Teresa Burke

Background: Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. In Ireland, a dearth of research on TBI means that we neither know the number of people affected by this injury, nor have the information required to improve neuro-rehabilitation services. Aims: This is the protocol for a study that will examine pathways through rehabilitation for survivors of TBI in the Republic of Ireland. The experiences of family members providing care or support to a person with TBI will also be explored. Additionally, the study will estimate the incidence and prevalence of TBI in Ireland. Epidemiological data and information on how people with TBI access rehabilitation and health services will support advocacy efforts towards the redevelopment of neuro-rehabilitation services. Methods: The research is a mixed method, observational cohort study design. Participants with moderate to severe TBI will be recruited through two brain injury service providers, two acute hospitals that provide neurosurgical services, and the National Rehabilitation Hospital. Questionnaires will be administered to participants with TBI on two separate occasions, six months apart, and to family members providing care or support to an individual with TBI, on one occasion. Data from the medical records of participants will be abstracted to capture key information about their brain injury. TBI survivor participants’ use of health care will be followed prospectively for six months. Expected outcomes: The study will outline participants’ pathways through rehabilitation in Ireland, to understand how rehabilitation services are accessed, and the barriers to accessing these services. The incidence and prevalence of TBI in Ireland will be estimated. Experiences of family members providing care or support to an individual with TBI will be detailed. The outcomes of the study will support ongoing efforts to improve care for TBI survivors in Ireland and to redevelop neuro-rehabilitation services.

Event-related potentials (ERPs) show promise to be objective indicators of cognitive functioning. The aim of the study was to examine if ERPs recorded during an oddball task would predict cognitive functioning and information processing speed in Multiple Sclerosis (MS) patients and controls at the individual level. Seventy-eight participants (35 MS patients, 43 healthy age-matched controls) completed visual and auditory 2- and 3-stimulus oddball tasks with 128-channel EEG, and a neuropsychological battery, at baseline (month 0) and at Months 13 and 26. ERPs from 0 to 700 ms and across the whole scalp were transformed into 1728 individual spatio-temporal datapoints per participant. A machine learning method that included penalized linear regression used the entire spatio-temporal ERP to predict composite scores of both cognitive functioning and processing speed at baseline (month 0), and months 13 and 26. The results showed ERPs during the visual oddball tasks could predict cognitive functioning and information processing speed at baseline and a year later in a sample of MS patients and healthy controls. In contrast, ERPs during auditory tasks were not predictive of cognitive performance. These objective neurophysiological indicators of cognitive functioning and processing speed, and machine learning methods that can interrogate high-dimensional data, show promise in outcome prediction.

Summary: Chronic hepatitis C is associated with health‐related quality of life and cognitive impairments, even in mild disease. Recent evidence demonstrating hepatitis C virus (HCV) neurotropism has strengthened a neuropathophysiological hypothesis. However, sample heterogeneity confounds study outcomes. A uniquely homogeneous cohort of Irish women, following an iatrogenic HCV outbreak, offers a rare opportunity to control for HCV chronicity and the virus’ purported impact on quality of life and cognition. A multi site, three‐group, cross‐sectional design was employed. Noncirrhotic, iatrogenically infected women, developing either acute or chronic infection, were recruited from prospective tertiary‐care liver clinics and the community. Well‐matched healthy controls were also recruited. All participants completed a psychosocial survey and were invited to undergo a comprehensive neuropsychological test battery. Significantly distressed psychosocial symptom profiles were observed in those with an iatrogenic HCV exposure history, which was independent of viral chronicity. Chronic and cleared HCV cohorts were not differentiated from each other. Two distinct subgroups, demarcated along ‘impaired’ vs ‘nonimpaired’ quality‐of‐life reports, were clearly identified and logistic regression analysis identified depressed mood and cognitive fatigue, rather than viral status, as statistically significant predictors of group membership. Compared with matched controls, significant cognitive impairments were not observed in either HCV cohort. Our findings provide strong evidence of nonviral factors accounting for quality of life impairment in chronic HCV and they also appear to question existing reports of cognitive dysfunction in mild disease. Depressed mood and cognitive fatigue appear to be critical psychosocial mediators of reduced quality‐of‐life and we hypothesize that metabolite abnormalities reported in HCV samples may also be confounded by these factors, given the associated literature.

Conduction along the optic nerve is often slowed in multiple sclerosis (MS). This is typically assessed by measuring the latency of the P100 component of the Visual Evoked Potential (VEP) using electroencephalography. The Visual Evoked Spread Spectrum Analysis (VESPA) method, which involves modulating the contrast of a continuous visual stimulus over time, can produce a visually evoked response analogous to the P100 but with a higher signal-to-noise ratio and potentially higher sensitivity to individual differences in comparison to the VEP. The main objective of the study was to conduct a preliminary investigation into the utility of the VESPA method for probing and monitoring visual dysfunction in multiple sclerosis. The latencies and amplitudes of the P100-like VESPA component were compared between healthy controls and multiple sclerosis patients, and multiple sclerosis subgroups. The P100-like VESPA component activations were examined at baseline and over a 3-year period. The study included 43 multiple sclerosis patients (23 relapsing-remitting MS, 20 secondary-progressive MS) and 42 healthy controls who completed the VESPA at baseline. The follow-up sessions were conducted 12 months after baseline with 24 MS patients (15 relapsing-remitting MS, 9 secondary-progressive MS) and 23 controls, and again at 24 months post-baseline with 19 MS patients (13 relapsing-remitting MS, 6 secondary-progressive MS) and 14 controls. The results showed P100-like VESPA latencies to be delayed in multiple sclerosis compared to healthy controls over the 24-month period. Secondary-progressive MS patients had most pronounced delay in P100-like VESPA latency relative to relapsing-remitting MS and controls. There were no longitudinal P100-like VESPA response differences. These findings suggest that the VESPA method is a reproducible electrophysiological method that may have potential utility in the assessment of visual dysfunction in multiple sclerosis.

Primary objective: The present study aimed to investigate the specific ways in which individuals reconstruct their sense of self following injury to the nervous system, by comparing individuals with acquired brain injury (ABI) and individuals with spinal cord injury (SCI), two groups that have experienced a sudden-onset injury with life-changing repercussions. Research design: Phenomenological qualitative research. Methods and procedures: Nine individuals with ABI and 10 individuals with SCI took part in an interview exploring the ways in which individuals reconstruct their sense of self following injury. Data were analysed using interpretative thematic analysis. Main outcomes and results: Findings showed similar themes identified within the interview data of the ABI and SCI groups. Both groups developed positive and negative self-narratives. Individuals employed strategies that facilitated the reconstruction of positive self-narratives. In addition, individuals described their sense of self as simultaneously continuous and changing. Discussion: Findings are discussed in relation to proposed models of self-reconstruction post-injury to the nervous system.

Background: The validity of self-rated anxiety inventories in people with multiple sclerosis (pwMS) is unclear. However, the appropriateness of self-reported depression scales has been widely examined. Given somatic symptom overlap between depression and MS, research emphasises caution when using such scales. Objective: This study evaluates symptom overlap between anxiety and MS in a group of 33 individuals with MS, using the Beck Anxiety Inventory (BAI). Methods: Participants underwent a neurological examination and completed the BAI. Results: A novel procedure using hierarchical cluster analysis revealed three distinct symptom clusters. Cluster one (‘wobbliness’ and ‘unsteady’) grouped separately from all other BAI items. These symptoms are well-recognised MS-related symptoms and we question whether their endorsement in pwMS can be considered to reflect anxiety. A modified 19-item BAI (mBAI) was created which excludes cluster one items. This removal reduced the number of MS participants considered ‘anxious’ by 21.21% (low threshold) and altered the level of anxiety severity for a further 27.27%. Conclusion: Based on these data, it is suggested that, as with depression measures, researchers and clinicians should exercise caution when using brief screening measures for anxiety in pwMS.

Cognitive impairment (CI), often examined with neuropsychological tests such as the Paced Auditory Serial Addition Test (PASAT), affects approximately 65% of multiple sclerosis (MS) patients. The P3b event-related potential (ERP), evoked when an infrequent target stimulus is presented, indexes cognitive function and is typically compared across subjects' scalp electroencephalography (EEG) data. However, the clustering of independent components (ICs) is superior to scalp-based EEG methods because it can accommodate the spatiotemporal overlap inherent in scalp EEG data. Event-related spectral perturbations (ERSPs; event-related mean power spectral changes) and inter-trial coherence (ITCs; event-related consistency of spectral phase) reveal a more comprehensive overview of EEG activity. Ninety-five subjects (56 MS patients, 39 controls) completed visual and auditory two-stimulus P3b event-related potential tasks and the PASAT. MS patients were also divided into CI and non-CI groups (n = 18 in each) based on PASAT scores. Data were recorded from 128-scalp EEG channels and 4 IC clusters in the visual, and 5 IC clusters in the auditory, modality were identified. In general, MS patients had significantly reduced ERSP theta power versus controls, and a similar pattern was observed for CI vs. non-CI MS patients. The ITC measures were also significantly different in the theta band for some clusters. The finding that MS patients had reduced P3b task-related theta power in both modalities is a reflection of compromised connectivity, likely due to demyelination, that may have disrupted early processes essential to P3b generation, such as orientating and signal detection. However, for posterior sources, MS patients had a greater decrease in alpha power, normally associated with enhanced cognitive function, which may reflect a compensatory mechanism in response to the compromised early cognitive processing.