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Transcranial Doppler and Near infrared Spectroscopy can evaluate the hemodynamic effect of of carotid artery occlusion
No full textEarly cerebral hemodynamic changes during passive movements and motor recovery after stroke.
No full textRecovery from hemiplegia is a complex phenomenon that depends on various adaptive
processes involving both the affected and the unaffected hemisphere. Our aim in
this study was to investigate changes in cerebral perfusion in hemiplegic stroke
patients during passive movements and their correlation with the subsequent motor
recovery. The study included 30 patients with single, subcortical ischemic
cerebral lesions. Within 14 days (range 8 to 14 days) from stroke onset, all
patients were examined for the effects of passive elbow movements on cerebral
blood flow in the middle cerebral arteries (MCAs) by means of bilateral
transcranial Doppler (TCD) ultrasonography. On the same day as TCD assessment,
they were also evaluated clinically with the Canadian Neurological Scale (CNS)
and with Medical Research Council (MRC) scale for motor deficit of the affected
arm. A clinical evaluation using the same scales was repeated after two months of
motor rehabilitation therapy. We investigated the relationship between changes of
Mean Flow Velocity (MFV) during passive movements and degree of recovery after
stroke. The logistic regression procedure indicated that out of all factors
considered as possibly related to a good clinical motor deficit recovery of the
affected arm, evaluated by means of MRC, only the MFV percentage increase played
a predictive role. In particular, for each additional point of contralateral MFV
percentage increase during passive movement of the affected arm, the relative
probability of good clinical recovery increased 5.68 times (95% CI=1.76-18.40;
p=0.004). Similar results were found when the clinical recovery was measured by
means of the CNS (slope=0.40, p<0.001). Passive movements in hemiplegic stroke
patients before clinical recovery elicit activation patterns that may be critical
for the restoration of motor function.I n particular, early and consistent
activation of the affected hemisphere, as detected with TCD, seems to predict the
positive evolution of a motor deficit
The effect of cerebral vasomotor reactivity and oxygen hemoglobin saturation in the follow-up of patients with carotid artery occlusion: a transcranial Doppler and near infrared spectroscopy study
No full textIs there a role of near infrared spectroscopy in predicting the outcome of patients with carotid artery occlusion?
No full textBACKGROUND: Transcranial Doppler (TCD) studies demonstrated that cerebral
vasomotor reactivity (VMR) can predict the outcome of carotid artery occlusion
(CAO). Near-infrared spectroscopy (NIRS) is a non-invasive optical method for
assessing hemoglobin (Hb) oxygenation parameters. The purpose of this study was
to evaluate the role of NIRS parameters as prognostic markers of stroke
occurrence in patients with CAO.
METHODS: Sixty-five patients (46 men, mean age 68.8 years) with CAO were
enrolled. Forty-two patients had previous cerebrovascular events (15 TIA, 27
minor stroke), the remaining 23 were asymptomatic. All subjects underwent
simultaneous TCD and NIRS examination at rest and after hypercapnia. All patients
completed follow-up (median, 36 months).
RESULTS: During follow-up, 11 strokes occurred. Cerebral VMR measured by TCD had
a prognostic role in stroke occurrence (p=0.042). The increase in Hb oxygen
saturation detected by NIRS during hypercapnia predicted the occurrence of new
cerebrovascular events, although without an overt significance (p=0.058). Hb
oxygen saturation at rest, however, failed to be of prognostic value (p=0.65).
CONCLUSIONS: NIRS is potentially useful in monitoring cerebral oxygenation;
however, at present NIRS does not effectively predict the outcomes of stroke or
vascular death in patients with CAO. This study does confirm the primary role of
TCD VMR in the outcome of carotid disease
NIRS parameter baseline hemoglobin saturation as a marker of hemodynamic compromise in patients with carotid occlusive disease
No full textCorrelations of flow velocity changes during simultaneous passive and active movements of the arms in post-stroke patients: a functional transcranial Doppler study
No full textPostpartum cerebellar infarction and haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome
No full textPregnancy is considered to be a hypercoagulable state per se with an increased risk for cerebrovascular events, however cerebellar infarction has been rarely described in pregnant women. A nulliparous pre-eclamptic woman at 25 weeks' gestation was submitted to an echocardiographic exam that showed an impaired cardiac structure and function. After 2 h, the patient underwent caesarean section for diagnosis of haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome. Afterwards her platelet count raised, and eight days later she developed nystagmus, ataxia, dysmetria and motor deficit in the right limbs and sensory impairment in the right side of the face and in the left limbs. Cerebral magnetic resonance imaging (MRI) demonstrated a right cerebellar and median posterior bulbar infarction. Colour-coded sonography of cerebral vessels showed an occlusion of the right vertebral artery. Coagulation pattern analysis evidenced double heterozygosis of the methylenetetrahydrofolate reductase (MTHFR) gene and single mutation of the prothrombin gene. This case report gives evidence of the importance of considering the different risk factors involved in stroke occurrence during pregnancy. © Springer-Verlag Italia 2005
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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