Cerebral infarct volume measurements to improve patient selection for endovascular treatment

Patients who have large cerebral infarctions may not be good candidates for endovascular treatment. Various methods for determining infarct volume have been used in clinical studies. We evaluated the effectiveness of several methods for measuring infarct volume, especially regarding futile outcomes despite endovascular treatment.Patients with acute ischemic stroke in unilateral anterior circulation territory who were treated with intra-arterial thrombectomy were included. For assessing infarct volume, the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) scoring system was applied to images obtained by noncontrast computed tomography (NCCT), postcontrast CT (PCCT), and diffusion-weighted imaging (DWI). DWI stroke volume was semiquantitatively measured with the manually outlined hyperintense lesion. Infarct core volume was calculated with a threshold apparent diffusion coefficient value of 600 × 10 mm/s. Intraclass correlation coefficients (ICC) were estimated to assess inter-reader reliability for ASPECTS scoring and DWI stroke volume. Receiver operating characteristic (ROC) curve analyses, and univariable and multivariable comparative analyses, were performed with each evaluation method to predict futile outcome (modified Rankin Scale score 5-6).The mean age of the included 79 patients was 65.1 ± 15.7 years. Among them, 55 (69.6%) patients demonstrated successful reperfusion after intra-arterial thrombectomy, but 34 (43.0%) patients had futile outcomes. Inter-reader agreement was excellent for measurement of the DWI stroke volume (ICC, 0.973), DWI ASPECTS (0.940), and PCCT ASPECTS (0.859), but was moderate for NCCT ASPECTS (0.694). Regarding prediction of futile outcomes, area under ROC curve was 0.551 on NCCT ASPECTS and it was significantly smaller than that in PCCT ASPECTS (area under ROC 0.651, P = 0.030), DWI ASPECTS (0.733, P = 0.003), DWI stroke volume (0.702, P = 0.022), and infarct core volume (0.702, P = 0.021). Besides old age and high National Institutes of Health Stroke Scale score on admission, MRI parameters such as DWI ASPECTS and infarct core volume indicating large volumes were independently associated with futile outcomes in multivariable analyses.DWI ASPECTS can be a good parameter predicting futility, which is easily measured and has high prediction power.

Abstract T P21: Complex Internal Carotid Artery T Occlusion By Computed Tomographic Angiography Is A Very Malignant Subtype With Massive Infarcts And Poor Outcomes Despite Revascularization Treatment

Background: ICA T/L occlusions appear to have a particular poor prognosis due to low recanalization with intravenous tissue plasminogen activator alone. What is not known however is whether all ICA T/L occlusions remain as good candidates for endovascular treatment. We divided ICA T/L occlusions into distinct types according to Willisian collaterals and compared infarct core volumes and clinical outcomes in the two groups as well as other anterior circulation occlusion sites.

Methods: We enrolled patients with acute ischemic stroke in anterior circulation whose CT angiography showed major intracranial artery occlusion. Patients were included if their MRI was taken just after CT scan and within 6 hours from onset. We classified patients into Complex ICA T, Simple ICA T/L, MCA M1, MCA M2, and extracranial to intracranial tandem groups. Among patients with ICA T/L occlusion, patients were classified into simple ICA T/L occlusion group if ACA A2 and PCA P2 segments are patent whereas those into complex ICA T group if A2, P2 or their distal branches were occluded, or contralateral occlusion was seen in ICA or contralesional A1 absent or hypoplastic. Other occlusion types were excluded in this study.

Results: Table shows comparisons among groups. Age, sex and vascular risk factors did not differ among groups. Initial NIHSS score was different among groups. Pretreatment infarct core volume with ADC value threshold of 600 x 10-5 mm2/s was significantly different according to cerebral artery occlusion types. Clinical outcome significantly differed among groups regarding NIHSS score at discharge, frequency of good outcome (mRS 0-2 at 3 months), and frequency of 3-month mortality.

Conclusion: We describe a subtype of carotid occlusions we have named as complex ICA T occlusions in which Willisian collateral flow is limited. This group is associated with very large infarct core volumes and poor 3-month outcomes despite acute revascularization treatment.

Epileptic nystagmus: A case report and systematic review

PURPOSE

We aimed to define the characteristics of epileptic nystagmus and correlate those with other clinical findings in a large number of patients.

METHODS

We report a patient with epileptic nystagmus and additionally reviewed the reported clinical features of 36 more patients through a systematic literature search. We analyzed the characteristics of epileptic nystagmus and attempted correlations of those with alertness of the patients and epileptic foci on EEG.

RESULTS

All 33 patients with unilateral horizontal nystagmus showed nystagmus beating away from the side of ictal discharges. Epileptic nystagmus was preceded by gaze deviation in 21 patients, with contraversive in 19 and ipsiversive in 2. Seizures associated with epileptic nystagmus were mostly focal (25/29, 86.2%) with or without loss of awareness. Ictal discharges originated from the occipital (n = 16), parietal (n = 9), temporo-occipital (n = 6), frontal (n = 4), and temporal (n = 3) areas, and two patients had multiple epileptic foci. Seizures were usually symptomatic (24/37, 64.9%). The presence of preceding gaze deviation and midline crossing of the nystagmus did not correlate with the ictal onset zone or alertness of the patients. Recording of epileptic nystagmus was available only in 6 patients, and the epileptic nystagmus could be localized to the saccadic areas in two and to the smooth pursuit areas in another two. Two patients showed the features of epileptic nystagmus from both areas.

CONCLUSION

Even though the localizing value of epileptic nystagmus seems limited in previous reports, the fast phase of epileptic nystagmus was almost always directed away from the epileptic focus that mostly arose from the posterior part of the cerebral hemisphere.