Cerebrospinal Fluid Refill Test as a Novel Diagnostic Tool for Cerebrospinal Fluid Hypovolemia: Preliminary Result.

OBJECTIVE: Cerebrospinal fluid (CSF) hypovolemia presents with orthostatic headaches due to CSF leakage. However, a direct association between the lack of CSF and clinical symptoms has not been found. CSF hypovolemia can be improved by refilling CSF. Therefore, we assessed the validity of a CSF refill test. METHODS: From November 2019 to August 2021, we included 10 patients (≥18 years old) with potential CSF hypovolemia, clear orthostatic headaches, and a CSF opening pressure <10 cmH2O. In the CSF refill test, 10 mL of artificial CSF was injected intrathecally. The primary outcome was improvement in orthostatic headache assessed using a visual analog scale (VAS), while the secondary outcomes were the 10-m walk time and adverse events. When the symptoms temporarily improved after intrathecal injection, the patients underwent radiologic imaging to identify the CSF leak, and an epidural blood patch was proposed accordingly. RESULTS: All patients showed post-test improvements in the VAS score (median [interquartile range], pretest 63.0 [50.3-74.3] vs. post-test 1.5 [0.0-26.0]). The 10-m walk time also significantly improved (9.5 [8.5-10.2] s vs. 8.2 [7.9-8.7] s). One patient experienced temporary right leg numbness associated with a lumbar puncture. After radiologic investigation, 9 patients underwent epidural blood patches, of which 6 were completely cured, and 3 revealed partial improvement. CONCLUSIONS: The cerebrospinal fluid (CSF) refill test was safe and effective in demonstrating the direct association between the lack of CSF and clinical symptoms and may help predict the outcome of an epidural blood patch.

Impact of areal socioeconomic status on prehospital delay of acute ischaemic stroke: retrospective cohort study from a prefecture-wide survey in Japan.

OBJECTIVES: To examine whether the Areal Deprivation Index (ADI), an indicator of the socioeconomic status of the community the patient resides in, is associated with delayed arrival at the hospital and poor outcomes in patients with acute ischaemic stroke from a prefecture-wide stroke database in Japan. DESIGN: Retrospective study. SETTING: Twenty-nine acute stroke hospitals in Kochi prefecture, Japan. PARTICIPANTS: Nine thousand and six hundred fifty-one patients with acute ischaemic stroke who were urgently hospitalised, identified using the Kochi Acute Stroke Survey of Onset registry. Capital and non-capital areas were analysed separately. PRIMARY AND SECONDARY OUTCOME MEASURES: Prehospital delay defined as hospital arrival ≥4-hour after stroke onset, poor hospital outcomes (in-hospital mortality and discharge to a nursing facility) and the opportunities of intravenous recombinant tissue plasminogen activator (rt-PA) and endovascular reperfusion therapy. RESULTS: In the overall cohort, prehospital delay was observed in 6373 (66%) patients. Among individuals residing in non-capital areas, those living in municipalities with higher ADI (more deprived) carried a significantly higher risk of prehospital delay (per one-point increase, OR (95% CI) 1.45 (1.26 to 1.66)) by multivariable logistic regression analysis. In-hospital mortality (1.45 (1.02 to 2.06)), discharge to a nursing facility (1.31 (1.03 to 1.66)), and delayed candidate arrival ≥2-hour of intravenous rt-PA (2.04 (1.30 to 3.26)) and endovascular reperfusion therapy (2.27 (1.06 to 5.00)), were more likely to be observed in the deprived areas with higher ADI. In the capital areas, postal-code-ADI was not associated with prehospital delay (0.97 (0.66 to 1.41)). CONCLUSIONS: Living in socioeconomically disadvantaged municipalities was associated with prehospital delays of acute ischaemic stroke in non-capital areas in Kochi prefecture, Japan. Poorer outcomes of those patients may be caused by delayed treatment of intravenous rt-PA and endovascular reperfusion therapy. Further studies are necessary to determine social risk factors in the capital areas. TRIAL REGISTRATION NUMBER: This article is linked to a clinical trial to UMIN000050189, No.: R000057166 and relates to its Result stage.

The Cervical Spine as a Predominant Site of Cerebrospinal Fluid Leak: Preliminary Results Using the Overflow Leak Test.

BACKGROUND: Cerebrospinal fluid (CSF) hypovolemia is usually treated via an epidural blood patch (EBP). Accurate placement of the EBP at the site of CSF leakage is required for successful treatment of CSF hypovolemia. The thoracolumbar spine is evidently a common site of leakage, but because rates of detection of the leakage site via conventional imaging have historically not been high, there may be other common leakage sites. In this study, CSF leakage sites were identified via a combination of conventional imaging, a new method called the overflow leak test, and patient interviews. METHODS: CSF leakage sites were identified using computed tomography myelography, radioisotope cisternography, and the overflow leak test in 14 patients with CSF hypovolemia. The patients were also asked about their history with regard to potential trauma. EBP was performed, and the accuracy of leakage site identification was assessed. RESULTS: Conventional imaging identified a leakage site in 7 of 14 patients, and in most cases it was in the lumbar spine. In the remaining 7 cases, the overflow leak test and ascertaining a history of trauma facilitated identification of the cervical spine as a leakage site. The site of the EBP was the cervical spine in 10 patients and the lumbar spine in 4 patients. Complete recovery was observed in 13 of 14 patients. CONCLUSIONS: The cervical spine was a common leakage site in this study. Leakage in the cervical spine was undetectable via conventional imaging, suggesting that many cases of cervical spine leakage may remain undetected.

[Preliminary Experience of a Biplane Flat Panel and Tailor-made Operating Table-equipped Hybrid Operating Room].

A hybrid operating room(Hybrid OR), where operative equipment and flat panel angiography are both available, is becoming common for complex cerebrovascular surgery. However, the current Hybrid OR remains suboptimal as it is not cost-effective and contains uncomfortable operating beds, and a single-plane flat panel. Therefore, we introduced a novel Hybrid OR system, which has a biplane flat panel detector and three mutually exchangeable tailor-made operating beds. In this article, we report our preliminary experience of this novel Hybrid OR, focusing on improved cost-effectiveness by the availability of diagnostic angiography and standard endovascular surgery, optimal selection of three different types of operating beds, and procedural workflow in individual hybrid cerebrovascular surgery.

Impact of temperature decline from the previous day as a trigger of spontaneous subarachnoid hemorrhage: case-crossover study of prefectural stroke database.

OBJECTIVE: Several environmental factors have been reported to correlate with incidence of spontaneous subarachnoid hemorrhage (SAH). However, because of different patient selection and study designs among these studies, meteorological factors that trigger the incidence of SAH in a short hazard period remain unknown. Among meteorological factors, daily temperature changes may disrupt and violate homeostasis and predispose to cerebrovascular circulatory disturbances and strokes. The authors aimed to investigate whether a decline in the temperature from the highest of the previous day to the lowest of the event day (temperature decline from the previous day [TDP]) triggers SAH in the prefecture-wide stroke database. METHODS: All 28 participating institutions with primary or comprehensive stroke centers located throughout Kochi Prefecture, Japan, were included in the study. Data collected between January 2012 and December 2016 were analyzed, and 715 consecutive SAH patients with a defined date of onset were enrolled. Meteorological data in this period were obtained from the Kochi Local Meteorological Observatory. A case-crossover study was performed to investigate association of TDP and other environmental factors with onset of SAH. RESULTS: The increasing TDP in 1°C on the day of the SAH event was associated with an increased incidence of SAH (OR 1.041, 95% CI 1.007-1.077) after adjustment for other environmental factors. According to the stratified analysis, a significant association between TDP and SAH was observed in women, patients < 65 years old, and patients with weekday onset. Among these factors, increasing TDP had a great impact on SAH onset in patients < 65 years old (p = 0.028, Mann-Whitney U-test). CONCLUSIONS: TDP, temperature decline from the highest of the previous day to the lowest of the day, was correlated with the incidence of spontaneous SAH, particularly in younger patients < 65 years old.

Secondary central nervous system lymphoma surrounding a region injured by subarachnoid hemorrhage and subsequent aneurysmal clipping.

The present case study describes a rare case of secondary central nervous system (CNS) lymphoma that infiltrated the dura and leptomeninges around the area injured by subarachnoid hemorrhage and subsequent aneurysmal clipping. Invasion of the CNS was observed by computed tomography as slurred fissures of the right parietal lobe adjacent to the surgery area. Subdural and subarachnoid enhancement overlapping the area injured by past surgical procedures was observed by contrast-enhanced magnetic resonance imaging. Surgical resection revealed B-cell lymphoma infiltrating the dura and leptomeninges surrounding the post-hemorrhagic area. The patient was subsequently diagnosed with systemic lymphoma and bone marrow invasion, and multiple lymph node swelling. To the best of our knowledge, this is the first report of malignant lymphoma involving the CNS overlapping a previously injured area.

The neuroprotective and neurorescue effects of carbamylated erythropoietin Fc fusion protein (CEPO-Fc) in a rat model of Parkinson's disease.

Parkinson's disease is characterized by progressive degeneration of dopaminergic neurons. Thus the development of therapeutic neuroprotection and neurorescue strategies to mitigate disease progression is important. In this study we evaluated the neuroprotective/rescue effects of erythropoietin Fc fusion protein (EPO-Fc) and carbamylated erythropoietin Fc fusion protein (CEPO-Fc) in a rat model of Parkinson's disease. Adult female Sprague-Dawley rats received intraperitoneal injection of EPO-Fc, CEPO-Fc or PBS. Behavioral evaluations consisted of rota-rod, cylinder and amphetamine-induced rotation tests. In the neuroprotection experiment, the CEPO-Fc group demonstrated significant improvement compared with the EPO-Fc group on the amphetamine-induced rotation test throughout the four-week follow-up period. Histologically, significantly more tyrosine hydroxylase (TH)-positive neurons were recognized in the substantia nigra (SN) pars compacta in the CEPO-Fc group than in the PBS and EPO-Fc groups. In the neurorescue experiment, rats receiving CEPO-Fc showed significantly better behavioural scores than those receiving PBS. The histological data concerning striatum also showed that the CEPO-Fc group had significantly better preservation of TH-positive fibers compared to the PBS and EPO-Fc groups. Importantly, there were no increases in hematocrit or hemoglobin levels in the CEPO-Fc group in either the neuroprotection or the neurorescue experiments. In conclusion, the newly developed CEPO-Fc might confer neuroprotective and neurorescue benefits in a rat model of Parkinson's disease without the side effects associated with polycythemia. CEPO-Fc might be a therapeutic tool for patients with Parkinson's disease.

Urinary 8-OHdG elevations in a partial lesion rat model of Parkinson's disease correlate with behavioral symptoms and nigrostriatal dopaminergic depletion.

Increased oxidative stress contributes to pathogenesis of Parkinson's disease (PD). 8-hydroxy-2'-deoxyguanosine (8-OHdG) is the oxidation product most frequently measured as an indicator of oxidative DNA damage. Several studies have shown increased 8-OHdG in PD patients. There are few basic laboratory data examining 8-OHdG levels in animal models of PD. In this study, we utilized hemiparkinsonian model of rats induced by intrastriatal injection of 6-hydroxydopamine (6-OHDA). The urinary 8-OHdG level was measured in relation to behavioral and pathological deficits arising from 6-OHDA-induced neurotoxic effects on the nigrostriatal dopaminergic pathway. All rats were subjected to a series of behavioral tests for 42 days after 6-OHDA injection. We collected urine samples with subsequent measurement of 8-OHdG level using ELISA kits. For immunohistochemical evaluation, tyrosine hydroxylase (TH) staining was performed. Significant increments in urinary 8-OHdG level were observed continuously from day 7 until day 35 compared to control group, which showed a trend of elevation as early as day 3. Such elevated urinary 8-OHdG level significantly correlated with all of the behavioral deficits measured here, suggesting that urinary 8-OHdG level provides a good index of severity of parkinsonism. Urinary 8-OHdG level also had a significant positive correlation with the survival rate of dopaminergic fibers or neurons, advancing the concept that oxidative stress during the early phase of 6-OHDA neurotoxicity may correspond to disease progression closely approximating neuronal degeneration in the nigrostriatal dopaminergic system. The present results demonstrate that alterations in urinary 8-OHdG level closely approximate onset and disease progression in PD.

Striatal stimulation nurtures endogenous neurogenesis and angiogenesis in chronic-phase ischemic stroke rats.

Deep brain stimulation (DBS) is used to treat a variety of neurological disorders including Parkinson's disease. In this study, we explored the effects of striatal stimulation (SS) in a rat model of chronic-phase ischemic stroke. The stimulation electrode was implanted into the ischemic penumbra at 1 month after middle cerebral artery occlusion (MCAO) and thereafter continuously delivered SS over a period of 1 week. Rats were evaluated behaviorally coupled with neuroradiological assessment of the infarct volumes using magnetic resonance imaging (MRI) at pre- and post-SS. The rats with SS showed significant behavioral recovery in the spontaneous activity and limb placement test compared to those without SS. MRI visualized that SS also significantly reduced the infarct volumes compared to that at pre-SS or without SS. Immunohistochemical analyses revealed a robust neurogenic response in rats that received SS characterized by a stream of proliferating cells from the subventricular zone migrating to and subsequently differentiating into neurons in the ischemic penumbra, which exhibited a significant GDNF upregulation. In tandem with this SS-mediated neurogenesis, enhanced angiogenesis was also recognized as revealed by a significant increase in VEGF levels in the penumbra. These results provide evidence that SS affords neurorestoration at the chronic phase of stroke by stimulating endogenous neurogenesis and angiogenesis.

Intravenous administration of mesenchymal stem cells exerts therapeutic effects on parkinsonian model of rats: focusing on neuroprotective effects of stromal cell-derived factor-1alpha.

BACKGROUND: Mesenchymal stem cells (MSCs) are pluripotent stem cells derived from bone marrow with secretory functions of various neurotrophic factors. Stromal cell-derived factor-1alpha (SDF-1alpha) is also reported as one of chemokines released from MSCs. In this research, the therapeutic effects of MSCs through SDF-1alpha were explored. 6-hydroxydopamine (6-OHDA, 20 microg) was injected into the right striatum of female SD rats with subsequent administration of GFP-labeled MSCs, fibroblasts, (i.v., 1 x 107 cells, respectively) or PBS at 2 hours after 6-OHDA injection. All rats were evaluated behaviorally with cylinder test and amphetamine-induced rotation test for 1 month with consequent euthanasia for immunohistochemical evaluations. Additionally, to explore the underlying mechanisms, neuroprotective effects of SDF-1alpha were explored using 6-OHDA-exposed PC12 cells by using dopamine (DA) assay and TdT-mediated dUTP-biotin nick-end labeling (TUNEL) staining. RESULTS: Rats receiving MSC transplantation significantly ameliorated behaviorally both in cylinder test and amphetamine-induced rotation test compared with the control groups. Correspondingly, rats with MSCs displayed significant preservation in the density of tyrosine hydroxylase (TH)-positive fibers in the striatum and the number of TH-positive neurons in the substantia nigra pars compacta (SNc) compared to that of control rats. In the in vitro study, SDF-1alpha treatment increased DA release and suppressed cell death induced by 6-OHDA administration compared with the control groups. CONCLUSIONS: Consequently, MSC transplantation might exert neuroprotection on 6-OHDA-exposed dopaminergic neurons at least partly through anti-apoptotic effects of SDF-1alpha. The results demonstrate the potentials of intravenous MSC administration for clinical applications, although further explorations are required.

Exercise exerts neuroprotective effects on Parkinson's disease model of rats.

Recent studies demonstrate that rehabilitation ameliorates physical and cognitive impairments of patients with stroke, spinal cord injury, and other neurological diseases and that rehabilitation also has potencies to modulate brain plasticity. Here we examined the effects of compulsive exercise on Parkinson's disease model of rats. Before 6-hydroxydopamine (6-OHDA, 20 microg) lesion into the right striatum of female SD rats, bromodeoxyuridine (BrdU) was injected to label the proliferating cells. Subsequently, at 24 h after the lesion, the rats were forced to run on the treadmill (5 days/week, 30 min/day, 11 m/min). As behavioral evaluations, cylinder test was performed at 1, 2, 3, and 4 weeks and amphetamine-induced rotational test was performed at 2 and 4 weeks with consequent euthanasia for immunohistochemical investigations. The exercise group showed better behavioral recovery in cylinder test and significant decrease in the number of amphetamine-induced rotations, compared to the non-exercise group. Correspondingly, significant preservation of tyrosine hydroxylase (TH)-positive fibers in the striatum and TH-positive neurons in the substantia nigra pars compacta (SNc) was demonstrated, compared to the non-exercise group. Additionally, the number of migrated BrdU- and Doublecortin-positive cells toward the lesioned striatum was increased in the exercise group. Furthermore, brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor increased in the striatum by exercise. The results suggest that exercise exerts neuroprotective effects or enhances the neuronal differentiation in Parkinson's disease model of rats with subsequent improvement in deteriorated motor function.

Continuous intraventricular infusion of erythropoietin exerts neuroprotective/rescue effects upon Parkinson's disease model of rats with enhanced neurogenesis.

Parkinson's disease (PD) is characterized by degeneration of nigrostriatal dopaminergic neuronal systems. Several therapeutic tools for PD include medication using L-DOPA and surgeries such as deep brain stimulation are established. However, the therapies are considered as symptomatic therapy, but not basic remedy for PD and a new regenerative therapy would be desired to explore. In this study, the neuroprotective/rescue effects of erythropoietin (EPO), a well known hematopoietic hormone, on dopaminergic neurons were explored with neurogeneic potencies of EPO. EPO (100 IU/day) was continuously administered with micro-osmotic pump for a week to PD model of rats induced by intrastriatal 6-hydroxydopamine (6-OHDA) injection with subsequent behavioral and immunohistochemical investigations. The number of amphetamine-induced rotations of EPO-treated rats significantly decreased, compared to the control rats. The preservation of dopaminergic neurons of EPO-treated rats were confirmed by tyrosine hydroxylase staining and Fluoro-Gold staining. The number of bromodeoxyuridine (BrdU)/polysialic acid-neural cell adhesion molecule (PSA-NCAM) double positive cells in the subventricular zone of EPO treated rats significantly increased with migratory potencies to the damaged striatum,compared to the control rats. Furthermore, TUNEL staining and phosphorylated Akt staining revealed that the neuroprotective/rescue effects of EPO might be mediated by anti-apoptotic effects through the increase of phosphorylated Akt. These results suggest that continuous low dose infusion of EPO exerts neuroprotective/rescue effects with neurogeneic potentials. EPO might be a strong tool for PD therapy, although the further experiments should be added.

[High b-value diffusion-weighted imaging of acute brain infarction].

High b-value diffusion-weighted (DW) imaging obtained with a b-value of 2,000 s/mm2 offers theoretical advantages over DW imaging obtained with a b-value of 1,000 s/mm2 for detection of acute brain infarction. The purpose of this study was to determine whether high b-value DW images (b=2,000) are better than b=1,000 images for detection of diffusion change in patients with acute brain infarction. We compared diffusion-weighted (DW) images obtained with a b-value of 1,000 s/mm2 with those obtained with a b-value of 2,000 s/mm2 in 84 patients with small lesions (brain stem infarction, lacuna infarction) examined within 24 hours of clinical onset. Qualitative analysis was performed concerning lesion conspicuity. In quantitative analysis, contrast ratios (CR) were measured and findings of b=1,000 and b=2,000 images were compared. False-negative rate of b=1,000 and b=2,000 images were 23.8% and 3.6%, respectively, relative to the presense or absense of infarction on the follow-up MR or CT images. On qualitative analysis, lesions were more conspicuous on b=2,000 images. On quantitative analysis, as the b-value increased, mean CR increased. DW images aquired with a b-value of 2,000 s/mm2 were better than DW images aquired with a b-value of 1,000 s/mm2 for detection of diffusion change in patients with acute brain infarction.