MCA Territory Infarcts Research Articles

Reversible uncal herniation in a neonate with a large MCA infarct

Uncal herniation due to a large cerebral infarct is well-described in adults, with high rates of morbidity and mortality. This phenomenon, however, has not been previously reported in neonates. We present a newborn male delivered via cesarean section with difficult extraction who presented with frequent seizures. He was found to have an acute left MCA territory infarct secondary to an M1 occlusion detected on MRI/MRA. He became lethargic and developed a left uncal herniation on CT at 72 h of life. He was treated medically with osmolar agents and hemodynamic support, and had resolution of the herniation on CT at 120 h of life. At 19 months he had residual moderate right hemiparesis with only mild gait disturbance and mild speech delay. As seen in this case, uncal herniation, though rare, may occur in neonates. Also, the outcome for this neonate was much better than for typical adults with a similar disease course.

Outcome of large hemispheric infarcts: an experience of 50 patients in Taiwan

Background Large hemispheric infarcts cause high mortality and morbidity. Understanding the clinical course and prognostic factors in patients with LHI, thereby enabling the identification of patients who will benefit from early aggressive intervention, is important. This study describes the clinical course of patients who had LHI and identifies the predictors for mortality. Methods A retrospective collection of clinical and laboratory data in patients admitted to a neurologic intensive care unit of a medical center was examined. Large hemispheric infarct was defined as an infarct that involved at least 2 of the 3 (deep, superior, and posterior) MCA territories. Patients who received a hemicraniectomy were not included. Results Fifty patients with radiologically confirmed LHI were analyzed. The 30-day mortality rate was 22%. Only patients who had massive infarcts (complete MCA territory infarcts and beyond) died, whereas none with i-MCAs died ( P < .001). For the 26 patients with massive infarcts, the 30-day mortality was 42.3%. Early deterioration, ipsilateral pupil dilation, and a low GCS were associated with mortality. Further analysis revealed that an age less than 70 years (OR 24.5, 95% CI 2.3-262.6) and a GCS less than 10 at the second day of stroke (OR 15, 95% CI 1.5-149.5) predicted a fatal outcome among patients with massive infarcts. A GCS less than 12 at the first day of stroke and early CT findings of hypodensity more than one half of the MCA territory were associated with massive infarct. Conclusions The extent of infarction is a crucial factor for mortality. The consciousness level may identify patients at risk for massive infarct at the first day of stroke and predict a fatal outcome as early as the second day. Early identification of the extent of infarction and close monitoring of the consciousness level help predict outcome.

Is 15 mm Size Criterion for Lacunar Infarction Still Valid? A Study on Strictly Subcortical Middle Cerebral Artery Territory Infarction Using Diffusion-Weighted MRI

Background and Purpose: The ‘lacunar hypothesis’ has been challenged, since small (diameter <15 mm) subcortical infarcts can be produced by middle cerebral artery disease (MCAD) or cardioembolism (CE), while a larger infarct can occur without evidence of MCAD or CE. We sought to assess whether the lacunar hypothesis based on size is still valid. Methods: We studied 118 patients who were admitted within 72 h after stroke onset and had acute deep subcortical MCA territory infarcts detected by diffusion-weighted MRI, and who had undergone angiography (mostly MR angiography). Stroke mechanisms were arbitrarily categorized regardless of lesion size: (1) MCAD when there was a corresponding MCA lesion; (2) internal carotid artery disease (ICAD) when there was a significant (>50%) ipsilateral ICAD; (3) CE when there was emboligenic heart disease without MCAD or ICAD, and (4) small vessel disease (SVD) when there was neither CE nor MCAD. SVD was further divided into definite SVD (dSVD, longest diameter <15 mm) or probable SVD (pSVD, longest diameter ≧15 mm). Results: Seventy-three patients (62%) had SVD, of which 38 (32%) had pSVD and 35 (30%) dSVD. Thirty-three patients (28%) had MCAD, five (4%) CE, and seven (6%) ICAD. The infarct diameter in MCAD was not larger than in SVD (p = 0.35), and there was no difference in clinical features or risk factors between MCAD and SVD, or between pSVD and dSVD. CE was distinguished from SVD by its larger size and cortical symptoms. Conclusions: There are no clinical and lesion-size differences between MCAD and SVD, suggesting that there seems to be no rationale for the 15 mm size criterion for lacunar or small-vessel infarction.

The ASPECTS template is weighted in favor of the striatocapsular region

The extent of cerebral infarction correlates with increased risk of intracerebral hemorrhage (ICH) following recombinant tissue plasminogen activator (rt-PA) administration. The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used, validated method which assesses involvement of 10 selected regions of the MCA territory. An ASPECTS score >7 is associated with a higher risk of ICH following thrombolysis than lower scores. To understand the internal structure of the ASPECTS template better, we estimated the infarct volume corresponding to each region. We hypothesized that, in the ASPECTS scoring system, the striatocapsular region is weighted disproportionally. Four experienced radiologists rated individual ASPECTS regions on subacute CT images (day 5–day 10) of 19 patients with MCA territory stroke. Infarct volume was determined from manual segmentation of infarcts on CT images. Linear regression was used to estimate the regional volume associated with each ASPECTS region. The ASPECTS regions are weighted unequally with the striatocapsular region accounting for 21% of the MCA territory infarct volume. Together, the 10 ASPECTS regions account for approximately 51% of the maximum MCA infarct territory volume. These findings should provide impetus for research to develop a scoring system explicitly based on regional hemorrhage risk as an aid to selecting patients for thrombolysis.

Hyperacute Middle Cerebral Artery Territory Infarction: Comparison of Unenhanced CT, Spin-Echo T2-weighted,Fast FLAIR, and Diffusion-weighted MR Imaging

Purpose : To compare the detection rate of unenhanced CT, spin-echo T2-weighted, fast fluid-attenuatedin-version- recovery(FLAIR), and diffusion-weighted MR imaging in the diagnosis of hyperacute middle cerebralartery(MCA) territory infarction. Materials and Methods : Sixteen patients with clinically proven hyperacute MCAterritory infarction were e-valuated with unenhanced CT and MR. All CT examinations were performed within sixhours of the onset of symptoms and all MR studies were performed within two hours of CT. All images were evaluatedindepen-dently by two radiologists in possession of brief clinical information. Positive imaging criteria wereparenchy-mal hypoattenuation, as seen on CT, and increased signal intensity, as seen on MR. For quantitativeanalysis, we measured the attenuation and signal intensity of the lesion and contralateral normal parenchyma, andper-centage contrast-to-noise ratios(CNRs) of the lesions were also calculated . Results : Positive findings weredetected in all patients on diffusion-weighted images, in 13(81%) on CT, in 10 ( 63 %) on fast FLAIR images, andin 7(44 %) on T2-weighted images. Lesion percentage CNRs were 30% for diffusion-weighted imaging, 15 % for CT, 18% for FLAIR MR imaging, and 16 % for T2-weighted MR imag-ing(p

Large middle cerebral artery infarction

Reply from the Authors: We appreciate the interest of Drs. Demchuk and Krieger in our article and their comments concerning large MCA territory infarcts. Drs. Demchuk and Krieger address the importance of the involvement of additional arterial in large MCA infarcts for the development of mortal brain edema, as supported by their own findings and the available literature.5,6 Although we agree with their statement, we would nevertheless add some details concerning the difference between the death rate of 78% found by Hacke et al.5 and the death rate of 17% in our study.1 Selection criterion in the …