Alan Carson

Depression after stroke and lesion location: a systematic review

BACKGROUND There is conflicting evidence on the hypothesis that the risk of depression after stroke is influenced by the location of the brain lesion. We undertook a systematic review to examine the hypotheses that depression is more commonly associated with left-hemisphere strokes than with right-hemisphere strokes and with lesions of the left anterior brain than with other regions. METHODS We did a computer-aided search of MEDLINE, BIDS ISI, and PsychLit databases supplemented by hand searches of key journals. We included all reports on the association of depression after stroke with the location of the brain lesion. Studies were systematically and independently examined by two investigators. Fixed-effects and random-effects meta-analyses were done. FINDINGS 143 reports were identified by the search strategy. 48 were eligible for inclusion. Not all reports included original data. Only two reports of original data supported the hypotheses and seven clearly did not. The pooled (random-effects) relative risk of depression after a left-hemisphere stroke, compared with a right-hemisphere stroke, was 0.95 (95% CI 0.83-1.10). For depression after a left anterior lesion compared with all other brain areas the pooled (random-effects) relative risk was 1-17 (0.87-1.62). Restriction of the analyses to reports from high-quality studies or major depressive disorder did not substantially affect the findings. Nor were they affected by stratification of the time between stroke and the assessment of depression. Multiple publications from the same samples of patients were apparent. INTERPRETATION This systematic review offered no support for the hypothesis that the risk of depression after stroke is affected by the location of the brain lesion.

Psychological approaches to treatment of postconcussion syndrome: a systematic review

Background and aim Postconcussion syndrome (PCS) is a term used to describe the complex, and controversial, constellation of physical, cognitive and emotional symptoms associated with mild brain injury. At the current time, there is a lack of clear, evidence-based treatment strategies. In this systematic review, the authors aimed to evaluate the potential efficacy of cognitive behavioural therapy (CBT) and other psychological treatments in postconcussion symptoms. Methods Four electronic databases were searched up to November 2008 for studies of psychological approaches to treatment or prevention of postconcussion syndrome or symptoms. Results The search identified 7763 citations, and 42 studies were included. This paper reports the results of 17 randomised controlled trials for psychological interventions which fell into four categories: CBT for PCS or specific PCS symptoms; information, reassurance and education; rehabilitation with a psychotherapeutic element and mindfulness/relaxation. Due to heterogeneity of methodology and outcome measures, a meta-analysis was not possible. The largest limitation to our findings was the lack of high-quality studies. Conclusion There was evidence that CBT may be effective in the treatment of PCS. Information, education and reassurance alone may not be as beneficial as previously thought. There was limited evidence that multifaceted rehabilitation programmes that include a psychotherapeutic element or mindfulness/relaxation benefit those with persisting symptoms. Further, more rigorous trials of CBT for postconcussion symptoms are required.

Brain Structure in Adolescents and Young Adults with Alcohol Problems: Systematic Review of Imaging Studies

AIMS Alcohol-dependent people who are middle-aged or older have a widespread loss of cortical grey and white matter, particularly in the prefrontal cortex (PFC). We examine if brain abnormalities are detectable in alcohol use disorders before the fifth decade (i.e., <40), and the brain structural differences associated with alcohol abuse/dependence in adolescence. METHODS Case-control studies comparing brain structure in alcohol-abusing/-dependent individuals with normal controls in which the mean age of participants was <40 were identified using Medline, EMBASE and PsychInfo. Studies in which mean age was over and under 21 were considered separately. RESULTS Twelve papers fulfilled inclusion criteria, five in the adolescent (14-21) and seven in the young adult age range. Two independent groups reported hippocampal and prefrontal volume reductions in adolescents, although this was consistently observed only in females. In young adults (aged 21-40), there were grey matter deficits in the PFC in both sexes. Adult women appeared to, particularly, exhibit white matter differences, evident as reduced area of the corpus callosum. Hippocampal volume reduction was observed in one study of young adults study but not another. CONCLUSION The available data suggest that quantitative structural abnormalities of the brain are detectable in young alcohol abusers. There is overlap between the abnormalities seen in adolescents and young adults, although hippocampal volume loss is most consistently seen in the former group. The adolescent hippocampus may be particularly susceptible to alcohol, potentially because of an interaction between adolescent brain development and alcohol exposure.

Patients whom neurologists find difficult to help.

Background: All doctors recognise that some patients are more “difficult to help” than others, but the issue has received little systematic investigation in neurological practice. Objective: To test the hypothesis that patients whose symptoms were less explained by organic disease would be perceived as more difficult to help. Methods: In a consecutive series of 300 new neurology outpatients, neurologists indicated on four point Likert-type scales how “difficult to help” they found the patient and to what extent the patient’s symptoms were explained by organic disease. The patients’ demographics, health status, number of somatic symptoms, and mental state were also assessed. Results: The neurologists rated 143 patients (48%) as “not at all difficult” to help, 111 (37%) as “somewhat difficult”, 27 (9%) as “very difficult”, and 18 (6%) as “extremely difficult”. A logistic regression model was constructed and the hypothesis that patients whose symptoms were less explained by organic disease would be perceived as more difficult to help was supported. The only other measured variable that contributed to perceived difficulty was physical disability, but it explained only a small amount of the variance. Conclusions: Neurologists find patients whose symptoms are not explained by organic disease more difficult to help than their other patients.

Are functional motor and sensory symptoms really more frequent on the left? A systematic review

Objectives: To test the hypothesis that unilateral motor and sensory symptoms unexplained by identifiable disease are more common on the left side of the body than the right. Methods: Systematic review of the literature published since 1965. Results: 121 eligible studies, involving 1139 patients, were analysed. The pooled proportion of functional left sided weakness and sensory symptoms in adults was 58% (95% confidence interval (CI) 55 to 61%). A much higher proportion of left sided symptoms (66%, 95% CI 61 to 71%) was found in studies where laterality featured in the title of the paper. However, when laterality was not mentioned in the title, no significant difference between left and right was observed (53% on the left, 95% CI 48 to 57%). This difference could not be explained on the basis of sex differences between the groups or the date of the study. Functional or “psychogenic” movement disorder was right sided in 68% (95% CI 61 to 75%). Handedness did not influence symptom lateralisation. Conclusions: The findings of this systematic review question whether functional weakness and sensory symptoms do in fact occur more commonly on the left side of the body. A type of outcome variable reporting bias in combination with non-blinding of investigators may be responsible for this long held but erroneous belief.

The outcome of depressive disorders in neurology patients: a prospective cohort study

Background: In a previous prospective study of 300 consecutive new attenders at neurology outpatient clinics, depressive disorders were diagnosed in 119 patients (40%) and major depressive disorder in 77 (26%). Objective: To describe the eight month outcome of depression in this cohort. Methods: Patients were reinterviewed eight months after their baseline assessment. Mental state was examined using the primary care evaluation of mental disorders (PRIME-MD) interview and the hospital anxiety and depression (HAD) self rating scale. Health status was measured using the medical outcome study 36 item short form scale (SF-36). Results: Of the original cohort of 300, 226 (75%) participated in the follow up. Among them, 88 had a depressive disorder at baseline and 69 (78%) of those were still depressed at follow up; 54 had major depression at baseline and 46 (85%) of those still had a major depressive disorder at follow up. Among the 138 patients who had no depression at baseline, 20 new major depressive disorders had developed by the time of follow up. Resolution of major depressive disorders was associated with an improvement in health status. Conclusions: Most depressive disorders detected in neurology outpatients persist at an eight month follow up, and a substantial number of new cases arise. Resolution of depressive disorders, particularly major depressive disorder, is associated with an improvement in health status.

Cognitive behavioural therapy for depression: systematic review of imaging studies.

Objective Although cognitive behavioural therapy (CBT) has been shown to be an effective treatment for depression, the biological mechanisms underpinning it are less clear. This review examines if it is associated with changes identifiable with current brain imaging technologies. Methods To better understand the mechanisms by which CBT exerts its effects, we undertook a systematic review of studies examining brain imaging changes associated with CBT treatment of depression. Results Ten studies were identified, five applying functional magnetic resonance imaging, three positron emission tomography, one single photon emission computer tomography, and one magnetic resonance spectroscopy. No studies used structural MRI. Eight studies included a comparator group; in only one of these studies was there randomised allocation to another treatment. CBT-associated changes were most commonly observed in the anterior cingulate cortex (ACC), posterior cingulate, ventromedial prefrontal cortex/orbitofrontal cortex (VMPFC/OFC) and amygdala/hippocampus. Discussion The evidence, such as it is, suggests resting state activity in the dorsal ACC is decreased by CBT. It has previously been suggested that treatment with CBT may result in increased efficiency of a putative ‘dorsal cognitive circuit’, important in cognitive control and effortful regulation of emotion. It is speculated this results in an increased capacity for ‘top-down’ emotion regulation, which is employed when skills taught in CBT are engaged. Though changes in activity of the dorsal ACC could be seen as in-keeping with this model, the data are currently insufficient to make definitive statements about how CBT exerts its effects. Data do support the contention that CBT is associated with biological brain changes detectable with current imaging technologies.

A 1908 systematic review of the laterality of hysterical hemiplegia

Since the publication of our systematic review of the laterality of functional or medically unexplained weakness and sensory disturbance (1965–2000)1 we have come across a study from 1908 with a similar aim. Ernest Jones, later an eminent figure in the psychoanalytic movement, …