Richard I. Aviv

CT Angiography “Spot Sign” Predicts Hematoma Expansion in Acute Intracerebral Hemorrhage

Background and Purpose— Morbidity and mortality in spontaneous intracerebral hemorrhage (ICH) are correlated with hematoma progression. We hypothesized that the presence of tiny, enhancing foci (“spot sign”) within acute hematomas is associated with hematoma expansion. Methods— We prospectively studied 39 consecutive patients with spontaneous ICH by computed tomography angiography within 3 hours of symptom onset. Scans were reviewed by 3 readers. Patients were dichotomized according to the presence or absence of the spot sign. Clinical and radiological outcomes were compared between groups. The predictive value of this sign was assessed in a multivariate analysis. Results— Thirteen patients (33%) demonstrated 31 enhancing foci. Baseline clinical variables were similar in both groups. Hematoma expansion occurred in 11 patients (28%) on follow-up. Seventy-seven percent of patients with and 4% without hematoma expansion demonstrated the spot sign (P<0.0001). Sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio for expansion were 91%, 89%, 77%, 96%, and 8.5, respectively. Interobserver agreement was high (&kgr;=0.92 to 0.94). In patients with the spot sign, mean volume change was greater (P=0.008), extravasation more common (P=0.0005), and median hospital stay longer (P=0.04), and fewer patients achieved a good outcome (modified Rankin Scale score <2), although the latter was not significant (P=0.16). No differences in hydrocephalus (P=1.00), surgical intervention (P=1.00), or death (P=0.60) were noted between groups. In multiple regression, the spot sign independently predicted hematoma expansion (P=0.0003). Conclusions— The computed tomography angiography spot sign is associated with the presence and extent of hematoma progression. Fewer patients achieve a good clinical outcome and hospital stay was longer. Further studies are warranted to validate the ability of this sign to predict clinical outcomes.

Identification of Penumbra and Infarct in Acute Ischemic Stroke Using Computed Tomography Perfusion–Derived Blood Flow and Blood Volume Measurements

Background and Purpose— We investigated whether computed tomography (CT) perfusion–derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients. Methods— Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9). Penumbra was operationally defined as tissue with an admission CBF <25 mL · 100 g−1 · min−1 that was not infarcted on the 5- to 7-day NCCT. Logistic regression was applied to differentiate between infarct and penumbra data points. Results— For recanalized patients, CBF was significantly lower (P<0.05) for infarct (13.3±3.75 mL · 100 g−1 · min−1) than penumbra (25.0±3.82 mL · 100 g−1 · min−1). CBV in the penumbra (2.15±0.43 mL · 100 g−1) was significantly higher than contralateral (1.78±0.30 mL · 100 g−1) and infarcted tissue (1.12±0.37 mL · 100 g−1). Logistic regression using an interaction term (CBF×CBV) resulted in sensitivity, specificity, and accuracy of 97.0%, 97.2%, and 97.1%, respectively. The interaction term resulted in a significantly better (P<0.05) fit than CBF or CBV alone, suggesting that the CBV threshold for infarction varies with CBF. For patients without recanalization, CBF and CBV for infarcted regions were 15.1±5.67 mL · 100 g−1 · min−1 and 1.17±0.41 mL · 100 g−1, respectively. Conclusions— We have shown in a limited sample of patients that CBF and CBV obtained from CTP can be sensitive and specific for infarction and should be investigated further in a prospective trial to assess their utility for differentiating between infarct and penumbra.

Seizures during stroke thrombolysis heralding dramatic neurologic recovery

Seizures during thrombolytic therapy for ischemic stroke have not previously been described as a favorable prognostic sign. We report three patients with severe stroke (NIH Stroke Scale [NIHSS] score 15 to 20) who experienced a seizure during tissue plasminogen activator (tPA) infusion. While initially raising alarm about possible hemorrhage, the seizures heralded dramatic recovery (an immediate 15-point NIHSS score improvement after tPA; NIHSS score 0 or 1 at 24 hours). We propose that the seizures during thrombolysis may indicate cortical reperfusion and/or hyperperfusion due to early recanalization of an acutely occluded intracranial artery.

CT angiographic depiction of a supraclinoid ICA fenestration mimicking aneurysm, confirmed with catheter angiography

Fenestrations (segmental duplications) of the intracranial arteries are rare anomalies that have been associated with aneurysms. Fenestrations of the supraclinoid ICA are extremely rare, with only a few reported cases. We present a supraclinoid ICA fenestration, which on axial CTA images initially mimicked an aneurysm, but was correctly delineated as a fenestration on multiplanar reformatted and 3D reconstructed images. Confirmation was made with conventional angiography. To our knowledge, this represents the first time that this rare variant has been identified with cross-sectional imaging. A review of the literature including proposed embryology is provided.

Turning a stroke into a TIA: curative thrombolysis with combined intravenous and intra-arterial tPA

Intravenous tissue plasminogen activator (tPA) is standard treatment for eligible patients with acute ischemic stroke, but may be less effective for very severe strokes caused by proximal intracranial artery occlusions. We report the case of a woman with a devastating stroke who recovered completely following emergency revascularization of an occluded proximal middle cerebral artery using a novel treatment approach that combines both intravenous (i.v.) and intra-arterial (IA) tPA. This case illustrates the potential value of the combined i.v.-IA thrombolytic approach, which is an emerging investigational treatment strategy for selected patients with severe acute ischemic stroke.