Rabinstein, Alejandro A.

Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is limited in sensitivity and specificity for detecting LRNC, plaque hemorrhage, and ulceration compared with MRI. Also summarized is how these advanced imaging techniques are being used in clinical practice to risk stratify patients with low- and high-grade carotid artery stenosis. For example, identification of IPH on MRI in patients with low-grade carotid artery stenosis is a risk factor for failure of medical therapy, and studies have shown that such patients may fair better with carotid endarterectomy (CEA). MR plaque imaging has also been found to be useful in identifying revascularization candidates who would be better candidates for CEA than carotid artery stenting (CAS), as high intraplaque signal on time of flight imaging is associated with vulnerable plaque and increased rates of adverse events in patients undergoing CAS but not CEA.

OBJECT External ventricular drainage (EVD) after intraventricular hemorrhage (IVH) without symptomatic hydrocephalus is controversial. The object of this study was to examine indicators or the timeframe for hydrocephalus in patients not immediately treated with EVD after IVH. METHODS Records from 2007 to 2014 were searched for “intraventricular hemorrhage” or “IVH.” Inclusion criteria were IVH after intracerebral hemorrhage (ICH), trauma, tumor, or vascular anomalies. Exclusion criteria were IVH with more than minimal subarachnoid hemorrhage, catastrophic ICH, layering IVH only, or hydrocephalus treated immediately with EVD. IVH was measured with the modified Graeb Score (mGS). An mGS of 5 indicates a full ventricle with dilation. Statistics included chi-square, Student’s t-test, and Mann-Whitney tests; receiver operating characteristics; and uni- and multivariate logistic regression. RESULTS One hundred five patients met the criteria; of these, 30 (28.6%) required EVD. Panventricular IVH was the most common pattern (n = 49, 46.7%), with 25 of these patients (51%) requiring EVD. The median mGS was 18 ± 5.4 (range 12–29) and 9 ± 4.5 (range 2–21) in the EVD and No-EVD groups, respectively (p < 0.001). Factors associated with EVD were radiological hydrocephalus at presentation, midline shift > 5 mm, Glasgow Coma Scale (GCS) score < 8, mGS > 13, third ventricle mGS = 5, and fourth ventricle mGS = 5. On multivariate analysis, GCS score < 8 [4.02 (range 1.13–14.84), p = 0.032], mGS > 13 [3.83 (range 1.02–14.89), p = 0.046], and fourth ventricle mGS = 5 [5.01 (range 1.26–22.78), p = 0.022] remained significant. Most patients treated with EVD (n = 25, 83.3%) required it soon after presentation [6.4 ± 3.3 (range 1.5–14) hrs]. The remaining 5 patients (16.7%) had a delayed EVD requirement [70.7 ± 22.7 (range 50–104.5) hrs]. CONCLUSIONS In this study population, the risk for EVD was variable, but greater with mGS > 13, coma, and a dilated fourth ventricle. While the need for EVD occurs within the 1st day after IVH in most patients, a minority require EVD after 48 hours.

OBJECT This study was undertaken to analyze the predisposing factors, clinical presentation, therapeutic management, and clinical recovery in patients with pituitary apoplexy, with an emphasis on the long-term visual, endocrine, and functional outcomes. METHODS The authors performed a retrospective analysis of consecutive cases involving patients treated at Mayo Clinic between 1992 and 2013. Patients were included in the study only if they had 1) abrupt onset of severe headache or visual disturbance in the presence of a pituitary adenoma and 2) radiological or surgical confirmation of a pituitary mass. The primary endpoints of analysis were the visual (ocular motility, visual fields, and visual acuity), endocrine, and functional outcomes (using the modified Rankin Scale). RESULTS Eighty-seven patients were identified (57 males and 30 females, mean age 50.9 years, range 15–91 years). Twenty-two patients (25.3%) had a known pituitary adenoma. Hypertension was the most common associated factor (39%). Headache was the most frequent presenting symptom (89.7%), followed by visual abnormalities (47.1%). Cranial nerve palsies were present in 39% and visual field defects in 34.1%. MRI detected hemorrhage in 89% patients, as compared with 42% detected by CT scan. Sixty-one patients (70.1%) underwent surgery during acute hospitalization (median time from apoplexy 5 days, IQR 3–10 days), 8 (9.2%) had delayed surgery, and 18 (20.7%) were treated conservatively. Histopathological examination revealed adenoma with pure necrosis in 18 (30%), pure hemorrhage in 4 (6.7%), and both in 6 (10%) patients. Four patients died during hospitalization. The average duration of follow-up was 44.2 ± 43.8 months. All survivors were independent and had complete resolution or substantial improvement in eye movements and visual fields at the last follow-up. Many patients needed long-term hormonal replacement with levothyroxine (62.7%) and cortisol (60%). Daily desmopressin was needed in 23% of all surgical patients at 3 months (versus none of the medically treated) and this requirement decreased slightly over time. Regrowth of pituitary adenoma was seen in 7 patients (8.6%). There were no statistically significant differences in any of the outcome measures across the treatment groups. CONCLUSIONS The outcome of most patients with pituitary apoplexy is excellent. Selected patients can be managed conservatively, and patients with severe neuro-ophthalmological deficits treated with early surgery can achieve an excellent recovery.

Most of the contraindications to the administration of intravenous (IV) recombinant tissue plasminogen activator (rtPA) originated as exclusion criteria in major stroke trials. These were derived from expert consensus for the National Institute of Neurological Disorders and Stroke (NINDS) trial. Despite the fact that the safety and efficacy of IV rtPA has been repeatedly confirmed in large international observational studies over the past 20 years, most patients with acute ischemic stroke disappointingly still do not receive thrombolytic treatment. Some of the original exclusion criteria have proven to be unnecessarily restrictive in real-world clinical practice. It has been suggested that application of relaxed exclusion criteria might increase the IV thrombolysis rate up to 20% with comparable outcomes to thrombolysis with more conventional criteria. We review the absolute and relative contraindications to IV rtPA for acute ischemic stroke, discussing the underlying rationale and evidence supporting these exclusion criteria.

SummaryObjectiveSeizures are common in patients with posterior reversible encephalopathy syndrome (PRES), which is reported in up to 70% of cases, and antiepileptic drugs (AEDs) are commonly prescribed. There is a paucity of data regarding the risk of subsequent seizures following resolution of PRES, and therefore the optimal duration of treatment with AEDs is currently unknown. The objective of this study was to identify the frequency of recurrent seizures and epilepsy following recovery from PRES.MethodsWe performed a retrospective review of consecutive adults diagnosed with PRES between 2000 and 2010.ResultsOne hundred twenty‐seven patients, median age 53 years (interquartile range [IQR] 37–64), were included in the analysis. The most common causes of PRES were hypertension (72%) and immunosuppression (20%). Renal failure was present in 47%. Eighty‐four patients (66%) had seizures at presentation (39 focal, 45 generalized), and 13 (15%) of them presented with status epilepticus. Median duration of follow‐up was 3.2 years (IQR 4 months to 6.9 years). Patients with seizures were treated with AEDs for a median of 3 months (IQR 2–7). Fifteen patients (12%) had provoked seizures during the follow‐up period; in eight (53%) patients seizures were caused by recurrent PRES. Only three patients had subsequent unprovoked seizures, one of whom was considered to have developed epilepsy.SignificanceWe conclude that unprovoked seizures and epilepsy are uncommon in patients who have recovered from PRES. Discontinuation of AEDs following resolution of PRES should be considered, provided there is adequate control of risk factors, and absence of factors that could substantially lower the seizure threshold.

A point-of-care workflow checklist in the form of an iOS (iPhone Operating System) app for use by stroke providers was introduced with the objective of standardizing acute stroke evaluation and documentation at 2 affiliated academic medical centers. Providers used the app in unselected, consecutive patients undergoing acute stroke evaluation in an emergency department or hospital setting between August 2012 and January 2013 and August 2013 and February 2014. Satisfaction surveys were prospectively collected pre- and postintervention from residents, staff neurologists, and clinical data specialists. Residents (20 preintervention and 16 postintervention), staff neurologists (6 pre and 5 post), and clinical data specialists (4 pre and 4 post) participated in this study. All 16 (100%) residents had increased satisfaction with their ability to perform an acute stroke evaluation postintervention but only 9 (56%) of 16 felt the app was more help than hindrance. Historical controls aligned with preintervention results. Staff neurologists conveyed increased satisfaction with resident presentations and decision making when compared to preintervention surveys. Stroke clinical data specialists estimated a 50% decrease in data abstraction when the app data were used in the clinical note. Concomitant effect on door-to-needle (DTN) time at 1 site, although not a primary study measure, was also evaluated. At that 1 center, the mean DTN time decreased by 16 minutes when compared to the corresponding months from the year prior. The point-of-care acute stroke workflow checklist app may assist trainees in presenting findings in a standardized manner and reduce data abstraction time. The app may help reduce DTN time, but this requires further study.

Summary Objective To describe the etiologies, clinical presentations, outcomes, and predictors of postencephalitic epilepsy ( PE ) in a large series of adult patients with acute encephalitis. Methods We conducted a retrospective review of patients diagnosed with acute encephalitis at Mayo Clinic, Rochester, between January 2000 and December 2012. The patients were categorized into two groups based on the presence or absence of PE at last follow‐up. Multivariate logistic regression analysis was used to analyze factors associated with PE . Results We identified 198 consecutive patients (100 [50.5%] male and 98 [49.5%] female) with a median age of 58 years (range 41.8–69). Etiologies included viral infection (n = 95, 48%), autoimmune (n = 44, 22%), and unknown/others (n = 59, 30%). During hospitalization, seizures were seen in patients with autoimmune encephalitis (n = 24, 54.5%), unknown/others (n = 20, 33.9%), and viral encephalitis (n = 23, 24.2%). Interictal epileptiform discharges on electroencephalography (EEG) were present in 34 (54%), whereas periodic lateralized epileptiform discharges (PLEDs) and generalized periodic discharges (GPDs) were seen in 14 (41.2%) and 2 (5.9%) patients. Forty‐six patients with seizures (70.8%) had fluid‐attenuated inversion recovery ( FLAIR )/T 2 abnormalities, 20 (31.3%) diffusion abnormalities, and 43 (66.2%) cortical involvement. Good outcome at discharge among patients with seizures was seen in 8/23 patients with viral etiology (34.8%), 10/24 patients with autoimmune encephalitis (45.5%), and 12/20 patients with unknown cause (60%). PE was present in 43 patients (29.9%). On multivariate regression analysis, the factors associated with PE were generalized seizures during hospitalization (p = 0.03), focal seizures (p ≤ 0.001), and the presence of FLAIR /T 2 abnormalities on brain magnetic resonance imaging ( MRI ) (p = 0.003). Significance The presence of seizures during hospitalization and an abnormal brain MRI are the strongest predictors of the development of PE . The etiology of encephalitis, presence of focal neurologic deficits, and interictal EEG abnormalities did not influence the development of PE .