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1.
Neurol Int ; 15(4): 1371-1382, 2023 Nov 08.
Article in English | MEDLINE | ID: mdl-37987460

ABSTRACT

Cognitive impairment is common in persons with spinal cord injury (SCI), impacting their daily functioning and rehabilitation. This study assesses the extent of self-reported cognitive failures in everyday life in persons with SCI and its relationships with objective neurocognitive measures and psychosocial factors, including depressive mood, anxiety, perceived control, and fatigue. The differences between forty-one adults with a chronic SCI and forty-one able-bodied controls were examined. The participants completed the Cognitive Failures Questionnaire (CFQ) to assess cognitive failure and neurocognitive tests assessing attention and executive functions, as well as a psychosocial assessment. The SCI group reported higher cognitive failure rates than the able-bodied group (31.7% versus 19%, p > 0.05). Objective neurocognitive tests did not significantly correlate with the CFQ scores in either group. However, the CFQ scores were positively associated with most psychosocial factors, even after controlling for covariates. The CFQ scores were significantly associated with depressive mood in persons with SCI. These findings highlight the importance of incorporating self-reported cognitive measures into neurocognitive assessments and rehabilitation planning for adults with SCI. Self-reports capture everyday cognitive challenges that objective tests may miss. Additionally, this study highlights the strong connections between cognitive failures and psychosocial issues, particularly mood disorders, emphasizing the need for comprehensive rehabilitation and psychosocial support post-SCI, addressing both cognitive and emotional wellbeing.

2.
J Nutr ; 152(11): 2409-2418, 2022 11.
Article in English | MEDLINE | ID: mdl-36774107

ABSTRACT

BACKGROUND: There is growing interest in Food is Medicine programs that incorporate food-based interventions into health care for patients with diet-related conditions. OBJECTIVES: We aimed to test the feasibility of a "produce prescription" program and its impact on diet quality for people with type 2 diabetes (T2D) experiencing food insecurity in Australia. METHODS: We conducted a pre-post intervention study in n = 50 adults experiencing food insecurity with T2D and glycated hemoglobin (HbA1c) ≥8%. Once enrolled, participants received healthy food boxes weekly free of charge, with the contents sufficient to create 2 meals/d, 5 d/wk for the entire household, over 12 wk. Participants were also provided with tailored recipes and behavioral change support. The primary outcome was change in diet quality assessed by 24-h diet recalls. Secondary outcomes included differences in cardiovascular disease risk factors; blood micronutrients; and feasibility indicators. Differences in the baseline and 12-wk mean primary and secondary outcomes were assessed by paired t tests. RESULTS: Participants were older adults with mean ± SD age 63 ± 9 y (range: 40-87 y), HbA1c 9.8% ± 1.5%, and 46% were female. Overall, 92% completed the final study follow-up for the primary outcome. Compared with baseline, diet quality improved at week 12, with an increase in the mean overall diet quality (Alternate Healthy Eating Index score) of 12.9 (95% CI: 8.7, 17.1; P < 0.001), driven by significant improvements in vegetables, fruits, whole grains, red/processed meat, trans fat, sodium, and alcohol consumption. Blood lipids also improved (total:HDL cholesterol: -0.48; 95% CI: -0.72, -0.24; P < 0.001), and there was significant weight loss (-1.74 kg; 95% CI: -2.80, -0.68 kg, P = 0.002), but no changes in other clinical outcomes. Participants reported high levels of satisfaction with the program. CONCLUSIONS: These findings provide strong support for an adequately powered randomized trial to assess effects of produce prescription as an innovative approach to improve clinical management among individuals with T2D experiencing food insecurity. This trial was registered at https://anzctr.org.au/ as ACTRN12621000404820.


Subject(s)
Diabetes Mellitus, Type 2 , Humans , Female , Aged , Middle Aged , Male , Glycated Hemoglobin , Feasibility Studies , Diet , Food Insecurity
3.
Spinal Cord ; 57(7): 579-585, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30760846

ABSTRACT

STUDY DESIGN: Prospective, double-blind, randomised, placebo-controlled, cross-over trial of nasal decongestion in tetraplegia. OBJECTIVES: Tetraplegia is complicated by severe, predominantly obstructive, sleep apnoea. First-line therapy for obstructive sleep apnoea is nasal continuous positive airway pressure, but this is poorly tolerated. High nasal resistance associated with unopposed parasympathetic activation of the upper airway contributes to poor adherence. This preliminary study tested whether reducing nasal decongestion improved sleep. SETTING: Participants' homes in Melbourne and Sydney, Australia. METHODS: Two sleep studies were performed in participants' homes separated by 1 week. Participants were given a nasal spray (0.5 mL of 5% phenylephrine or placebo) in random order and posterior nasal resistance measured immediately. Outcomes included sleep apnoea severity, perceived nasal congestion, sleep quality and oxygenation during sleep. RESULTS: Twelve middle-aged (average (SD) 52 (12) years) overweight (body mass index 25.3 (6.7) kg/m2) men (C4-6, AIS A and B) participated. Nasal resistance was reduced following administration of phenylephrine (p = 0.02; mean between treatment group difference -5.20: 95% confidence interval -9.09, -1.32 cmH2O/L/s). No differences were observed in the apnoea hypopnoea index (p = 0.15; -6.37: -33.3, 20.6 events/h), total sleep time (p = 0.49; -1.33: -51.8, 49.1 min), REM sleep% (p = 0.50; 2.37: -5.6, 10.3), arousal index (p = 0.76; 1.15: -17.45, 19.75), 4% oxygen desaturation index (p = 0.88; 0.63: -23.5, 24.7 events/h), or the percentage of mouth breathing events (p = 0.4; -8.07: -29.2, 13.0) between treatments. The apnoea hypopnoea index did differ between groups, however, all except one participant had proportionally more hypopnoeas than apnoeas during sleep after decongestion. CONCLUSIONS: These preliminary data found that phenylephrine acutely reduced nasal resistance but did not significantly change sleep-disordered breathing severity.


Subject(s)
Nasal Decongestants/therapeutic use , Phenylephrine/therapeutic use , Sleep Apnea, Obstructive/drug therapy , Spinal Cord Injuries/complications , Adult , Cervical Cord , Double-Blind Method , Female , Humans , Male , Middle Aged , Quadriplegia/complications , Sleep Apnea, Obstructive/etiology
4.
J Clin Neurosci ; 59: 136-140, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30414809

ABSTRACT

Two recent randomized controlled trials (RCTs) showed selected patients treated with endovascular thrombectomy (EVT) more than 6 h from acute ischemic stroke (AIS) onset had significant improvement in functional outcome at 90 days compared with standard care alone. Our aim is to determine the outcome and predictors of good outcome in AIS patients undergoing EVT with unknown-onset, or late presentation, stroke after 6 h from time last seen well, or witnessed stroke onset, at two Australian comprehensive stroke centres. A retrospective analysis of functional outcome and mortality at 90-days from a prospective cohort of 56 consecutive patients with unknown-onset, or late presentation, stroke with large vessel occlusion (LVO) in the anterior cerebral circulation undergoing EVT over a 15-month period (2016-2017). We evaluated factors which correlated with good functional outcome defined as a 90-day modified Rankin scale (mRS) 0-2. Recanalization times and symptomatic intracranial haemorrhage (sICH) rates were also examined. A good functional outcome was achieved in 35 patients (62%). Eight patients died (14%). Median time-to-recanalization was 7.6 h. SICH occurred in four patients (7%). Factors which predicted good 90-day functional outcome included baseline National Institutes of Health Stroke Scale (NIHSS) < 16, 24 h NIHSS < 10, baseline Alberta Stroke Program Early CT Score (ASPECTS) ≥ 8, pre-procedural CT perfusion imaging and LVO lesion location. This study shows good 'real world' outcomes, comparable to published RCTs, in patients with unknown-onset, or late presentation, stroke treated with EVT more than 6 h from stroke onset.


Subject(s)
Stroke/surgery , Thrombectomy/methods , Aged , Aged, 80 and over , Australia , Endovascular Procedures/methods , Female , Humans , Middle Aged , Patient Selection , Retrospective Studies , Treatment Outcome
5.
J Physiol ; 596(14): 2853-2864, 2018 07.
Article in English | MEDLINE | ID: mdl-29658103

ABSTRACT

KEY POINTS: Protective reflexes in the throat area (upper airway) are crucial for breathing. Impairment of these reflexes can cause breathing problems during sleep such as obstructive sleep apnoea (OSA). OSA is very common in people with spinal cord injury for unknown reasons. This study shows major changes in protective reflexes that serve to keep the upper airway open in response to suction pressures in people with tetraplegia and OSA. These results help us understand why OSA is so common in people with tetraplegia and provide new insight into how protective upper airway reflexes work more broadly. ABSTRACT: More than 60% of people with tetraplegia have obstructive sleep apnoea (OSA). However, the specific causes are unknown. Genioglossus, the largest upper-airway dilator muscle, is important in maintaining upper-airway patency. Impaired genioglossus muscle function following spinal cord injury may contribute to OSA. This study aimed to determine if genioglossus reflex responses to negative upper-airway pressure are altered in people with OSA and tetraplegia compared to non-neurologically impaired able-bodied individuals with OSA. Genioglossus reflex responses measured via intramuscular electrodes to ∼60 brief (250 ms) pulses of negative upper-airway pressure (∼-15 cmH2 O at the mask) were compared between 13 participants (2 females) with tetraplegia plus OSA and 9 able-bodied controls (2 females) matched for age and OSA severity. The initial short-latency excitatory reflex response was absent in 6/13 people with tetraplegia and 1/9 controls. Genioglossus reflex inhibition in the absence of excitation was observed in three people with tetraplegia and none of the controls. When the excitatory response was present, it was significantly delayed in the tetraplegia group compared to able-bodied controls: excitation onset latency (mean ± SD) was 32 ± 16 vs. 18 ± 9 ms, P = 0.045; peak excitation latency was 48 ± 17 vs. 33 ± 8 ms, P = 0.038. However, when present, amplitude of the excitation response was not different between groups, 195 ± 26 vs. 219 ± 98% at baseline, P = 0.55. There are major differences in genioglossus reflex morphology and timing in response to rapid changes in airway pressure in people with tetraplegia and OSA. Altered genioglossus function may contribute to the increased risk of OSA in people with tetraplegia. The precise mechanisms mediating these differences are unknown.


Subject(s)
Pharyngeal Muscles/physiology , Quadriplegia/physiopathology , Reflex , Sleep Apnea, Obstructive/physiopathology , Ventilators, Negative-Pressure , Adult , Aged , Female , Humans , Male , Middle Aged
6.
Intern Med J ; 48(3): 330-334, 2018 Mar.
Article in English | MEDLINE | ID: mdl-28892278

ABSTRACT

BACKGROUND: The benefit of palliative care referral for severe stroke patients on end-of-life care pathway (EOLCP) is increasingly recognised. Palliative care provides assistance with symptom management and transition to end-of-life care. Advance care planning (ACP) may help accommodate patient/family expectations and guide management. METHODS: This is a retrospective study of all stroke deaths (2014-2015) at Liverpool Hospital, Sydney, Australia. Data examined included age, comorbidities, living arrangements, pre-existing ACP, palliative care referral rates and 'survival time'. RESULTS: In total, 123 patient (mean age ± SD = 76 ± 13 years) deaths were identified from 1067 stroke admissions (11.5% mortality); 64 (52%) patients had ischaemic stroke and 59 (48%) intracerebral haemorrhage (ICH), and 40% suffered a prior stroke, and 43% required a carer at home or were in an aged care facility. Survival time from admission was significantly longer in patients with ischaemic stroke compared to intracerebral haemorrhage (median, interquartile range [IQR]: 9.5 [18] vs 2 [4] days, P < 0.001). Only two patients had pre-existing ACP; 44% of patients were referred to palliative care and 41% were commenced on dedicated EOLCP. Palliative care referral was less likely in patients who died under neurosurgery. EOLCP were significantly less likely to be commenced in patients who underwent acute intervention or were not referred to palliative care. CONCLUSION: In this cohort, palliative care referral and EOLCP were commenced in less than 50% of patients, highlighting significant variations in clinical care. These data support the need to promote awareness of ACP, particularly in patients with prior stroke or significant comorbidities. This may help reduce potentially futile invasive investigations and treatment.


Subject(s)
Hospital Mortality/trends , Palliative Care/trends , Referral and Consultation/trends , Stroke/mortality , Stroke/therapy , Terminal Care/trends , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Male , Middle Aged , New South Wales/epidemiology , Palliative Care/methods , Retrospective Studies , Terminal Care/methods
7.
Respir Physiol Neurobiol ; 235: 27-33, 2017 01.
Article in English | MEDLINE | ID: mdl-27697626

ABSTRACT

Obstructive sleep apnoea (OSA) is highly prevalent in people with tetraplegia. Nasal congestion, a risk factor for OSA, is common in people with tetraplegia. The purpose of this study was to quantify objective and perceived nasal resistance and its stability over four separate days in people with tetraplegia and OSA (n=8) compared to able-bodied controls (n=6). Awake nasal resistance was quantified using gold standard choanal pressure recordings (days 1 and 4) and anterior rhinomanometry (all visits). Nasal resistance (choanal pressure) was higher in people with tetraplegia versus controls (5.3[6.5] vs. 2.1[2.4] cmH2O/L/s, p=0.02) yet perceived nasal congestion (modified Borg score) was similar (0.5[1.8] vs. 0.5[2.0], p=0.8). Nasal resistance was stable over time in both groups (CV=0.23±0.09 vs. 0.16±0.08, p=0.2). These findings are consistent with autonomic dysfunction in tetraplegia and adaptation of perception to high nasal resistance. Nasal resistance may be an important therapeutic target for OSA in this population but self-assessment cannot reliably identify those most at risk.


Subject(s)
Airway Resistance , Nasal Cavity , Quadriplegia/physiopathology , Quadriplegia/psychology , Sleep Apnea, Obstructive/physiopathology , Sleep Apnea, Obstructive/psychology , Adult , Aged , Cervical Vertebrae , Female , Humans , Male , Middle Aged , Nasal Cavity/physiopathology , Perception , Pressure , Quadriplegia/complications , Rhinomanometry , Sleep Apnea, Obstructive/complications , Spinal Cord Injuries/complications , Spinal Cord Injuries/physiopathology , Spinal Cord Injuries/psychology
8.
Article in English | MEDLINE | ID: mdl-25571334

ABSTRACT

This paper presents research that investigated the effects of mental fatigue on brain activity using electroencephalogram (EEG) signals. Since EEG signals are considered to be non-stationary, time-frequency analysis has frequently been used for analysis. The S-transform is a time-frequency analysis method and is used in this paper to analyze EEG signals during alert and fatigue states during a driving simulator task. Repeated-measure MANOVA results show significant differences between alert and fatigue states within the alpha (8-13Hz) frequency band. The two sites demonstrating the greatest increases in alpha activity during fatigue were the Cz and P4 sites. The results show that S-transform analysis can be used to distinguish between alert and fatigue states in the EEG and also supports the use of the S-transform for EEG analysis.


Subject(s)
Mental Fatigue/diagnosis , Adolescent , Adult , Automobile Driving , Computer Simulation , Electroencephalography/methods , Female , Humans , Male , Mental Fatigue/physiopathology , Signal Processing, Computer-Assisted , Young Adult
9.
J Pain ; 14(9): 911-20, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23707693

ABSTRACT

UNLABELLED: Chronic pain, chronic fatigue, and depressive mood are prevalent conditions in people with spinal cord injury (SCI). The objective of this research was to investigate the relationship between these conditions in adults with SCI. Multivariate analysis of variance, contingency analyses, and hierarchical regression were used to determine the nature of the relationship, as well as the contribution to this relationship of self-efficacy, a potential mediator variable. Seventy participants with SCI living in the community completed an assessment regimen of demographic and psychometric measures, including validated measures of pain, fatigue, depressive mood, and self-efficacy. Results indicated that participants with high levels of chronic pain had clinically elevated depressive mood, confusion, fatigue, anxiety and anger, low vigor, and poor self-efficacy. Participants with high chronic pain had 8 times the odds of having depressive mood and 9 times the odds of having chronic fatigue. Regression analyses revealed that chronic pain contributed significantly to elevated depressive mood and that self-efficacy mediated (cushioned) the impact of chronic pain on mood. Furthermore, both chronic pain and depressive mood were shown to contribute independently to chronic fatigue. Implications of these results for managing chronic pain in adults with SCI are discussed. PERSPECTIVE: The relationship between pain, negative mood, fatigue, and self-efficacy in adults with SCI was explored. Results support a model that proposes that chronic pain lowers mood, which is mediated (lessened) by self-efficacy, whereas pain and mood independently increase chronic fatigue. Results provide direction for treating chronic pain in SCI.


Subject(s)
Chronic Pain/epidemiology , Depression/epidemiology , Fatigue Syndrome, Chronic/epidemiology , Self Efficacy , Spinal Cord Injuries/epidemiology , Spinal Cord Injuries/psychology , Adult , Aged , Chronic Pain/etiology , Depression/etiology , Fatigue Syndrome, Chronic/etiology , Female , Humans , Male , Middle Aged , Multivariate Analysis , Psychiatric Status Rating Scales , Psychological Theory , Psychometrics , Regression Analysis , Residence Characteristics , Spinal Cord Injuries/complications , Young Adult
10.
J Clin Neurophysiol ; 30(1): 59-65, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23377444

ABSTRACT

This investigation examined the impact of spinal cord injury (SCI) on task-relevant processing using event-related potentials. Thirty-seven participants with chronic SCI and 37 healthy able-bodied controls were tested in this study. An auditory two-tone button press oddball discrimination paradigm was used to evoke the N100, P200, N200, and P300 components of the event-related potential. During the early sensory/perceptual stages of target stimulus processing, the SCI group showed an earlier right posterior P200 latency relative to the controls. In the later more cognitive stages, a pattern of diminished left and right posterior P300 amplitude was also evident. This was further coupled with increased false-positive errors and greater variability of response time in the SCI group. The results of this study indicate that people with SCI show disturbances in inhibitory function and alterations in both early perceptual encoding processes and in later executive functioning that engages contextual/memory-updating operations.


Subject(s)
Cerebral Cortex/physiopathology , Evoked Potentials/physiology , Spinal Cord Injuries/physiopathology , Acoustic Stimulation , Adult , Aged , Female , Humans , Male , Middle Aged , Paraplegia/etiology , Paraplegia/physiopathology , Quadriplegia/etiology , Quadriplegia/physiopathology , Reaction Time/physiology , Spinal Cord Injuries/complications
11.
Pain Ther ; 2(2): 113-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-25135149

ABSTRACT

INTRODUCTION: Chronic and persistent pain is a prevalent and debilitating secondary condition in patients with a neurological injury such as spinal cord injury (SCI). Patients with SCI have an increased risk of developing other co-morbid conditions such as elevated negative mood states. Arguably, the presence of chronic pain would act to intensify the chances of developing negative mood states as opposed to resilient mental states. The objective of this research was to investigate the association between pain intensity and levels of negative mood states in adult patients with SCI. METHODS: Participants included 107 adults with SCI living in the community who completed an assessment regimen in a relaxed environment. Mean pain intensity over a period of 1 week and the Profile of Mood States, a validated psychometric measure of mood states (anxiety, depressed mood, anger, vigor, fatigue, confusion and total negative mood score) were used to determine associations between pain intensity and mood states. The sample was divided into a low pain intensity sub-group (<4 where 0 = no pain; 10 = worst pain imaginable) and a clinically significant or high pain intensity sub-group (≥4), allowing negative mood to be compared between the sub-groups. RESULTS: Mean age was 47.1 years, and 87% of the sample was male. Clinically significant pain intensity over the week prior to assessment was found in 52% of the 107 participants. The high pain intensity sub-group was found to have significantly elevated anxiety, depressed mood, anger, fatigue, confusion and significantly reduced vigor. CONCLUSION: These results provide further evidence that patients with SCI experience clinically elevated negative mood states if they have intense levels of pain over extended periods of time. In contrast, patients without intense pain have mood states similar to those in the able-bodied community. Implications for the treatment of SCI are discussed.

12.
J Psychosom Res ; 73(3): 205-10, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22850261

ABSTRACT

OBJECTIVE: Fatigue is a common symptom in people with neurological injury such as spinal cord injury (SCI), though its nature and occurrence in people with SCI are not well understood. The objective of this research was to investigate fatigue and its relationship to factors such as mood states and self efficacy in adult people with SCI compared to able-bodied controls. METHODS: Participants included 41 adults with SCI living in the community and 41 able-bodied controls matched for age and sex ratios and education. All participants first completed a comprehensive psychological assessment and were then asked to take part in a 2-3 hour session composed of a regimen of cognitive tasks that required constant concentration and attention. Participants were assessed after completing this task. RESULTS: The SCI group was found to have significantly elevated levels of fatigue, as well as elevated depressive mood, anxiety and poor self-efficacy. The SCI group was also found to suffer excessive levels of tiredness as a consequence of the 2-3 hour task. Factors such as depressive mood and poor self-efficacy were shown to increase the risk of excessive tiredness. CONCLUSION: People with a neurological injury such as SCI have a high risk of having fatigue and are susceptible to experiencing excessive tiredness when performing extended tasks, and the presence of elevated depressive mood or poor expectations towards self management will increase this susceptibility. Implications for managing fatigue and improving social access in SCI populations are discussed.


Subject(s)
Fatigue/etiology , Spinal Cord Injuries/complications , Wakefulness , Adult , Aged , Anxiety/etiology , Case-Control Studies , Depression/etiology , Fatigue/psychology , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Psychological Tests , Self Efficacy , Spinal Cord Injuries/psychology , Young Adult
13.
Arch Phys Med Rehabil ; 93(2): 319-24, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22289244

ABSTRACT

OBJECTIVE: To study the impact of fatigue on health-related quality of life (HR-QOL) associated with spinal cord injury (SCI). DESIGN: Matched group design with several independent measures. SETTING: University-based laboratory. PARTICIPANTS: Persons with SCI (n=41) and an average 16.5 years duration of community living with SCI and a group of able-bodied controls (n=41) with similar sex ratio, age, and level of education. Participants with SCI were enrolled through rehabilitation unit contacts and through advertising in newsletters. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The main independent measures reported in this article include the Iowa Fatigue Scale and the Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: As expected, persons with SCI were found to have significantly lower HR-QOL. Fatigue was found to be more prevalent in the SCI group, and was associated with lower HR-QOL in both groups. Factorial analysis of variance indicated significant interactions in which persons with SCI with low fatigue levels had similar HR-QOL to the able-bodied controls regardless of their fatigue level, while persons with SCI with elevated fatigue had significantly reduced HR-QOL. Factors such as age, education, completeness and level of lesion, and community integration were not associated with increased fatigue levels. However, a shorter time since injury was found to be significantly associated with higher levels of fatigue. CONCLUSIONS: The Iowa Fatigue Scale data suggest over 50% of the SCI group had elevated fatigue, which was associated with significantly reduced HR-QOL. Research is needed that identifies factors that raise vulnerability to fatigue, and strategies designed to address the negative impacts of fatigue need to be evaluated.


Subject(s)
Fatigue/complications , Fatigue/psychology , Quality of Life , Spinal Cord Injuries/complications , Adult , Aged , Analysis of Variance , Case-Control Studies , Female , Humans , Male , Middle Aged , Time Factors
14.
Psychophysiology ; 49(4): 574-82, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22324302

ABSTRACT

Assessing brain wave activity is a viable strategy for monitoring fatigue when performing tasks such as driving, and numerous studies have been conducted in this area. However, results of a systematic review on changes in brain wave activity associated with fatigue have revealed equivocal findings. This study investigated brain wave activity associated with fatigue in 48 nonprofessional healthy drivers as they participated in a simulated driving task until they fatigued. The results showed that as a person fatigues, slow wave activity increased over the entire cortex, in theta and in alpha 1 and 2 bands, while no significant changes were found in delta wave activity. Substantial increases also occurred in fast wave activity, though mostly in frontal sites. The results suggest that as a person fatigues, the brain loses capacity and slows its activity, and that attempts to maintain vigilance levels lead to increased beta activity.


Subject(s)
Brain/physiology , Electroencephalography , Fatigue/physiopathology , Adult , Alpha Rhythm/physiology , Analysis of Variance , Artifacts , Beta Rhythm/physiology , Circadian Rhythm/physiology , Cognition/physiology , Data Interpretation, Statistical , Female , Functional Laterality/physiology , Humans , Male , Psychomotor Performance/physiology , Surveys and Questionnaires
15.
Article in English | MEDLINE | ID: mdl-22254988

ABSTRACT

This paper presents research that investigated the effects of mental fatigue on brain activity associated with eyes open and eyes closed conditions. The changes associated with electroencephalography (EEG) alpha wave activity (8-13 Hz) during eye closure has previously been shown to be an effective strategy for switching and activating devices as an environmental control system (ECS) designed for people with severe disability like spinal cord injury (SCI). The results showed that switching times did increase due to fatigue, however, these increases were not large (around 1 second longer to switch) and this difference was not significant. When baselines were readjusted taking into account the change in alpha wave activity due to the fatigue, switching reduced to times typically seen when the person was alert. Error rates were similar between the alert and fatigue sates. Implications of these results for a hands-free ECS are discussed.


Subject(s)
Brain/physiopathology , Cognition , Fatigue/physiopathology , Electroencephalography , Fourier Analysis , Humans
16.
Article in English | MEDLINE | ID: mdl-21095771

ABSTRACT

Fatigue can be defined as a state that involves psychological and physical tiredness with a range of symptoms such as tired eyes, yawning and increased blink rate. It has major implications for work place and road safety as well as a negative symptom of many acute and chronic illnesses. As such there has been considerable research dedicated to systems or algorithms that can be used to detect and monitor the onset of fatigue. This paper examines using electroencephalography (EEG) signals to classify fatigue and alert states as a function of subjective self-report, driving performance and physiological symptoms. The results show that EEG classification network for fatigue improved from 75% to 80% when these factors are applied, especially when the data is grouped by subjective self-report of fatigue with classification accuracy improving to 84.5%.


Subject(s)
Algorithms , Automobile Driving , Brain Mapping/methods , Electroencephalography/methods , Fatigue/prevention & control , Fatigue/physiopathology , Task Performance and Analysis , Fatigue/diagnosis , Humans , Reproducibility of Results , Sensitivity and Specificity , Technology Assessment, Biomedical
17.
Article in English | MEDLINE | ID: mdl-19964657

ABSTRACT

Fatigue is a negative symptom of many illnesses and also has major implications for road safety. This paper presents results using a method called microstate segmentation (MSS). It was used to distinguish changes from an alert to a fatigue state. The results show a significant increase in MSS instantaneous amplitude during the fatigue state. Plotting the linear gradient of the nonlinear part of the phase data from the MSS also showed a significant difference (P<0.01) in the gradients of the alert state compared to the fatigue state. The results suggest that MSS can be used in analyzing spontaneous electroencephalography (EEG) signals to detect changes in physiological states. The results have implications for countermeasures used in detecting fatigue.


Subject(s)
Electroencephalography/methods , Fatigue/physiopathology , Wakefulness/physiology , Adolescent , Adult , Brain/physiology , Female , Humans , Male , Middle Aged , Young Adult
18.
Int J Psychophysiol ; 63(1): 77-86, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17007946

ABSTRACT

Driver fatigue is a major risk for road accidents that can often result in injury and death. However, considerable debate still exists concerning factors associated with driver fatigue. Because of the complex nature of fatigue, this paper reports a study that investigated both physiological and psychological determinants of fatigue. Three fatigue outcome measures were used, including a physiological, psychological and a combined physiological and psychological measure. Fifty participants performed a driving simulator task till they showed symptoms of fatigue and were assessed before and after the task. Significant factors associated with physiological fatigue included higher levels of baseline delta activity and an extraverted personality. Factors related to the psychological fatigue outcome measure included sleepiness, low healthy lifestyle status, an extraverted personality and tension-prone personality, and negative mood states. The combined fatigue outcome measure was associated with factors such as a tension-prone and extraverted personality, low systolic blood pressure, and negative mood states. The findings emphasize the importance of assessing fatigue using a range of outcome measures in order to achieve a thorough understanding of what factors contribute to fatigue and highlight the need to develop fatigue countermeasures that employ a broad range of measures.


Subject(s)
Fatigue/physiopathology , Fatigue/psychology , Psychophysiology , Adult , Demography , Female , Humans , Male , Physical Examination , Psychological Tests
19.
Biol Psychol ; 72(1): 78-87, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16137817

ABSTRACT

Driver fatigue is associated with risks of road accidents that result in injury and death. Research has been limited by several issues such as confusion over definitions, how best to measure fatigue, and the contribution of psychological factors to fatigue. This study addressed these limitations by investigating the relationship between psychological factors and fatigue. Participants were assessed and were required to perform a monotonous task till they tired. Results found few psychological factors to be related to physiological and performance decrement fatigue outcome measures. However, psychological factors were found to correlate consistently with self-reported fatigue. The results suggest that fatigue is associated with a predisposition to be anxious, depressive, less self-assured, more conscientious (rule bound), less socially bold, less adaptable and low vigour. The results indicate that future research should employ a range of fatigue outcome measures in order to best understand what factors contribute to fatigue.


Subject(s)
Automobile Driving/psychology , Fatigue , Adolescent , Adult , Blood Pressure/physiology , Demography , Electrooculography , Fatigue/diagnosis , Fatigue/etiology , Fatigue/psychology , Female , Galvanic Skin Response/physiology , Heart Rate/physiology , Humans , Male , Middle Aged , Severity of Illness Index , Surveys and Questionnaires , Videotape Recording
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