Left-sided Stroke Research Articles

Cardiac autonomic derangement and arrhythmias in right-sided stroke with insular involvement.

The insula of the right cerebral hemisphere may have a major role in cardiac autonomic control. This study was aimed at assessing the effects of acute right insular ischemic damage on heart rate variability (HRV) and arrhythmias. Holter monitoring for 24 hours was performed in 103 consecutive patients with first-ever acute ischemic stroke. Time and frequency domain measures of HRV and arrhythmias were considered in all cases. Forty-nine patients (47.5%) had a right-sided infarction, whereas 54 (52.5%) had a left-sided infarction. Insular involvement was present in 33 patients with right-sided stroke (67.3%) and in 36 patients with left-sided stroke (66.6%). When compared with all other stroke patients, subjects with right-sided insular damage showed significantly lower values of the standard deviation of all normal-to-normal (SDNN) R wave to R wave (RR) intervals and of the root mean square of differences (rMSSD) of adjacent normal-to-normal RR intervals, and higher low-frequency/high-frequency ratio values (P<0.05). Right insular stroke was also associated with more complex arrhythmias than any other localization (P<0.05). Moreover, in the whole population of stroke patients, lower values of SDNN were associated with the presence of more frequent and complex arrhythmias. These findings further support the notion that the right insula is implicated in the autonomic control of cardiac activity and that acute right insular damage may lead to a derangement of cardiac function with potential prognostic implications.

Ambient Sensory Conditions: Modification of Receptive Speech Deficits in Left-Side Stroke Patients Using Bright Light

Previous research has demonstrated the potential for the use of ambient sensory conditions to improve cognitive functioning. Both light and sound have been shown to improve task performance in various populations including children, younger adults, and elderly participants; however, these cognitive gains may possibly be offset by detrimental cardiovascular reactivity in elderly persons. We now have some evidence for ambient sensory conditions affecting cognitive function following left- or right-side cerebrovascular accidents.

Subjective Change in Emotive, Cognition and Behaviour After Stroke: Factors Affecting the Perception of Patients and Partners

The presence and severity of changes in emotion and cognition experienced by left- and right-sided stroke patients and observed by their partners were compared at 3 months poststroke. The results showed that, regardless of the side of stroke, several changes were reported by half of the stroke patients and their partners. It appeared that while left hemisphere stroke patients agreed with their partners on the number and severity of most changes, partners of right hemisphere patients reported more frequent and more severe changes than the patients themselves. The level of observability of the altered behaviour, distress of the partner, distress of left-sided stroke patients and hemispatial neglect of right-sided stroke patients emerged as factors related to disagreement between stroke patient and partner.

Is the association of National Institutes of Health Stroke Scale scores and acute magnetic resonance imaging stroke volume equal for patients with right- and left-hemisphere ischemic stroke?

The National Institutes of Health Stroke Scale (NIHSS) is an established measure of neurological impairment; however, it can award more points for tests of presumed left-hemisphere function, such as language, than for tests of right-hemisphere function, such as neglect. This difference may be important if a low NIHSS score is used to exclude patients with right-hemisphere stroke from clinical trials or established treatments. The aim of this study was to investigate whether the relationship between acute NIHSS score and acute stroke volume as determined by acute diffusion- and perfusion-weighted MRI (DWI and PWI) differs between right- and left-sided stroke. This was a retrospective study of 153 patients with acute stroke seen at Beth Israel Deaconess Medical Center between January 1995 and March 2000 who underwent an MRI examination and NIHSS within 24 hours of stroke onset. NIHSS score was recorded prospectively by the admitting stroke fellow at the time of acute presentation, immediately preceding imaging. Computerized volumetric analysis of the MRI lesions was performed by investigators blinded to clinical data. There were significant correlations between the acute NIHSS scores and acute DWI lesion volumes (r=0.48 right, r=0.58 left) and between acute NIHSS scores and perfusion-weight imaging hypoperfusion volumes (r=0.62 right, r=0.60 left). For patients with NIHSS scores of 0 to 5, the DWI volume of right cerebral lesions was greater than that of left-sided lesions (mean volume, 8.8 versus 3.2 cm3; P=0.04). Among patients with DWI lesions larger than the median volume (9 cm3), 8 of 37 with right-sided stroke had an NIHSS score of 0 to 5 compared with 1 of 39 patients with left-sided stroke (P=0.01). Multiple linear regression analysis revealed a significantly lower acute NIHSS on the right compared with the left side when adjusted for stroke volume on chronic T2 imaging (P=0.03). Patients with right-sided stroke may have a low NIHSS score despite substantial DWI lesion volume. Acute imaging information, such as that available with multimodal MRI, may be useful to identify patients for inclusion in acute stroke protocols when there is clinical uncertainty about eligibility. Prospective evaluation of criteria incorporating acute imaging data is required.

Sequential activation brain mapping after subcortical stroke: changes in hemispheric balance and recovery.

We prospectively studied 5 patients while they were recovering from left-sided subcortical stroke affecting the cortico-spinal tract, and examined them twice with H(2)(15)O-PET over several months while performing an identical task with the affected hand. Concomitant motor recovery was assessed by measuring the number of thumb-to-index tappings performed in 15 s at each PET session. Across patients, the hemispheric activation balance tended to shift over time toward the unaffected hemisphere, but the magnitude of this shift was highly variable from patient to patient and significantly correlated with recovery. Thus, in subcortical stroke, a shift of activation balance towards the unaffected hemisphere appears associated with lesser initial recovery and, conversely, the more this physiological balance is maintained over time the better the recovery.

Dyspnea During Interscalene Block After Recent Coronary Bypass Surgery

Dyspnea During Interscalene Block After Recent Coronary Bypass Surgery

Intellectual decline after stroke: the Framingham Study.

The causes and characteristics of cognitive decline after stroke are poorly defined, because most studies have relied on the diagnosis of dementia after stroke, without measurement of prestroke cognitive function. The Mini-Mental State Examination (MMSE) was used to assess the cognitive performance of 74 subjects from the Framingham Study cohort who had suffered a stroke during a 13-year period. We compared their poststroke cognitive performance with the prestroke MMSE scores collected during their biennial examinations, and their prestroke/poststroke changes in MMSE score were then compared with those of 74 control subjects matched for age and sex. Cases and controls underwent testing for symptoms of depression using the Center for Epidemiologic Studies of Depression (CES-D) scale, and these findings were correlated with their cognitive performance. Changes in cognitive performance in the cases were correlated with the CT-documented characteristics of the stroke. The cases had a significantly lower mean+/-SE MMSE score at prestroke baseline (27.28+/-0.34) than did the control subjects (28.08+/-0.21), a difference that became more pronounced (23.57+/-0.92 versus 28.31+/-0.25; P<.001) after stroke. The poststroke decline in cognitive function in the cases was correlated only with a large, left-sided stroke on CT. The CES-D scores were significantly higher in the cases, but nondepressed cases had significantly lower MMSE scores than nondepressed controls. Stroke is followed by a significant decline in cognitive performance when prestroke and poststroke measurements are compared. Although depression is more frequent in the stroke patients, their intellectual decline appears to be independent from the presence of depression.

Lateralization of Categorical and Coordinate Spatial Functions: A Study of Unilateral Stroke Patients

Abstract Sixty patients with unilateral stroke (half with left hemisphere damage and half with right hemisphere damage) and a control group (N = 15) matched for age and educational level were tested in two experiments. In one experiment they were first shown, on each trial, a sample drawing depicting one or more objects. Following a short delay, they were asked to identify the drawing when it was paired with a drawing in which the same object(s) was transformed in categorical or coordinate spatial relations. In the other experiment, the same subjects first were shown, on each trial, a sample drawing. They then judged which of two variants (each in one type of spatial relation) looked more similar to the sample drawing. Typically, patients with left-sided stroke mistakenly identified the categorical transformation for the sample drawing in the first task; in the second task, they judged the categorical transformation as more similar to the sample drawing. Patients with right-sided stroke mistakenly identified the coordinate transformations for the sample drawing in the first task, and, in the second task, typically judged the drawings transformed along coordinate spatial relations as more similar to the sample drawing. These findings provide evidence for complementary lateralization of the two types of spatial perception. It can therefore be inferred that separate functional subsystems process the two types of spatial relations.

Effects of cortical lesion location on psychiatric consultation referral for depressed stroke inpatients.

Although post-stroke depression occurs with lesions to either cortical hemisphere, increasing evidence supports the view that depression is more prevalent after left hemispheric damage. This retrospective study of depressed post-stroke inpatients referred for psychiatric consultation shows a significantly higher referral rate for patients with right-hemispheric lesions. The results suggest an underutilization of psychiatric consultation to patients with left-sided lesions, and perhaps underrecognition of affective disorders in these patients. Various reasons for this underutilization are proposed, including the greater likelihood of speech impairment in left-sided brain-damaged stroke patients, who may have greater difficulty verbally communicating their psychic distress. Increased physician awareness of the clinical presentations of post-stroke depression will result in more patients benefitting from available treatments.

APATHETIC THYROTOXICOSIS

A previously fit 37-year-old woman was admitted with acute left ventricular failure, atrial fibrillation and a left-sided thromboembolic stroke. Her ventricular rate progressively increased despite full digitalisation. She had a cardiac arrest and was successfully resuscitated. Investigations revealed evidence of hyperthyroidism and she was treated for thyrotoxic crisis. She has made a complete recovery from the hemiparesis and is now in sinus rhythm. She denied any symptoms of hyperthyroidism. This patient had apathetic thyroid crisis, which is exceedingly rare in the young.