Utility of the Addenbrooke's Cognitive Examination III online calculator to differentiate the primary progressive aphasia variants.

The Addenbrooke's Cognitive Examination III is a brief cognitive screening tool that is widely used for the detection and monitoring of dementia. Recent findings suggest that the three variants of primary progressive aphasia can be distinguished based on their distinct profiles on the five subdomain scores of this test. Here, we investigated the utility of the Addenbrooke's Cognitive Examination III to differentiate the primary progressive aphasia variants based on their item-by-item performance profiles on this test. From these results, we created an interactive primary progressive aphasia Addenbrooke's Cognitive Examination III calculator which predicts the variant based on a patient's unique item-by-item profile. Twenty-eight logopenic variant, 25 non-fluent variant and 37 semantic variant primary progressive aphasia patients and 104 healthy controls completed the Addenbrooke's Cognitive Examination III at first clinical presentation. Multinomial regression analyses were conducted to establish performance profiles among groups, and R Shiny from RStudio was used to create the interactive Addenbrooke's Cognitive Examination III diagnostic calculator. To verify its accuracy, probability values of the regression model were derived based on a 5-fold cross-validation of cases. The calculator's accuracy was then verified in an independent sample of 17 logopenic, 19 non-fluent and 13 semantic variant primary progressive aphasia patients and 68 Alzheimer's disease patients who had completed the Addenbrooke's Cognitive Examination III (or an older version of this test: Revised) and had in vivo amyloid-PET imaging and/or brain autopsy pathological confirmation. Cross-validation of cases in the calculator model revealed different rates of sensitivity in classifying variants: semantic = 100%, non-fluent = 80.6% and logopenic = 79.9%; healthy controls were distinguished from primary progressive aphasia patients with 100% sensitivity. Verification of in vivo amyloid and/or autopsy-confirmed patients showed that the calculator correctly classified 10/13 (77%) semantic variant, 3/19 (16%) non-fluent variant and 4/17 (24%) logopenic variant patients. Importantly, for patients who were not classified, diagnostic probability values mostly pointed toward the correct clinical diagnosis. Furthermore, misclassified diagnoses of the primary progressive aphasia cohort were rare (1/49; 2%). Although 22 of the 68 Alzheimer's disease patients (32%) were misclassified with primary progressive aphasia, 19/22 were misclassified with the logopenic variant (i.e. falling within the same neuropathological entity). The Addenbrooke's Cognitive Examination III primary progressive aphasia diagnostic calculator demonstrates sound accuracy in differentiating the variants based on an item-by-item Addenbrooke's Cognitive Examination III profile. This calculator represents a new frontier in using data-driven approaches to differentiate the primary progressive aphasia variants.

The behavioural variant frontotemporal dementia phenocopy syndrome is a distinct entity - evidence from a longitudinal study.

BACKGROUND: This study aimed to i) examine the frequency of C9orf72 expansions in a cohort of patients with the behavioural variant frontotemporal dementia (bvFTD) phenocopy syndrome, ii) observe outcomes in a group of phenocopy syndrome with very long term follow-up and iii) compare progression in a cohort of patients with the phenocopy syndrome to a cohort of patients with probable bvFTD. METHODS: Blood was obtained from 16 phenocopy cases. All met criteria for possible bvFTD and were labeled as phenocopy cases if they showed no functional decline, normal cognitive performance on the Addenbrooke's Cognitive Examination-Revised (ACE-R) and a lack of atrophy on brain imaging, over at least 3 years of follow-up. In addition, we obtained very long term follow-up data in 6 cases. A mixed model analysis approach determined the pattern of change in cognition and behaviour over time in phenocopy cases compared to 27 probable bvFTD cases. RESULTS: All 16 patients were screened for the C9orf72 expansion that was present in only one (6.25%). Of the 6 cases available for very long-term follow-up (13 - 21 years) none showed progression to frank dementia. Moreover, there was a decrease in the caregiver ratings of behavioural symptoms over time. Phenocopy cases showed significantly slower rates of progression compared to probable bvFTD patients (p < 0.006). CONCLUSION: The vast majority of patients with the bvFTD phenocopy syndrome remain stable over many years. An occasional patient can harbor the C9orf72 expansion. The aetiology of the remaining cases remains unknown but it appears very unlikely to reflect a neurodegenerative syndrome due to lack of clinical progression or atrophy on imaging.

Apathy and its impact on patient outcome in amyotrophic lateral sclerosis.

Apathy is one of the most common behavioural symptoms of amyotrophic lateral sclerosis (ALS), yet there are few studies that have investigated the relationship between apathy and quality of life (QOL) as they are experienced by the patient. A cohort of 60 ALS patients were evaluated using the Apathy Evaluation Scale which measured cognitive, behavioural, emotional and non-specific symptoms of apathy combined with the Personal Wellbeing Index, a multidimensional measure of QOL. The relationship between patient-rated apathy and QOL scores, controlling for potential clinical and psychological confounders were analysed using univariate and multivariate methods. Apathy was identified in 30% of ALS patients. Patients with apathy reported higher levels of depression (p = 0.0001). Compared to non-apathetic patients, patients with apathy had lower overall QOL (p = 0.001), most pronounced in the domains related to achievements in life (p = 0.001) and community-connectedness (p = 0.0001). Of the cognitive, behavioural, emotional and non-specific manifestations of apathy, only the emotional symptoms explained a significant amount of variance in achievements in life (p = 0.003) and community-connectedness (p = 0.001). As such, emotional manifestations of apathy may underlie worse QOL in ALS patients presenting with behavioural impairment. Patient-reported outcomes, particularly those assessing psychosocial functioning may be important for demonstrating the efficacy of interventions designed to improve QOL in ALS patients with behavioural impairment.

Quantitative muscle ultrasound as a biomarker in Charcot-Marie-Tooth neuropathy.

OBJECTIVE: The utility of quantitative muscle ultrasound as a marker of disease severity in Charcot-Marie-Tooth (CMT) disease subtypes was investigated. METHODS: Muscle ultrasound was prospectively performed on 252 individual muscles from 21 CMT patients (9 CMT1A, 8 CMTX1, 4 CMT2A) and compared to 120 muscles from 10 age and gender-matched controls. Muscle ultrasound recorded echogenicity and thickness in representative muscles including first dorsal interosseus (FDI) and tibialis anterior (TA). RESULTS: Muscle volume of FDI and thickness of TA correlated with MRC strength. Muscle echogenicity was significantly increased in FDI (65.05 vs 47.09; p<0.0001) and TA (89.45 vs 66.30; p<0.0001) of CMT patients. In TA, there was significantly higher muscle thickness (23 vs 18 vs 16mm; p<0.0001) and lower muscle echogenicity (80 vs 95 vs 108; p<0.0001) in CMT1A compared to CMTX1 and CMT2A. This corresponded to disease severity based on muscle strength (MRC grading CMT1A vs CMTX1 vs CMT2A: 59 vs 48 vs 44; p=0.002). CONCLUSION: In CMT, quantitative muscle ultrasound of FDI and TA is a useful marker of disease severity. SIGNIFICANCE: The current findings suggest that quantitative muscle ultrasound has potential as a surrogate marker of disease progression in future interventional trials in CMT.

Cognition and eating behavior in amyotrophic lateral sclerosis: effect on survival.

It is increasingly recognized that metabolic factors influenced by eating behavior, may affect disease progression in neurodegeneration. In frontotemporal dementia (FTD), which shares a significant overlap with Amyotrophic lateral sclerosis (ALS), patients are well known to develop changes in eating behavior. Whether patients with pure ALS and those with cognitive and behavioral changes associated with ALS also develop similar changes is not known. The current study aimed to examine caloric intake, eating behavioral changes, body mass index, and using cox regression analyses survival across the spectrum of 118 ALS-FTD patients (29 pure ALS, 12 ALS-plus and 21 ALS-FTD, 56 behavioral variant FTD), compared with 25 control subjects. The current study found contrary to previous assumptions eating changes are not restricted to FTD, but a spectrum of eating behavioral changes occur in ALS, present in those with pure ALS and worsening as patients develop cognitive changes. ALS patients with cognitive impairment exhibited changes in food preference, with caloric intake and BMI increasing with the development of cognitive/behavioral changes. Both pure ALS and those with cognitive impairment demonstrated increased saturated fat intake. Survival analyses over the mean patient follow-up period of 6.9 years indicated that increasing eating behavioral changes were associated with an improved survival (threefold decrease risk of dying). Changes in eating behavior and metabolism occur in ALS in association with increasing cognitive impairment, perhaps exerting a protective survival influence. These changes provide insights into the common neural networks controlling eating and metabolism in FTD and ALS and provide potential targets to modify disease prognosis and progression.

Apathy is associated with poor prognosis in amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Apathy is the most commonly reported behavioural change in amyotrophic lateral sclerosis (ALS). However, the degree to which it affects prognosis and overlaps with depression in this population is unknown. The present study examined the relationship between level of apathy, mortality and survival time and whether apathy was linked to specific symptom clusters of depression. METHODS: A cohort of 76 consecutive ALS patients attending specialized multidisciplinary clinics were classified according to level of apathy. The effects of clinical factors and apathy on survival time were analysed using univariate and multivariate methods. RESULTS: The majority of patients with moderate to severe apathy died during the study (P = 0.003) and had a median survival time of 21.7 months, considerably shorter than patients with mild apathy (46.9 months) and no apathy (51.9 months) (P = 0.0001). Apathy remained a significant predictor of survival even after controlling for clinical factors and symptom duration at the time of study entry (hazard ratio 3.8, 95% confidence interval 1.9-7.5, P = 0.0001). Depression with demoralization was not associated with level of apathy (P = 0.172) whereas depression with anhedonia was more common in patients with apathy than in those without apathy (P = 0.006). CONCLUSIONS: The presence of severe apathy is an independent, negative prognostic factor in ALS.

Clinical heterogeneity of the C9orf72 genetic mutation in frontotemporal dementia.

The C9orf72 genetic mutation represents the most common cause of familial frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Studies over the last 2 years have revealed a number of key features of this mutation in the fields of clinical neurology, imaging, pathology, and genetics. Despite these efforts, the clinical phenotype appears to extend beyond FTD and ALS into the realm of psychiatric disease, and while highly variable survival rates have been reported, the clinical course of carriers remains relatively unexplored. This report describes two contrasting C9orf72 cases, one with a protracted indolent course dominated by neuropsychiatric features and the other with a rapidly progressive dementia. In both cases, initial structural brain imaging was relatively normal.