Ecological validity of performance-based cognitive screeners in amyotrophic lateral sclerosis: preliminary evidence.

BACKGROUND: This study aimed at preliminarily assessing, in a cohort of non-demented amyotrophic lateral sclerosis (ALS) patients, the ecological validity, and more specifically the veridicality, of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and the ALS Cognitive Behavioral Screen (ALS-CBS™), by relating their scores to caregiver-report ratings of cognitive changes. METHODS: N = 147 patient-caregiver dyads were recruited. Patients were administered the ECAS and ALS-CBS™, whilst caregiver the Caregiver Behavioral Questionnaire (CBQ) and Beaumont Behavioural Inventory (BBI). An Ecological Cognitive Functioning Index (ECFI) was derived from those items of the CBQ and BBI that tap on executive and language changes. Ecological validity was assessed via both correlational and predictive analyses net of caregiver-rated behavioural changes (as assessed by the ECAS-Carer Interview). RESULTS: The ECFI was associated with the total scores on both the ECAS (p = .014) and ALS-CBS™ (p = .017). When looking at ECAS and ALS-CBS™ subscales, those assessing verbal fluency were selectively associated with the ECFI. The ECFI was higher in patients performing defectively on the ECAS (p = .004) and on the ALS-CBS™ (p = .027). DISCUSSION: This study suggests that both the ECAS and the ALS-CBS™ represent a valid estimate of non-demented ALS patients' cognitive status in the real world, also highlighting the clinical relevance of cognitive changes reported by caregivers.

Clinical validity of the Italian adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB) in Mild Cognitive Impairment and Alzheimer's Disease.

BACKGROUND: The identification and staging of Alzheimer's Disease (AD) represent a challenge, especially in the prodromal stage of Mild Cognitive Impairment (MCI), when cognitive changes can be subtle. Worldwide efforts were dedicated to select and harmonize available neuropsychological instruments. In Italy, the Italian Network of Neuroscience and Neuro-Rehabilitation has promoted the adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB), collecting normative data from 433 healthy controls (HC). Here, we aimed to explore the ability of I-UDSNB to differentiate between a) MCI and HC, b) AD and HC, c) MCI and AD. METHODS: One hundred thirty-seven patients (65 MCI, 72 AD) diagnosed after clinical-neuropsychological assessment, and 137 HC were included. We compared the I-UDSNB scores between a) MCI and HC, b) AD and HC, c) MCI and AD, with t-tests. To identify the test(s) most capable of differentiating between groups, significant scores were entered in binary logistic and in stepwise regressions, and then in Receiver Operating Characteristic curve analyses. RESULTS: Two episodic memory tests (Craft Story and Five Words test) differentiated MCI from HC subjects; Five Words test, Semantic Fluency (vegetables), and TMT-part B differentiated AD from, respectively, HC and MCI. CONCLUSIONS: Our findings indicate that the I-UDSNB is a suitable tool for the harmonized and concise assessment of patients with cognitive decline, showing high sensitivity and specificity for the diagnosis of MCI and AD.

Longitudinal Feasibility of the Montreal Cognitive Assessment (MoCA) in Non-Demented ALS Patients.

INTRODUCTION: The present study aimed at testing the longitudinal feasibility of the Montreal Cognitive Assessment (MoCA) in an Italian cohort of non-demented amyotrophic lateral sclerosis (ALS) patients. METHODS: N = 39 non-demented ALS patients were followed-up at a 5-to-10-month interval (M = 6.8; SD = 1.4) with the MoCA and the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). Practice effects, test-retest reliability, and predictive validity (against follow-up ECAS scores) were assessed. Reliable change indices (RCIs) were derived via a regression-based approach by accounting for retest interval and baseline confounders (i.e., demographics, disease duration, and severity and progression rate). RESULTS: At retest, 100% and 69.2% of patients completed the ECAS and the MoCA, respectively. Patients who could not complete the MoCA showed a slightly more severe and fast-progressing disease. The MoCA was not subject to practice effects (t[32] = -0.80; p = 0.429) and was reliable at retest (intra-class correlation = 0.82). Moreover, baseline MoCA scores predicted the ECAS at retest. RCIs were successfully derived - with baseline MoCA scores being the only significant predictor of retest performances (ps < 0.001). CONCLUSIONS: As long as motor disabilities do not undermine its applicability, the MoCA appears to be longitudinally feasible at a 5-to-10-month interval in non-demented ALS patients. However, ALS-specific screeners - such as the ECAS - should be preferred whenever possible.

Frontotemporal-spectrum disorders and functional independence in non-demented ALS patients.

BACKGROUND: The present study aimed at determining whether, net of motor confounders, neuropsychological features affect functional independence (FI) in activities of daily living (ADLs) in non-demented amyotrophic lateral sclerosis (ALS) patients. METHODS: N = 88 ALS patients without frontotemporal dementia were assessed for FI-Katz's Basic ADL Scale (BADL) and Lawton-Brody's Instrumental ADL Scale (IADL)-, cognition-Edinburgh Cognitive and Behavioural ALS Screen (ECAS)-and behaviour-Beaumont Behavioural Inventory and Dimensional Apathy Scale. The association between cognitive and behavioural measures and BADL/IADL scores was assessed by covarying for demographics, anxiety and depression levels, disease duration and motor confounders-i.e. ALS Functional Rating Scale-Revised (ALSFRS-R) scores, progression rate and both King's and Milano-Torino stages. RESULTS: Higher scores on the ECAS-Language were associated with higher IADL scores (p = 0.005), whilst higher apathetic features-as measured by the Dimensional Apathy Scale (DAS)-were inversely related to the BADL (p = 0.003). Whilst IADL scores were related to all ECAS-Language tasks, the DAS-Initiation was the only subscale associated with BADL scores. Patients with abnormal ECAS-Language (p = 0.023) and DAS (p = 0.008) scores were more functionally dependent than those without. DISCUSSION: Among non-motor features, language changes and apathetic features detrimentally affect FI in non-demented ALS patients.

Validity, diagnostics and feasibility of the Italian version of the Montreal Cognitive Assessment (MoCA) in Huntington's disease.

BACKGROUND: This study is aimed at assessing the clinimetric properties and feasibility of the Italian version of the Montreal Cognitive Assessment (MoCA) in patients with Huntington's disease (HD). METHODS: N = 39 motor-manifest HD patients, N = 74 Parkinson's disease (PD) patients and N = 92 matched HCs were administered the MoCA. HD patients further underwent the Unified Huntington's Disease Rating Scale (UHDRS), self-report questionnaires for anxiety and depression and a battery of first- and second-level cognitive tests. Construct validity was tested against cognitive and behavioural/psychiatric measures, whereas ecological validity against motor-functional subscales of the UHDRS. Sensitivity to disease severity was tested, via a logistic regression, by exploring whether the MoCA discriminated between patients in Shoulson-Fahn stage ≤ 2 vs. > 2. The same analysis was employed to test its ability to discriminate HD patients from HCs and PD patients. RESULTS: The MoCA converged towards cognitive and behavioural measures but diverged from psychiatric ones, being also associated with motor/functional measures from the UHDRS. In identifying patients with cognitive impairment, adjusted MoCA scores were highly accurate (AUC = .92), yielding optimal diagnostics at the cut-off of < 19.945 (J = .78). The MoCA was able to discriminate patients in the middle-to-advanced from those in the early-to-middle stages of the disease (p = .037), as well as to differentiate HD patients from both HCs (p < .001) and PD patients (p < .001). CONCLUSIONS: The MoCA is a valid, diagnostically sound and feasible cognitive screener in motor-manifest HD patients, whose adoption is thus encouraged in clinical practice and research.

An exploratory study on counterfactual thinking in amyotrophic lateral sclerosis.

Objectives: This study aimed at exploring (1) the motor and non-motor correlates of counterfactual thinking (CFT) abilities in non-demented amyotrophic lateral sclerosis (ALS) patients and (2) the ability of CFT measures to discriminate these patients from healthy controls (HCs) and patients with and without cognitive impairment. Methods: N = 110 ALS patients and N = 51 HCs were administered two CFT tasks, whose sum, resulting in a CFT Index (CFTI), was addressed as the outcome. Patients further underwent an in-depth cognitive, behavioral, and motor-functional evaluation. Correlational analyses were run to explore the correlates of the CFTI in patients. Logistic regressions were performed to test whether the CFTI could discriminate patients from HCs. Results: The CFTI was selectively associated (p ≤ 0.005) with fluency and memory subscales of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS), but not with other variables. CFTI scores discriminated patients from HCs (p < 0.001) with high accuracy (82%), but not patients with a normal vs. defective performance on the ECAS-Total. Conclusion: CFT measures in non-demented ALS patients were associated with verbal fluency and memory functions, and they were also able to discriminate them from HCs.

Coexistence of Amyotrophic Lateral Sclerosis and Alzheimer's Disease: Case Report and Review of the Literature.

We describe a case of amyotrophic lateral sclerosis (ALS) associated with Alzheimer's disease (AD) and review the literature about the coexistence of the two entities, highlighting the following: mean age at onset is 63.8 years, with slight female predominance; ALS tends to manifest after cognitive impairment and often begins in the bulbar region; average disease duration is 3 years; cognitive phenotype is mostly amnestic; the pattern of brain involvement is, in most cases, consistent with AD. Our case and the reviewed ones suggest that patients with ALS and dementia lacking unequivocal features of FTD should undergo additional examinations in order to recognize AD.

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.

Influence of kidney function and CSF/serum albumin ratio on plasma Aß42 and Aß40 levels measured on a fully automated platform in patients with Alzheimer's disease.

INTRODUCTION: Alzheimer's disease  (AD) is characterized by decreased cerebrospinal fluid (CSF) Aß42 and Aß42/Aß40 ratio. Aß peptides can now be measured also in plasma and are promising peripheral biomarkers for AD. We evaluated the relationships of plasma Aß species with their CSF counterparts, kidney function, and serum/CSF albumin ratio (Q-Alb) in AD patients. MATERIALS AND METHODS: We measured plasma Aß42 and Aß40, as well as CSF AD biomarkers, with the fully automated Lumipulse platform in a cohort of N = 30 patients with clinical and neurochemical diagnosis of AD. RESULTS: The two plasma Aß peptides correlated strongly with each other (r = 0.7449), as did the corresponding CSF biomarkers (r = 0.7670). On the contrary, the positive correlations of plasma Aß42, Aß40, and Aß42/Aß40 ratio with their CSF counterparts and the negative correlation of plasma Aß42/Aß40 ratio with CSF P-tau181 were not statistically significant. Plasma levels of both Aß species negatively correlated with estimated glomerular filtration rate (eGFR) (Aß42: r = -0.4138; Aß40: r = -0.6015), but plasma Aß42/Aß40 ratio did not. Q-Alb did not correlate with any plasma Aß parameter. DISCUSSION: Plasma Aß42 and Aß40 are critically influenced by kidney function; however, their ratio is advantageously spared from this effect. The lack of significant correlations between plasma Aß species and their CSF counterparts is probably mainly due to small sample size and inclusion of only Aß + individuals. Q-Alb is not a major determinant of plasma Aß concentrations, highlighting the uncertainties about mechanisms of Aß transfer between CNS and periphery.

Single task-level, 2SD-based cutoffs for the Italian version of the Edinburgh Cognitive and Behavioral ALS screen (ECAS).

The present study aimed at deriving, by means of a traditional "2 standard deviation-based" (2SD) approach, single task-level cutoffs for the Italian version of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). Cutoffs were derived - as M-2*SD - from the sample of healthy participants (HPs) included within 2016 Poletti et al.'s normative study - N = 248; 104 males; age: 57.8 ± 10.6; education: 14.1 ± 4.6 - separately for the four, original demographic classes: 1) education <14 years and age ≤60 years; 2) education <14 years and age >60 years; 3) education ≥14 years and age ≤60 years; 4) education ≥14 years and age >60 years. The prevalence of deficits on each task was then estimated within a cohort of N = 377 amyotrophic lateral sclerosis (ALS) patients without dementia. The distribution of abnormal performance prevalences was overall consistent with the cognitive phenotype of ALS. In conclusion, the single task-level cutoffs herewith provided for the Italian version of the ECAS, which complement those already available within Poletti et al.'s normative framework, will help better profile Italian ALS patients' cognitive phenotype within both clinical and research settings.

Equating norms between the ALS Cognitive Behavioral Screen (ALS-CBS™) and the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) in non-demented ALS patients.

BACKGROUND: The present study aimed at deriving equating norms to estimate scores on the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) based on those on the ALS Cognitive Behavioral Screen (ALS-CBS™) in an Italian cohort of non-demented ALS patients. METHODS: ALS-CBS™ and ECAS scores of 293 ALS patients without frontotemporal dementia were retrospectively retrieved. Concurrent validity of the ALS-CBS™ towards the ECAS was tested by covarying for demographics, disease duration and severity, presence of C9orf72 hexanucleotide repeat expansion and behavioural features. A linear-smoothing equipercentile equating (LSEE) model was employed to derive ALS-CBS™-to-ECAS cross-walks. Gaps in LSEE-based estimation were managed via a linear regression-based equating approach. Equivalence between empirical and derived ECAS scores was tested via a two-one-sided test (TOST) procedure for the dependent sample. RESULTS: The ALS-CBS™ predicted the ECAS (ß = 0.75), accounting for the vast majority of its variance (60% out of an R2 = 0.71). Consistently, a strong, one-to-one linear association between ALS-CBS™ and ECAS scores was detected (r = 0.84; R2 = 0.73). The LSEE was able to estimate conversions for the full range of the ALS-CBS™, except for raw scores equal to 1 and 6 - for whom a linear equating-based equation was derived. Empirical ECAS scores were equivalent to those derived with both methods. DISCUSSION: Italian practitioners and researchers have been herewith provided with valid, straightforward cross-walks to estimate the ECAS based on ALS-CBS™ scores in non-demented ALS patients. Conversions herewith provided will help avoid cross-sectional/longitudinal inconsistencies in test adoption within research, and possibly clinical, settings.

Phenotypic correlates of serum neurofilament light chain levels in amyotrophic lateral sclerosis.

Objective: To investigate the relationship between serum levels of the neuroaxonal degeneration biomarker neurofilament light chain (NFL) and phenotype in ALS. Materials and methods: Serum NFL (sNFL) concentration was quantified in 209 ALS patients and 46 neurologically healthy controls (NHCs). Results: sNFL was clearly increased in ALS patients and discriminated them from NHCs with AUC = 0.9694. Among ALS patients, females had higher sNFL levels, especially in case of bulbar onset. sNFL was more increased in phenotypes with both upper (UMN) and lower motor neuron (LMN) signs, and particularly in those with UMN predominance, compared to LMN forms. At the same time, primary lateral sclerosis (PLS) had significantly lower levels compared to UMN-predominant ALS (AUC = 0.7667). sNFL correlated negatively with disease duration at sampling and ALSFRS-R score, positively with disease progression rate, differed among King's stages, and was negatively associated with survival. It also correlated with clinical/neurophysiological indices of UMN and LMN dysfunction (Penn UMN Score, LMN score, MRC composite score, active spinal denervation score). On the contrary, sNFL was not associated with cognitive deficits nor with respiratory parameters. Notably, we found a negative correlation between sNFL and estimated glomerular filtration rate (eGFR). Interpretation: We confirm that ALS is characterized by increased sNFL levels, whose main determinant is the rate of degeneration of both UMNs and LMNs. sNFL is a biomarker of only motor, not of extra-motor, disease. The negative correlation with kidney function might reflect varying renal clearance of the molecule and deserves further investigation before introducing sNFL measurement as routine test in clinical care of ALS patients.

Clinical usability of the Story-Based Empathy Task (SET) in non-demented ALS patients.

BACKGROUND: This study aimed at assessing the clinical usability of the Story-Based Empathy Task (SET) in non-demented amyotrophic lateral sclerosis (ALS) patients. METHODS: N = 106 non-demented ALS patients and N = 101 healthy controls (HCs) were administered the SET, which includes three subtests assessing Emotion Attribution (SET-EA), Intention Attribution (SET-IA) and causal inference (SET-CI) - the latter being a control task. Patients also underwent the Reading the Mind in the Eyes Test (RMET), the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and a thorough behavioural and motor-functional evaluation. The diagnostics of the SET-EA and -IA were tested against a defective performance on the RMET. The association between SET subtests and cognitive/behavioural outcomes was examined net of demographic and motor-functional confounders. Case-control discrimination was explored for each SET subtest. RESULTS: Demographically adjusted SET-EA and -IA scores accurately detected defective RMET performances at the optimal cutoffs of <3.04 (AUC = .84) and <3.61 (AUC = .88), respectively. By contrast, the SET-CI performed poorly in doing so (AUC = .58). The SET-EA converged with the RMET, as well as with ECAS-Executive and -Memory scores, whilst the SET-IA was unrelated to cognitive measures (including the RMET); the SET-CI was related to the ECAS-Language the ECAS-Executive. SET subscores were unrelated to behavioural outcomes. Only the SET-EA discriminated patients from HCs. CONCLUSIONS: The SET as a whole should not be addressed as a social-cognitive measure in this population. At variance, its subtest tapping on emotional processing - i.e., the SET-EA - is recommended for use as an estimate of social-cognitive abilities in non-demented ALS patients.

Clinimetrics and feasibility of the Italian version of the Frontal Assessment Battery (FAB) in non-demented Parkinson's disease patients.

BACKGROUND: This study aimed at assessing the cross-sectional and longitudinal clinimetrics and feasibility of the Frontal Assessment Battery (FAB) in non-demented Parkinson's disease (PD) patients. METHODS: N = 109 PD patients underwent the FAB and the Montreal Cognitive Assessment (MoCA). A subsample of patients further underwent a thorough motor, functional and behavioral evaluation (the last including measures of anxiety, depression and apathy). A further subsample was administered a second-level cognitive battery tapping on attention, executive functioning, language, memory, praxis and visuo-spatial abilities. The following properties of the FAB were tested: (1) concurrent validity and diagnostics against the MoCA; (2) convergent validity against the second-level cognitive battery; (4) association with motor, functional and behavioral measures; (5) capability to discriminate patients from healthy controls (HCs; N = 96); (6) assessing its test-retest reliability, susceptibility to practice effects and predictive validity against the MoCA, as well as deriving reliable change indices (RCIs) for it, at a ≈ 6-month interval, within a subsample of patients (N = 33). RESULTS: The FAB predicted MoCA scores at both T0 and T1, converged with the vast majority of second-level cognitive measures and was associated with functional independence and apathy. It accurately identified cognitive impairment (i.e., a below-cut-off MoCA score) in patients, also discriminating patients from HCs. The FAB was reliable at retest and free of practice effects; RCIs were derived according to a standardized regression-based approach. DISCUSSION: The FAB is a clinimetrically sound and feasible screener for detecting dysexecutive-based cognitive impairment in non-demented PD patients.

Lower semantic fluency scores and a phonemic-over-semantic advantage predict abnormal CSF P-tau181 levels in Aß + patients within the Alzheimer's disease clinical spectrum.

BACKGROUND: The present study aimed to determine whether patients with mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD), semantic verbal fluency (SVF), and the semantic-phonemic discrepancy (SPD) could predict abnormal cerebrospinal fluid (CSF) phosphorylated tau (P-tau181) and total tau (T-tau) levels. METHODS: Phonemic verbal fluency (PVF) and SVF scores of N = 116 Aß-positive patients with either MCI due to AD (N = 39) or probable AD dementia (ADD; N = 77) were retrospectively collected. The SPD was computed by subtracting PVF scores from SVF ones (positive and negative values corresponding to a semantic and phonemic advantage, respectively). Patients were cognitively phenotyped via a thorough test battery and profiled according to the amyloidosis/tauopathy/neurodegeneration (ATN) framework via CSF analyses. Two separate sets of logistic regressions were run to predict normal vs. abnormal P-tau181 and T-tau levels by encompassing as predictors SVF + PVF and SPD and covarying for demographic, disease-related features, and cognitive profile. RESULTS: Lower SVF, but not PVF, scores, as well as a greater phonemic advantage (i.e., negative SPD values), predicted abnormal CSF P-tau181 levels (p ≤ .01). Moreover, lower SVF scores were selectively predictive of abnormal CSF T-tau levels too (p = .016), while the SPD was not. DISCUSSION: SVF and the SPD are able to predict tauopathy across the AD spectrum, thus supporting their status of valid, and sufficiently specific, cognitive markers of AD.

Italian reference values and brain correlates of verbal fluency index - vs standard verbal fluency test - to assess executive dysfunction in ALS.

Objectives: In amyotrophic lateral sclerosis (ALS), verbal fluency index (Vfi) is used to investigate fluency accounting for motor impairment. This study has three aims: (1) to provide Vfi reference values from a cohort of Italian healthy subjects; (2) to assess the ability of Vfi reference values (vs standard verbal fluency test [VFT]) in distinguishing ALS patients with and without executive dysfunction; and (3) to investigate the association between Vfi and brain structural features of ALS patients. Methods: We included 180 healthy subjects and 157 ALS patients who underwent neuropsychological assessment, including VFT and Vfi, and brain MRI. Healthy subjects were split into four subgroups according to sex and education. For each subgroup, we defined the 95th percentile of Vfi as the cutoff. In ALS, the distributions of "abnormal" cases based on Vfi and standard VFT cutoffs were compared using Fisher's exact test. Using quantile regressions in patients, we assessed the association between Vfi and VFT scores, separately, with gray matter volumes and white matter (WM) tract integrity. Results: Applying Vfi and VFT cutoffs, 9 and 13% of ALS cases, respectively, had abnormal scores (p < 0.001). In ALS, while higher Vfi scores were associated with WM changes of callosal fibers linking supplementary motor area, lower VFT performances related to corticospinal tract alterations. Discussion: We provided Italian reference values for the spoken Vfi. Compared to VFT, Vfis are critical to disentangle motor and cognitive deficits in ALS. In patients, abnormal Vfis were associated with damage to WM tracts specifically involved in ideational information processing.

Motor, cognitive and behavioural profiles of C9orf72 expansion-related amyotrophic lateral sclerosis.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) individuals carrying the hexanucleotide repeat expansion (HRE) in the C9orf72 gene (C9Pos) have been described as presenting distinct features compared to the general ALS population (C9Neg). We aim to identify the phenotypic traits more closely associated with the HRE and analyse the role of the repeat length as a modifier factor. METHODS: We studied a cohort of 960 ALS patients (101 familial and 859 sporadic cases). Motor phenotype was determined using the MRC scale, the lower motor neuron score (LMNS) and the Penn upper motor neuron score (PUMNS). Neuropsychological profile was studied using the Italian version of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS), the Frontal Behavioral Inventory (FBI), the Beck Depression Inventory-II (BDI-II) and the State-Trait Anxiety Inventory (STAI). A two-step PCR protocol and Southern blotting were performed to determine the presence and the size of C9orf72 HRE, respectively. RESULTS: C9orf72 HRE was detected in 55/960 ALS patients. C9Pos patients showed a younger onset, higher odds of bulbar onset, increased burden of UMN signs, reduced survival and higher frequency of concurrent dementia. We found an inverse correlation between the HRE length and the performance at ECAS ALS-specific tasks (P = 0.031). Patients also showed higher burden of behavioural disinhibition (P = 1.6 × 10-4), lower degrees of depression (P = 0.015) and anxiety (P = 0.008) compared to C9Neg cases. CONCLUSIONS: Our study provides an extensive characterization of motor, cognitive and behavioural features of C9orf72-related ALS, indicating that the C9orf72 HRE size may represent a modifier of the cognitive phenotype.

Serum levels of glial fibrillary acidic protein in patients with amyotrophic lateral sclerosis.

OBJECTIVE: To compare serum levels of the astrocyte biomarker glial fibrillary acidic protein (GFAP) in patients with amyotrophic lateral sclerosis (ALS) and neurologically healthy controls and to analyze the relations between serum GFAP (sGFAP) and phenotype in ALS. METHODS: We studied 114 ALS patients and 38 controls. sGFAP was quantified with single molecule array (Simoa) technology. RESULTS: In both ALS patients and controls, sGFAP moderately correlated with age. ALS patients had higher sGFAP levels compared to controls, but this yielded a weak discriminative performance (AUC = 0.6198). In ALS, sGFAP was not associated with most of the motor phenotypic features, including site of onset, functional status, disease progression rate, disease stage, and indices of upper (UMN) and lower motor neuron (LMN) impairment. However, sGFAP negatively correlated with cognitive scores regarding ALS-nonspecific functions, particularly memory (r = -0.2082) and tended to be higher in ALS patients with eye movement abnormalities (p = 0.0628). sGFAP also correlated with polysomnographic indices of oxygen desaturation (ODI; r = 0.2639) and apnea-hypopnea (AHI; r = 0.2858). In a multivariate analysis, sGFAP was negatively associated with survival (HR = 1.005). Relevantly, we found a negative correlation between sGFAP and estimated glomerular filtration rate (eGFR; r = -0.3500). INTERPRETATION: Our work provides neurochemical evidence of astrocyte involvement in ALS pathophysiology and particularly in the development of extra-motor manifestations (namely, cognitive - memory - impairment) and respiratory dysfunction. The negative correlation between sGFAP and eGFR has practical relevance and should not be disregarded in future investigations.