Patricia Lillo

Grey and White Matter Changes across the Amyotrophic Lateral Sclerosis-Frontotemporal Dementia Continuum

There is increasing evidence that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a clinical, pathological and genetic continuum with patients of one disease exhibiting features of the other. Nevertheless, to date, the underlying grey matter and white matter changes across the ALS-FTD disease continuum have not been explored. In this study fifty-three participants with ALS (n = 10), ALS-FTD (n = 10) and behavioural variant FTD (bvFTD; n = 15) as well as controls (n = 18), underwent detailed clinical assessment plus structural imaging using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analysis of magnetic resonance brain imaging to examine grey and white matter differences and commonalities across the continuum. Importantly, patient groups were matched for age, education, gender and disease duration. VBM and DTI results showed that changes in the ALS group were confined mainly to the motor cortex and anterior cingulate as well as their underlying white matter tracts. ALS-FTD and bvFTD showed widespread grey matter and white matter changes involving frontal and temporal lobes. Extensive prefrontal cortex changes emerged as a marker for bvFTD compared to other subtypes, while ALS-FTD could be distinguished from ALS by additional temporal lobe grey and white matter changes. Finally, ALS could be mainly distinguished from the other two groups by corticospinal tract degeneration. The present study shows for the first time that FTD and ALS overlap in anterior cingulate, motor cortex and related white matter tract changes across the whole continuum. Nevertheless, frontal and temporal atrophy as well as corticospinal tract degeneration emerged as marker for subtype classification, which will inform future diagnosis and target disease management across the continuum.

How common are behavioural changes in amyotrophic lateral sclerosis

Abstract Our objectives were to assess the frequency of behavioural changes in patients with amyotrophic lateral sclerosis (ALS) and to compare the clinical profile of ALS patients with those with behavioural variant frontotemporal dementia (bvFTD). Ninety-two patients with ALS and their carers participated in a postal survey. ALS patients completed self-report measures of motor function and mood. Eighty-one carers of ALS patients and 25 carers of bvFTD patients completed the revised version of the Cambridge Behavioural Inventory (CBI-R). Results showed that reduced motivation was reported in more than 80% of the ALS cases, with almost 41% of them having moderate-severe apathy. Depression was present in 30% of ALS patients and did not contribute significantly to the presence of behavioural symptoms. Bulbar and limb onset ALS patients did not differ. Abnormal behaviour and stereotypical and motor behaviours were present to a moderate-severe degree in around 20%, and 11% reached the criteria for FTD. The rate of behavioural symptoms was significantly higher in the bvFTD group than ALS in all behavioural domains (p <0.001). In conclusion, apathy was the most prominent feature in ALS patients. A substantial proportion of ALS patients manifested behavioural changes of the type seen in FTD, with 11% fulfilling the criteria for FTD.

Frontotemporal dementia and motor neurone disease: Overlapping clinic-pathological disorders

Advances in genetics and pathology have supported the idea of a continuum between frontotemporal dementia (FTD) and motor neurone disease (MND), which is strengthened by the discovery of the trans-activating responsive (Tar) sequence DNA binding protein (TDP-43) as a key component in the underlying pathology of FTD, FTD-MND and sporadic and familial MND patients. MND is a multisystem disorder associated with cognitive and behavioural changes which in some instances reaches the criteria for FTD, while a proportion of patients with FTD develop frank MND. We review the overlap between FTD and MND, emphasizing areas of controversy and uncertainty.

Neurobehavioral Features in Frontotemporal Dementia With Amyotrophic Lateral Sclerosis

OBJECTIVE To compare the clinical features at presentation in patients with frontotemporal dementia (FTD) who develop amyotrophic lateral sclerosis (ALS) with those of patients with behavioral variant FTD (bvFTD) who do not develop ALS. DESIGN Archival data analysis on 61 deceased patients with FTD. We reviewed the clinical features at presentation (behavioral changes, psychotic symptoms, language, and executive and memory problems) and survival. SETTING Early Onset Dementia Clinic, Cambridge, England. Patients From a total of 156 patients with a clinical diagnosis of behavioral FTD, we selected 61 deceased patients with comprehensive medical records, including 43 with bvFTD and 18 with FTD/ALS. MAIN OUTCOME MEASURES Clinical features and survival. RESULTS There was a significant association between the presence of delusions (50%; odds ratio, 4.4; 95% confidence interval, 1.3-14.5) and diagnosis of FTD/ALS (n = 18), whereas the behavioral features were identical in both groups. The interval between the onset of behavioral changes and diagnosis of ALS was less than 2 years in 12 (67%) of the patients with FTD/ALS. The median survival from symptom onset was significantly shorter for the FTD/ALS group (2.4 years; 95% confidence interval, 1.8-3.0 years) than for the bvFTD group (6.6 years; 5.6-7.6 years). CONCLUSIONS Delusions are particularly common in patients who develop FTD/ALS. The occurrence of delusions in the context of behavioral FTD should lead to an early search for ALS features.

Amyotrophic lateral sclerosis and frontotemporal dementia: A behavioural and cognitive continuum

Abstract Our objective was to compare the cognitive and behavioural profile of patients with amyotrophic lateral sclerosis (ALS) and behavioural variant frontotemporal dementia (bvFTD), and to explore the continuum between these disorders according to neuropsychological and behavioural performance using novel methods of testing and analysis. Twenty patients with ALS, 20 bvFTD patients and 20 healthy controls completed a neuropsychiatric and neuropsychological assessment including cognitive screening, working memory, inhibitory control, decision making and emotion recognition. The resulting neuropsychological and behavioural data were analysed by Rasch analysis. ALS patients showed a similar profile to bvFTD patients on tests of working memory, inhibitory control and behavioural measures. Nine ALS patients (45%) had cognitive impairment and five (25%) met criteria for bvFTD. Even in a subset of MND patients with no impairment on the ACE-R, subtle impairment of inhibitory control together with moderate to severe apathy, were found. The Rasch analysis confirmed that all patients could be ranked on the same continuum, based on their neuropsychological performance and behaviour. Thus, the cognitive and behavioural profiles of ALS mirror those seen in bvFTD. Impaired inhibitory control and behavioural changes suggest subtle orbitofrontal dysfunction in ALS. The Rasch analysis revealed a clear overlap between bvFTD and ALS.

Caregiver burden in amyotrophic lateral sclerosis is more dependent on patients' behavioral changes than physical disability: a comparative study.

BackgroundBehavioral changes in patients with amyotrophic lateral sclerosis (ALS) mirror those found in frontotemporal dementia (FTD). Considering the high rate of neuropsychiatric symptoms found in ALS patients, this paper examines whether caregiver burden is associated with behavioral changes over and above the physical disability of patients with ALS, and if the presence of caregivers’ depression, anxiety and stress also impacts on caregiver burden.Methods140 caregivers of patients with ALS participated in a postal survey investigating patients’ neuropsychiatric symptoms (Cambridge Behaviour Inventory Revised CBI-R), motor function (Amyotrophic Lateral Sclerosis Functional Rating Scale Revised - ALSFRS-R), caregiver burden (Zarit Burden Interview), and caregiver mood (Depression, Anxiety and Stress Scale- DASS21). Seventy four percent of them were caregivers of patients with limb onset and 25.7% were caregivers of patients with bulbar onset.ResultsModerate to severe behavioral changes were reported in 10-40% of patients with ALS. The levels of depression, anxiety and stress in the caregivers reached 20%. Burden was high in 48% of the caregivers. The strongest predictor of high caregiver burden was ALS patients’ abnormal behavior rather than physical disability, with an odds ratio of 1.4, followed by caregivers’ stress.ConclusionsOur study has identified that behavioral changes (e.g. disinhibition, impulsivity) and caregiver stress have greater impact on caregiver burden than level and pattern of physical disability.

Cortical atrophy in ALS is critically associated with neuropsychiatric and cognitive changes

Objective: To characterize the patterns of brain atrophy in patients with amyotrophic lateral sclerosis (ALS) with and without cognitive and neuropsychiatric symptoms, in comparison to controls and patients with ALS–frontotemporal dementia (FTD). Methods: A total of 57 participants (ALS = 22; ALS-FTD = 17; controls = 18) were included, following current ALS and FTD criteria. Patients with ALS were further subclassified into ALS with cognitive and behavioral symptoms (ALS-plus; n = 8) and those without (ALS; n = 14). By definition, ALS-plus did not reach the diagnostic threshold for ALS-FTD. All patients underwent neuropsychological and neuropsychiatric assessments, and underwent a brain MRI. Voxel-based morphometry analysis was conducted to establish patterns of brain atrophy. Results: Cortical atrophy in ALS was linked to neuropsychiatric and cognitive changes (ALS-plus vs ALS). Patients with ALS-plus had significant atrophy across motor and somatosensory as well as adjacent frontal and parietal areas, even after strict multiple comparison correction. By contrast, patients with ALS showed no significant cortical atrophy, and only brainstem atrophy. Importantly, atrophy in ALS-plus was not as widespread as in ALS-FTD, with ALS-plus atrophy mostly confined to motor and somatosensory areas, while atrophy in ALS-FTD also included substantial frontal and temporal atrophy. Conclusions: The present findings establish that cortical atrophy in ALS is highly dependent upon neuropsychiatric and cognitive changes. Previous inconsistent findings of cortical atrophy in ALS likely relate to the inclusion of cognitively affected patients and patients with pure motor ALS.

Determinants of survival in behavioral variant frontotemporal dementia

Background: Behavioral variant frontotemporal dementia (bvFTD) is a common cause of younger onset dementia. Little is known about its rate of progression but a recently identified subgroup seems to have an excellent prognosis. Other determinants of survival are unclear. Methods: We analyzed survival in a large group of clinically diagnosed bvFTD patients (n = 91) with particular attention to demographic and clinical features at presentation. Of the 91 cases, 50 have died, with pathologic confirmation in 28. Results: Median survival in the whole group was 9.0 years from symptom onset, and 5.4 years from diagnosis. After the exclusion of 24 “phenocopy” cases, the analysis was repeated in a subgroup of 67 patients. The mean age at symptom onset of the pathologic group was 58.5 years and 16% had a positive family history. Their median survival was 7.6 years (95% confidence interval [CI] 6.6–8.6) from symptom onset and 4.2 years (95% CI 3.4–5.0) from diagnosis. The only factor associated with shorter survival was the presence of language impairment at diagnosis. Conclusions: Patients with definite frontotemporal dementia have a poor prognosis which is worse if language deficits are also present. This contrasts with the extremely good outcome in those with the phenocopy syndrome: of our 24 patients only 1 has died (of coincident pathology) despite, in some cases, many years of follow-up.

Neuropsychiatric changes precede classic motor symptoms in ALS and do not affect survival

Objectives: To investigate patient susceptibility to neuropsychiatric symptoms in the context of progression of more classic motor symptoms in amyotrophic lateral sclerosis (ALS) and to examine the impact of neuropsychiatric symptoms on survival. Methods: The study cohort consisted of 219 patients with ALS (limb onset = 159; bulbar onset = 60), with neuropsychiatric symptoms measured using the Motor Neuron Disease Behavioural Scale and more classic ALS symptoms assessed by the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised. For detection of symptom susceptibility (neuropsychiatric vs classic motor), a Rasch analysis was applied (n = 219). Cox proportional hazard regression models were used for the survival analysis (n = 115 patients), which incorporated neuropsychiatric and classic motor symptoms. Results: Rasch analysis demonstrated that neuropsychiatric symptoms appeared earlier than classic motor features of ALS. However, differences in neuropsychiatric scores did not affect survival: patients with abnormalities in neuropsychiatric domains did not exhibit a different rate of survival than those without (χ2, 3.447, p = 0.328, −2 log-likelihood 377.341). Conclusions: Neuropsychiatric symptoms appear before classic motor features in ALS, which corroborates the notion that ALS and frontotemporal dementia lie on a disease continuum. The early detection of neuropsychiatric symptoms will be critical to inform clinical decisions and alleviate carer burden. Importantly, subtle neuropsychiatric symptoms alone do not affect survival in ALS, which in turn confirms their pervasive nature in ALS.

Feeling, learning from and being aware of inner states: interoceptive dimensions in neurodegeneration and stroke

Interoception is a complex process encompassing multiple dimensions, such as accuracy, learning and awareness. Here, we examined whether each of those dimensions relies on specialized neural regions distributed throughout the vast interoceptive network. To this end, we obtained relevant measures of cardiac interoception in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal brain damage: behavioural variant fronto-temporal dementia (bvFTD), Alzheimers disease (AD) and fronto-insular stroke. Neural correlates of the three dimensions were examined through structural and functional resting-state imaging, and online measurements of the heart-evoked potential (HEP). The three patient groups presented deficits in interoceptive accuracy, associated with insular damage, connectivity alterations and abnormal HEP modulations. Interoceptive learning was differentially impaired in AD patients, evidencing a key role of memory networks in this skill. Interoceptive awareness results showed that bvFTD and AD patients overestimated their performance; this pattern was related to abnormalities in anterior regions and associated networks sub-serving metacognitive processes, and probably linked to well-established insight deficits in dementia. Our findings indicate how damage to specific hubs in a broad fronto-temporo-insular network differentially compromises interoceptive dimensions, and how such disturbances affect widespread connections beyond those critical hubs. This is the first study in which a multiple lesion model reveals fine-grained alterations of body sensing, offering new theoretical insights into neuroanatomical foundations of interoceptive dimensions. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’.