Search

The aim of this study was to test, in patients with multiple sclerosis (MS), whether the concept of helplessness might improve the understanding of the relationship between disease severity (neurological impairment) and personality characteristics (emotional instability) on one hand, and depressive mood and fatigue severity on the other hand. Data pertain to 89 patients with a definite diagnosis of MS (Expanded Disability Status Scale [EDSS] ratings: 1–8). Helplessness, fatigue severity, depressive mood and emotional instability were rated with validated questionnaires. Model testing revealed that more neurological impairment and more emotional instability were associated with more helplessness, while higher levels of helplessness were associated with more fatigue and depressive mood. The initially observed direct relationship between EDSS and fatigue disappeared. Emotional instability also had a direct significant relationship with depressive mood, and depressive mood had only a small relationship with fatigue severity. The results indicated that helplessness affected both depressive mood and fatigue severity and that fatigue was not merely a symptom of depressive mood. The correlation between neurological impairment and fatigue severity was largely explained by the mediating effect of helplessness. These findings suggest that MS patients troubled by disabling fatigue might benefit from a psychological intervention targeting unfavourable illness cognitions. [ABSTRACT FROM AUTHOR]

Background: The clock drawing test (CDT) and the Mini Mental State Examination (MMSE) are frequently used screening instruments for cognitive impairment, however, the precise contribution of the CDT to the MMSE is largely unknown., Methods: We studied patients with subjective cognitive impairment (SCI, n = 481), mild cognitive impairment (MCI, n = 628) and Alzheimer's disease (AD, n = 1099). Discrimination between patients was examined with multiple logistic regression, adjusted for age, sex, and education. Four groups were constructed based on a normal/abnormal MMSE (cut-off <24/30) versus normal/abnormal CDT (cut-off ≤2/3). Visually rated medial temporal lobe atrophy (MTA) on CT was used as parameter of neurodegeneration., Results: The CDT significantly contributed to the MMSE in discriminating SCI from both MCI and AD patients. Our four group analyses showed that of those patients with a normal MMSE and incorrectly classified as SCI, an abnormal CDT could significantly identify 10.0% as MCI and 13.2% as AD. Among those with an abnormal MMSE, the percentage AD patients shifted from 53.1% to 82.1% due to an abnormal CDT. Presence of an abnormal CDT was significantly related to MTA increase, regardless of the MMSE score., Conclusion: The CDT is an important additional screening tool to the MMSE. An abnormal CDT with a normal MMSE is an indicator for cognitive impairment. An abnormal CDT in combination with an abnormal MMSE can be considered as an indicator of disease progression., (© 2023 John Wiley & Sons Ltd.)

Purpose: Clinically observed discrepancies between electrocardiogram findings and subjective report of symptoms related to atrial fibrillation (AF) often remain unexplained. One could hypothesize that after a technically successful ablation, preoperative panic behavior might affect the report of AF-related symptoms. However, research on comorbid panic behavior in patients with AF is limited., Methods: In this observational prospective cohort study, we investigated psychological characteristics, in particular the prevalence of panic features, among 112 patients with AF and its possible influence on experienced outcome of subsequent ablation treatment., Results: Twelve percent of the AF patients (n = 12) were pre-operatively characterized by panic features. This group experienced higher levels of distress and more limitations in daily life compared to AF patients without panic features, but was not characterized by higher levels of neuroticism. However, AF-ablation resulted in a similar reduction of experienced limitations in daily functioning and levels of distress in both groups., Conclusion: Patients with panic features experience more distress and more limitations in daily life from AF, but these complaints are reduced by AF ablation in a similar rate as in patients without panic features. Additional psychological therapy is suggested as a method to further reduce subjective AF disease burden in these patients.

Cognitive changes after minor stroke or TIA have been reported, with studies describing a 'vascular' cognitive profile with spared episodic memory. Still, many patients also report memory complaints. Studies using long-term forgetting paradigms have detected memory impairment after prolonged intervals in contrast to standard delayed testing in other patient groups. This study examined whether accelerated long-term forgetting (ALF) is present in patients with minor stroke or TIA by comparing one-week delayed recall and recognition with the performance of a healthy control group. Results revealed that the patients' performance after one week was worse than the controls, in the absence of an impairment after a short delay. Patients did, however, not report more memory worries than controls. Possibly, reduced effort, attention or mnemonic strategies may contribute to subtle consolidation problems, which go undetected in daily functioning., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: Severe fatigue is highly prevalent in various chronic diseases. Disease-specific fatigue models have been developed, but it is possible that fatigue-related factors in these models are similar across diseases. The purpose of the current study was to determine the amount of variance in fatigue severity explained by: (a) the specific disease, (b) factors associated with fatigue across different chronic diseases (transdiagnostic factors), and (c) the interactions between these factors and specific diseases., Method: Data from 15 studies that included 1696 patients with common chronic diseases and disorders that cause long-term disabilities were analyzed. Linear regression analysis with the generalized least-squares technique was used to determine fatigue-related factors associated with fatigue severity, that is, demographic variables, health-related symptoms and psychosocial variables., Results: Type of chronic disease explained 11% of the variance noted in fatigue severity. The explained variance increased to 55% when the transdiagnostic factors were added to the model. These factors were female sex, age, motivational and concentration problems, pain, sleep disturbances, physical functioning, reduced activity and lower self-efficacy concerning fatigue. The predicted variance increased to 61% when interaction terms were added. Analysis of the interactions revealed that the relationship between fatigue severity and relevant predictors mainly differed in strength, not in direction., Conclusions: Fatigue severity can largely be explained by transdiagnostic factors; the associations vary between chronic diseases in strength and significance. This suggests that severely fatigued patients with different chronic diseases can probably benefit from a transdiagnostic fatigue-approach which focuses on individual patient needs rather than a specific disease. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)

It has been suggested that the memory complaints of patients who are not impaired on formal memory tests may reflect accelerated forgetting. We examined this hypothesis by comparing the 1-week delayed recall and recognition test performance of outpatients who were referred for neuropsychological assessment and who had normal memory performance during standard memory assessment with that of a non-patient control group. Both groups performed equally in verbal learning and delayed recall. However, after 1 week, the patients performed worse than controls on both recall and recognition tests. Although subjective memory ability predicted short-term memory function in patients, it did not predict long-term delayed forgetting rates in either the patients or controls. Thus, long-term delayed recall and recognition intervals provided no additional value to explain poor subjective memory ability in the absence of objective memory deficits.

The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests, days, to weeks, after initial learning) are more sensitive measures than standard delayed recall measures to detect memory problems in various patient groups. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed in other populations. Here, we identified eleven studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to those of healthy controls. Signs of accelerated forgetting were found in three studies. The results of eight studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on these results, we recommend the use of a combined recall and recognition procedure to examine accelerated forgetting and we discuss the relevance of standard and optimized learning procedures in clinical practice.

Objective: A subgroup of patients with Chronic Fatigue Syndrome (CFS) has cognitive impairments, reflected by deviant neuropsychological test performance. However, abnormal test scores can also be caused by suboptimal effort. We hypothesized that worse neuropsychological test performance and underperformance were related to each other and to a smaller reduction in fatigue, functional impairments, physical limitations and higher dropout rates following cognitive behavior therapy (CBT) for CFS., Methods: Data were drawn from a previous trial, in which CFS patients were randomized to two conditions; 1) guided self-instruction and additional CBT (n=84) or 2) waiting period followed by regular CBT for CFS (n=85). Underperformance was assessed using the Amsterdam Short Term Memory Test (<84). To test neuropsychological test performance, the Symbol Digit Modalities Task, a simple reaction time task and a choice reaction time task were used. Interaction effects were determined between underperformance and neuropsychological test performance on therapy outcomes., Results: Underperformance was associated to worse neuropsychological test performance, but there were no significant interaction effects of these two factors by therapy on fatigue severity, functional impairments and physical limitations, but there was a significant main effect of underperformance on functional impairments, physical limitations and dropout rates., Conclusion: Underperformance or neuropsychological test performance was not related to the change in fatigue, functional impairments, and physical limitations following CBT for CFS. However, underperforming patients did drop out more often. Therapists should pay attention to beliefs and behavioral or environmental factors that might maintain underperformance and increase the risk of dropout., (© 2013.)

The expression of memory worries and the self-reporting of daily forgetfulness easily spark discussion among sufferers and their family or friends about what is normal or abnormal forgetfulness. One way to investigate whether the reporting of forgetfulness might be excessive is to use a standardized memory questionnaire--for instance, the Multifactorial Memory Questionnaire (MMQ). The MMQ measures worries, daily forgetfulness, and memory strategy use. In this study we present a psychometric evaluation of the Dutch translation of the MMQ and provide normative data to determine the significance of individual differences in subtest scores. In addition, clinical examples are given of the use and interpretation of percentile norms and single-case statistics.

Introduction: Effects of systemic inflammation on cerebral function are not clear, as both inflammation-induced encephalopathy as well as stress-hormone mediated alertness have been described., Methods: Experimental endotoxemia (2 ng/kg Escherichia coli lipopolysaccharide [LPS]) was induced in 15 subjects, whereas 10 served as controls. Cytokines (TNF-alpha, IL-6, IL1-RA and IL-10), cortisol, brain specific proteins (BSP), electroencephalography (EEG) and cognitive function tests (CFTs) were determined., Results: Following LPS infusion, circulating pro- and anti-inflammatory cytokines, and cortisol increased (P < 0.0001). BSP changes stayed within the normal range, in which neuron specific enolase (NSE) and S100-beta changed significantly. Except in one subject with a mild encephalopathic episode, without cognitive dysfunction, endotoxemia induced no clinically relevant EEG changes. Quantitative EEG analysis showed a higher state of alertness detected by changes in the central region, and peak frequency in the occipital region. Improved CFTs during endotoxemia was found to be due to a practice effect as CFTs improved to the same extent in the reference group. Cortisol significantly correlated with a higher state of alertness detected on the EEG. Increased IL-10 and the decreased NSE both correlated with improvement of working memory and with psychomotor speed capacity. No other significant correlations between cytokines, cortisol, EEG, CFT and BSP were found., Conclusions: Short-term systemic inflammation does not provoke or explain the occurrence of septic encephalopathy, but primarily results in an inflammation-mediated increase in cortisol and alertness., Trial Registration: NCT00513110.

Primary Objective: To investigate how the type of stimulus (pictures or words) and the method of reproduction (free recall or recognition after a short or a long delay) affect the sensitivity and specificity of a 3-item memory test in the assessment of post traumatic amnesia (PTA)., Methods: Daily testing was performed in 64 consecutively admitted traumatic brain injured patients, 22 orthopedically injured patients and 26 healthy controls until criteria for resolution of PTA were reached. Subjects were randomly assigned to a test with visual or verbal stimuli. Short delay reproduction was tested after an interval of 3-5 minutes, long delay reproduction was tested after 24 hours. Sensitivity and specificity were calculated over the first 4 test days., Results: The 3-word test showed higher sensitivity than the 3-picture test, while specificity of the two tests was equally high. Free recall was a more effortful task than recognition for both patients and controls. In patients, a longer delay between registration and recall resulted in a significant decrease in the number of items reproduced., Conclusions: Presence of PTA is best assessed with a memory test that incorporates the free recall of words after a long delay.

Objectives: Recently, it has become clear that neuralgic amyotrophy (NA; idiopathic and hereditary brachial plexus neuropathy) has a less optimistic prognosis than usually assumed. To optimize treatment and management of these patients, one needs to know the residual symptoms and impairments they suffer. Therefore, the objective of this study was to describe the prevalence of pain, psychologic symptoms, fatigue, functional status, and quality of life in patients with NA., Setting: Neurology outpatient department of an academic teaching hospital., Participants: NA patients (N=89) were studied, and clinical details were recorded. Self-report data were on average collected 2 years after the onset of the last NA episode., Main Outcome Measures: Pain was assessed with the McGill Pain Questionnaire, fatigue with the Checklist Individual Strength, and psychologic distress with the Symptom Checklist 90. Functional status and handicap were assessed with the modified Rankin Scale and Medical Outcomes Study 36-Item Short-Form Health Survey., Results: Pain was usually localized in the right shoulder and upper arm, matching the clinical predilection site for paresis in NA. About a quarter to a third of the patients reported significant long-term pain and fatigue, and half to two thirds still experienced impairments in daily life. Over one third of the individual patients suffered from severe fatigue. The group did not fulfill the criteria of chronic fatigue or major psychologic distress. There was no correlation of pain or fatigue with the level of residual paresis on a Medical Research Council scale, but patients with a comorbid condition fared worse than patients without., Conclusions: A significant number of NA patients suffer from persistent pain and fatigue, leading to impairment. Symptoms were not correlated with psychologic distress. This makes it likely that they are caused by residual shoulder or arm dysfunction but not as part of a chronic pain or fatigue syndrome in these patients.

Background: Pre-eclampsia and eclampsia relate to cerebral damage. Memory and concentration problems are frequently reported after these pregnancy-related vascular complications. We tested the hypothesis that in formerly pre-eclamptic women cognitive functioning is impaired as compared with healthy parous controls., Methods: Women with a recent history of pre-term pre-eclampsia (PPE; n = 47), term pre-eclampsia (TPE; N = 18), pre-term birth (PBI; n = 32) or an uneventful pregnancy (UPR; n = 72) completed a set of questionnaires, measuring cognitive problems, PTSD, depression, anxiety and fatigue. In addition, in PPE and UPR participants we tested neuropsychological performance., Results: PBI is related to higher levels of post-traumatic distress symptoms, which in turn diminished the neuropsychological test performance of PPE women. Nonetheless, women in the PPE and TPE groups did not report more cognitive problems than women in the PBI and UPR groups, but PPE raised the need for psychosocial cared., Conclusions: Cognitive complaints are common amongst young mothers. When tested, only those with psychological co-morbidity have neuropsychological impairment.

Remembering complex, multidimensional information typically requires strategic memory retrieval, during which information is structured, for instance by spatial- or temporal associations. Although brain regions involved in strategic memory retrieval in general have been identified, differences in retrieval operations related to distinct retrieval strategies are not well-understood. Thus, our aim was to identify brain regions whose activity is differentially involved in spatial-associative and temporal-associative retrieval. First, we showed that our behavioral paradigm probing memory for a set of object-location associations promoted the use of a spatial-associative structure following an encoding condition that provided multiple associations to neighboring objects (spatial-associative condition) and the use of a temporal-associative structure following another study condition that provided predominantly temporal associations between sequentially presented items (temporal-associative condition). Next, we used an adapted version of this paradigm for functional MRI, where we contrasted brain activity related to the recall of object-location associations that were either encoded in the spatial- or the temporal-associative condition. In addition to brain regions generally involved in recall, we found that activity in higher-order visual regions, including the fusiform gyrus, the lingual gyrus, and the cuneus, was relatively enhanced when subjects used a spatial-associative structure for retrieval. In contrast, activity in the globus pallidus and the thalamus was relatively enhanced when subjects used a temporal-associative structure for retrieval. In conclusion, we provide evidence for differential involvement of these brain regions related to different types of strategic memory retrieval and the neural structures described play a role in either spatial-associative or temporal-associative memory retrieval., ((c) 2007 Wiley-Liss, Inc.)

Objective: To compare nonreferred, emergency department (ED)-admitted mild traumatic brain injury (MTBI) patients with and without self-reported cognitive complaints on (1) demographic variables and injury characteristics; (2) neuropsychological test performance; (3) 12-day self-monitoring of perceived cognitive problems; and (4) emotional distress, physical functioning, and personality., Methods: (Neuro)psychological assessment was carried out 6 months post-injury in 79 patients out of a cohort of 618 consecutive MTBI patients aged 18-60, who attended the ED of our level I trauma centre. Cognitive complaints were assessed with the Rivermead Postconcussional Symptoms Questionnaire (RPSQ). In addition, patients monitored concentration problems and forgetfulness during 12 consecutive days., Results: Self-reported cognitive complaints were reported by 39% of the patients. These complaints were strongly related to lower educational levels, emotional distress, personality, and poorer physical functioning (especially fatigue) but not to injury characteristics. Severity of self-reported cognitive complaints was neither associated with the patients' daily observations of cognitive problems nor with outcome on a range of neuropsychological tests., Conclusion: Self-reported cognitive complaints were more strongly related to premorbid traits and physical and emotional state factors than to actual cognitive impairments. In line with previous work, this suggests that treatment of emotional distress and fatigue may also reduce cognitive complaints. Cognitive outcome assessment of symptomatic MTBI patients should not be restricted to checklist ratings only, but also include a (neuro)psychological screening. In addition, daily monitoring of complaints is a useful method to gather information about the frequency and pattern of cognitive problems in daily life.

Introduction: Previous studies of writer's cramp have detected cerebral sensorimotor abnormalities in this disorder and, more specifically, a reduced striatal D2-binding as assessed by [(123)I]IBZM SPECT. However, empirical data were lacking about the influence of effective biofeedback-based sensorimotor training on D2 receptor binding., Methods: To determine whether there is a restoration of D2-binding after successful sensorimotor treatment, pre- and posttreatment SPECTs were compared in five patients with writer's cramp and correlated with improvement in handwriting., Results: After treatment, the clinical and electromyographic picture appeared substantially improved connected with a significant increase in D2-binding to nearly normal levels similar to normative data in age/sex-matched healthy subjects., Conclusion: The current study supported the view that writer's cramp results from a plastic adaptation of a rectifiable nigrostriatal dopaminergic system and that effective sensorimotor training leads to increased efficacy of striatal dopaminergic transmission.

Many patients with mild traumatic brain injury (MTBI) concurrently sustain extracranial injuries; however, little is known about the impact of these additional injuries on outcome. We assessed the impact of additional injuries on the severity of postconcussional symptoms (PCS) and functional outcome 6 months post-injury. A questionnaire (including the Rivermead Post-Concussion Questionnaire and SF-36) was sent to consecutive MTBI patients (hospital admission Glasgow Coma Score 13-15; age range 18-60 years) admitted to the emergency department of a level-I trauma center, and, to serve as a baseline for PCS, a control group of minor-injury patients (ankle or wrist distortion). Of the 299 MTBI respondents (response rate 52%), 89 had suffered additional injuries (mean Injury Severity Score [ISS] of 14.5 +/- 7.4). After 6 months, 44% of the patients with additional injuries were still in some form of treatment, compared to 14% of patients with isolated MTBI and 5% of the controls. Compared to patients with isolated injury, MTBI patients with additional injuries had resumed work less frequently and reported more limitations in physical functioning. Overall, they did not report higher levels of PCS, despite somewhat more severe head injury. Regardless of the presence of additional injuries, patients that were still in treatment reported significantly more severe PCS, with highest rates in patients with isolated MTBI. In conclusion, many patients with additional extracranial injuries are still in the process of recovery at 6 months after injury. However, despite more severe impact to the head and inferior functional outcomes, these patients do not report more severe PCS.

Physiological fatigue, a loss of maximal force producing capacity, may originate both from changes at the peripheral and at the central level. The readiness potential (RP) provides a measure to study adaptations to physiological fatigue at the motor cortex. We have studied the RP in the course of repetitive contractions at a high force level. Fourteen female healthy subjects made repetitive force grip contractions at 70% of their maximal voluntary contraction (MVC) for 30 min. Contractions were self-paced and inter-squeeze interval was about 7 s. During the repetitive contractions, the area under the curve of the RP almost doubled at electrode Cz and increased fourfold at electrodes C3' and C4'. The onset of negativity moved forward from 1.5 to 1.9 s before force onset at Cz and from 1.0 to 1.6 s and 1.7 s before force onset at C3' and C4', respectively. EMG amplitude and median frequency did not change significantly and MVC after the fatiguing exercise was 93% of MVC before, indicating relatively little physiological fatigue. The increase of the RP during the repetitive contractions is clearly in excess of the almost absent signs of peripheral fatigue. Because the increase of the RP does not lead to an increased force production, we propose that it is a central adaptation counteracting the decrease of cortical efficiency during repetitive contractions.

Objective: To assess the prevalence of severe fatigue and its relation to functional impairment in daily life in patients with relatively common types of neuromuscular disorders., Methods: 598 patients with a neuromuscular disease were studied (139 with facioscapulohumeral dystrophy, 322 with adult onset myotonic dystrophy, and 137 with hereditary motor and sensory neuropathy type I). Fatigue severity was assessed with Checklist Individual Strength (CIS-fatigue). Functional impairments in daily life were measured with the short form 36 item health questionnaire (SF-36)., Results: The three different neuromuscular patient groups were of similar age and sex. Severe experienced fatigue was reported by 61-74% of the patients. Severely fatigued patients had more problems with physical functioning, social functioning, mental health, bodily pain, and general health perception. There were some differences between the three disorders in the effects of fatigue., Conclusions: Severe fatigue is reported by the majority of patients with relatively common types of neuromuscular disorders. Because experienced fatigue severity is associated with the severity of various functional impairments in daily life, it is a clinically and socially relevant problem in this group of patients.

Objective: We have investigated whether central activation failure (CAF) is increased during local muscle fatigue in chronic fatigue syndrome (CFS)., Methods: Fourteen female CFS patients and 14 age-matched healthy female controls made a 2 min sustained maximal voluntary contraction (MVC) of the biceps brachii muscle. Before, during, and after sustained MVC, electrical endplate stimulation was applied. Force and 5 channel surface EMG (sEMG) were registered., Results: Although force responses upon stimulation during rest did not differ between patients and controls, MVC was significantly lower in patients. Already at the beginning of sustained MVC, CFS patients showed significantly larger CAF than controls (36.5+/-17.0% and 12.9+/-13.3%, respectively). For all individual patients mean CAF over the first 45 s was higher than 30%, while it was below 30% for all controls. Less peripheral fatigue in patients was demonstrated by the changes in muscle fibre conduction velocity and the differences between force responses before and after contraction., Conclusions: Central activation is diminished in CFS patients. Possible causes include changed perception, impaired concentration, reduced effort and physiologically defined changes, e.g. in the corticospinal excitability or the concentration of neurotransmitters. As a consequence, demands on the muscle are lower, resulting in less peripheral fatigue., Significance: CFS patients show reduced central activation during MVC. The underlying pathophysiological processes remain still to be determined.

Chronic fatigue is a symptom of diseases such as cancer, multiple sclerosis, Parkinson's and cerebrovascular disease. Fatigue can also be present in people with no demonstrable somatic disease. If certain criteria are met, chronic-fatigue syndrome may be diagnosed in these cases. Fatigue is a multi-dimensional concept with physiological and psychological dimensions. The 'Short Fatigue Questionnaire' consisting of 4 questions is a tool to measure fatigue with a high degree of reliability and validity. Within the group of neuromuscular disorders, fatigue has been reported by patients with post-polio syndrome, myasthenia gravis, and Guillain-Barré syndrome. The percentage of neuromuscular patients suffering from severe fatigue (64%) is comparable with that of patients with multiple sclerosis, a disease in which fatigue is an acknowledged symptom. Now that reliable psychological and clinical neurophysiological techniques are available, a multidisciplinary approach to fatigue in patients with well-defined neuromuscular disorders may contribute towards the elucidation of the pathophysiological mechanisms of chronic fatigue, with the ultimate goal being to develop methods of treatment for fatigue in neuromuscular patients.

Background: Several studies suggested that the surroundings of chronic fatigue syndrome (CFS) patients are of importance in the persistence of complaints. Contrary to what was expected, participation in support groups has not led to clinical improvement. The purpose of the present study was to describe social support in CFS patients as compared with other fatigued and non-fatigued groups. Further, changes in social support and the influence of social support on the course of CFS over a period of more than 1 year were studied in patients with and without treatment., Methods: Baseline data were assessed in 270 CFS patients, 150 disease-free breast cancer patients, 151 fatigued employees on sick-leave and 108 healthy subjects using the Social Support List and Significant Others Scale. CFS patients were followed in cognitive behaviour therapy (CBT), guided support groups and natural course at 8 and 14 months., Results: CFS patients and fatigued employees reported more negative interactions and insufficiency of supporting interactions than cancer patients and healthy controls. No differences in frequency of supporting interactions were found. Negative interactions decreased significantly after treatment with CBT, but did not change in support groups or natural course. In the natural course, higher fatigue severity at 8 months was predicted by more negative interactions at baseline., Conclusions: In CFS patients and fatigued employees, social support is worse than in disease-free cancer patients and healthy controls. Lack of social support was identified as a new factor in the model of perpetuating factors of fatigue severity and functional impairment in CFS., (Copyright 2004 S. Karger AG, Basel)

Unlabelled: Patients with Parkinson's disease (PD) have difficulty in processing learning tasks that lack external guidelines and, consequently, necessitate the subjects to generate their own problem-solving strategy. While the contribution of striatal dopaminergic deficiency to PD-specific motor symptoms is well established, its role in the PD-characteristic deviant learning style remains unclear. The aim of this study was to assess the relation between striatal dopamine activity as revealed by single photon emission computed tomography (SPECT) with (123)I-FP-CIT, a ligand for the dopamine transporter (DaT), and type of learning strategy, as identified by the California Verbal Learning Task (CVLT) in 19 patients with probable PD. The results showed a robust inverse correlation between striatal dopamine DaT binding and the externally guided, serial learning strategy: the lower the DaT in caudate nucleus as well as in putamen, the more the patient group appeared to rely on externally structured learning. Additionally, a significant positive correlation was found between caudatal DaT activity and the internally generated, semantic learning strategy. Unlike these strategic learning characteristics, IQ equivalent and recall total score appeared to vary independently from striatal DaT availability., Conclusion: our findings provide direct evidence that striatal dopaminergic activity is specifically involved in the regulation of strategic learning processes.

Hypoglycemia unawareness is thought to be the consequence of recurrent hypoglycemia, yet the underlying mechanism is still incompletely understood. The aim of the present study was to determine the role of antecedent elevated adrenaline in the pathogenesis of hypoglycemia unawareness. Sixteen healthy volunteers (eight of either sex) participated in two experiments, performed in random order and at least 3 wk apart. During the morning, three consecutive doses of 0.04, 0.06, and 0.08 microg.kg(-1).min(-1) of adrenaline or matching placebo (normal saline) were infused for the total duration of 1 h. Three hours later, a hyperinsulinemic (360 pmol.m(-2).min(-1)) two-step hypoglycemic (5.0-3.5-2.5 mmol.liter(-1)) clamp study was performed. During hypoglycemia, hypoglycemic symptoms, counterregulatory hormones, cardiovascular responses, and cognitive function were monitored. Hypoglycemia induced similar responses of autonomic and neuroglycopenic symptoms, counterregulatory hormones, and lengthening in reaction time on the choice reaction time task, irrespective of antecedent infusions. However, prior adrenaline was associated with higher exogenous glucose requirements at hypoglycemic nadir (10.1 +/- 1.3 vs. 7.3 +/- 1.3 micromol.kg(-1).min(-1), P = 0.017), an attenuated hypoglycemia-induced fall in blood pressure (mean arterial pressure, -13 +/- 2 vs. -8 +/- 2 mm Hg, P = 0.006), and preserved cognitive function as assessed by the symbol digit test during hypoglycemia, when compared with prior placebo. We conclude that elevated adrenaline attenuates the responsiveness to, but not the release of counterregulatory hormones during subsequent hypoglycemia. As such, adrenaline's role in the development of hypoglycemia unawareness is limited.

Objective: To describe the course of fatigue in chronic fatigue syndrome (CFS) patients with a relatively short duration of complaints and to test which psychosocial factors predict spontaneous improvement 1 year later., Methods: Seventy-nine patients with a complaint duration of less than 2 years were tested at baseline and 78 of the same group at 1-year follow-up. During this time period, no systematic intervention took place. Self-reported improvement and fatigue severity were the main outcome measures., Results: Forty-six percent (95% confidence intervals, 95CI = 35-58%) of the patients with a short illness duration reported to be improved. This was a significantly (chi(2) = 20.3, P < .001) higher percentage compared to the 20% (95CI = 15-26%) self-reported improvement in a previously published natural-course study among 246 CFS patients with a longer illness duration. Persistence of complaints after 1-year follow-up was associated with high baseline levels of experienced concentration problems, less strong psychosocial causal explanations for the complaints, and higher levels of the experienced lack of social support. Baseline fatigue severity predicted fatigue severity at follow-up., Conclusion: The results showed that CFS patients with a relatively short duration of complaints had a more favourable outcome compared to patients with a long illness duration. The data also indicated that complete recovery only occurred in patients with a complaint duration of less than 15 months. This finding has important implications, since it suggests that after such a time period spontaneous recovery hardly occurs., (Copyright 2002 Elsevier Science Inc.)

Objective: The aim of this study was to assess the potential influence of body consciousness and levels of somatic symptom report upon information processing speed in patients with chronic fatigue syndrome (CFS)., Background: According to a model of a fixed information processing capacity, it was predicted that in a group of patients with CFS, high body consciousness in combination with a high report of somatic symptoms would affect information-processing speed negatively., Methods: Information- and motor-processing speed were simultaneously measured with a simple- and a choice-reaction time task, whereas cognitive complaints were rated with two questionnaires. The hypothesized influence of private body consciousness and somatic symptom report upon information-processing speed was tested in a model. A symptom-validity test was used to screen for possible illness behavior., Results: Private body consciousness was directly related to information-processing speed and somatic symptom report. Somatic symptom report was related to both test performance and memory and concentration complaints., Conclusions: Levels of private body consciousness directly affected somatic symptom report and information-processing speed. This finding supports the role of attentive processes in CFS, and offers, besides possible cerebral dysfunction, an alternative explanation for slowing of information processing in CFS.

Although the experience of abnormal fatigue is recognised as a major disabling symptom in many chronic neurological diseases, little is known about the persistence of severe fatigue after an abrupt neurological incident like a stroke. Therefore, the objectives of this study were to test whether the experience of severe fatigue persists long after a stroke has occurred, and to assess the relation between experienced fatigue and levels of physical impairment and depression. Ninety stroke outpatients and 50 controls returned mailed questionnaires. Compared to age-matched controls, a significantly larger proportion (16 vs. 51%) of the stroke respondents experienced severe fatigue, while 20% of the patients and 16% of the controls had elevated depression symptom scores. The time which had elapsed since the stroke occurred could not explain levels of fatigue. In the control group, the number of depressive symptoms explained most of the variance in levels of fatigue, while impairment of locomotion explained most of the variance in the stroke group., (Copyright 2001 S. Karger AG, Basel)

Objective: Changes in physical activity are thought to play an important role in maintaining symptoms in chronic fatigue syndrome (CFS). The aim of this study was to describe intraindividual physical activity patterns in more detail and to identify pervasively passive patients., Methods: With help of a movement-sensing device, physical activity levels were registered continuously over a 12-day period in 277 CFS patients. Within this registration period, the 10 largest activity peaks were computed. The intensity and duration of these activity peaks and their subsequent rest periods were described and compared to those of 47 healthy controls. In addition, the patients' 12 daily activity scores were used to identify patients who were characterised by low levels of physical activity throughout the registration period., Results: The CFS sample had less intense and shorter activity peaks, while the average rest periods that followed these peaks lasted longer. Approximately one-fourth of the CFS sample differed distinctly from the control group and was labelled as pervasively passive., Conclusion: The measurements and classification of actual physical activity levels were found to reduce heterogeneity in the CFS population and therefore could provide the opportunity to optimise behavioural intervention protocols for CFS.

Objective: The aim of this study was to assess the potential impact of effort in comparative studies assessing neurocognitive dysfunction in patients with and without a neurologic diagnosis., Background: It was hypothesized that a subgroup within a group of patients with prominent neurocognitive complaints but without a neurologic diagnosis would have impaired performance on a task originally designed to detect malingering., Method: We compared the neuropsychological performance of a group of 40 patients with a definite diagnosis of multiple sclerosis (MS) with that of 67 patients with chronic fatigue syndrome (CFS). The Amsterdam Short-Term Memory Test, a forced-choice memory task, served as measure to detect submaximal effort. In addition, we administered a regular neuropsychological task generally considered to be sensitive for cognitive deterioration., Results: Compared with the MS group (13%), a larger proportion of the matched CFS group (30%) obtained scores indicative of reduced effort. In contrast, the proportions of patients scoring below the cutoff value on a conventional neuropsychological test did not differ significantly (17% of MS patients and 16% of CFS patients)., Conclusions: The results obtained raise the question of to what extent abnormal test findings in the absence of documented neurologic impairment should be interpreted as a sign of cerebral impairment. The suggestion has been made to screen more often for biased results in comparative research studies so as to enhance valid interpretation of neuropsychological findings.

Although fatigue is a frequent complaint of patients with multiple sclerosis (MS), little is known about the origins of multiple-sclerosis-associated fatigue. Our primary focus was to study if the extent of cerebral abnormalities, as shown on magnetic resonance imaging (MRI), had any relation with the frequency and intensity of fatigue complaints of patients with a definite diagnosis of MS. Fatigue severity was rated by the patients with the use of a 2-week diary and a fatigue questionnaire, while conventional T1- and T2-weighted MRI provided several measures for cerebral abnormalities. In total, 72% of 45 patients reported to be seriously fatigued at least several times a week over the last 3-month period. Fatigue severity was not related to the total extent of cerebral abnormalities, or to MRI-based atrophy measures. Regional lesion load did not differ between fatigued and non-fatigued subjects. Although neurological disability, as measured by the Expanded Disability Status Scale (EDSS) and Neurological Rating Scale (NRS), did correlate significantly with most MRI measures, it showed no relation with fatigue severity. Neurological progression rates and number of exacerbations in the 2-year period prior to assessment were not significantly associated with the fatigue measures. Therefore, our findings suggest that differences in levels of self-reported fatigue in patients with multiple sclerosis cannot merely be explained by the degree of clinical disease activity, neurological disability or the extent of MRI abnormalities. These results are compared to other research findings and the possible role of alternative factors influencing fatigue in multiple sclerosis are discussed.