Post-stroke Changes Research Articles

1H/13C MR spectroscopic imaging of regionally specific metabolic alterations after experimental stroke

Loss of function and subsequent spontaneous recovery after ischaemic stroke are associated with functional and structural alterations in brain tissue. Acute functional tissue damage involves distortion of key metabolic processes, such as oxidative glycolysis and neurotransmitter metabolism. Nevertheless, initially perturbed metabolism may be restored at later stages, e.g. in perilesional areas, which could play a key role in post-stroke recovery of brain function. The pattern of metabolic recovery in relation to ischaemic tissue damage, however, is basically unknown. The goal of our study was to reveal changes in glycolysis and glutamatergic neurotransmitter metabolism that could underlie post-stroke changes in functional status. We performed in vivo (1)H/(13)C magnetic resonance spectroscopic imaging (MRSI) during (13)C-labelled glucose infusion, and MRI, at 24 h (n = 6) and 3 weeks (n = 8) after stroke in a rat model to characterize alterations in baseline metabolite levels, glutamate (Glu) and glutamine (Gln) turnover, and active lactate (Lac) formation in areas with different degrees of ischaemic injury. Inside the lesion, we detected significant reductions in baseline metabolite levels, ongoing Lac formation and seriously diminished Glu and Gln turnover at both time points, indicative of irreversible functional tissue damage. In perilesional areas, significant decrease of N-acetyl aspartate (NAA) levels, and Glu and Gln turnover indicated neuronal dysfunction at 24 h. After 3 weeks, when animals showed significant neurological improvement, anaerobic glycolysis had ceased, NAA levels were normalized, Glu turnover was maintained and Gln turnover had recovered. These findings point out that early metabolic impairment in the lesion borderzone can be restored over time. Alterations in brain metabolism in perilesional areas probably contribute significantly to changes in functional status in stroke subjects, and may provide a gateway for therapeutic strategies directed at improvement of functional recovery after stroke.

Fear of Falling: An Emerging Issue After Stroke

Purpose: Qualitative data regarding stroke survivors’ recovery experiences were used to describe factors important in the development of fear of falling (FoF) during the first 6 months after stroke. Method: Stroke survivors were interviewed 1 and 6 months after stroke to obtain data on their experiences related to stroke recovery trajectory. Analyses identified FoF as a naturally occurring part of stroke survivors’ descriptions of their everyday lives. Interviews were reexamined to identify and describe personal experiences related to FoF in this population. Results: Forty-two (32%) veterans who participated in the larger study discussed FoF during the first 6 months after stroke. Analyses indicate three important factors may be associated with the development of poststroke FoF: (a) the initial fall coinciding with stroke onset, (b) perception of poststroke body changes, and (c) a pervasive everyday fear of future falls. Conclusion: These factors related to FoF need to be further studied in the poststroke population. It is possible that individualized interventions may be necessary to assist stroke survivors to manage FoF, decrease fear, and reduce falls after discharge home poststroke.

GRAND ROUNDS: Pre- and Post-Right Middle Cerebral Artery Stroke in a Young Adult: A Case Study Examining the Sensitivity of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)

Right-hemisphere strokes are associated with a number of neurobehavioral deficits. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a relatively new, but widely used screening battery; however, there is little published research in patients who have sustained strokes. We present a rare case of stroke in a 22-year-old psychiatric patient, who received neuropsychological evaluations before and after sustaining a right middle cerebral artery (MCA) stroke. The RBANS demonstrated sensitivity to post-stroke changes despite pre-stroke cognitive impairments and a complex psychiatric overlay, with the Visuospatial/Constructional index being one of the most sensitive indicators of right hemisphere dysfunction. Line Orientation fell from normal to defective levels; these findings were associated with decline in related standard neuropsychological measures.

Sexual Functioning in Chinese Stroke Patients with Mild or No Disability

This study was conducted to assess the effects of stroke on sexual functioning of patients with mild or no disability and to explore the associations of clinical and psychosocial factors with post-stroke changes in sexual functions. Consecutive stable Chinese patients were invited to complete a self-administered questionnaire concerning their pre- and post-stroke sexual functions and habits. Results from this cohort of 63 men and 43 women revealed a post-stroke decrease in libido, coital frequency, sexual arousal, orgasm and sexual satisfaction in 54.3%, 43.8%, 25.0% (women) to 51.6% (men), 20.0% (women) to 45.9% (men) and 28.6% of patients, respectively. Logistic regression indicated unwillingness for sex and a belief in an adverse effect of stroke on sexuality as explanatory factors for decreased sexual satisfaction. Thus, sexual dysfunctions are common in Chinese stroke patients with mild or no disability.

Sexual functioning among stroke patients and their spouses.

The aim of this study was to assess effects of stroke on sexual functioning of stroke patients and their spouses and to study the associations of clinical and psychosocial factors with poststroke changes in sexual functions. One hundred ninety-two stroke patients and 94 spouses participating in stroke adjustment courses sponsored by the Finnish Stroke and Aphasia Federation completed a self-administered questionnaire concerning their prestroke and poststroke sexual functions and habits. The main outcome measures were (1) libido, (2) coital frequency, (3) sexual arousal, including erectile and orgastic ability and vaginal lubrication, and (4) sexual satisfaction. A majority of the stroke patients reported a marked decline in all the measured sexual functions, ie, libido, coital frequency, erectile and orgastic ability, and vaginal lubrication, as well as in their sexual satisfaction. The most important explanatory factors for these changes were the general attitude toward sexuality (odds ratio [OR] range, 7.4 to 21.9; logistic regression analysis), fear of impotence (OR, 6.1), inability to discuss sexuality (OR range, 6.8 to 18.5), unwillingness to participate in sexual activity (OR range, 3.1 to 5. 4), and the degree of functional disability (OR range, 3.2 to 5.0). The spouses also reported a significant decline in their libido, sexual activity, and sexual satisfaction as a consequence of stroke. Sexual dysfunction and dissatisfaction with sexual life are common in both male and female stroke patients and in their spouses. Psychological and social factors seem to exert a strong impact on sexual functioning and the quality of sexual life after stroke.

Catecholamine levels and turnover during brain ischemia in the rat.

Unilateral brain ischemia was induced in the rat by injecting radioactive microspheres into the left internal carotid artery. The microspheres were mainly distributed in the left cerebral hemisphere which contained 8 to 10 times more microspheres than the contralateral hemisphere. Embolization caused dopamine (DA) and noradrenaline (NA) depletion only in the left hemisphere. NA levels were already reduced 2 hours after injury while DA was still unaltered after 6 hours. A 30--40% depletion was observed for the two amines after 24 hours. Catecholamine turnover was estimated by measuring the amine depletion after synthesis inhibition with alpha-methyl-p-tyrosine. During the first 2 hours following embolization, DA and NA depletions were slightly increased only in the left hemisphere, indicating an increase in catecholamine efflux. At times 24 hours, an important retardation in amine disappearance after synthesis inhibition was found for DA and NA in the left hemisphere and to a lesser extent for DA in the right hemisphere, suggesting a reduction of the physiological activity of catecholaminergic neurons. These biochemical alterations can be related to the post-stroke behavioural changes of the embolized animals which exhibited an initially increased motor activity followed by a lethargic state.