amyotrophic lateral sclerosis: current view

Behavioral disorders, with an average prevalence of 30-60% are important non-motor symptoms in amyotrophic lateral sclerosis (ALS) that have a negative impact on prognosis, management and quality of life, yet the underlying neurobiology is poorly understood. Among people with ALS, apathy, fatigue, anxiety, irritability and other behavioral symptoms are the most prominent, although less frequent than cognitive impairment. The present review explores the current understanding of behavioral changes in ALS with particular emphasis on our current knowledge about their structural and functional brain correlates, substantiating a multisystem degeneration with particular dysfunction of frontal-subcortical circuits and dysfunction of fronto-striatal, frontotemporal and other essential brain systems. The natural history of behavioral dysfunctions in ALS and their relationship to frontotemporal lobe degeneration (FTLD) are not fully understood, although they form a clinical continuum, suggesting a differential vulnerability of non-motor brain networks, ALS being considered a brain network disorder. An assessment of risks or the early detection of brain connectivity signatures before structural changes may be helpful in investigating the pathophysiological mechanisms of behavioral impairment in ALS. Treatment of both ALS and co-morbid behavioral disorders is a multidisciplinary task, but whereas no causal or disease-modifying therapies for ALS are available, symptomatic treatment of a variety of behavioral symptoms plays a pivotal role in patient care, although the management of behavioral symptoms in clinical care still remains limited.

Exploring neuropsychiatric symptoms in Friedreich ataxia

Neuropsychiatric symptoms (NPS) are common in hereditary ataxias as a part of the cerebellar cognitive affective syndrome. In Friedreich ataxia (FRDA), one of the most common hereditary ataxias, depressive symptoms were previously reported, but little is known about other NPS. We aimed to study the presence and severity of a broad range of NPS in individuals with FRDA and assess the relationship between the NPS and the disease severity, cognition, and quality of life and to examine the concordance between the NPS reported by the patients and by their informants. Mild Behavioral Impairment Checklist (MBI-C), a questionnaire designed for screening NPS in the early stages of neurodegenerative diseases, was administered to informants of individuals with FRDA and healthy controls and to people with FRDA themselves. Compared to healthy controls, patients with FRDA scored significantly higher in the total MBI-C score, emotion dysregulation domain (corresponding to depression and anxiety), and decreased motivation domain. When assessed by caregiver, the total MBI-C score and several NPS domains correlated with activities of daily living. Only psychotic symptoms were related to ataxia severity and general cognition. When endorsed by patients, only the relation between few MBI-C domains and quality of life was observed. We found slight to moderate agreement between informant-rated and patient-rated scores. NPS, particularly emotion dysregulation and decreased motivation, are common and clinically relevant in FRDA and should receive more attention due to their potential impact on quality of life and the possibility of therapeutic intervention.

Circulating endocannabinoidome signatures of disease activity in amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

Preclinical studies of amyotrophic lateral sclerosis (ALS) have shown altered endocannabinoid (eCB) signalling that may contribute to the disease. Results from human studies are sparse and inconclusive. The aim of this study was to determine the association between serum levels of eCBs or their congeners, the so-called endocannabinoidome, and disease status and activity in ALS patients.

METHODS

Serum concentrations of 2-arachidonoylglycerol and N-arachidonoylethanolamine (AEA), and AEA congeners palmitoylethanolamide (PEA), oleoylethanolamide (OEA), eicosapentaenoylethanolamide (EPEA), 2-docosahexaenoylglycerol (2-DHG) and docosahexaenoylethanolamide (DHEA) were measured in samples from 65 ALS patients, 32 healthy controls (HCs) and 16 neurological disease controls (NALS). A subset of 46 ALS patients underwent a longitudinal study. Disease activity and progression were correlated with eCB and congener levels.

RESULTS

Most circulating mediators were higher in ALS than HCs (all p < 0.001), but not NALS. Across clinical stages, ALS patients showed increased levels of PEA, OEA and EPEA (all p < 0.02), which were confirmed by the longitudinal study (all p < 0.03). Serum PEA and OEA levels were independent predictors of survival and OEA levels were higher in patients complaining of appetite loss. Cluster analysis revealed two distinct profiles of circulating mediators associated with corresponding patterns of disease activity (severe vs. mild). Patients belonging to the 'severe' cluster showed significantly higher levels of OEA and PEA and lower levels of 2-DHG compared to NALS and HCs.

CONCLUSION

Circulating endocannabinoidome profiles are indicative of disease activity, thus possibly paving the way to a personalized, rather than a 'one-fits-all', therapeutic approach targeting the endocannabinoidome.

Neuropsychiatric symptoms in spinocerebellar ataxias and Friedreich ataxia

Apart from its role in motor coordination, the importance of the cerebellum in cognitive and affective processes has been recognized in the past few decades. Spinocerebellar ataxias (SCA) and Friedreich ataxia (FRDA) are rare neurodegenerative diseases of the cerebellum presenting mainly with a progressive loss of gait and limb coordination, dysarthria, and other motor disturbances, but also a range of cognitive and neuropsychiatric symptoms. This narrative review summarizes the current knowledge on neuropsychiatric impairment in SCA and FRDA. We discuss the prevalence, clinical features and treatment approaches in the most commonly reported domains of depression, anxiety, apathy, agitation and impulse dyscontrol, and psychosis. Since these symptoms have a considerable impact on patients' quality of life, we argue that further research is mandated to improve the detection and treatment options of neuropsychiatric co-morbidities in ataxia patients.

Hippocampal Metabolic Alterations in Amyotrophic Lateral Sclerosis: A Magnetic Resonance Spectroscopy Study

BACKGROUND

Magnetic resonance spectroscopy (MRS) in amyotrophic lateral sclerosis (ALS) has been overwhelmingly applied to motor regions to date and our understanding of frontotemporal metabolic signatures is relatively limited. The association between metabolic alterations and cognitive performance in also poorly characterised.

MATERIAL AND METHODS

In a multimodal, prospective pilot study, the structural, metabolic, and diffusivity profile of the hippocampus was systematically evaluated in patients with ALS. Patients underwent careful clinical and neurocognitive assessments. All patients were non-demented and exhibited normal memory performance. 1H-MRS spectra of the right and left hippocampi were acquired at 3.0T to determine the concentration of a panel of metabolites. The imaging protocol also included high-resolution T1-weighted structural imaging for subsequent hippocampal grey matter (GM) analyses and diffusion tensor imaging (DTI) for the tractographic evaluation of the integrity of the hippocampal perforant pathway zone (PPZ).

RESULTS

ALS patients exhibited higher hippocampal tNAA, tNAA/tCr and tCho bilaterally, despite the absence of volumetric and PPZ diffusivity differences between the two groups. Furthermore, superior memory performance was associated with higher hippocampal tNAA/tCr bilaterally. Both longer symptom duration and greater functional disability correlated with higher tCho levels.

CONCLUSION

Hippocampal 1H-MRS may not only contribute to a better academic understanding of extra-motor disease burden in ALS, but given its sensitive correlations with validated clinical metrics, it may serve as practical biomarker for future clinical and clinical trial applications. Neuroimaging protocols in ALS should incorporate MRS in addition to standard structural, functional, and diffusion sequences.