Risk factors for cognitive impairment in amyotrophic lateral sclerosis: a systematic review and meta-analysis

Prevalence and motor-functional correlates of frontotemporal-spectrum disorders in a large cohort of non-demented ALS patients

BACKGROUND

This study aimed at (1) delivering generalizable estimates of the prevalence of frontotemporal-spectrum disorders (FTSDs) in non-demented ALS patients and (2) exploring their motor-functional correlates.

METHODS

N = 808 ALS patients without FTD were assessed for motor-functional outcomes-i.e., disease duration, severity (ALSFRS-R), progression rate (ΔFS), and stage (King's and Milano-Torino-MiToS-systems)-cognition-via the cognitive section of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS)-and behaviour-via the ECAS-Carer Interview. Neuropsychological phenotypes were retrieved via Strong's revised criteria-i.e., ALS cognitively and behaviourally normal (ALScbn) or cognitively and/or behaviourally impaired (ALSci/bi/cbi).

RESULTS

Defective ECAS-Total performances were detected in ~ 29% of patients, with the ECAS-Executive being failed by the highest number of patients (~ 30%), followed by the ECAS-Language, -Fluency, and -Memory (~ 15-17%) and -Visuospatial (~ %8). Apathy was the most frequent behavioural change (~ 28%), followed by loss of sympathy/empathy (~ 13%); remaining symptoms were reported in < 4% of patients. The distribution of Strong's classifications was as follows: ALScbn: 46.7%; ALSci/bi/cbi: 22.9%/20.0%/10.4%. Multinomial regressions on Strong's classifications revealed that lower ALSFRS-R scores were associated with a higher probability of ALSbi and ALScbi classifications (p ≤ .008). Higher King's and MiToS stages were associated with a higher probability of ALSbi classification (p ≤ .031).

CONCLUSIONS

FTSDs affect ~ 50% of non-demented ALS patients, with cognitive deficits being as frequent as behavioural changes. A higher degree of motor-functional involvement is associated with worse behavioural outcomes-with this link being weaker for cognitive deficits.

Factors associated with Edinburgh Cognitive and Behavioural ALS Screen (ECAS) alteration at time of diagnosis, in amyotrophic lateral sclerosis

BACKGROUND

Edinburgh Cognitive and Behavioral ALS Screen (ECAS) is a validated assessment designed to screen cognitive functions and behavioral disorders in amyotrophic lateral sclerosis (ALS). Objective of this study is to determine the factors associated with ECAS impairment in a cohort of ALS patients without a co-morbid diagnosis of dementia, at the time of diagnosis.

METHODS

We enrolled 71 non-demented ALS patient. We collected clinical and demographic data, ALS familiarity, analysis of the most commonly mutated genes in ALS, ALS Milano Torino Staging System and ALS Functional Rate Scale revised scores, progression rate; finally, we recorded whether symptoms onset involved spinal or bulbar area. The alteration of the ECAS was estimated based on age and education-adjusted-validated cut off for each of the items included in ECAS. A multivariable regression analysis was done.

RESULTS

The significant determinants of ECAS alterations were: bulbar onset in both ALS-specific test and total ECAS score; bulbar onset and familiarity in ALS-non-specific test; finally, familiarity and diagnosis delay in ALS-behavioral test. All the subjects carrying C9orf72 mutations had alteration of both total ECAS score and ALS-specific tests.

DISCUSSION

At diagnosis, bulbar-onset ALS, family history, diagnosis delay and C9orf72 hexanucleotide repeat expansion may contribute to impairment of ECAS.

Genotype-phenotype correlation of SQSTM1 variants in patients with amyotrophic lateral sclerosis

BACKGROUND

Several variants of sequestosome 1 (SQSTM1) were screened in patients with amyotrophic lateral sclerosis (ALS), while the pathogenicity and genotype-phenotype correlation remains unclear.

METHODS

We screened variants of SQSTM1 gene in 2011 Chinese patients with ALS and performed a burden analysis focusing on the rare variants. Furthermore, we conducted a comprehensive analysis of patients with variants of SQSTM1 gene in patients with ALS from our cohort and published studies.

RESULTS

In our cohort, we identified 32 patients with 25 different SQSTM1 variants with a mutant frequency of 1.6%. Notably, 26% (5/19) of the patients with ALS with SQSTM1 variant in our cohort had comorbid cognitive impairment and 43% (3/7) of them had behavioural variant frontotemporal dementia (FTD). Our meta-analysis found a total frequency of SQSTM1 variants in 7183 patients with ALS was 2.4%; burden analysis indicated that patients with ALS had enrichment of ultra-rare (minor allele frequency<0.01%) probably pathogenic variants in SQSTM1. Most variants were missense variants and distributed in various domains of p62 protein, some of which might be related to comorbidities of Paget's disease of bone and FTD.

CONCLUSION

Our study established the largest cohort of patients with ALS with SQSTM1 variants, expanded the mutation spectrum and investigated the genotype-phenotype correlations of SQSTM1 variants.

Cognitive reserve as a modulator of cognitive decline and of behavioral symptoms in patients with amyotrophic lateral sclerosis

Introduction: Amyotrophic lateral sclerosis (ALS) has heterogeneous manifestations ranging from motor neuron degeneration to cognitive and behavioral impairment. This study aims to clarify the interactions between cognition and behavioral symptoms with relevant disease predictors and with cognitive reserve (CR), quantified through education, physical activity, and occupation proxies. Methods: A prospective sample of 162 ALS patients and 61 controls were evaluated with the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) (dependent variable), a Cognitive Reserve Index questionnaire (CRIq) and demographic data (age and sex), and, for patients, clinical variables: disease duration, site of onset, the ALS Functional Rating Scale (ALSFRS), forced vital capacity (FVC), and gene mutation chromosome 9 open reading frame 72 (C9orf72) (independent variables). Multiple regression and mediation analyses were performed to predict cognitive and behavioral symptoms. Results: For the ALS group, the statistical model explained 38.8% of variance in ECAS total (p < 0.001), 59.4% of executive functions (p < 0.001), and 55% of behavioral symptoms (p < 0.001). For controls, it accounted for 52.8% of variance in ECAS total (p < 0.001). Interaction effects and mediation analysis showed CR is an ECAS total modulator, with a differential effect within groups (p < 0.001). Verbal fluency was the single best cognitive score to differentiate patients from controls (p = 0.004), and the gene mutation C9orf72 was found to be a behavioral symptom' predictor in patients (p = 0.009). Conclusion: This study supports the proposed concept that CR acts as a cognitive modulator in ALS patients and healthy individuals. Moreover, CR also modulates behavioral manifestations in ALS.

Cognitive reserve in ALS: the role of occupational skills and requirements

OBJECTIVE

Amyotrophic Lateral Sclerosis (ALS) is a heterogeneous neurodegenerative condition featuring variable degrees of motor and cognitive impairment. We assessed the impact of specific, empirically derived occupational skills and requirements on cognitive and motor functioning in ALS.

METHODS

Individuals with ALS (n = 150) were recruited from the University of Pennsylvania's Comprehensive ALS Clinic. The Edinburgh Cognitive and Behavioral ALS Screen (ECAS) measured cognition, and the Penn Upper Motor Neuron (PUMNS) and ALS Functional Rating Scales (ALSFRS-R) measured motor symptoms. We derived 17 factors representing distinct occupational skills and requirements from the Occupational Information Network (O*NET), which were related to cognitive and motor scores using multiple linear regression.

RESULTS

Occupational roles involving greater reasoning ability (β = 2.12, p < .05), social ability (β = 1.73, p < .05), analytic skills, (β = 3.12, p < .01) and humanities knowledge (β = 1.83, p<.01) were associated with better performance on the ECAS, while jobs involving more exposure to environmental hazards (β=-2.57, p < .01) and technical skills (β=-2.16, p<.01) were associated with lower ECAS scores. Jobs requiring more precision skills (β = 1.91, p < .05) were associated with greater motor dysfunction on the PUMNS.

CONCLUSIONS

Occupational histories involving more cognitively complex skills and activities were related to preserved cognitive functioning in ALS consistent with the cognitive reserve hypothesis, while jobs with greater exposure to environmental hazards and technical demands were linked to poorer cognitive functioning. Jobs involving more repetitive movements were associated with worse motor functioning, possibly due to overuse. Occupational history provides insight into protective and risk factors for variable degrees of cognitive and motor dysfunction in ALS.

Peripheral immunity involvement in the cognitive impairment of sporadic amyotrophic lateral sclerosis

Background

Recent research has indicated the significance of immune activation in amyotrophic lateral sclerosis (ALS). However, the impact of peripheral immunity on cognitive impairment in sporadic ALS remains poorly characterized. Therefore, we aim to assess the relationship between peripheral immune parameters and cognitive impairment in patients with sporadic ALS.

Methods

A case-control study involving 289 patients with sporadic ALS was conducted. All participants underwent cognitive assessment and measurements of blood immune parameters. The main outcomes included adjusted odds ratios (ORs) in multivariate logistic regression analysis and adjusted coefficients in a multivariate linear regression model. Sensitivity analysis was performed with stratification by the King's clinical stage.

Results

Cognitive impairment was observed in 98 (33.9%) patients. Higher counts of leukocyte (OR, 0.53; 95% CI, 0.29 to 0.95; p = 0.03), neutrophil (OR, 0.48; 95% CI, 0.26 to 0.88; p = 0.02), and monocyte (OR, 0.33; 95% CI, 0.18 to 0.60; p < 0.001) were significantly associated with better cognitive preformence in sporadic ALS, particularly among patients in King's clinical stages 1 and 2. Conversely, a higher percentage of CD4+ T cells was linked to an increased risk of cognitive impairment (OR, 2.79; 95% CI, 1.52 to 5.09; p = 0.001), particularly evident in patients in King's clinical stage 3.

Conclusion

These results highlight the involvement of peripheral immunity in the cognitive impairment of sporadic ALS and suggest dynamic and intricate roles that vary across disease stages. Elucidating the links between immunity and ALS sheds light on the pathophysiological mechanisms underlying this fatal neurodegenerative disorder and informs potential immunotherapeutic strategies.

Biochemical parameters as a tool to assess the nutritional status of patients with amyotrophic lateral sclerosis

Background

The research aimed to analyze blood biochemical parameters in patients with amyotrophic lateral sclerosis and to determine whether they can be used to assess their nutritional status.

Methods

The study included 45 patients diagnosed with amyotrophic lateral sclerosis (ALS): 28 (62.2%) were men and 17 (37.8%) were women. The mean age of the study participants was 50.69 ± 7.24 years. The control group consisted of 30 practically healthy individuals.

Results

Compared with practically healthy individuals, patients with ALS had significantly lower blood parameters, including total lymphocyte count (1.49 ± 0.11 vs. 2.86 ± 0.25, p < 0.05), total protein (60.55 ± 2.38 vs. 77.80 ± 4.41, p < 0.05), albumin (33.70 ± 2.03 vs. 46.49 ± 3.22, p < 0.05), urea (3.09 ± 0.36 vs. 5.37 ± 0.50, p < 0.05), creatinine (51.28 ± 4.42 vs. 70.91 ± 5.13, p < 0.05), and transferrin (1.84 ± 0.12 vs. 2.32 ± 0.10, p < 0.05). These parameters correspond to first-degree malnutrition. There were direct correlations between anthropometric and biochemical parameters in the ALS group. BMI correlated with the blood levels of total protein (r = 0.22, p < 0.05), albumin (r = 0.27, p < 0.05), urea (r = 0.33, p < 0.05), creatinine (r = 0.30, p < 0.05), transferrin (r = 0.18, p < 0.05), and total lymphocyte count (r = 0.20, p < 0.05). PNI correlated with the blood levels of total protein (r = 0.53, p < 0.05), albumin (r = 0.87, p < 0.05), total cholesterol (r = 0.34, p < 0.05), transferrin (r = 0.40, p < 0.05), total lymphocyte count (r = 0.79, p < 0.05), urea (r = 0, 37, p < 0.05), and creatinine (r = 0.32, p < 0.05).

Conclusion

The study presents compelling evidence supporting the utilization of biochemical parameters, including total protein, albumin, urea, creatinine, transferrin, and total lymphocyte count, for potentially evaluating the nutritional status of individuals diagnosed with ALS.

Impairment of oculomotor functions in patients with early to advanced amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) can result into an incomplete locked in state (iLIS), in which communication depends on eye tracking computer devices. Oculomotor function impairments in ALS have been reported, but there is little research, particularly with respect to patients in iLIS. In the present study, we compared reflexive and executive oculomotor function by means of an eye tracking test battery between three groups: advanced ALS patients in iLIS (n = 22), patients in early to middle ALS stages (n = 44) and healthy subjects (n = 32). Patients with ALS showed significant deteriorations in oculomotor functions, with stronger impairments in iLIS. More specifically, ALS patients produced visually guided prosaccades with longer latencies and more frequent hypometria compared to healthy subjects. Longest latencies were obtained in iLIS patients, with a stronger prolongation for vertical than for horizontal prosaccades. ALS patients made more antisaccade errors and generated antisaccades with longer latencies. Smooth pursuit was also impaired in ALS. In the earlier ALS stages, bulbar onset patients presented stronger antisaccade and smooth pursuit deficits than spinal onset patients. Our findings reveal a relevant deterioration of important oculomotor functions in ALS, which increases in iLIS. It includes impairments of reflexive eye movements to loss of executive inhibitory control, indicating a progressing pathological involvement of prefrontal, midbrain and brainstem areas. The assessment of oculomotor functions may therefore provide clinically relevant bio- and progression marker, particularly in advanced ALS.

ALS-plus related clinical and genetic study from China

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. An increasing number of researchers have found extra motor features in ALS, which are also called ALS-plus syndromes. Besides, a great majority of ALS patients also have cognitive impairment. However, clinical surveys of the frequency and genetic background of ALS-plus syndromes are rare, especially in China.

METHODS

We investigated a large cohort of 1015 patients with ALS, classifying them into six groups according to different extramotor symptoms and documenting their clinical manifestations. Meanwhile, based on their cognitive function, we divided these patients into two groups and compared demographic characteristics. Genetic screening for rare damage variants (RDVs) was also performed on 847 patients.

RESULTS

As a result, 16.75% of patients were identified with ALS-plus syndrome, and 49.5% of patients suffered cognitive impairment. ALS-plus group had lower ALSFRS-R scores, longer diagnostic delay time, and longer survival times, compared to ALS pure group. RDVs occurred less frequently in ALS-plus patients than in ALS-pure patients (P = 0.042) but showed no difference between ALS-cognitive impairment patients and ALS-cognitive normal patients. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus symptoms than ALS-cognitive normal group (P = 0.001).

CONCLUSION

In summary, ALS-plus patients in China are not rare and show multiple differences from ALS-pure patients in clinical and genetic features. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus syndrome than ALS-cognitive normal group. Our observations correspond with the theory that ALS involves several diseases with different mechanisms and provide clinical validation.

The Spectrum of Cognitive Dysfunction in Amyotrophic Lateral Sclerosis: An Update

Cognitive dysfunction is an important non-motor symptom in amyotrophic lateral sclerosis (ALS) that has a negative impact on survival and caregiver burden. It shows a wide spectrum ranging from subjective cognitive decline to frontotemporal dementia (FTD) and covers various cognitive domains, mainly executive/attention, language and verbal memory deficits. The frequency of cognitive impairment across the different ALS phenotypes ranges from 30% to 75%, with up to 45% fulfilling the criteria of FTD. Significant genetic, clinical, and pathological heterogeneity reflects deficits in various cognitive domains. Modern neuroimaging studies revealed frontotemporal degeneration and widespread involvement of limbic and white matter systems, with hypometabolism of the relevant areas. Morphological substrates are frontotemporal and hippocampal atrophy with synaptic loss, associated with TDP-43 and other co-pathologies, including tau deposition. Widespread functional disruptions of motor and extramotor networks, as well as of frontoparietal, frontostriatal and other connectivities, are markers for cognitive deficits in ALS. Cognitive reserve may moderate the effect of brain damage but is not protective against cognitive decline. The natural history of cognitive dysfunction in ALS and its relationship to FTD are not fully understood, although there is an overlap between the ALS variants and ALS-related frontotemporal syndromes, suggesting a differential vulnerability of motor and non-motor networks. An assessment of risks or the early detection of brain connectivity signatures before structural changes may be helpful in investigating the pathophysiological mechanisms of cognitive impairment in ALS, which might even serve as novel targets for effective disease-modifying therapies.

Bulbar involvement and cognitive features in amyotrophic lateral sclerosis: a retrospective study on 347 patients

Background

This study aimed at clarifying the role of bulbar involvement (BI) as a risk factor for cognitive impairment (CI) in non-demented amyotrophic lateral sclerosis (ALS) patients.

Methods

Data on N = 347 patients were retrospectively collected. Cognition was assessed via the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). On the basis of clinical records and ALS Functional Rating Scale-Revised (ALSFRS-R) scores, BI was characterized as follows: (1) BI at onset-from medical history; (2) BI at testing (an ALSFRS-R-Bulbar score ≤11); (3) dysarthria (a score ≤3 on item 1 of the ALSFRS-R); (4) severity of BI (the total score on the ALSFRS-R-Bulbar); and (5) progression rate of BI (computed as 12-ALSFRS-R-Bulbar/disease duration in months). Logistic regressions were run to predict a below- vs. above-cutoff performance on each ECAS measure based on BI-related features while accounting for sex, disease duration, severity and progression rate of respiratory and spinal involvement and ECAS response modality.

Results

No predictors yielded significance either on the ECAS-Total and -ALS-non-specific or on ECAS-Language/-Fluency or -Visuospatial subscales. BI at testing predicted a higher probability of an abnormal performance on the ECAS-ALS-specific (p = 0.035) and ECAS-Executive Functioning (p = 0.018). Lower ALSFRS-R-Bulbar scores were associated with a defective performance on the ECAS-Memory (p = 0.025). No other BI-related features affected other ECAS performances.

Discussion

In ALS, the occurrence of BI itself, while neither its specific features nor its presence at onset, might selectively represent a risk factor for executive impairment, whilst its severity might be associated with memory deficits.

Cognitive reserve in ALS: The role of occupational skills and requirements

Background

Amyotrophic Lateral Sclerosis (ALS) is a heterogeneous neurodegenerative condition featuring variable degrees of motor decline and cognitive impairment. We test the hypothesis that cognitive reserve (CR), defined by occupational histories involving more complex cognitive demands, may protect against cognitive decline, while motor reserve (MR), defined by working jobs requiring complex motor skills, may protect against motor dysfunction.

Methods

Individuals with ALS (n=150) were recruited from the University of Pennsylvania's Comprehensive ALS Clinic. Cognitive performance was evaluated using the Edinburgh Cognitive and Behavioral ALS Screen (ECAS), and motor functioning was measured using Penn Upper Motor Neuron (PUMNS) scale and ALS Functional Rating Scales (ALSFRS-R). The Occupational Information Network (O*NET) Database was used to derive 17 factors representing distinct worker characteristics, occupational requirements, and worker requirements, which were related to ECAS, PUMNS, and ALSFRS-R scores using multiple linear regression.

Results

A history of working jobs involving greater reasoning ability (β=2.12, p<.05), social ability (β=1.73, p<.05), analytic skills, (β=3.12, p<.01) and humanities knowledge (β=1.83, p<.01) was associated with better performance on the ECAS, while jobs involving more exposure to environmental hazards (β=-2.57, p<.01) and technical skills (β=-2.16, p<.01) were associated with lower ECAS Total Scores. Jobs involving greater precision skills (β=1.91, p<.05) were associated with greater disease severity on the PUMNS. Findings for the ALSFRS-R did not survive correction for multiple comparisons.

Discussion

Jobs requiring greater reasoning abilities, social skills, and humanities knowledge were related to preserved cognitive functioning consistent with CR, while jobs with greater exposure to environmental hazards and technical demands were linked to poorer cognitive functioning. We did not find evidence of MR as no protective effects of occupational skills and requirements were found for motor symptoms, and jobs involving greater precision skills and reasoning abilities were associated with worse motor functioning. Occupational history provides insight into protective and risk factors for variable degrees of cognitive and motor dysfunction in ALS.

Prevalence and associated factors of apathy in Chinese ALS patients

Objectivve

This study aimed to explore the prevalence and clinical correlates of apathy in amyotrophic lateral sclerosis (ALS) in a cohort of Chinese patients.

Methods

A total of 1,013 ALS patients were enrolled in this study. Apathy was recorded during face-to-face interviews using Frontal Behavioral Inventory, and other patient characteristics, including depression, anxiety, and cognitive function, were collected using Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), and Chinese version of Addenbrooke’s Cognitive Examination-revised. Health-related quality of life of ALS patients and their caregivers was also evaluated, and the potential factors associated with apathy were explored using forward binary regression analysis. Survival was analyzed using the Cox proportional hazards model.

Results

The prevalence of apathy in all patients was 28.9%. Patients in the late disease stage had a higher prevalence of apathy than those in the early disease stage. Furthermore, patients with apathy had a lower ALS Functional Rating Scale revised (ALSFRS-R) score, higher HDRS score, HARS score and higher proportion of reported problems in the anxiety/depression. Additionally, their caregivers had higher score of depression and higher Zarit-Burden Interview scores. Multivariate regression analysis revealed that apathy in ALS was associated with the onset region (p = 0.027), ALSFRS-R score (p = 0.007), depression (p = 0.001) and anxiety (p &lt; 0.001). Apathy had a significant negative effect on survival in ALS patients (p = 0.032).

Conclusion

Apathy is relatively common (28.9%) in Chinese patients with ALS. Apathy is related to both the severity of the disease, and the presentation of non-motor symptoms in ALS, such as depression and anxiety disorders. Apathy is an independent prognostic factor for survival and requires early intervention and management.

Cognition in the course of ALS-a meta-analysis

Objective: The goal of this meta-analysis is to improve insight into the development of cognition over the course of ALS and to assess predictors of cognitive performance.Method: A literature search was conducted in Pubmed and Web of Science on 29 July 2019 and 16 March 2021. Data were screened in Endnote^® Version X9 (London, UK). Meta-analyses and meta-regressions were calculated for cross-sectional data using Rstudio^®. Studies were assigned to temporal and physical categories and Hedges' g was calculated for the respective categories to provide an estimate of a cognitive course based on cross-sectional data. Due to low numbers and heterogeneity in reporting, longitudinal studies were analyzed descriptively.Results: A total of N = 45 cross-sectional and N = 13 longitudinal studies were included. Impairments in all cognitive domains, except verbal IQ, were found in ALS patients (PALS). PALS showed stable cognitive performances in cross-sectional and in most longitudinal studies. PALS with symptoms for 18-24 months and PALS who had an ALSFRS-R score of 40-36 were the most frequently reported subgroup regarding neuropsychology. Age was related to visuospatial functioning, and depressiveness to attention. In longitudinal studies, impact of site of onset and cognitive status at baseline on cognitive course was found.Conclusion: Despite vast evidence for cognitive impairment at disease onset in different domains, evidence for evolution of these deficits is rather limited, suggesting that PALS present with cognitive impairment early in the course possibly in a sense of disease trait.

Cognitive and behavioral involvement in ALS has been known for more than a century

BACKGROUND

Among clinicians and researchers, it is common knowledge that, in ALS, cognitive and behavioral involvement within the spectrum of frontotemporal degenerations (FTDs) begun to be regarded as a fact in the late 1990s of the twentieth century. By contrast, a considerable body of evidence on cognitive/behavioral changes in ALS can be traced in the literature dating from the late nineteenth century.

METHODS

Worldwide reports on cognitive/behavioral involvement in ALS dating from 1886 to 1981 were retrieved thanks to Biblioteca di Area Medica "Adolfo Ferrate," Sistema Bibliotecario di Ateneo, University of Pavia, Pavia, Italy and qualitatively synthetized.

RESULTS

One-hundred and seventy-four cases of ALS with co-occurring FTD-like cognitive/behavioral changes, described in Europe, America, and Asia, were detected. Neuropsychological phenotypes were consistent with the revised Strong et al.'s consensus criteria. Clinical observations were not infrequently supported by histopathological, post-mortem verifications of extra-motor, cortical/sub-cortical alterations, as well as by in vivo instrumental exams-i.e., assessments of brain morphology/physiology and psychometric testing. In this regard, as earlier as 1907, the notion of motor and cognitive/behavioral features in ALS yielding from the same underlying pathology was acknowledged. Hereditary occurrences of ALS with cognitive/behavioral dysfunctions were reported, as well as familial associations with ALS-unrelated brain disorders. Neuropsychological symptoms often occurred before motor ones. Bulbar involvement was at times acknowledged as a risk factor for cognitive/behavioral changes in ALS.

DISCUSSION

Historical observations herewith delivered can be regarded as the antecedents of current knowledge on cognitive/behavioral impairment in the ALS-FTD spectrum.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a fatal CNS neurodegenerative disease. Despite intensive research, current management of amyotrophic lateral sclerosis remains suboptimal from diagnosis to prognosis. Recognition of the phenotypic heterogeneity of amyotrophic lateral sclerosis, global CNS dysfunction, genetic architecture, and development of novel diagnostic criteria is clarifying the spectrum of clinical presentation and facilitating diagnosis. Insights into the pathophysiology of amyotrophic lateral sclerosis, identification of disease biomarkers and modifiable risks, along with new predictive models, scales, and scoring systems, and a clinical trial pipeline of mechanism-based therapies, are changing the prognostic landscape. Although most recent advances have yet to translate into patient benefit, the idea of amyotrophic lateral sclerosis as a complex syndrome is already having tangible effects in the clinic. This Seminar will outline these insights and discuss the status of the management of amyotrophic lateral sclerosis for the general neurologist, along with future prospects that could improve care and outcomes for patients with amyotrophic lateral sclerosis.

Primary progressive aphasia and motor neuron disease: A review

Background

This study aims at reviewing, within the framework of motor neuron disease-frontotemporal degeneration (MND-FTD)-spectrum disorders, evidence on the co-occurrence between primary progressive aphasia (PPA) and MND in order to profile such a complex at pathological, genetic and clinical levels.

Methods

This review was pre-registered (osf.io/ds8m4) and performed in accordance with the 2020 PRISMA guidelines. Case reports/series and group studies were included if addressing (1) progressive non-fluent aphasia (PNFA) or semantic dementia (SD) with MND or (2) MND patients with co-morbid PNFA/SD.

Results

Out of 546 initial records, 56 studies were included. As to case reports/series (N = 35), which included 61 PPA-MND patients, the following findings yielded: (1) PNFA is more frequent than SD in PPA-MND; (2) in PPA-MND, the most prevalent motor phenotypes are amyotrophic lateral sclerosis and predominant-upper MND, with bulbar involvement being ubiquitous; (3) extrapyramidal features are moderately frequent in PPA-MND; (4) PPA-MND patients usually display frontotemporal, left-greater-than-right involvement; (5) TDP-43-B is the typical pathological substrate of PPA-MND; (6) TBK1 mutations represent the most frequent genetic risk factors for PPA-MND.

As to group studies, including 121 patients, proportional meta-analytic procedures revealed that: (1) the lifetime prevalence of MND in PPA is 6%; (2) PPA occurs in 19% of patients with co-morbid MND and FTD; (3) MND is more frequent in PNFA (10%) than in SD patients (3%).

Discussion

Insights herewith delivered into the clinical, neuropathological and genetic features of PPA-MND patients prompt further investigations aimed at improving clinical practice within the MND-FTD spectrum.

Cognition and motor phenotypes in ALS: a retrospective study

Background

Amyotrophic lateral sclerosis (ALS) is phenotypically heterogeneous in motor manifestations, and the extent of upper vs. lower motor neuron involvement is a widespread descriptor. This study aimed to examine cognition across different ALS motor phenotypes.

Methods

ALS patients (N = 124) were classified as classical (N = 66), bulbar (N = 13), predominant-upper motor neuron (PUMN; N = 19), and predominant-lower motor neuron (PLMN; N = 26) phenotypes. Cognition was assessed with the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and function with the ALS Functional Rating Scale—Revised (ALSFRS-R). Revised ALS-FTD consensus criteria were applied for cognitive/behavioral phenotyping.

Results

Defective ECAS-total scores were detected in all groups — bulbar: 15.4%, classical: 30.3%, PLMN: 23.1%, and PUMN: 36.8%. Classical and PUMN ALS patients performed worse than PLMN ones on ECAS-total, ALS-specific, Fluency, and Executive measures. No other difference was detected. Worse ASLFRS-R scores correlated with poorer ECAS-total scores in classical ALS patients.

Conclusions

Frontotemporal cognitive deficits are more prevalent in PUMN and classical ALS and linked to disease severity in the latter, but occur also in PLMN phenotypes.

Supplementary information

The online version contains supplementary material available at 10.1007/s10072-022-06157-x

Association between vascular risk factors and cognitive impairment in amyotrophic lateral sclerosis: a case-control study

Objective: The disease-modifying effects of type 2 diabetes mellitus (T2DM), and hyperlipidemia on the risk and prognosis of amyotrophic lateral sclerosis (ALS) have gained significant attention. We aim to evaluate the association between common vascular risk factors and cognitive impairment in patients with ALS. Methods: Patients with ALS were consecutively recruited between June 2012 and November 2019 from a tertiary referral center for ALS at the West China Hospital. Vascular risk factors (hypertension, T2DM, hyperlipidemia, overweight, and smoking) were confirmed based on clinical data. Cognitive function was evaluated by the Chinese version of Addenbrooke's Cognitive Examination-revised. With careful confounder adjustment, multivariable logistic regression analysis was performed separately and accumulatively to determine the association between cognitive impairment and vascular risk factors in ALS. Results: Of 870 patients, 266 (30.6%) had cognitive impairment. No cognitive burden from vascular risk factors was found in patients with ALS. On the contrary, we first observed that T2DM (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.25-0.98; p = 0.04) and hyperlipidemia (OR, 0.50; 95% CI, 0.26-0.97; p = 0.04) showed protective effects against cognitive decline in ALS, adjusted for age, sex, educational level, site of onset, Revised-ALS Functional Rating Scale score, predominant upper motor neuron phenotype, family history of ALS, and the remaining vascular risk factors. Sensitivity analyses of sex did not substantially reverse the risk estimates. Conclusions: T2DM and hyperlipidemia decrease the risk of cognitive impairment in patients with ALS. The fitness hypothesis in ALS has been tested and expanded in our work.

Genetic factors for survival in amyotrophic lateral sclerosis: an integrated approach combining a systematic review, pairwise and network meta-analysis

BACKGROUND

The time of survival in patients with amyotrophic lateral sclerosis (ALS) varies greatly, and the genetic factors that contribute to the survival of ALS are not well studied. There is a lack of a comprehensive study to elucidate the role of genetic factors in the survival of ALS.

METHODS

The published studies were systematically searched and obtained from PubMed, EMBASE, and the Cochrane Library without any language restrictions from inception to Oct 27, 2021. A network meta-analysis for ALS causative/risk genes and a systematic review and pairwise meta-analysis for other genetic modifiers were conducted. The PROSPERO registration number: CRD42022311646.

RESULTS

A total of 29,764 potentially relevant references were identified, and 71 papers were eligible for analysis based on pre-decided criteria, including 35 articles in network meta-analysis for 9 ALS causative/risk genes, 17 articles in pairwise meta-analysis for four genetic modifiers, and 19 articles described in the systematic review. Variants in three genes, including ATXN2 (HR: 3.6), C9orf72 (HR: 1.6), and FUS (HR:1.8), were associated with short survival of ALS, but such association was not identified in SOD1, TARDBP, TBK1, NEK1, UBQLN2, and CCNF. In addition, UNC13A rs12608932 CC genotype and ZNF521B rs2275294 C allele also caused a shorter survival of ALS; however, APOE ε4 allele and KIFAP3 rs1541160 did not be found to have any effect on the survival of ALS.

CONCLUSIONS

Our study summarized and contrasted evidence for prognostic genetic factors in ALS and would help to understand ALS pathogenesis and guide clinical trials and drug development.

Progressive medial temporal degeneration with TDP-43 pathology is associated with upper limb and bulbar onset types of amyotrophic lateral sclerosis

OBJECTIVE

This study aimed to clarify the relationship between progressive medial temporal atrophy and onset subtype in patients with amyotrophic lateral sclerosis (ALS).

METHODS

Medial temporal atrophy, ALS functional rating scale (ALSFRS), and cognitive function were assessed in 119 patients who were grouped into three ALS subtypes: bulbar, upper limb, and lower limb onset. Medial temporal atrophy, represented by a Z-score, was determined using an analysis software of magnetic resonance images known as the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD). Among 119 patients, 60 underwent follow-up VSRAD, ALSFRS, and cognitive testing. The sequential data were compared among onset subtypes. Furthermore, TDP-43 pathology was assessed in 20 autopsied patients (including seven who underwent VSRAD before death) to examine the relationships among medial temporal atrophy, onset subtypes, and severity of the hippocampal TDP-43 pathology.

RESULTS

Multiple regression analysis revealed that the Z-score at baseline was associated with the age of onset and duration of illness. A high Z-score at baseline and the bulbar/upper limb subtypes affected the progression rate of Z-score. Pathological examination revealed increased hippocampal TDP-43 pathology score associated with bulbar and upper limb subtypes. Moreover, the Z-score before death correlated with the hippocampal TDP-43 pathology score.

CONCLUSION

Medial temporal atrophy in ALS is associated with bulbar and upper limb onset subtypes. This progression may be related to the extent of TDP-43 pathology.

Italian adaptation of the Beaumont Behavioral Inventory (BBI): psychometric properties and clinical usability

Objective. Up to 50% of patients affected by amyotrophic lateral sclerosis (ALS) show behavioral changes within the spectrum of frontotemporal degeneration (FTD). Behavioral dysfunctions in ALS patients negatively impact on management, prognosis and survival. It is, thus, crucial to develop ALS-specific psychometric tools for early detecting alterations in behavior. This study aimed at investigating psychometric properties and feasibility of the Beaumont Behavioral Impairment (BBI), a proxy-report questionnaire designed to screen for FTD-like behavioral symptoms in ALS patients.Methods. Ninety ALS patients were compared to 100 healthy participants (HPs) on the BBI. ALS patients underwent clinical, cognitive, mood/anxiety and further behavioral (Frontal System Behavior Scale, FrSBe; Frontal Behavioral Inventory, FBI) evaluation. Validity, reliability, sensitivity and specificity of the BBI were assessed.Results. The BBI was significantly related to FrSBe and FBI scores, whereas not to other measures. A Principal Component Analysis yielded a mono-component structure; Cronbach's α was .93. The BBI proved to be sensitive to changes in behavior as well as to discriminate between different degrees of dysfunction. By addressing the FrSBe as the gold standard, the BBI reached optimal sensitivity (85.7%) and specificity (79.7%) at a cutoff of 10.5. Moreover, the BBI proved to be more accurate than the FrSBe and the FBI in clinical classifications.Conclusion. The BBI showed high internal consistency, as well as good construct, convergent and divergent validity. Its clinical usability is encouraged in ALS patients as being able to sensitively and specifically detect FTD-like behavioral changes.