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43 result(s) for "Pender, Niall"
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Cognitive impairment in amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a motor neuron disease that has sporadic and inherited forms. ALS is the most common neurodegenerative disorder of young and middle-aged adults, and few treatments are available. Although the degeneration predominantly affects the motor system, cognitive and behavioural symptoms have been described for over a century, and there is evidence that ALS and frontotemporal dementia overlap clinically, radiologically, pathologically, and genetically. Cognitive decline in ALS is characterised by personality change, irritability, obsessions, poor insight, and pervasive deficits in frontal executive tests. This presentation is consistent with the changes to character, social conduct, and executive function in frontotemporal dementia. We highlight genetic, imaging, and neuropathological evidence that non-motor systems are affected in ALS and explain the importance of recent discoveries. We review studies of cognitive impairment in ALS and common neuropsychological test results. We also provide advice about clinical assessment of frontotemporal dysfunction in patients with ALS, and suggest future research. Understanding of cognitive impairment in ALS will improve care for patients and their families and provide valuable insights into the pathogenesis of neurodegeneration.
The Study of Language in the Amyotrophic Lateral Sclerosis - Frontotemporal Spectrum Disorder: a Systematic Review of Findings and New Perspectives
Amyotrophic Lateral Sclerosis is a neurodegenerative disorder characterized primarily by motor network disruption. Extra-motor manifestations including executive functions, social cognition, and behavioral changes are now well recognized as important features of ALS, and are associated with frontotemporal and frontostriatal network disruption. However, the presence and characterization of language changes has received less attention. This systematic review characterizes the profile of reported language dysfunction in ALS. PRISMA guidelines were implemented to carry out and report the review. Current evidence suggests that areas of neuroanatomical disruption in ALS spread to language centers such as posterior, inferior frontal and superior temporal areas leading to deficits in word retrieval, syntactic and grammatical processing, and spelling. However, the majority of studies of language in ALS have been limited by the recruitment of small clinic-based prevalent samples and important questions remain regarding the incidence and progression of language impairment in ALS. Further studies from population-based incident cohorts will help to determine the range of language deficits in ALS, and how these relate to previously defined executive and behavioral sub-phenotypes.
Predicting prognosis in amyotrophic lateral sclerosis: a simple algorithm
The objective of the study was to develop and validate a practical prognostic index for patients with amyotrophic lateral scleroses (ALS) using information available at the first clinical consultation. We interrogated datasets generated from two population-based projects (based in the Republic of Ireland and Italy). The Irish patient cohort was divided into Training and Test sub-cohorts. Kaplan–Meier methods and Cox proportional hazards regression were used to identify significant predictors of prognoses in the Training set. Using a weighted grading system, a prognostic index was derived that separated three risk groups. The validity of index was tested in the Irish Test sub-cohort and externally confirmed in the Italian replication cohort. In the Training sub-cohort ( n  = 117), significant predictors of prognoses were site of disease onset (HR = 1.7, p  = 0.012); ALSFRS-R slope prior to first evaluation (HR = 2.8, p  < 0.0001), and executive dysfunction (HR = 2.11, p  = 0.001). The risk group system generated using these results predicted median survival time in the Training set, the Test set ( n  = 87) and the Italian cohort ( n  = 122) with no overlap of the 95 % CI ( p  < 0.0001). In the validation cohorts, a high-risk classification was associated with a positive predictive value for poor prognosis of 73.3–85.7 % and a negative predictive value (NPV) for good prognosis of 93.3–100 %. Classification into the low-risk group was associated with an NPV for bad prognosis of 100 %. A simple algorithm using variables that can be gathered at first patient encounter, validated in an independent patient series, reliably predicts prognoses in ALS patients.
Dynamic Blood–Brain Barrier Regulation in Mild Traumatic Brain Injury
Whereas the diagnosis of moderate and severe traumatic brain injury (TBI) is readily visible on current medical imaging paradigms (magnetic resonance imaging [MRI] and computed tomography [CT] scanning), a far greater challenge is associated with the diagnosis and subsequent management of mild TBI (mTBI), especially concussion which, by definition, is characterized by a normal CT. To investigate whether the integrity of the blood–brain barrier (BBB) is altered in a high-risk population for concussions, we studied professional mixed martial arts (MMA) fighters and adolescent rugby players. Additionally, we performed the linear regression between the BBB disruption defined by increased gadolinium contrast extravasation on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on MRI and multiple biomechanical parameters indicating the severity of impacts recorded using instrumented mouthguards in professional MMA fighters. MMA fighters were examined pre-fight for a baseline and again within 120 h post–competitive fight, whereas rugby players were examined pre-season and again post-season or post-match in a subset of cases. DCE-MRI, serological analysis of BBB biomarkers, and an analysis of instrumented mouthguard data, was performed. Here, we provide pilot data that demonstrate disruption of the BBB in both professional MMA fighters and rugby players, dependent on the level of exposure. Our data suggest that biomechanical forces in professional MMA and adolescent rugby can lead to BBB disruption. These changes on imaging may serve as a biomarker of exposure of the brain to repetitive subconcussive forces and mTBI.
Cognitive reserve in amyotrophic lateral sclerosis (ALS): a population-based longitudinal study
BackgroundAmyotrophic lateral sclerosis (ALS) is often associated with cognitive and/or behavioural impairment. Cognitive reserve (CR) may play a protective role in offsetting cognitive impairment. This study examined the relationship between CR and longitudinal change in cognition in an Irish ALS cohort.MethodsLongitudinal neuropsychological assessment was carried out on 189 patients over 16 months using the Edinburgh cognitive and behavioural ALS screen (ECAS) and an additional battery of neuropsychological tests. CR was measured by combining education, occupation and physical activity data. Joint longitudinal and time-to-event models were fitted to investigate the associations between CR, performance at baseline and decline over time while controlling for non-random drop-out.ResultsCR was a significant predictor of baseline neuropsychological performance, with high CR patients performing better than those with medium or low CR. Better cognitive performance in high CR individuals was maintained longitudinally for ECAS, social cognition, executive functioning and confrontational naming. Patients displayed little cognitive decline over the course of the study, despite controlling for non-random drop-out.ConclusionsThese findings suggest that CR plays a role in the presentation of cognitive impairment at diagnosis but is not protective against cognitive decline. However, further research is needed to examine the interaction between CR and other objective correlates of cognitive impairment in ALS.
Measurement of Social Cognition in Amyotrophic Lateral Sclerosis: A Population Based Study
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. Executive dysfunction is common in patients with ALS, with up to 50% of patients performing within an impaired range. There is evidence that social cognitive deficits associated with ALS are a function of deficits in executive function. The 'Reading the Mind in the Eyes' Test is a recognized test of social cognitive function, although the reliability of this instrument remains to be established. Patients with ALS (n = 106), and age and IQ matched controls (n = 50) were recruited and asked to perform the Reading the Mind in the Eyes Test as part of an on-going population-based study of cognitive function. ALS patients were sub-stratified based on the presence, and/or extent of executive dysfunction. Cronbach's Alpha of .73 was observed, indicating good reliability on this measure. Split-half reliability analysis further confirms these findings (p = 0.826). The Reading the Mind in the Eyes test had excellent psychometric properties when discriminating between ALS patients who are cognitively intact, and those who have executive impairment, with an overall medium difficulty. There was a large magnitude significant difference between patients and controls (p< 0.001; η2 = .19). Post-hoc analysis revealed that controls performed significantly higher than patients with executive impairment (p< 0.001), and patients with single executive deficits (p = 0.002). Executive dysfunction impacts on social cognitive performance. This study contributes not only to the psychometric knowledge of this measure, but also to the usability, efficacy, and reliability of social cognitive assessment in ALS. Using population-specific normative data, we confirm the Reading the Mind in the Eyes Test is a reliable measure of social cognitive processes in ALS.
Blood-brain barrier permeability imaging as a predictor for delayed cerebral ischaemia following subarachnoid haemorrhage. A narrative review
Background Aneurysmal subarachnoid haemorrhage is associated with significant morbidity and mortality due to the myriad of complications contributing to early brain injury and delayed cerebral ischaemia. There is increasing interest in the exploration of the association between blood-brain barrier integrity and risks of delayed cerebral ischaemia and poor outcomes. Despite recent advances in cerebral imaging, radiographic imaging of blood-brain barrier disruption, as a biomarker for outcome prediction, has not been adopted in clinical practice. Methods We performed a narrative review by searching for articles describing molecular changes or radiological identification of changes in BBB permeability following subarachnoid haemorrhage (SAH) on MEDLINE. Preclinical studies were analysed if reported structural changes and clinical studies were included if they investigated for radiological markers of BBB disruption and its correlation with delayed cerebral ischaemia. Results There is ample preclinical evidence to suggest that there are structural changes in BBB permeability following SAH. The available clinical literature has demonstrated correlations between permeability imaging and outcomes following aneurysmal subarachnoid haemorrhage (aSAH). Conclusion Radiological biomarkers offer a potential non-invasive prognostication tool and may also allow early identifications of patients who may be at risk of DCI.
Cognitive and clinical characteristics of patients with amyotrophic lateral sclerosis carrying a C9orf72 repeat expansion: a population-based cohort study
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of upper and lower motor neurons, associated with frontotemporal dementia (FTD) in about 14% of incident cases. We assessed the frequency of the recently identified C9orf72 repeat expansion in familial and apparently sporadic cases of ALS and characterised the cognitive and clinical phenotype of patients with this expansion. A population-based register of patients with ALS has been in operation in Ireland since 1995, and an associated DNA bank has been in place since 1999. 435 representative DNA samples from the bank were screened using repeat-primed PCR for the presence of a GGGGCC repeat expansion in C9orf72. We assessed clinical, cognitive, behavioural, MRI, and survival data from 191 (44%) of these patients, who comprised a population-based incident group and had previously participated in a longitudinal study of cognitive and behavioural changes in ALS. Samples from the DNA bank included 49 cases of known familial ALS and 386 apparently sporadic cases. Of these samples, 20 (41%) cases of familial ALS and 19 (5%) cases of apparently sporadic ALS had the C9orf72 repeat expansion. Of the 191 patients for whom phenotype data were available, 21 (11%) had the repeat expansion. Age at disease onset was lower in patients with the repeat expansion (mean 56·3 [SD 8·3] years) than in those without (61·3 [10·6] years; p=0·043). A family history of ALS or FTD was present in 18 (86%) of those with the repeat expansion. Patients with the repeat expansion had significantly more co-morbid FTD than patients without the repeat (50%vs 12%), and a distinct pattern of non-motor cortex changes on high-resolution 3 T magnetic resonance structural neuroimaging. Age-matched univariate analysis showed shorter survival (20 months vs 26 months) in patients with the repeat expansion. Multivariable analysis showed an increased hazard rate of 1·9 (95% 1·1–3·7; p=0·035) in those patients with the repeat expansion compared with patients without the expansion Patients with ALS and the C9orf72 repeat expansion seem to present a recognisable phenotype characterised by earlier disease onset, the presence of cognitive and behavioural impairment, specific neuroimaging changes, a family history of neurodegeneration with autosomal dominant inheritance, and reduced survival. Recognition of patients with ALS who carry an expanded repeat is likely to be important in the context of appropriate disease management, stratification in clinical trials, and in recognition of other related phenotypes in family members. Health Seventh Framework Programme, Health Research Board, Research Motor Neuron, Irish Motor Neuron Disease Association, The Motor Neurone Disease Association of Great Britain and Northern Ireland, ALS Association.
Longitudinal predictors of caregiver burden in amyotrophic lateral sclerosis: a population-based cohort of patient–caregiver dyads
ObjectiveCaregiver burden is a recognised consequence of caring for a patient with neurodegeneration. Amyotrophic lateral sclerosis (ALS) differs from other neurodegenerations by its rapid progression and impairment of motor, cognitive, and behavioural function, which contribute to caregiver burden. However, longitudinal factors that determine the extent of caregiver burden, and in particular the impact of psychological distress among caregivers, have not been fully established.MethodsPatients with ALS (n = 85) and their primary caregivers (n = 85) completed three serial evaluations. Caregiver burden was measured using the Zarit Burden Interview (ZBI). Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale (HADS). The Edinburgh Cognitive-Behavioural ALS Screen (ECAS) was used to determine cognitive function in patients. The ALS Functional Rating Scale (ALSFRS-R) measured disease progression.ResultsUsing the ZBI, caregivers were categorised as high or low burden. In the low burden group, anxiety scores from the HADS predicted caregiver burden (r = 0.410, F = 3.73, p = 0.033), whereas the depression sub-score from the HADS was predictive of caregiver burden in the high burden group (r = 0.501, F = 5.87, p = 0.006) for cross-sectional analyses. Longitudinally, an elevated score on the HADS at Time 1 was the largest predictor of caregiver burden across serial assessments.ConclusionIn a patient cohort with relatively preserved cognitive function (65%), anxiety and depression at Time 1, as measured by the HADS, were the best predictors of caregiver burden at Time 3. This observation provides a mechanism by which caregiver burden can be identified by health-care professionals and a stepped care programme of intervention initiated.
Extra-motor cerebral changes and manifestations in primary lateral sclerosis
Primary lateral sclerosis (PLS) is classically considered a ‘pure’ upper motor neuron disorder. Motor cortex atrophy and pyramidal tract degeneration are thought to be pathognomonic of PLS, but extra-motor cerebral changes are poorly characterized. In a prospective neuroimaging study, forty PLS patients were systematically evaluated with a standardised imaging, genetic and clinical protocol. Patients were screened for ALS and HSP associated mutations, as well as C9orf72 hexanucleotide repeats. Clinical assessment included composite reflex scores, spasticity scales, functional rating scales, and screening for cognitive and behavioural deficits. The neuroimaging protocol evaluated cortical atrophy patterns, subcortical grey matter changes and white matter alterations in whole-brain and region-of-interest analyses. PLS patients tested negative for known ALS- and HSP-associated mutations and C9orf72 repeat expansions. Voxel-wise analyses revealed anterior cingulate, dorsolateral prefrontal, insular, opercular, orbitofrontal and bilateral mesial temporal grey matter changes and white matter alterations in the fornix, brainstem, temporal lobes, and cerebellum. Significant thalamus, caudate, hippocampus, putamen and accumbens nucleus volume reductions were also identified. Extra-motor clinical manifestations were dominated by verbal fluency deficits, language deficits, apathy and pseudobulbar affect. Our clinical and radiological evaluation confirms considerable extra-motor changes in a population-based cohort of PLS patients. Our data suggest that PLS should no longer be considered a neurodegenerative disorder selectively affecting the pyramidal system. PLS is associated with widespread extra-motor changes and manifestations which should be carefully considered in the multidisciplinary management of this low-incidence condition.