Workload in Emergency Rooms among Clinical Specialties and Overburdened Neurologists

Background@#To evaluate workload in emergency rooms (ERs) among clinical specialties including neurology and investigate characteristics of neurological consultations in ER. @*Methods@#A nationwide survey was conducted to evaluate the number of specialists, resident physicians/surgeons, and emergency consultations of each clinical specialty in Korean tertiary referral hospitals from 2018 to 2019. Characteristics of neurological emergency consultations during the same period were investigated in one of the hospitals that participated. @*Results@#A total of 23 hospitals were included. Four irrelevant clinical specialties were excluded. The number of neurology specialists and resident physicians were 12.5/hospital (4.1% of all specialists) and 6.4/hospital (3.4% of all resident physicians/surgeons), respectively, while the mean numbers of specialists and resident physicians or surgeons per clinical specialty were 13.7/hospital and 8.6/hospital, respectively. Neurological consultations accounted for 11.0% of all ER consultations for severe patients (Korean Triage and Acuity Scale level 1-3). Annual ER consultations for severe patients per neurology specialist was 274.1, which was only second to pediatrics (290.0). Annual ER consultations for severe patients per resident physician was 406.6 which was 1.6 times higher than the second highest (internal medicine, 247.0). Frequent conditions for neurological ER consultation were dizziness (24.8%), motor weakness (23.9%), headache (10.6%), dysarthria (9.9%), and seizures (7.7%). Frequent primary diagnoses were cerebrovascular diseases (29.0%) and episodic and paroxysmal disorders (24.9%). @*Conclusions@#Workloads of neurology specialists for ER consultation were significantly heavy, and the workload of neurology resident physicians was the heaviest among all specialties. This should be considered in health care policies.

The Investigation on the Burden of Neurology Residents to Manage the Patient who Received Thrombolytic Treatment in the Emergency Department with Hyperacute Stroke

Background@#Because Korea is the fastest aging country, the stroke incidence is increasing rapidly. We investigate the trend of the number of patients with acute stroke in recent years and estimate the burden of the neurologist to treat the acute stroke patient visited the emergency department. @*Methods@#We requested a questionnaire survey to all teaching hospitals on the number of hospital beds, the number of stroke patients who visited the emergency department, the number of stroke patients in charge of the neurologist, and the number of days on duty of residents from 2016 to 2019. @*Results@#Of 69 teaching hospitals, 41 hospitals answered the survey. The average hospital beds per hospital were increased annually from 909 to 916. The average patients who visited the emergency department with stroke and were in charged to neurologists were rapidly increased from 799 to 867 per hospital. In particular, the number of patients with hyperacute cerebral infarction requiring the thrombolytic administration or mechanical thrombectomy were rapidly increased from 105 to 131. On the other hand, the average number of residents per hospital was decreased from 5.1 to 4.8. Therefore, the days on duty per resident were increased from 74 to 77. @*Conclusions@#The number of acute stroke patients, especially, hyperacute stroke required the rapid cooperation and high labor were increasing rapidly in recent years. However, because the number of residents were decreased, the burden was increasing. To improve the quality of acute stroke treatment, it is necessary to increase the number of residents.

Hyperintense Vessel Sign in Large-Vessel Occlusion Stroke of Mild-to-Moderate Severity Ineligible for Recanalization

Background@#and PurposeThe impact of fluid-attenuated inversion recovery hyperintense vessels (FHVs) on outcomes in patients ineligible for recanalization therapy with large-vessel occlusion (LVO) is unclear. We investigated the impact of FHVs determined using the FHV– Alberta Stroke Program Early CT Score (ASPECTS) on clinical outcomes in patients with LVO stroke of mild-to-moderate severity ineligible for recanalization therapy. @*Methods@#Sixty-eight consecutive patients with M1-middle cerebral artery occlusion who underwent magnetic resonance imaging within 24 hours of symptom onset and were ineligible for recanalization were included. Patients were dichotomized into a severe-FHV group (FHV-ASPECTS ≤4; n=33) and a mild-FHV group (FHV-ASPECTS >4; n=35), and multiple logistic regression analysis was used to examine the relationships of FHV scores with early neurological deterioration (END) and an unfavorable 3-month outcome (modified Rankin Scale score ≥3). @*Results@#Mean age was 66.2±13.5 years (mean±SD), and 30 (44%) were female. The severe-FHV group had a larger infarct volume (median, 5.5 mL vs. 3 mL) and more frequently exhibited the susceptibility vessel sign (30% vs. 3%) than the mild-FHV group. Ipsilateral old nonlacunar infarct was more frequent in the mild-FHV group than in the severe-FHV group (37% vs. 15%). The severe-FHV group had a fivefold higher risk of END (odds ratio [OR] 5.02, 95% confidence interval [CI] 1.36–18.45) and unfavorable outcome (OR 5.97, 95% CI 1.18–33.31, p=0.03) compared with the mild-FHV group. @*Conclusions@#Greater FHV extent was associated with higher risk of END and unfavorable outcome in patients with LVO stroke of mild-to-moderate severity.

Hyperintense Vessel Sign in Large-Vessel Occlusion Stroke of Mild-to-Moderate Severity Ineligible for Recanalization

Background@#and PurposeThe impact of fluid-attenuated inversion recovery hyperintense vessels (FHVs) on outcomes in patients ineligible for recanalization therapy with large-vessel occlusion (LVO) is unclear. We investigated the impact of FHVs determined using the FHV– Alberta Stroke Program Early CT Score (ASPECTS) on clinical outcomes in patients with LVO stroke of mild-to-moderate severity ineligible for recanalization therapy. @*Methods@#Sixty-eight consecutive patients with M1-middle cerebral artery occlusion who underwent magnetic resonance imaging within 24 hours of symptom onset and were ineligible for recanalization were included. Patients were dichotomized into a severe-FHV group (FHV-ASPECTS ≤4; n=33) and a mild-FHV group (FHV-ASPECTS >4; n=35), and multiple logistic regression analysis was used to examine the relationships of FHV scores with early neurological deterioration (END) and an unfavorable 3-month outcome (modified Rankin Scale score ≥3). @*Results@#Mean age was 66.2±13.5 years (mean±SD), and 30 (44%) were female. The severe-FHV group had a larger infarct volume (median, 5.5 mL vs. 3 mL) and more frequently exhibited the susceptibility vessel sign (30% vs. 3%) than the mild-FHV group. Ipsilateral old nonlacunar infarct was more frequent in the mild-FHV group than in the severe-FHV group (37% vs. 15%). The severe-FHV group had a fivefold higher risk of END (odds ratio [OR] 5.02, 95% confidence interval [CI] 1.36–18.45) and unfavorable outcome (OR 5.97, 95% CI 1.18–33.31, p=0.03) compared with the mild-FHV group. @*Conclusions@#Greater FHV extent was associated with higher risk of END and unfavorable outcome in patients with LVO stroke of mild-to-moderate severity.

Platelet-Derived Growth Factor Is Associated with Progression of Symptomatic Intracranial Atherosclerotic Stenosis

Background@#and Purpose We aimed to determine the relationships of 33 biomarkers of inflammation, oxidation, and adipokines with the risk of progression of symptomatic intracranial atherosclerotic stenosis (ICAS). @*Methods@#Fifty-two of 409 patients who participated in the TOSS-2 (Trial of Cilostazol in Symptomatic Intracranial Stenosis-2) showed progression of symptomatic ICAS in magnetic resonance angiography at 7 months after an index stroke. We randomly selected 20 patients with progression as well as 40 age- and sex-matched control patients. We serially collected blood samples at baseline, 1 month, and 7 months after an index stroke. Multiplex analysis of biomarkers was then performed. @*Results@#Demographic features and risk factors such as hypertension, diabetes, and smoking history were comparable between the two groups. Univariate analyses revealed that the levels of platelet-derived growth factor (PDGF)-AA [median (interquartile range)=1.64 (0.76–4.57) vs. 0.77 (0.51–1.71) ng/mL], PDGF-AB/BB [10.31 (2.60–25.90) vs. 2.35 (0.74–6.70) ng/mL], and myeloperoxidase [10.5 (7.5–22.3) vs. 7.8 (5.5–12.2) ng/mL] at 7 months were higher in the progression group. In the multivariate analysis using logistic regression, the PDGF AB/BB level at 7 months was independently associated with the progression of ICAS (p=0.02). @*Conclusions@#The PDGF-AB/BB level is associated with the progression of ICAS, and so may play a significant role in the progression of human ICAS.

Estimation of Acute Infarct Volume with Reference Maps: A Simple Visual Tool for Decision Making in Thrombectomy Cases / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Thrombectomy within 24 hours can improve outcomes in selected patients with a clinical-infarct mismatch. We devised an easy-to-use visual estimation tool that allows infarct volume estimation in centers with limited resources. METHODS: We identified 1,031 patients with cardioembolic or large-artery atherosclerosis infarction on diffusion-weighted images (DWIs) obtained before recanalization therapy and within 24 hours of onset, and occlusion of the internal carotid or middle cerebral artery. Acute DWIs were mapped onto a standard template and used to create visual reference maps with known lesion volumes, which were then used in a validation study (with 130 cases) against software estimates of infarct volume. RESULTS: The DWI reference map chart comprises 144 maps corresponding to 12 different infarct volumes (0.5, 1, 2, 3, 5, 7, 9, 11, 13, 15, 17, and 19 mL) in each of 12 template slices (Montreal Neurological Institute z-axis –15 to 51 mm). Infarct volume in a patient is estimated by selecting a slice with a similar infarct size at the corresponding z-axis level on the reference maps and then adding up over all slices. The method yielded good correlations to software volumetrics and was easily learned by both experienced and junior physicians, with approximately 1 to 2 minutes spent per case. The sensitivity, specificity, and accuracy for detecting threshold infarct volumes ( 90%). CONCLUSIONS: We developed easy-to-use reference maps that allow prompt and reliable visual estimation of infarct volumes for triaging patients to thrombectomy in acute stroke.

Present and Future of Neurologist: Do We Have Enough Neurologists?

Korea is one of the fastest aging country in the world. As the old population increases, incidence of stroke would rapidly increase. We estimated future of the neurologist supply in Korea, and assessed whether the present neurologist supply is appropriate to cope with future increase of stroke. We reviewed the resource database of neurologists affiliated to Korean Neurological Association. Age, sex, location of workplace, and work positions were identified. The stroke incidence was calculated from age group specific incidence data and projected age group number. Age group specific incidence data was adapted from the 2006 report of the Construction of National Surveillance System for Cardiovascular and Cerebrovascular Disease. Total 1,828 neurologists in practice were identified. Six hundred and fifty-five (30%) worked in training hospitals. 457 (21%) in other general hospitals, 305 (14%) in private clinics, and 148 (7%) worked in nursing hospitals. Assuming that the neurologists are trained 82 people per year as in the present, 2,073 neurologists would be present in 2020, 2,659 in 2030. However, stroke incidence would show more rapid increment, and is expected about 170,000 per year in 2020 and 300,000 per year in 2030. Therefore, there will be a shortage of neurologists needed for stroke care in the future. Because of rapid increase in the elderly population, current supply of neurologists may not meet the expected need for stroke care. Therefore, national health system needs more neurologists to cope with that situation.

Numerical Considerations of the Neurologist in Korea for Appropriate Management of Dementia

As the number of dementia patients increases due to rapid aging, the burden of dementia becomes a big social problem. In response to this, various policies have been introduced in Korea. In particular, as the new policy of national responsibility for dementia care has been implemented in 2017, detailed plans for improving health care and long-term care support for dementia patients and their caregivers have been introduced. The most important thing in carrying out the comprehensive government plan will be securing sufficient the professional health and social care workforce. However, the number of neurologists to play an important role in the management of dementia will be more and more insufficient. Therefore, the need to supply an adequate number of neurologists in Korea should be discussed.

Adipokines, Superoxide Dismutases and Progression of Symptomatic Intracranial Atherosclerotic Stenosis

OBJECTIVE: We aimed to investigate the relationship between adipokines and antioxidation enzyme and the risk of progression of symptomatic intracranial atherosclerotic stenosis (ICAS). METHODS: Of 409 patients who participated in the TOSS-2 (trial of cilostazol in symptomatic intracranial stenosis-2) study, 52 patients showed progression of symptomatic ICAS on magnetic resonance angiography at seven months after an index stroke. We randomly selected 20 patients with progression and 20 age- and sex-matched control patients. We serially collected blood sample initially, one month, and seven months after an index stroke. Then, multiplex analysis of biomarkers was performed for adiponectin, resistin, leptin, and superoxide dismutase-1, 2, 3. RESULTS: Demographic features and risk factors such as hypertension, diabetes, and smoking history were comparable between the two groups. Control group showed higher adiponectin levels at 7 months than progression group (P=0.05) and a significant in-creasing trend (P for trend=0.01). Resistin, leptin, and superoxide dismutase-1, 2, 3 levels were not different between the progression and control group initially, one month, and seven months after an index stroke. CONCLUSION: Increase of adiponectin level showed protective effect in the progression of ICAS. Resistin, leptin, and superoxide dismutase-1, 2, 3 levels are not different between the groups. Further large numbers of patients with longer follow-up studies are needed.

Probable Isolated Hypertensive Brainstem Encephalopathy Combined with Intracerebral Hemorrhage: a Case Report

Hypertensive encephalopathy and basal ganglia intracerebral hemorrhage (ICH) are a medical emergency caused by a sudden elevation of systemic blood pressure. Although the relationship between hypertensive encephalopathy and large ICH has not been clarified yet, Cushing reflex in acute elevations of ICP due to large ICH may induce or aggravate hypertensive encephalopathy. We report a rare case of isolated hypertensive brainstem encephalopathy combined with hypertensive ICH.

Complementarity between 18F-FDG PET/CT and Ultrasonography or Angiography in Carotid Plaque Characterization

BACKGROUND AND PURPOSE: To estimate clinical roles of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) versus angiography and ultrasonography in carotid plaque characterization. METHODS: We characterized two groups of patients with recently (<1 month) symptomatic (n=14; age=71.8+/-8.6 years, mean+/-SD) or chronic (n=13, age=68.9+/-9.0 years) carotid stenosis using a battery of imaging tests: diffusion magnetic resonance (MR) imaging, MR or transfemoral angiography, duplex ultrasonography (DUS), and carotid FDG-PET/computed tomography. RESULTS: The degree of angiographic stenosis was greater in patients with recently symptomatic carotid plaques (67.5+/-21.5%) than in patients with chronic carotid plaques (32.4+/-26.8%, p=0.001). Despite the significant difference in the degree of stenosis, lesional maximum standardized uptake values (maxSUVs) on the carotid FDG-PET did not differ between the recently symptomatic (1.56+/-0.53) and chronic (1.56+/-0.34, p=0.65) stenosis groups. However, lesional-to-contralesional maxSUV ratios were higher in the recently symptomatic stenosis group (113+/-17%) than in the chronic stenosis group (98+/-10%, p=0.017). The grayscale median value of the lesional DUS echodensities was lower in the recently symptomatic stenosis group (28.2+/-10.0, n=9) than in the chronic stenosis group (53.9+/-14.0, n=8; p=0.001). Overall, there were no significant correlations between angiographic stenosis, DUS echodensity, and FDG-PET maxSUV. Case/subgroup analyses suggested complementarity between imaging modalities. CONCLUSIONS: There were both correspondences and discrepancies between the carotid FDG-PET images and DUS or angiography data. Further studies are required to determine whether FDG-PET could improve the clinical management of carotid stenosis.

Comparison of Electroencephalography and Diffusion-Weighted MR Findings in Transient Global Amnesia Patients

BACKGROUND: The etiology of transient global amnesia (TGA) is uncertain. Recent studies have demonstrated a high signal intensity on diffusion MRI in TGA patients. In this study we reviewed and compared the use of electroencephalography (EEG) and diffusion-weighted imaging (DWI) in TGA in order to determine their sensitivity and to reveal clues about the etiology of this condition. METHODS: Twenty patients (7 males and 13 females; aged 58.0+/-12.1 years, mean+/-SD) who had been diagnosed with TGA at Dongguk University International Hospital within a 2-year period (2007 and 2008) were included in the study. All patients underwent EEG and DWI. RESULTS: The EEG of 12 of the 20 patients (60.0%) exhibited abnormalities; all 12 exhibited slowing on either the left side (n=6) or bilaterally (n=6). Spikes or sharp waves were detected in two patients. DWI revealed unilateral high signal intensities in the hippocampus of eight patients; five of these patients had left hippocampal lesions, and the other three had right hippocampal lesions. Four patients with a unilateral DWI lesion exhibited bilateral EEG abnormalities, and six patients exhibited only EEG abnormalities (without DWI abnormalities). Three patients had a high-signal-intensity lesion on DWI without EEG abnormalities. Five patients had normal EEG and DWI results. Interestingly, no patient had EEG abnormalities confined to the right temporal area. CONCLUSIONS: These findings suggest that left temporal dysfunction is important for the development of TGA. EEG might be complementary to DWI in TGA investigations, and may be superior at illustrating the associated memory dysfunction.

Wernicke's Encephalopathy and Peripheral Polyneuropathy Developed during Long Term Metronidazole Therapy in a Patient with a Brain Abscess: A Case Report

Metronidazole can induce serious neurologic problems including peripheral neuropathy, seizures, and encephalopathy. We examined a patient with acute Wernicke's encephalopathy and peripheral polyneuropathy that had developed after prolonged metronidazole therapy without a history of chronic alcoholism or poor nutritional intake. The 68-year-old man had been hospitalized for a brain abscess and was treated for 10 weeks with metronidazole (2 grams per day). This patient, who showed symptoms of numbness and tingling in the legs, was referred for electromyography (EMG) and was diagnosed with peripheral polyneuropathy. A few days later, he developed sudden ataxia, dizziness, and diplopia. The neurologic examination revealed nystagmus and ophthalmoplegia, and the FLAIR brain MRI showed symmetrical high signal intensity lesions in the cerebellar dentate nucleus, midbrain, tegmentum around the periaqueductal gray matter, and tectum. After administering intravenous thiamine and stopping the metronidazole therapy, he recovered from the ophthalmoplegia and ataxia. Brain MR showed complete recovery within 3 weeks; however the EMG remained abnormal for a further 6 months, although the symptoms were almost completely resolved by this time.

High Levels of Remnant Lipoprotein Cholesterol Is a Risk Factor for Large Artery Atherosclerotic Stroke

BACKGROUND AND PURPOSE: Remnant lipoproteins (RLPs) are products of partially catabolized chylomicrons and very-low-density lipoprotein, from which some triglycerides have been removed. These particles are smaller and denser than the parent particles and are believed to be strongly atherogenic. We explored the association between RLP cholesterol (RLP-C) and ischemic stroke, including stroke subtypes. METHODS: A cohort of 142 ischemic stroke patients (90 men and 52 women; age, 65.2+/-12.8 years, mean+/-SD) was enrolled; all had acute infarcts confirmed by diffusion-weighted MRI, and had fasting lipograms. A full stroke-related evaluation was conducted on each patient. An outpatient population of 88 subjects without a history of cerebrovascular or cardiovascular disease served as a control group. Serum RLP fractions were isolated using an immunoaffinity gel containing specific antiapolipoprotein (anti-apo)B-100 and anti-apoA-I antibodies. RLP-C values were considered to be high when they were in the highest quartile of all values in the study. RESULTS: High RLP-C values were more common in stroke patients than in control patients (31.0% vs. 14.8%, p=0.01), when 5.6 mg/dL (>75th percentile) was used as the cutoff value. Multivariable analyses indicated that RLP-C was a risk factor for stroke, with an odds ratio of 2.54 (p=0.045). The RLP-C level was higher in the large artery atherosclerosis subgroup (5.7+/-3.9 mg/dL) than in any other stroke subgroup (small vessel occlusion, 4.9+/-5.9 mg/dL; cardioembolism, 1.8+/-2.3 mg/dL; stroke of undetermined etiology, 3.1+/-2.9 mg/dL). CONCLUSIONS: We have found an association between high RLP-C levels and ischemic stroke, and in particular large artery atherosclerotic stroke.

Occipital Neuralgia as the Only Presenting Symptom of Foramen Magnum Meningioma

BACKGROUND: Occipital neuralgia (ON) is a condition characterized by a paroxysmal stabbing pain in the area of the greater or lesser occipital nerves; it is usually regarded by clinicians as idiopathic. Some have suggested that ON can be induced by trauma or injury of the occipital nerves or their roots, but tumor has rarely been reported as a cause of ON. CASE REPORT: We report herein a case of foramen magnum meningioma in a 55-year-old woman who presented with ON triggered by head motion as the only symptom without any signs of myelopathy. CONCLUSIONS: This case indicates that it is important to consider the underlying causes of ON. Precise neurologic and radiological evaluations such as cervical spine magnetic resonance imaging are needed.

Molecular Imaging of Atherosclerosis

Atherosclerosis is characterized by progressive accumulation of lipids and inflammatory cells within the artery wall. It is a diffuse systemic disease; however, some atherosclerotic plaques are more prone to rupture causing sudden thromboembolic vascular occlusions, while others are clinically silent. Therefore, to prevent such devastating vascular events as stroke or myocardial infarction, clinicians need to have smart tools to localize high-risk vulnerable plaques, which have been a huge challenge to date. Molecular imaging, which visualizes biologic processes at the cellular and molecular level, has a potential to assess plaque vulnerability and consequently identify high-risk patients prior to the development of the clinical events. In this review, we summarize important updates on the molecular imaging of atherosclerosis in the field of optical imaging, magnetic resonance imaging, positron emission tomography, and computerized tomography imaging.

Molecular Imaging of Atherosclerosis

Atherosclerosis is characterized by progressive accumulation of lipids and inflammatory cells within the artery wall. It is a diffuse systemic disease; however, some atherosclerotic plaques are more prone to rupture causing sudden thromboembolic vascular occlusions, while others are clinically silent. Therefore, to prevent such devastating vascular events as stroke or myocardial infarction, clinicians need to have smart tools to localize high-risk vulnerable plaques, which have been a huge challenge to date. Molecular imaging, which visualizes biologic processes at the cellular and molecular level, has a potential to assess plaque vulnerability and consequently identify high-risk patients prior to the development of the clinical events. In this review, we summarize important updates on the molecular imaging of atherosclerosis in the field of optical imaging, magnetic resonance imaging, positron emission tomography, and computerized tomography imaging.

Hypoglycemic Encephalopathy With Delayed Lesion on Magnetic Resonance Imaging

We report on delayed emergence of restricted diffusion on MRI after hypoglycemia. A 56-year-old man with type 2 diabetes was admitted with mental change. Initial serum glucose was 19 mg/dl. Fifteen hours after presumed symptom onset, brain imaging did not show any definite abnormality. However, areas of restricted diffusion emerged evident in both basal ganglia 9 days later. Hypoglycemia can cause delayed cytotoxic edema even after normalization of the serum glucose.

A Case of Ischemic Stroke Associated with Phendimetrazine as an Appetite Suppressant

The published case series have suggested that appetite suppressants had some association with the development of stroke. Phendimetrazine is an appetite suppressant with sympathomimetic activity and it has a similar chemical structure with amphetamines. We report that a 22-year-old woman who had taken phendimetrazine for one month developed sudden right homonymous hemianopsia. MRI showed acute infarction in the territory of left posterior cerebral artery (PCA). Phendimetrazine should be considered as a cause of ischemic stroke.

Endogenous Neural Stem Cell Proliferation after Intracerebral Hemorrhage in Rat Model

BACKGROUND: Focal and global ischemia was shown to be potent in inducing neurogenesis in the subventricular zone (SVZ). However, it is unknown whether these new neurons can replace those lost following damage, such as intracerebral hemorrhage (ICH). We tested the hypothesis that ICH leads to an increase of cell proliferation in the SVZ and that the new neurons migrate into the damaged area of the hemorrhagic striatum. METHODS: Experimental ICH was induced by an intrastriatal administration of collagenase in adult rats. Proliferating cells were labeled with intraperitoneal injections of 5-bromo-2'-deoxyuridine-5'-monophosphate (BrdU) over 3-day periods before sacrificing the animals, 0, 6, 9, 12 or 15 days after ICH. BrdU+ cells in the dorsolateral SVZ and the striatum were counted in three coronal sections per animal. RESULTS: BrdU+ cells were found in the bilateral SVZs, the third ventricle, and ipsilateral cortex near the needle insertion site. The number of BrdU+ cells in the damaged striatum and the ipsilateral SVZ reached maximum counts 9 days after ICH. The BrdU+ cells were double-labeled with a neuronal marker, neuronal nuclear antigen (NeuN), and a glial marker, the glial fibrillary acidic protein (GFAP), in the hemorrhagic hemisphere. The percentage of BrdU+ cells that expressed NeuN and GFAP was about 13% and about 72%, respectively. CONCLUSIONS: These results suggest new evidence that endogenous neural stem cells are activated in the dorsolateral SVZ after ICH, and that the newly formed cells play a role for ICH-induced neurogenesis in what may be an adaptive process that contributes to recovery after a hemorrhagic stroke.