Clinical characteristics, Risk factors, and outcomes of Posterior circulation stroke: A retrospective study between younger and older adults in Saudi Arabia.

INTRODUCTION: Posterior circulation stroke (PCS) may be less prevalent than its anterior counterpart but contributes to substantial morbidity and mortality. The aim was to characterize PCS's demographics, clinical presentation, management, and outcomes between younger and older adults in Saudi Arabia. METHODS: This retrospective cohort study was conducted at two tertiary medical centers in Saudi Arabia between March 2016 and December 2020. All patients who presented with symptoms of posterior circulation stroke and had positive brain imaging were included. RESULTS: The study involved 160 posterior circulation stroke patients, stratified into two age groups: 71 patients aged 18-59 years and 89 patients aged 60 years and above. The mean age of the entire cohort was 60.9 years, and 77 % were males. Hypertension was more prevalent in the older age group (88 % vs. 69 %, p=0.005), and smoking was significantly higher among younger patients (38 % vs. 15 %; p=0.0009). Only 22.4 % received thrombolysis and/or thrombectomy. Most strokes involved the posterior cerebral artery (45.6 %). Large artery atherosclerosis was the most common subtype. At discharge, younger patients had higher NIHSS compared to older patients. CONCLUSION: Our investigation of 160 PCS patients in Saudi Arabia uncovers notable trends: a mere 22.4 % received thrombolysis and/or thrombectomy and a significant prevalence of posterior cerebral artery involvement due to large artery atherosclerosis. The study further reveals younger patients disproportionately had severe outcomes. Highlighting the need for improved stroke care and heightened awareness, this research contributes vital data to an underexplored domain, urging further study to optimize care and understand PCS dynamics in Saudi Arabia.

Clinical Course of Acute Ischemic Stroke Due to Medium Vessel Occlusion With and Without Intravenous Alteplase Treatment.

BACKGROUND AND PURPOSE: Available data on the clinical course of patients with acute ischemic stroke due to medium vessel occlusion (MeVO) are mostly limited to those with M2 segment occlusions. Outcomes are generally better compared with more proximal occlusions, but many patients will still suffer from severe morbidity. We aimed to determine the clinical course of acute ischemic stroke due to MeVO with and without intravenous alteplase treatment. METHODS: Patients with MeVO (M2/M3/A2/A3/P2/P3 occlusion) from the INTERRSeCT (The Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography) and PRoveIT (Precise and Rapid Assessment of Collaterals Using Multi-Phase CTA in the Triage of Patients With Acute Ischemic Stroke for IA Therapy) studies were included. Baseline characteristics and clinical outcomes were summarized using descriptive statistics. The primary outcome was a modified Rankin Scale score of 0 to 1 at 90 days, describing excellent functional outcome. Secondary outcomes were the common odds ratio for a 1-point shift across the modified Rankin Scale and functional independence, defined as modified Rankin Scale score of 0 to 2. We compared outcomes between patients with versus without intravenous alteplase treatment and between patients who did and did not show recanalization on follow-up computed tomography angiography. Logistic regression was used to provide adjusted effect-size estimates. RESULTS: Among 258 patients with MeVO, the median baseline National Institutes of Health Stroke Scale score was 7 (interquartile range: 5-12). A total of 72.1% (186/258) patients were treated with intravenous alteplase and in 41.8% (84/201), recanalization of the occlusion (revised arterial occlusive lesion score 2b/3) was seen on follow-up computed tomography angiography. Excellent functional outcome was achieved by 50.0% (129/258), and 67.4% (174/258) patients gained functional independence, while 8.9% (23/258) patients died within 90 days. Recanalization was observed in 21.4% (9/42) patients who were not treated with alteplase and 47.2% (75/159) patients treated with alteplase (P=0.003). Early recanalization (adjusted odds ratio, 2.29 [95% CI, 1.23-4.28]) was significantly associated with excellent functional outcome, while intravenous alteplase was not (adjusted odds ratio, 1.70 [95% CI, 0.88-3.25]). CONCLUSIONS: One of every 2 patients with MeVO did not achieve excellent clinical outcome at 90 days with best medical management. Early recanalization was strongly associated with excellent outcome but occurred in <50% of patients despite intravenous alteplase treatment.

Early Brain Imaging Shows Increased Severity of Acute Ischemic Strokes With Large Vessel Occlusion in COVID-19 Patients.

BACKGROUND AND PURPOSE: Reports are emerging regarding the association of acute ischemic strokes with large vessel occlusion and coronavirus disease 2019 (COVID-19). While a higher severity of these patients could be expected from the addition of both respiratory and neurological injury, COVID-19 patients with strokes can present with mild or none respiratory symptoms. We aimed to compare anterior circulation large vessel occlusion strokes severity between patients with and without COVID-19. METHODS: We performed a comparative cohort study between patients with COVID-19 who had anterior circulation large vessel occlusion and early brain imaging within 3 hours from onset, in our institution during the 6 first weeks of the COVID-19 outbreak and a control group admitted during the same calendar period in 2019. RESULTS: Twelve COVID-19 patients with anterior circulation large vessel occlusion and early brain imaging were included during the study period and compared with 34 control patients with anterior circulation large vessel occlusion and early brain imaging in 2019. Patients in the COVID-19 group were younger (P=0.032) and had a history of diabetes mellitus more frequently (P=0.039). Patients did not significantly differ on initial National Institutes of Health Stroke Scale nor time from onset to imaging (P=0.18 and P=0.6, respectively). Patients with COVID-19 had more severe strokes than patients without COVID-19, with a significantly lower clot burden score (median: 6.5 versus 8, P=0.016), higher rate of multivessel occlusion (50% versus 8.8%, P=0.005), lower DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Scores; median: 5 versus 8, P=0.006), and higher infarct core volume (median: 58 versus 6 mL, P=0.004). Successful recanalization rate was similar in both groups (P=0.767). In-hospital mortality was higher in the COVID-19 patients' group (41.7% versus 11.8%, P=0.025). CONCLUSIONS: Early brain imaging showed higher severity large vessel occlusion strokes in patients with COVID-19. Given the massive number of infected patients, concerns should be raised about the coming neurovascular impact of the pandemic worldwide.

Use of 3-Dimensional, Black-Blood, Contrast-Enhanced, T1-Weighted Magnetic Resonance Imaging to Identify Vascular Occlusion in the Posterior Circulation After Acute Ischemic Stroke.

BACKGROUND: Three-dimensional, black-blood, contrast-enhanced, T1-weighted magnetic resonance imaging (3D-BB-ceT1-MRI) could play a role in detection of thrombi and symptomatic intracranial atherosclerotic stenosis. We investigated the role of 3D-BB-ceT1-MRI in patients with acute ischemic stroke in the posterior circulation, and compared our findings with those from susceptibility-weighted imaging (SWI). MATERIALS AND METHODS: We retrospectively reviewed 3D-BB-ceT1-MRI for patients between January 2017 and August 2018 with acute ischemic symptoms in the posterior circulation. During this period, 199 patients with acute infarction in the posterior circulation were enrolled. Time-of-flight-magnetic resonance angiography or cerebral angiography was used as the reference standard. RESULTS: Of these 199 patients, 47 had vessel occlusion associated with acute infarction. The sensitivity of 3D-BB-ceT1-MRI for detection of vessel occlusion was significantly higher than that of SWI (95.7% versus 53.2%, P < .001). Twenty-one lesions with strong enhancement on 3D-BB-ceT1-MRI showed a negative susceptibility vessel sign (SVS) on SWI. CONCLUSIONS: 3D-BB-ceT1-MRI showed strong enhancement (due to contrast stagnation) in the intra-arterial thrombi of patients with acute infarction in the posterior circulation. 3D-BB-ceT1-MRI had higher sensitivity than that of an SVS on SWI for detection of intra-arterial thrombi.

Differences in Ischemic Anterior and Posterior Circulation Strokes: A Clinico-Radiological and Outcome Analysis.

BACKGROUND: There are limited data comparing posterior (PC) and anterior (AC) circulation acute ischemic strokes (AIS). We aimed to identify specific features of PC and AC strokes regarding clinical, etiological, radiological, and outcome factors. METHODS: Patients from the Acute STroke Registry and Analysis of Lausanne, a prospective cohort of consecutive AIS, from years 2003 to 2008 were included. The stroke territory was determined by a combination of neuroimaging and clinical symptoms. Patients with uncertain localization or with simultaneous AC and PC strokes were excluded. Multivariate associations between territory and multiple variables were investigated. RESULTS: A total of 1449 patients were included, 466 (32.2%) had a PC territory stroke and 983 (67.8%) an AC. On multivariate analysis, those with PC AIS had lower National Institutes of Health Stroke Scale at admission, more often showed decreased consciousness, visual field defects, and vestibulo-cerebellar signs, but less hemisyndromes, dysarthria, and cognitive symptoms compared to AC AIS patients. Male sex, arterial dissection, lacunar mechanisms, and endovascular recanalization were more frequent in PC strokes, whereas cardioembolic strokes and IV-thrombolysis rates were lower. Less early ischemic signs on admission CT, overall arterial pathology, and 24-hour recanalization were present in PC strokes but intracranial arterial pathology was more prevalent than in AC. The adjusted clinical outcome at 3 months was similar in both groups. CONCLUSIONS: In this large retrospective consecutive AIS series, there were specific differences in clinical presentation, etiology, and arterial pathology between PC and AC strokes which did not influence clinical outcome. These findings could lead to a tailored diagnostic work-up, acute treatment strategies, and secondary prevention.

Ischemic Stroke Associated With Calcitonin Gene-Related Peptide Inhibitor Therapy for Migraine: A Case Report.

Calcitonin gene-related peptide (CGRP) is involved in nociception and neurogenic inflammation in migraine, but also serves as a potent vasodilator acting on intracranial arteries. This latter effect raises concern about the possibility of drugs inhibiting CGRP precipitating cerebral ischemia. We describe a 41-year-old woman with migraine without aura who developed a right thalamic infarction following a first dose of erenumab, a CGRP-receptor blocker. Stroke onset occurred during a typical migraine. Imaging demonsrated right posterior cerebral artery near-occlusion initially with normalization of the vessel at follow-up imaging 2 months later, suggesting vasospasm as a possible mechanism. Extensive evaluation revealed no other specific cause of stroke or vascular risk factors aside from long-term use of oral contraceptive pills. CGRP inhibitors might be associated with ischemic stroke due to blockade of normal cerebral vasodilatory regulatory function.

Percheron Infarction: Is It Just a Rare Cerebrovascular Variant or a Forewarning of Severe Multiple Posterior Circulation Infarcts.

Percheron infarction, arising from occlusion of the Artery of Percheron, is few, which can result in bilateral thalamic and mesencephalic infarctions. We herein showcase a confirmed case of the Percheron infarction at the admission day, in which the patient advanced into severe multiple posterior circulation infarcts, along with petechial hemorrhage within the infarcts, even given the right therapy without delay. It reminds us that whether we could or should take this special infarction as a forewarning of more harmful infarcts getting in the way, or at least a precaution of poor vessel condition.

A Posterior Circulation Ischemia Risk Score System to Assist the Diagnosis of Dizziness.

BACKGROUND: We aimed to establish a risk score system without radio-image examination, which could help clinicians to differentiate patients with vertigo and posterior circulation ischemia (PCI) rapidly from the other dizzy patients. METHODS: We analyzed 304 patients with vertigo (50% PCI). The attributes with more significant contributions were selected as the risk factors for the PCI risk score system, and every one of them was assigned a value according to their respective odds ratio values. We also compared the respective receiver operating characteristic curves of the 3 diagnostic methods (PCI score system, ABCD2, and Essen score systems) to evaluate their prediction effectiveness. RESULTS: Nine risk factors were ultimately selected for PCI score system, including high blood pressure (1'), diabetes mellitus (1'), ischemic stroke (1'), rotating and rocking (-1'), difficulty in speech (5'), tinnitus (-5'), limb and sensory deficit (5'), gait ataxia (1'), and limb ataxia (5'). According to their respective PCI risk scores, the patients were divided into 3 subgroups: low risk (≤0', risk <37.4%), medium risk (1'-5'), and high risk (≥6', risk >95.0%). When 0' was selected as a cutoff point for differentiating the patients with PCI from patients without PCI, the sensitivity was 94.1%, with a specificity of 41.4%. The areas under the receiver operator curve value of PCI score system was .82 (P = .000), much higher than the areas under the receiver operator curve value of ABCD2 (.69, P = .000) and that of the Essen system (.67, P = .000) CONCLUSION: The PCI score system could help clinicians to differentiate patients with vertigo and PCI rapidly from the other dizzy patients.

Severe Reversible Cerebral Vasoconstriction Syndrome with Large Posterior Cerebral Infarction.

Reversible cerebral vasoconstriction syndrome is characterized by thunderclap headache and multifocal cerebral vasoconstriction. Cerebral vasoconstriction is reversible, and most cases have good prognosis. However, clinical outcome is possibly severe when it is complicated by stroke, yet detailed reports on such a case are few. We experienced a case of severe reversible cerebral vasoconstriction syndrome in a 32-year-old woman with medical history of preeclampsia 3years prior. She presented with sudden sharp headache followed by altered mental status and vasoconstriction of the bilateral posterior cerebral arteries. She was treated with intravenous and oral calcium channel blockers, edaravone, and glycerol. However, the cerebral infarction in the posterior circulation subsequently remained, and her impaired consciousness did not recover. Furthermore, although imaging findings of vasoconstriction showed improvement a day after the occurrence of symptom, the same vessels showed poor visualization 7 weeks later, which indicated the recurrence of vasoconstriction, without additional symptom due to the fixed infarction. Although most cases of reversible cerebral vasoconstriction syndrome show good prognosis, neurologists must monitor the possibility of worse clinical course and permanent neurological deficit when associated with stroke, such as cerebral infarction. Strict management and treatment are needed in these cases.

Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke.

BACKGROUND AND PURPOSE: Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. METHODS: This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. RESULTS: Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. CONCLUSIONS: Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone.

The Posterior Limb of the Internal Capsule as the Subcortical Transitional Zone of the Anterior and Posterior Circulations: Insights from Human 7T MRI.

BACKGROUND: In patients with cerebral infarction, identifying the distribution of infarction and the relevant artery is essential for ascertaining the underlying vascular pathophysiological mechanisms and preventing subsequent stroke. However, visualization of the basal perforating arteries (BPAs) has had limited success, and simultaneous viewing of background anatomical structures has only rarely been attempted in living human brains. Our study aimed at identifying the BPAs with 7T MRI and evaluating their distribution in the subcortical structures, thereby showing the clinical significance of the technique. METHODS: Twenty healthy subjects and 1 patient with cerebral infarction involving the posterior limb of the internal capsule (ICpost) and thalamus underwent 3-dimensional fast spoiled gradient-echo sequence as time-of-flight magnetic resonance angiography (MRA) at 7T with a submillimeter resolution. The MRA was modified to detect inflow signals from BPAs, while preserving the background anatomical signals. BPA stems and branches in the subcortical structures and their origins were identified on images, using partial maximum intensity projection in 3 dimensions. RESULTS: A branch of the left posterior cerebral artery (PCA) in the patient ran through both the infarcted thalamus and ICpost and was clearly the relevant artery. In 40 intact hemispheres in healthy subjects, 571 stems and 1,421 branches of BPAs were detected in the subcortical structures. No significant differences in the numbers of stems and branches were observed between the intact hemispheres. The numbers deviated even less across subjects. The distribution analysis showed that the subcortical structures of the telencephalon, such as the caudate nucleus, anterior limb of the internal capsule, and lenticular nucleus, were predominantly supplied by BPAs from the anterior circulation. In contrast, the thalamus, belonging to the diencephalon, was mostly fed by BPAs from the posterior circulation. However, compared with other subcortical structures, the ICpost, which marks the anatomical boundary between the telencephalon and the diencephalon, was supplied by BPAs with significantly more diverse origins. These BPAs originated from the internal carotid artery (23.1%), middle cerebral artery (38.5%), PCA (17.3%), and the posterior communicating artery (21.1%). CONCLUSIONS: The modified MRI method allowed the detection of the relevant BPA within the infarcted area in the stroke survivor as well as the BPAs in the subcortical structures of living human brains. Based on in vivo BPA distribution analyses, the ICpost is the transitional zone of the anterior and posterior cerebral circulations.

e-NIHSS: an Expanded National Institutes of Health Stroke Scale Weighted for Anterior and Posterior Circulation Strokes.

BACKGROUND: The National Institutes of Health Stroke Scale (NIHSS) is the most widespread clinical scale used in patients presenting with acute stroke. The merits of the NIHSS include simplicity, quickness, and agreement between clinicians. The clinical evaluation on posterior circulation stroke remains still a limit of NIHSS. METHODS: We assessed the application of a new version of NIHSS, the e-NIHSS (expanded NIHSS), adding specific elements in existing items to explore signs/symptoms of a posterior circulation stroke. A total of 22 consecutive patients with suspected vertebrobasilar stroke were compared with 25 patients with anterior circulation stroke using NIHSS and e-NIHSS. RESULTS: We compared the NIHSS and e-NIHSS scores obtained by the 2 examiners, in patients with posterior circulation infarct (POCI), using the Wilcoxon test. Patients with POCI evaluated with e-NIHSS had an average of 2 points higher than patients evaluated with classical NIHSS. The difference was statistically significant (P < .05), weighted by the new expanded items. CONCLUSIONS: The NIHSS is a practical scale model, with high reproducibility between trained, different examiners, focused on posterior circulation strokes, with the same total score and number of items of the existing NIHSS. The e-NHISS could improve the sensitivity of NIHSS in posterior circulation stroke and could have an impact on clinical trials, as well as on outcomes. Further studies are needed to investigate a larger number of patients and the correlation between the e-NIHSS score and neuroimaging findings.

Neural correlates of visual motion processing without awareness in patients with striate cortex and pulvinar lesions.

Patients with striate cortex lesions experience visual perception loss in the contralateral visual field. In few patients, however, stimuli within the blind field can lead to unconscious (blindsight) or even conscious perception when the stimuli are moving (Riddoch syndrome). Using functional magnetic resonance imaging (fMRI), we investigated the neural responses elicited by motion stimulation in the sighted and blind visual fields of eight patients with lesions of the striate cortex. Importantly, repeated testing ensured that none of the patients exhibited blindsight or a Riddoch syndrome. Three patients had additional lesions in the ipsilesional pulvinar. For blind visual field stimulation, great care was given that the moving stimulus was precisely presented within the borders of the scotoma. In six of eight patients, the stimulation within the scotoma elicited hemodynamic activity in area human middle temporal (hMT) while no activity was observed within the ipsilateral lesioned area of the striate cortex. One of the two patients in whom no ipsilesional activity was observed had an extensive lesion including massive subcortical damage. The other patient had an additional focal lesion within the lateral inferior pulvinar. Fiber-tracking based on anatomical and functional markers (hMT and Pulvinar) on individual diffusion tensor imaging (DTI) data from each patient revealed the structural integrity of subcortical pathways in all but the patient with the extensive subcortical lesion. These results provide clear evidence for the robustness of direct subcortical pathways from the pulvinar to area hMT in patients with striate cortex lesions and demonstrate that ipsilesional activity in area hMT is completely independent of conscious perception.

Etiology and Risk Factors of Posterior Circulation Infarction Compared with Anterior Circulation Infarction.

BACKGROUND: Many clinicians regard posterior circulation infarction (PCI) as different from anterior circulation infarction (ACI), leading them to apply different treatments. Few studies have validated this practice by directly comparing the etiology and risk factors of PCI and ACI. METHODS: We compared the etiology and risk factors of 2245 consecutive patients with a diagnosis of PCI or ACI confirmed by magnetic resonance imaging in the Chengdu Stroke Registry. Stroke etiology in each patient was classified according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. RESULTS: Our sample included 482 patients (21.5%) with PCI and 1763 (78.5%) with ACI. The most frequent etiology for both infarction types was small-artery occlusion, occurring in 37.6% of patients with PCI and 37.1% of those with ACI. Cardioembolism caused infarction in a significantly smaller proportion of patients with PCI (5.4%) than in patients with ACI (13.3%; odds ratio [OR] = .373; 95% confidence interval [CI], .245-.566). Frequencies of other stroke etiologies were similar between the 2 patient groups. Analysis of risk factor frequencies in the 2 groups showed hypertension to be the most common, occurring in 47.9% of patients in either group. Multivariable analysis identified 2 factors as conferring greater risk of PCI than ACI: male gender (OR = 1.392; 95% CI, 1.085-1.786) and diabetes mellitus (OR = 1.667; 95% CI, 1.275-2.180). The same analysis identified 2 factors as conferring greater risk of ACI: atrial fibrillation (OR = .530; 95% CI, .295-.951) and heart valve disease (OR = .433; 95% CI, .203-.922). Frequencies of other possible risk factors were similar between the 2 groups. CONCLUSIONS: These findings suggest that PCI and ACI are more similar than different in their etiology and risk factors and that the 2 types of infarction should be treated based more on etiology and risk factors than on their posterior or anterior localization.

Endovascular therapy for posterior cerebral artery occlusion: systematic review with meta-analysis.

Endovascular therapy (EVT) is a highly effective stroke treatment, but trials validating this intervention did not include patients with posterior cerebral artery (PCA) occlusion. The aim of this systematic review with meta-analysis was to assess the efficacy and safety of EVT for acute PCA occlusion. PubMed, Scopus, ISI, and CENTRAL were searched for studies assessing EVT in adult patients with PCA occlusion. Outcomes of interest were recanalization, symptomatic intracerebral haemorrhage (sICH), mortality, functional independence, and excellent functional outcome at 90 days. Frequencies and odds ratios (ORs) were pooled using random effect models and heterogeneity was measured using the I2 statistic and explored by means of meta-regression. Fifteen studies were included, all observational. Recanalization rates were high [81%, 95% CI (73-88%)] and sICH rates low [2%, 95% CI (1-4%)]. Heterogeneity was high for recanalization (I2 = 80%) but not for sICH, and not accounted for by any of the moderators tested. Compared to best medical treatment, EVT was associated with higher chances of sICH [OR = 2.04, 95% CI (1.12-3.71)] and no effect in functional independence [OR = 0.98, 95% CI (0.63-1.54)], with a tendency to higher chances of excellent functional outcome [OR = 1.29, 95% CI (0.90-1.86)] and mortality [OR = 1.56, 95% CI (0.84-2.90)]. EVT for acute PCA occlusion is technically feasible but associated with higher chance of sICH. There is no evidence to support this treatment to achieve higher rates of functional independence, but other gains that can impact patients' quality of life cannot be excluded. More studies are required with robust design, better patient selection, and comprehensive outcome evaluation.

Factors related to the initial stroke severity of posterior circulation ischemic stroke.

BACKGROUND: Posterior circulation (PC) stroke, which was previously less well known than anterior circulation (AC) stroke, has become more identified due to the development of imaging equipment. Recently, the initial stroke severity assessed by the NIH Stroke Scale (NIHSS) was reported as a useful measure for predicting the outcome of PC as well as AC stroke. The aim of our study was to investigate the factors related to the stroke severity of PC ischemic stroke as assessed by the baseline NIHSS and the predictors of progressive neurological deficit and 3-month outcome. METHODS: All patients with first-time PC stroke (onset ≤ 7 days), admitted for a 5-year period and given a complete evaluation including brain MRI and angiographic studies, were enrolled. Patients were divided into two groups by the baseline NIHSS: moderate-to-severe stroke (MTSS, NIHSS > 5) and mild stroke (MS, NIHSS ≤ 5). Baseline characteristics, symptoms and progression, etiological subtypes, lesion characteristics from imaging, and patient 3-month outcome assessed by the modified Rankin Scale (mRS) were compared between the two groups. RESULTS: Among 604 enrolled patients with PC ischemic stroke, 143 belonged to the MTSS group and 461 to the MS group. In logistic regression analysis, MTSS was independently associated with white blood cell count (odds ratio, OR = 1.00, p = 0.001), high sensitivity C-reactive protein level (OR = 1.23, p = 0.004), dysarthria (OR = 2.59, p = 0.013), weakness (OR = 6.43, p < 0.001), dysphagia (OR = 5.77, p < 0.001) and decreased consciousness (OR = 10.54, p < 0.001). The independent predictors associated with progressive neurological deficit were MTSS (OR = 3.82, p = 0.001), the distal territory classified by lesion location (OR = 0.09, p = 0.004) and dysphagia (OR = 2.38, p = 0.010). The independent predictors associated with a 3-month mRS of 3-6 were MTSS (OR = 7.69, p < 0.001), diplopia (OR = 0.26, p = 0.023), visual field defect (OR = 4.87, p = 0.014), dysphagia (OR = 3.15, p < 0.001) and progressive neurological deficit (OR = 4.27, p < 0.001). CONCLUSIONS: The initial severity categorization of PC ischemic stroke by the NIHSS has provided several distinctions and could help with the prediction of neurological deficit progression and 3-month clinical outcome.

Head-shaking aids in the diagnosis of acute audiovestibular loss due to anterior inferior cerebellar artery infarction.

OBJECTIVE: To determine the patterns and diagnostic value of head-shaking nystagmus (HSN) in patients with acute audiovestibular loss. METHOD: Eighteen patients underwent evaluation of spontaneous nystagmus, gaze-evoked nystagmus, HSN, head impulse test, ocular tilt reaction, subjective visual vertical, bithermal caloric tests, and pure-tone audiogram. The findings were compared with those of 21 patients with labyrinthitis. RESULTS: Fifteen patients (83%) exhibited HSN, and the horizontal HSN usually beat contralesionally (10/14, 71%). However, 9 (50%) patients also showed patterns of central HSN that included perverted HSN (n=7), HSN in the opposite direction of spontaneous nystagmus (n=4), and HSN beating towards unilateral canal paresis or abnormal head impulse testing (n=3). Overall, central HSN, gaze-evoked nystagmus, and normal head impulse testing were specific for anterior inferior cerebellar artery (AICA) infarction. Moreover, central HSN was the only sign that indicated stroke in 1 of our patients with isolated audiovestibular syndrome. Lesion subtraction analyses revealed that damage to the flocculus was relatively frequent in patients with perverted HSN. CONCLUSIONS: In AICA infarction, HSN was common with both peripheral and central patterns. Careful evaluation of HSN may provide clues for AICA infarction in patients with acute audiovestibular loss.

Neonatal posterior cerebral artery stroke: clinical presentation, MRI findings, and outcome.

AIM: To report the clinical presentation, magnetic resonance imaging (MRI) findings, and follow-up data of newborn infants with perinatal arterial ischemic stroke in the territory of the posterior cerebral artery (PCA). METHOD: Data on 18 newborn infants from three neonatal intensive care units (11 males, seven females) with an MRI-confirmed PCA stroke were analysed and reported. Infants were born at a mean gestational age of 38.7 weeks (SD 3.4) with a mean birthweight of 3244g (SD 850). RESULTS: Fourteen infants presented with clinical seizures. Five of these had associated hypoxic-ischemic encephalopathy, four had hypoglycaemia, and five had neither hypoxic-ischemic encephalopathy nor hypoglycaemia. Subclinical seizures were present in one infant with hypoxic-ischemic encephalopathy and one with meningitis. One preterm infant presented with apnoeas and one had hypoxic-ischemic encephalopathy without seizures. Neurodevelopmental follow-up of 17 children at a median age of 36 months (SD 28, range 12-120mo) showed five with a global delay. Two children with additional injury developed postneonatal epilepsy and one child with extensive injury developed hemiplegia. A visual field defect was observed in nine children (six hemianopia, three quadrantanopia). In the 11 children with a second MRI at 3 months, the asymmetry of the optic radiation correlated with the development of a visual field deficit. INTERPRETATION: Outcome after PCA stroke is fairly good, depending on additional brain injury. Follow-up is required, as subsequent visual field defects are frequently observed. Further research will be needed to clarify the role of hypoglycaemia in perinatal arterial ischemic stroke.