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Biomedical subjects

R G Robinson

Publications and source records attributed to R G Robinson.

At least 145 records · Page 8Linked to original sources
PubMed1990

Hemispheric asymmetry in behavioral response to D1 and D2 receptor agonists in the nucleus accumbens.

The present study examined the locomotor response of rats to unilateral injections of the mixed D1/D2 agonist apomorphine, the D2 agonist quinpirole, and the D1 agonist SKF 38393 into the left or right nucleus accumbens (NA) of male Sprague-Dawley rats. There were 2 main findings. First, unilateral (left or right) injections of apomorphine, quinpirole, or SKF 38393 all provoked locomotor hyperactivity. The second and more important finding was that, at specific dosages, apomorphine and SKF 38393 injections into the right NA produced significantly more locomotor hyperactivity than identical injections into the left NA. These findings suggest the presence of asymmetries in the NA which may involve quantitative differences in the distribution of D1 and D2 receptors.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1990

Remote lateralized changes in cortical [3H]spiperone binding following focal frontal cortex lesions in the rat.

Positron emission tomography (PET) studies in stroke patients have shown that right hemisphere lesions lead to increases in ipsilateral (compared to contralateral) cortical S2-serotonin receptors, while left hemisphere lesions do not. To assess whether similar lateralized changes in cortical S2-receptors could be demonstrated in response to brain injury in the rat, [3H]spiperone (SP) autoradiography was performed 30 days after unilateral cortical suction lesions. Right lesions produced bilateral increases in total SP binding in frontal cortex (excluding the lesion site): 48% greater than after left lesions, and 23% greater than shams. Left lesions led to bilateral decreases in S2-receptors in the frontal and perirhinal cortex and these decreases were asymmetric. There was a greater decrease in the hemisphere contralateral to the lesion than in the side with the lesion. Frontal S2-receptor binding was positively correlated with running wheel activity in all animals with lesions, regardless of lesion side. These results suggest that there is a lateralized receptor and behavioral response to focal injury in rats, analogous to that previously observed in humans.

Animals↗
PubMed1990

The impact of poststroke depression on recovery in activities of daily living over a 2-year follow-up.

The impact of clinically diagnosed depression on recovery in activities of daily living over a 2-year follow-up was examined in a prospective study of 63 stroke patients. Although impairment in activities of daily living, neurologic diagnoses and findings, lesion location and volume as measured on computed tomographic scan, demographic variables, cognitive impairment, and social functioning were comparable between depressed (n = 25) and nondepressed (n = 38) patients during their acute hospitalization, the two groups had different patterns of recovery in activities of daily living. At 2 years after suffering a stroke, patients with an in-hospital diagnosis of depression (either major or minor depression) were significantly more impaired in both physical activities and language functioning than were non-depressed patients. Among patients with major depression, this disparity in the recovery profile was present even after the depression had remitted. This study emphasizes the need for early recognition and treatment of poststroke depression.

Activities of Daily Living↗
PubMed1990

Relationship between anxiety disorders and depressive disorders in patients with cerebrovascular injury.

The interaction between anxiety disorder and major depressive disorder in patients with cerebrovascular lesions was examined in a controlled, 2 x 2 study design. A consecutive series of 24 patients who met criteria for major depression only were compared with 6 patients who met criteria for both major depression and generalized anxiety disorder, and 45 patients who did not meet criteria for either major depression of generalized anxiety. Among patients with positive computed tomographic scans, the anxious-depressed group (n = 19) showed a significantly higher frequency of cortical lesions, while patients with major depression only (n = 15) had a significantly higher frequency of subcortical (basal ganglia) strokes. No significant between-group differences were found in other variables, such as demographic variables, familial and personal history of psychiatric disorders, and neurologic deficits. These findings suggest that, in this mostly black, low-socioeconomic-status population, cortical vs subcortical lesion location may play an important role in determining whether severe anxiety occurs in patients with post-stroke major depression.

Anxiety Disorders↗
PubMed1990

Mania after brain injury: neuroradiological and metabolic findings.

We present a consecutive series of 8 patients who developed a manic episode after a brain injury. Five patients had cortical lesions (4 with damage to the right basotemporal region, and 1 with bilateral damage to the orbitofrontal area). While the other 3 patients had subcortical lesions (white matter of the right frontal lobe, right anterior limb of the internal capsule, and right head of the caudate), a fluorodeoxyglucose positron emission tomography scan showed hypometabolism in the right lateral basotemporal region in all 3 patients. These findings suggest a major role for the basal region of the right temporal lobe in the modulation of mood.

Adult↗
PubMed1990

Selective hypometabolism in the inferior frontal lobe in depressed patients with Parkinson's disease.

Depression is a frequent finding in patients with Parkinson's disease (PD). Regional cerebral glucose metabolism was measured in depressed and nondepressed patients with PD and in age-comparable normal control subjects using 2-[18F]-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). Relative metabolic activity in the caudate and orbital-inferior region of the frontal lobe was significantly lower in the depressed patients with PD as compared to both nondepressed patients and control subjects. There was a significant inverse correlation between relative glucose metabolism in the orbital-inferior area of the frontal lobe and depression scores. This study suggests that depression in PD is associated with dysfunction in the caudate and orbital-inferior area of the frontal lobe. This metabolic pattern is unlike that seen in patients with PD who have other behavioral deficits such as dementia, and suggests that disruption of basal ganglia circuits involving the inferior region of the frontal lobe may affect the regulation of mood.

Aged↗
PubMed1990

Depression in Parkinson's disease.

A consecutive series of 105 outpatients with Parkinson's disease (PD) were examined for the presence of depression. Twenty-one percent met diagnostic criteria for major depression, 20% had minor depression, and the remainder were not depressed. The frequency of depression showed a bimodal distribution over time, with highest frequencies occurring in the early and late stages of the disease. Although other factors such as a positive family history of psychiatric disorders, quality of social functioning, and severity of tremor, rigidity, and akinesia did not show a significant association with depression, depressed patients had significantly higher impairment scores in activities of daily living and cognitive function than nondepressed PD patients. There was also a significant correlation between impairment and depression scores. In addition, among patients with mainly unilateral symptoms, depression was significantly associated with greater left hemisphere involvement. These findings suggest that depression in the early stages of the disease may be related to left hemisphere dysfunction, while later in the disease, depression and impairment in activities of daily living are interrelated. This may indicate more than one etiology of depression or that depression may have an adverse impact on the course of the disease.

Cognition Disorders↗
PubMed1990

Specificity of affective and autonomic symptoms of depression in Parkinson's disease.

Previous investigators have suggested that numerous symptoms used to diagnose depression, such as sleep or appetite disturbance, are non-specific in medically ill patients, and alternative diagnostic criteria should be developed. In the study this hypothesis was tested in Parkinson's disease (PD) by comparing patients with PD who reported a depressive mood with patients having PD but without a depressive mood. Depressed patients showed a significantly higher frequency of both autonomic and affective symptoms of depression. Depressed patients with PD reported a significantly higher frequency of worrying, brooding, loss of interest, hopelessness, suicidal tendencies, social withdrawal, self-depreciation, ideas of reference, anxiety symptoms, loss of appetite, initial and middle insomnia, and loss of libido when compared with non-depressed patients. No significant between-group differences, however, were observed in the frequency of anergia, motor retardation, and early morning awakening.

Aged↗
PubMed1990

Cognitive impairments and depression in Parkinson's disease: a follow up study.

The presence of depression and cognitive impairments was examined in seventy patients with Parkinson's disease (PD). Forty nine patients of this original cohort were re-examined between three and four years after the first evaluation. While both depressed and non-depressed patients showed a significant decline in cognitive function during the follow up period, intellectual decline was significantly more severe for the depressed group. Depressed patients also showed a faster rate of progression of motor signs (mainly tremor) than the non-depressed group. Patients that died during the follow up period showed significantly more cognitive impairments than patients who were alive at follow up. These findings suggest that either there may be two forms of PD: one with depression and rapid cognitive decline and one without depression and a gradual cognitive decline; or that the mechanisms of cognitive impairment in PD and depression may interact to produce a more rapid evolution in cognitive impairment among PD patients with a previous depression than among patients without a previous depression.

Aged↗
PubMed1990

Current research in affective disorders following stroke.

The prevalence, diagnosis, clinical presentation, evolution, and treatment of depression and mania following stroke are discussed. Among the many studies presented in the review is one that indicates major depression following right hemisphere lesions is associated with a positive family history of psychiatric disorder and lesions involving the parietal cortex. The co-occurrence of major depression and generalized anxiety disorder is associated with cortical lesions, while depression alone is associated with subcortical lesions. A recent study has also shown a strong association between mania and direct or indirect dysfunction of the basotemporal cortex in the right hemisphere. Possible mechanisms for both mania and depression following stroke are presented, and ideas for future directions in research are suggested.

Bipolar Disorder↗
PubMed1990

Anosognosia and major depression in 2 patients with cerebrovascular lesions.

We report 2 patients who developed a neglect syndrome, anosognosia, and major depression immediately after a right hemisphere cerebrovascular lesion. These cases demonstrate that neglect, anosognosia, and major depression may coexist in the same patient, and that the presence of anosognosia does not preclude the patient's recognition of emotional impairment.

Aged↗
PubMed1990

Prevalence and course of depressive disorders in hospitalized stroke patients.

In a sample of ninety-nine patients seen two months post-stroke, 18 percent were diagnosed as having minor depression and 14 percent major depression. At follow-up, fifteen months later, the prevalence of depressive disorder had declined substantially, to 12 percent overall. Major depression was characterized by an average duration of thirty-nine weeks, a mortality rate of 23 percent and was associated with positive family history of affective or anxiety disorder. Among patients with left hemisphere lesions, major depression was associated with cognitive impairment. Minor depression had a shorter average duration (twelve weeks) and was more common in males. These two syndromes may define distinct types of post-stroke depression with implications for treatment interventions.

Activities of Daily Living↗
PubMed1990

Depression and cerebrovascular disease.

Depressive disorder is a common complication of stroke. Although somatic symptoms of stroke may be mistaken for depression, DSM-III criteria for major depression are appropriate for use in this clinical setting. The etiology of poststroke depression can be viewed from a number of perspectives. Evidence from examining lesion characteristics and depression suggests that a disease model is suitable for some cases of poststroke depression. Alternatively, adequacy of social support and gender differences influence the occurrence of poststroke depression. Poststroke depression can be effectively treated with tricyclic antidepressants, and the use of these agents may also enhance physical and cognitive recovery.

Cerebrovascular Disorders↗