Hyperdense Middle Cerebral Artery Research Articles

Correlation of neurologic dysfunction with CT findings in early acute stroke.

To determine the frequency of early computed tomographic (CT) findings of ischemia and their relationship to symptom duration and neurologic dysfunction within 3 hours of ischemic stroke. The CT scans of 39 acute stroke patients were evaluated for signs of early ischemic change within 3 hours of symptom onset and without knowledge of the patient's neurologic deficit or results of a 24 hour follow-up post-thrombolysis CT. Early CT signs of acute ischemic change or thromboembolism were hypoattenuation of the insular ribbon, obscuration of the lentiform nucleus, cortical hypodensity/effacement, and hyperdense middle cerebral artery sign. Signs of acute ischemic change were seen on the baseline scan in 25/39 patients (64%). Hypoattenuation of the insular ribbon was seen in 11 patients, obscuration of the lentiform nucleus in 13, cortical hypodensity/effacement in 13, and hyperdense middle cerebral artery sign in 7. The prevalence of early ischemic signs was directly associated with increasing neurologic disability at the time of presentation. No clear relationship existed between symptom duration and the presence of CT signs. Evidence of cerebral ischemia is frequently seen on CT within 3 hours of symptom onset. The degree of neurologic disability correlates with CT signs of ischemia.

Posterior circulation infarcts simulating anterior circulation stroke. Perspective of the acute phase.

Ischemic stroke patients whose initial clinical presentation suggests an involvement of the anterior circulation (AC) are sometimes found to have a posterior circulation (PC) infarct, a fact that may generate erroneous decisions in clinical management. We investigated the prevalence of this misdiagnosis in the first few hours after stroke onset. We performed a cohort study of 158 patients hospitalized within 5 hours of onset of a presumed AC ischemic stroke, as diagnosed on clinical grounds. Final CT or pathology diagnosis was AC infarct in 128 patients (81%), a repeatedly negative CT in 14 (9%), PC infarct (5 pons, 1 midbrain and cerebellum, 6 supratentorial territory of the posterior cerebral artery) in 12 (8%), and other or undiagnosed lesions in 4 (3%). AC and PC stroke patients did not differ in terms of age, vascular risk factors, and initial severity, but the latter were more frequently men (83% versus 53%; P = .04), were hospitalized later (mean +/- SD, 168 +/- 86 versus 109 +/- 55 minutes; P = .001), and presented a pure motor hemiparesis or a sensorimotor stroke (50% versus 33%) more often than their counterparts. At baseline CT, PC stroke patients never exhibited an early parenchymal hypodensity in the carotid territory or a hyperdense middle cerebral artery, which were instead found in 59% (P = .0003) and 31% (P = .02) of AC stroke patients, respectively. Early neurological deterioration, 1 month case-fatality rate, and disablement in survivors were comparable in the two groups. Shortly after onset the clinical discrimination between AC and nontypical PC infarcts is not reliable, which explains the frequent occurrence of this misdiagnosis. Emergency CT scan helps in the differential diagnosis only when it demonstrates an early focal hypodensity within the carotid territory.

Early CT signs in acute middle cerebral artery infarction

During the first hours after acute ischemic stroke, the CT usually shows no abnormalities. Therapeutic trials of ischemia in the middle cerebral artery (MCA) territory involves decision-making when the CT may not show obvious ischemic changes. We reviewed 100 consecutive patients, admitted within 14 hours after a first stroke. Selective criteria were clinical presentation with MCA ischemia and at least two CTs (1 initial and 1 control). All CTs were retrospectively analyzed by at least two physicians blinded to the patient's status. On the first CT, early signs were hyperdense MCA sign (HMCAS), early parenchymatous signs (attenuation of the lentiform nucleus [ALN], loss of the insular ribbon [LIR], and hemispheric sulcus effacement [HSE]), midline shift, and early infarction. Subsequent infarct locations were classified according to total, partial superficial (superior or inferior), deep, or multiple MCA territories. Clinical features, etiology, and Rankin scale were collected. There were 52 women (mean age 70.8). The CTs were performed at mean 6.4 hours (1 to 14 hours) and before the sixth hour in 62% of the patients. Early CT was abnormal in 94% of the cases, and the abnormalities found were an HMCAS in 22 patients, ALN in 48, LIR in 59, HSE in 69, midline shift in 5, and early infarct in 7. CT was normal in six patients where it was performed earliest (mean 4.5 hours) and in the oldest patients (mean age 80.1). Early parenchymatous CT signs were significantly associated with subsequent MCA infarct location and extension: ALN and deep infarct, HSE and superficial infarct, LIR and large infarct. HMCAS was never found in isolation and was always associated with the three other signs in extended MCA infarct. The presence of two or three signs (ALN, LIR, or HSE) was associated with extended MCA infarct (p < 0.001) and poor outcome (p < 0.001). Our findings suggest that CT frequently discloses parenchymal abnormalities during the first hours of ischemic stroke. Early signs allow the prediction of subsequent infarct locations; CT may provide a simple tool in evaluating the early prognosis of MCA infarction and thus may be useful in selecting better treatments.

Early predictors of death and disability after acute cerebral ischemic event.

Many clinical trials are currently being conducted to evaluate the ability of neuroprotectors and thrombolytic agents to improve survival and functional outcome after ischemic stroke. Such trials require early predictors of survival and disability for ethical and methodological reasons. The aim of the study was to determine which variables, of those easily assessable during the first 24 hours after stroke onset, would be predictors of 8-day mortality rate and 3-month clinical outcome. One hundred fifty-two consecutive patients with an acute ischemic event were evaluated within 24 hours after symptom onset. We determined (1) the 8-day mortality rate and (2) the 3-month functional outcome (Glasgow Outcome Scale). The following potential predictors of outcome were tested by means of a stepwise logistic regression analysis: age, sex, body mass index, atrial fibrillation, previous stroke, existence of headache, Orgogozo score, level of consciousness, swallowing disturbances, hemianopia, pulse rate, mean blood pressure, hematocrit, glycemia, and computed tomographic scan data (cerebral atrophy score, hyperdense middle cerebral artery sign, number of silent infarcts, leukoaraiosis score). The multivariate analysis revealed that the 8-day mortality rate depended only on the level of consciousness at admission (P = .0001); death or dependence at month 3 (scores 3 to 5 on the Glasgow Outcome Scale) depended on the severity of the clinical deficits (P = .0001), previous stroke (P = .0018), and age (P = .0237). In future drug trials, the distribution of patients between "active treatment" and "placebo" groups should be balanced regarding the severity of clinical deficits, history of stroke, and age.

Prevalence and significance of hyperdense middle cerebral artery in acute stroke.

Early noncontrast computed tomographic scans may visualize a hyperdense middle cerebral artery before the infarct becomes visible. This sign disappears within a few days, corresponds to the clot itself, and might be associated with a poor prognosis. The aim of the study was to determine its prevalence, diagnostic value, relationship to demographic data, ability to separate embolic from nonembolic causes, short-term prognostic value, evolution over time, and relationship to arterial occlusion on angiography. We performed this study using computed tomographic scans performed within 12 hours after onset in 272 consecutive unselected patients with a first acute cerebrovascular event. Seventy-three subjects had the hyperdense middle cerebral artery sign, leading to a prevalence of 26.8% in the whole group and 41.2% in patients with a middle cerebral artery infarct. Specificity was 100%, but sensitivity was only 30%. This sign was not dependent on cerebrovascular risk factors, but was more likely to occur in cortical and in large, deep, middle cerebral artery infarcts (p less than 0.01). It provided only a 3.5% gain in predicting death, and one fifth of patients with the sign recovered within 2 weeks; this sign was not an independent variable of poor outcome on multiple linear regression. It spontaneously disappeared within a few days and was always related to an occlusion of the middle cerebral artery in patients who underwent early angiography. The hyperdense middle cerebral artery sign is useful in the diagnosis of middle cerebral artery occlusion but does not always predict a poor prognosis.

Hyperdense middle cerebral artery CT sign

The early CT finding of an hyperdensity of a portion of the middle cerebral artery Hyperdense Middle Cerebral Artery Sign (HMCAS), in patients with supratentorial stroke, is often indicative of an embolic occlusion. Aim of this study was to verify the incidence and reliability of the HMCAS and its possible correlation with early CT findings and with the extent of late brain damage. We studied 36 patients presenting with symptoms of stroke in the MCA territory, by means of CT and angiography performed respectively within 4 and 6 hours. Follow-up CT scans were then obtained after one week and three months from the ischemic event. The HMCAS was present in 50% of our patients and in this group it always correlated positively with the angiographic finding of occlusion. The same group presented a high incidence of early CT hypodensity (88%). Finally the presence of HMCAS might be considered a negative prognostic sign for the development of extensive brain damage.

Hyperdense middle cerebral artery: incidence and quantitative significance.

The hyperdense middle cerebral artery sign (HMCAS) is recognized as a CT finding that indicates thrombus or embolus within the middle cerebral artery. The incidence and significance of this sign are quantitatively evaluated in 50 patients entered into experimental drug studies for treatment of cerebral infarction.