Giorgio Rubin

Factors affecting survival rates for acute vertebrobasilar artery occlusions treated with intra-arterial thrombolytic therapy: a meta-analytical approach.

OBJECTIVE To determine whether recanalization, coma at presentation, or clot location in the basilar artery influences the relative mortality risk after intra-arterial thrombolytic therapy for acute vertebrobasilar artery occlusions. METHODS Studies were identified using the MEDLINE database for January 1987 to November 1997. Series were included if they involved 10 or more patients with basilar or vertebrobasilar artery occlusions, used urokinase and/or recombinant tissue plasminogen activator, and were written in English. A fixed-effect meta-analysis approach was used to estimate the risk of death with the aforementioned risk factors. Each study was weighted according to sample size. Relative risks were calculated with 95% confidence intervals. RESULTS As calculated from peer-reviewed published data, the relative mortality risk for patients for whom recanalization was attempted but not achieved was 2.34 (95% confidence interval, 1.48-3.71; n = 126). Coma at presentation was associated with a relative mortality risk of 1.95 (95% confidence interval, 1.26-2.99; n = 145). Clot locations in the distal one-third of the basilar artery were shown to favor survival, compared with clots located in the proximal and/or middle portions of the basilar artery (relative risk, 0.52; 95% confidence interval, 0.31-0.86; n = 126). CONCLUSION The combined data suggest that coma at presentation has an independent and adverse effect on survival rates. Complete recanalization, distal clot location, and responsiveness at the time of presentation are statistically significant factors for increased patient survival rates.

Natural history of conservatively treated meningiomas.

Asymptomatic brain meningiomas are often diagnosed incidentally during investigations for minor neurologic symptoms. Their management is controversial because not enough data have been collected on the growth rate,1–7⇓⇓⇓⇓⇓⇓ and it may vary according to tumor location or patient age. We reviewed the natural history of conservatively treated brain meningiomas with a focus on the features associated with tumor growth. The files of 43 patients with 51 brain meningiomas that were treated conservatively at Beilinson hospital between 1989 and 1999 were reviewed. The diagnosis was based on a finding of an extra-axial dural-based enhancing mass on CT or MRI. Follow-up was performed 6 to 9 months after diagnosis and yearly thereafter. Tumor size was calculated according to largest diameter in the anterio-posterior, medio-lateral, or oblique dimension (perpendicular analysis). Growth was defined as a change in tumor size of at least 2 mm. The tumors were classified as …

Relation between cerebral blood flow and neurologic deficit resolution in acute ischemic stroke

Background and objective: Early intervention remains the key to acute ischemic stroke therapy. Many patients whose deficits would later resolve without intervention are exposed to the risks of stroke treatment without benefit. The purpose of this study was to determine whether patients with transient deficits could be distinguished from patients with evolving strokes on the basis of acute cerebral blood flow (CBF) measurements before any clinical distinction could be made. Methods: Fifty-three patients who presented with acute hemispheric stroke symptoms and who underwent xenon-enhanced CT (XeCT) CBF studies within 8 hours of onset of symptoms (and before any clinical improvement) were studied. Results: Eight patients (15%) had a complete resolution of their symptoms within 24 hours (not related to treatment). All eight patients with deficits that resolved had normal CBF in the symptomatic vascular territories (mean time to XeCT = 3 hours, 51 min). Mean CBF in the regions of interest of the symptomatic vascular territories of patients who had deficits that resolved was 35.4 ± 8.1 mL · 100 g-1 · min-1 compared with 17.3 ± 9.3 patients with evolving strokes (p= 0.00058). Conclusions: Patients with ischemic neurologic deficits that will later resolve can be acutely distinguished from patients with evolving cortical infarctions using XeCT CBF measurements. CBF measurements may assist in the triage of patients for acute stroke therapy by selecting patients with a favorable prognosis and may not benefit from therapy but would still be exposed to the potential risks and expense of treatment.

Remote Effects of Acute Ischemic Stroke: A Xenon CT Cerebral Blood Flow Study

Objective: The purpose of this study was to verify transhemispheric diaschisis in the early hours after an ischemic event. Methods: XeCT cerebral blood flow (CBF) studies within 8 h of stroke were studied in 23 patients. Mean CBF was evaluated in the ischemic area, contralateral hemisphere and ipsilateral cerebellum. Results: A severe CBF reduction was found in the ischemic area (mean 9 ± 3 ml/100 g/min). The mean CBF in the unaffected hemisphere (33 ± 10 ml/100 g/min) was 35% less compared to the normal mean value. CBF was decreased in the cerebellum ipsilateral to the stroke (mean 31 ± 12 ml/100 g/min) suggesting a blood flow depression of the whole brain. Conclusions: During the initial hours of cerebral ischemia, the asymptomatic hemisphere demonstrated CBF depression that was part of the global flow reduction.

Relationship between Cerebral Blood Flow and Clinical Outcome in Acute Stroke

Objective: The purpose of this study was to determine the relationship between cerebral blood flow (CBF) measurements in acute stroke and early clinical outcome. Material and Methods: The xenon-enhanced computed tomography (XeCT) CBF studies performed in 50 patients in the acute stage (within 8 h) of a hemispheric stroke were retrospectively analyzed. The mean CBF of the symptomatic vascular territory was compared to the corresponding territory in the contralateral hemisphere. Clinical assessment on admission and discharge was performed using the National Institutes of Health stroke scale (NIHSS). Results: Three groups were defined according to the degree of CBF asymmetry between the symptomatic and the contralateral asymptomatic vascular region. The CBF asymmetry was mild in group A (≤20%), moderate in group B (>20% and <60%) and severe in group C (≥60%). Patients in group A (n = 18) had a good outcome with a mean NIHSS score of 2 ± 2 at discharge. In group B, the patients (n = 22) had intermediate but variable outcomes: 2 patients died and the mean NIHSS score for the survivors was variable (mean NIHSS score: 9 ± 6). The patients in group C (n = 10) had a very poor outcome: 4 patients died and the survivors had a mean NIHSS score of 15 ± 1. Conclusions: Quantitative XeCT CBF measurements may be useful for selecting subgroups of stroke patients with different clinical outcomes. The possibility of predicting patient prognosis as early as in the first hours after the ischemic event may help to identify the appropriate target population that will benefit from aggressive stroke therapy.

Xenon-enhanced computed tomography cerebral blood flow measurements in acute cerebral ischemia: Review of 56 cases

OBJECTIVE Ischemic stroke must be diagnosed promptly if patients are to be treated with thrombolytic therapy. The diagnosis of acute cerebral ischemia, however, is usually based on clinical and computed tomography (CT) scan findings. CT scans are often normal in the first few hours after stroke. The purpose of this study was to determine whether Xenon-enhanced CT (XeCT) cerebral blood flow (CBF) studies could increase the sensitivity of stroke detection in the acute stage. METHODS CBF studies performed within 8 hours of symptom onset were evaluated in 56 patients who presented with hemispheric stroke symptoms. Mean CBF in the symptomatic vascular territory was calculated and compared with the corresponding contralateral area. CBF values below 18 mL/100g/min on 2 adjacent regions of interest were considered ischemic lesions. CT scans and angiograms were compared with the XeCt findings. Neurological condition on admission and discharge was evaluated by using National Institutes of Health Stroke Scale (NIHSS) scores. RESULTS The mean NIHSS score on admission was 12+/-5. Early CT scans were abnormal in 28 (50%) patients. There were 9 (16%) patients who had normal XeCT scans because of spontaneous reperfusion of the ischemic area. XeCT studies showed an ischemic lesion in 47 (84%) patients. In these patients, the mean CBF in the affected vascular territory was 16+/-8 mL/100g/min compared with 35+/-13 mL/100g/min in the contralateral specular territory (P<0.001). There were no false positive or negative XeCT studies, and the location of the perfusion defect corresponded with the CT and/or angiographic findings in all cases. Eight patients died (14%), and the 48 survivors (86%) had a mean NIHSS score of 9+/-6 on discharge. CONCLUSIONS CBF measurements were correlated with the CT and angiographic results and greatly assisted in the diagnosis of acute ischemic stroke. XeCT studies used for estimating the location and extent of cerebral ischemia may be important in the triage of patients for acute stroke therapy.

The effect of reperfusion therapy on cerebral blood flow in acute stroke

The effect of reperfusion therapy on cerebral blood flow (CBF) in acute cerebral ischemia was studied using xenon-enhanced computed tomography (XeCT). The XeCT CBF studies of 10 patients were evaluated before and after thrombolytic therapy. CBF evidence of reperfusion was evaluated in relation to the angiographic results and the clinical outcomes. Six patients had occlusions of the middle cerebral artery and four of the internal carotid artery. The mean CBF of the ischemic areas before attempted reperfusion was 9 +/- 3 mL/100g/min compared with 34 +/- 9 mL/100g/min in the contralateral asymptomatic region (P<.001). Intra-arterial-thrombolysis was performed in nine patients, and in one patient the intravenous route was used. Reperfusion of the ischemic region was shown in 9 of 10 patients, both angiographically and with the XeCT CBF studies (the mean CBF increased from 9 +/- 3 mL/100g/min to 32 +/- 10 mL/100g/min, P<.001). Among the nine successfully reperfused patients, seven were neurologically improved, one was unchanged, and one died. The mean National Institutes of Health stroke scale in the eight reperfused survivors was 12 on admission and decreased to 6 on discharge. XeCT CBF measurements are correlated with the angiographic results and can assist in the understanding of the effects of thrombolytic therapy on CBF in acute stroke. Re-establishment of CBF is associated with an improved clinical outcome but exceptions can be found. Reperfusion can occur in ischemic brain regions even with very low CBF (approaching 0 mL/100g/min) although it is not associated with prevention of infarction.

Development of obstructive hydrocephalus with lumboperitoneal shunting following subarachnoid hemorrhage

Hydrocephalus is a frequent complication of subarachnoid hemorrhage (SAH). The optimum method of treating hydrocephalus in this setting has not been determined. We review our experience with patients developing communicating hydrocephalus secondary to SAH and subsequently treated with lumboperitoneal (LP) shunts. Following hospitalization for the treatment of SAH, patients who developed clinical symptoms and radiologic signs of hydrocephalus were treated with (ventriculoperitoneal) VP or LP shunting. Eighteen patients received an LP shunt, of which seven (28%) developed a non-communicating or obstructive hydrocephalus. These seven patients underwent replacement with a VP shunt and have not had further complications. In the setting of post-SAH communicating hydrocephalus, obstructive hydrocephalus may develop after LP shunt placement. Patients who develop this complication and have their LP shunts converted to VP shunts have a favorable prognosis.