Association of Bypass Surgery and Mortality in Moyamoya Disease.

Background Patients with moyamoya disease (MMD) have a high risk of stroke or death. We investigated whether extracranial to intracranial bypass surgery can reduce mortality by preventing strokes in patients with MMD. Methods and Results This nationwide retrospective cohort study encompassed patients with MMD registered under the Rare Intractable Diseases program via the Relieved Co-Payment Policy between 2006 and 2019, using the Korean National Health Insurance Service database. Following a 4-year washout period, landmark analyses were employed to assess mortality and stroke occurrence between the bypass surgery group and the nonsurgical control group at specific time points postindex date (1 month and 3, 6, 12, and 36 months). The study included 18 480 patients with MMD (mean age, 40.7 years; male to female ratio, 1:1.86) with a median follow-up of 5.6 years (interquartile range, 2.5-9.3; mean, 6.1 years [SD, 4.0 years]). During 111 775 person-years of follow-up, 265 patients in the bypass surgery group and 1144 patients in the nonsurgical control group died (incidence mortality rate of 618.1 events versus 1660.3 events, respectively, per 105 person-years). The overall adjusted hazard ratio (HR) revealed significantly lower all-cause mortality in the bypass surgery group from the 36-month landmark time point, for any stroke mortality from 3- and 6-month landmark time points, and for hemorrhagic stroke mortality from the 6-month landmark time point. Furthermore, the overall adjusted HRs for hemorrhagic stroke occurrence were beneficially maintained from all 5 landmark time points in the bypass surgery group. Conclusions Bypass surgery in patients with MMD was associated with a lower risk of all-cause and hemorrhagic stroke mortality and hemorrhagic stroke occurrence compared with nonsurgical control.

A simple prediction score system for malignant brain edema progression in large hemispheric infarction.

Malignant brain edema (MBE) due to hemispheric infarction can result in brain herniation, poor outcomes, and death; outcome may be improved if certain interventions, such as decompressive craniectomy, are performed early. We sought to generate a prediction score to easily identify those patients at high risk for MBE. 121 patients with large hemispheric infarction (LHI) (2011 to 2014) were included. Patients were divided into two groups: those who developed MBE and those who did not. Independent predictors of MBE were identified by logistic regression and a score was developed. Four factors were independently associated with MBE: baseline National Institutes of Health Stroke Scale (NIHSS) score (p = 0.048), Alberta Stroke Program Early Computed Tomography Score (ASPECTS) (p = 0.007), collateral score (CS) (p<0.001) and revascularization failure (p = 0.013). Points were assigned for each factor as follows: NIHSS ≤ 8 (= 0), 9-17 (= 1), ≥ 18 (= 2); ASPECTS≤ 7 (= 1), >8 (= 0); CS<2 (= 1), ≥2 (= 0); revascularization failure (= 1),success (= 0). The MBE Score (MBES) represents the sum of these individual points. Of 26 patients with a MBES of 0 to 1, none developed MBE. All patients with a MBES of 6 developed MBE. Both MBE development and functional outcomes were strongly associated with the MBES (p = 0.007 and 0.002, respectively). The MBE score is a simple reliable tool for the prediction of MBE.

Bypass surgery versus medical treatment for symptomatic moyamoya disease in adults.

OBJECTIVE In this study the authors evaluated whether extracranial-intracranial bypass surgery can prevent stroke occurrence and decrease mortality in adult patients with symptomatic moyamoya disease (MMD). METHODS The medical records of 249 consecutive adult patients with symptomatic MMD that was confirmed by digital subtraction angiography between 2002 and 2011 at 8 institutions were retrospectively reviewed. The study outcomes of stroke recurrence as a primary event and death during the 6-year follow-up and perioperative complications within 30 days as secondary events were compared between the bypass and medical treatment groups. RESULTS The bypass group comprised 158 (63.5%) patients, and the medical treatment group comprised 91 (36.5%) patients. For 249 adult patients with MMD, bypass surgery showed an HR of 0.48 (95% CI 0.27-0.86, p = 0.014) for stroke recurrence calculated by Cox regression analysis. However, for the 153 patients with ischemic MMD, the HR of bypass surgery for stroke recurrence was 1.07 (95% CI 0.43-2.66, p = 0.887). For the 96 patients with hemorrhagic MMD, the multivariable adjusted HR of bypass surgery for stroke recurrence was 0.18 (95% CI 0.06-0.49, p = 0.001). For the treatment modality, indirect bypass and direct bypass (or combined bypass) did not show any significant difference for stroke recurrence, perioperative stroke, or mortality (log rank; p = 0.524, p = 0.828, and p = 0.616, respectively). CONCLUSIONS During the treatment of symptomatic MMD in adults, bypass surgery reduces stroke recurrence for the hemorrhagic type, but it does not do so for the ischemic type. The best choice of bypass methods in adult patients with MMD is uncertain. In adult ischemic MMD, a prospective randomized study to evaluate the effectiveness and safety of bypass surgery to prevent recurrent stroke is necessary.

Thirteen-year Experience of 44 Patients with Adult Hemorrhagic Moyamoya Disease from a Single Institution: Clinical Analysis by Management Modality.

Our objective was a retrospective assessment of the management modalities that provided the most beneficial treatment in hemorrhagic moyamoya disease during the last 13 years at our institution. The clinical results of 44 patients with hemorrhagic moyamoya disease were investigated, comparing revascularization surgery (direct, indirect, and combined bypass) or conservative treatment. Angiographic features, rebleeding, and clinical outcome were investigated. Six of the 35 patients (17.1%) with revascularization surgery experienced rebleeding, as did 4 of 9 patients (44.4%) with conservative treatment. However, patients who underwent bypass surgery had a lower chance of rebleeding. No significant difference in chance of rebleeding was observed between bypass surgery and non surgery groups (p > 0.05). Cerebral angiography performed after bypass surgery showed that for achieving good postoperative revascularization, direct and combined bypass methods were much more effective (p < 0.05). While the risk of rebleeding in the revascularization group was generally lower than in the conservative treatment group, there was no statistically significant difference between treatment modalities and conservative treatment. Although statistical significance was not attained, direct and combined bypass may reduce the risk of hemorrhage more effectively than indirect bypass.

Early superficial temporal artery to middle cerebral artery bypass in acute ischemic stroke.

OBJECTIVE: To evaluate the effects and safety of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in the early stage after an acute ischemic event and the improvement of present symptoms in patients with intracranial atherosclerotic occlusive disease with stroke/stroke in progress. METHODS: From 2006 to 2010, 20 patients (15 males and five females) with atherosclerotic cerebrovascular disease were treated with an STA-MCA bypass. All of the patients presented with an acute ischemic stroke or stroke in progress despite maximal medical treatment. The patients underwent an STA-MCA bypass within 7 days from symptom onset. The clinical outcome and hemodynamic study of the 20 patients were preoperatively and postoperatively investigated. A pooled analysis was performed, and the results were compared with those obtained from other delayed STA-MCA bypass studies. RESULTS: Among the 20 patients who underwent an early STA-MCA bypass, fourteen (70%) patients achieved a good functional outcome (mRS 0, n=3; mRS 1, n=9; mRS 2, n=2). Prior to surgery, the mean basal regional cerebral blood flow (rCBF) and cerebrovascular reserve capacity (CVR) in the symptomatic hemisphere were 37.3±4.3 ml/100 g/min and -1.68±2.9%. The mean basal rCBF and CVR had significantly increased postoperatively, and no reperfusion-induced hemorrhage had occurred. In the pooled analysis, no significant differences were observed in the clinical outcome (P=0.328) or in the incidence of postoperative complications (P=0.516) between patients who underwent an early STA-MCA bypass and in patients who underwent a delayed STA-MCA bypass in previous studies. CONCLUSIONS: In this study, which consisted of 20 carefully selected patients with acute ischemic stroke, an early STA-MCA bypass was safely and effectively performed, and in some cases, an early STA-MCA bypass resulted in rapid neurological improvement. An early STA-MCA bypass was beneficial in select patients who had acute ischemic stroke with imaging evidence of a small infarction.

Surgical treatment of moyamoya disease in adults: combined direct and indirect vs. indirect bypass surgery.

Combined superficial temporal artery-middle cerebral artery anastomosis and encephalo-duro-arterio-galeo-synangiosis (EDAGS) were retrospectively compared with indirect bypass, EDAGS with or without inversion, in 134 hemispheres of 96 adult patients with non-hemorrhagic moyamoya disease (MMD) in terms of angiographic findings, perioperative complications, and clinical outcome. Angiographic revascularization seemed to be better in the combined bypass group compared with the EDAGS group (p = 0.045), but perioperative complication tended to be slightly more common in the combined bypass group. No statistical differences were found in clinical outcome. EDAGS is a very reliable alternative to combined bypass in adult MMD. However, randomized clinical trials are needed to assess the long-term efficacy of any bypass surgery in adult patients with MMD.

Long-term follow-up results in 142 adult patients with moyamoya disease according to management modality.

BACKGROUND: To clarify the most beneficial treatment of the management modality based on our experience with adult moyamoya disease (MMD). METHODS: From 1998 to 2010, clinical results of 142 patients (ischemic, 98; hemorrhagic, 44) with adult MMD were investigated according to management modality. Revascularization surgery (direct, indirect, and combined bypass) was performed in 124 patients. We observed the clinical course of 18 patients who were treated conservatively. Clinical outcome, angiographic features, hemodynamic change, and incidence of recurrent stroke were investigated pre- and postoperatively. RESULTS: In patients with ischemic MMD, direct and combined bypasses were more effective treatments to prevent recurrent ischemic stroke than indirect bypass surgery (P < 0.05). In patients with hemorrhagic MMD, rebleeding was less likely to occur in patients who had undergone bypass surgery. However, no significant difference was observed in the rebleeding rate between patients with and without revascularization surgery (P > 0.05). An angiogram after bypass surgery comparing the extent of revascularization and reduction of moyamoya vessels in patients treated with direct, indirect, and combined bypass showed a significant difference (P < 0.05) in favor of direct and combined bypass. Postoperative angiographic changes and SPECT results demonstrated significant statistical correlation (P < 0.05). CONCLUSION: Revascularization surgery was effective in further ischemic stroke prevention to a statistically significant extent. Direct and combined bypasses were more effective to prevent recurrent ischemic stroke than indirect bypass. However, there is still no clear evidence that revascularization surgery significantly prevents rebleeding in adult MMD patients. More significant angiographic changes were observed in direct and combined bypasses compared with indirect bypass.

Hybrid surgery of multilevel cervical degenerative disc disease : review of literature and clinical results.

OBJECTIVE: In the present study, we evaluated the effect, safety and radiological outcomes of cervical hybrid surgery (cervical disc prosthesis replacement at one level, and interbody fusion at the other level) on the multilevel cervical degenerative disc disease (DDD). METHODS: Fifty-one patients (mean age 46.7 years) with symptomatic multilevel cervical spondylosis were treated using hybrid surgery (HS). Clinical [neck disability index (NDI) and Visual Analogue Scale (VAS) score] and radiologic outcomes [range of motion (ROM) for cervical spine, adjacent segment and arthroplasty level] were evaluated at routine postoperative intervals of 1, 6, 12, 24 months. Review of other similar studies that examined the HS in multilevel cervical DDD was performed. RESULTS: Out of 51 patients, 41 patients received 2 level hybrid surgery and 10 patients received 3 level hybrid surgery. The NDI and VAS score were significantly decreased during the follow up periods (p<0.05). The cervical ROM was recovered at 6 and 12 month postoperatively and the mean ROM of inferior adjacent segment was significantly larger than that of superior adjacent segments after surgery. The ROM of the arthoplasty level was preserved well during the follow up periods. No surgical and device related complications were observed. CONCLUSION: Hybrid surgery is a safe and effective alternative to fusion for the management of multilevel cervical spondylosis.

Motor-evoked potential confirmation of functional improvement by transplanted bone marrow mesenchymal stem cell in the ischemic rat brain.

This study investigated the effect of bone marrow mesenchymal stem cells (BMSCs) on the motor pathway in the transient ischemic rat brain that were transplanted through the carotid artery, measuring motor-evoked potential (MEP) in the four limbs muscle and the atlantooccipital membrane, which was elicited after monopolar and bipolar transcortical stimulation. After monopolar stimulation, the latency of MEP was significantly prolonged, and the amplitude was less reduced in the BMSC group in comparison with the control group (P < .05). MEPs induced by bipolar stimulation in the left forelimb could be measured in 40% of the BMSC group and the I wave that was not detected in the control group was also detected in 40% of the BMSC group. Our preliminary results imply that BMSCs transplanted to the ischemic rat brain mediate effects on the functional recovery of the cerebral motor cortex and the motor pathway.

Surgical treatment of craniovertebral junction instability : clinical outcomes and effectiveness in personal experience.

OBJECTIVE: Craniovertebral junction (CVJ) consists of the occipital bone that surrounds the foramen magnum, the atlas and the axis vertebrae. The mortality and morbidity is high for irreducible CVJ lesion with cervico-medullary compression. In a clinical retrospective study, the authors reviewed clinical and radiographic results of occipitocervical fusion using a various methods in 32 patients with CVJ instability. METHODS: Thirty-two CVJ lesions (18 male and 14 female) were treated in our department for 12 years. Instability resulted from trauma (14 cases), rheumatoid arthritis (8 cases), assimilation of atlas (4 cases), tumor (2 cases), basilar invagination (2 cases) and miscellaneous (2 cases). Thirty-two patients were internally fixed with 7 anterior and posterior decompression with occipitocervical fusion, 15 posterior decompression and occipitocervical fusion with wire-rod, 5 C1-2 transarticular screw fixation, and 5 C1 lateral mass-C2 transpedicular screw. Outcome (mean follow-up period, 38 months) was based on clinical and radiographic review. The clinical outcome was assessed by Japanese Orthopedic Association (JOA) score. RESULTS: Nine neurologically intact patients remained same after surgery. Among 23 patients with cervical myelopathy, clinical improvement was noted in 18 cases (78.3%). One patient died 2 months after the surgery because of pneumonia and sepsis. Fusion was achieved in 27 patients (93%) at last follow-up. No patient developed evidence of new, recurrent, or progressive instability. CONCLUSION: The authors conclude that early occipitocervical fusion to be recommended in case of reducible CVJ lesion and the appropriate decompression and occipitocervical fusion are recommended in case of irreducible craniovertebral junction lesion.

Spinal cord injury in cervical spinal stenosis by minor trauma.

BACKGROUND: The size of the spinal canal is a factor that contributes to the neurologic deficits associated with cervical OPLL and CSM. We investigate the development of neurologic deterioration after minor trauma and the clinical results of decompressive surgery in cervical spinal stenosis retrospectively. METHOD: We treated 200 cases (98 cervical OPLLs and 102 CSMs) of cervical spinal stenosis for 8 years. There were 63 (33.5%) minor trauma cases to the cervical spine in 200 patients. Of these 63 patients, 18 developed myelopathy, 13 showed deterioration of preexisting myelopathy, and no neurologic change was observed in 32 patients. The neurologic status was assessed by the JOA score. The patients were divided into 2 groups according to the residual cervical spinal canal diameter: group I (<10 mm cervical spinal canal) and group II (> or =10 mm cervical spinal canal). RESULTS: Neurologic outcome depended on the diameter of the residual spinal canal; 22 of the 25 patients in group I developed neurologic deterioration, whereas that occurred in 8 of the 38 patients in group II (P < .05). After surgical decompression, 8 patients in group I and 30 patients in group II came out with an improved JOA score of more than 50% (P < .05). CONCLUSION: Even indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal. It may be beneficial to check lateral radiograph of the cervical spine as a screening tool for early detection of cervical spinal stenosis especially in Asian people older than 40 years.

Risk factors and surgical treatment for symptomatic adjacent segment degeneration after lumbar spine fusion.

OBJECTIVE: The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. METHODS: Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. RESULTS: Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. CONCLUSION: The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

Cytotoxicity of human umbilical cord blood-derived mesenchymal stem cells against human malignant glioma cells.

BACKGROUND: Mesenchymal stem cells (MSCs) represent a potential useful source for cell-based glioma therapies because these cells evidence both orthodox and unorthodox plasticity and also show tropism for cancer. In this study, the authors attempted to access the cytotoxicity of human umbilical cord blood (hUCB)-derived MSCs, with or without cytokine activations against malignant glioma cells. MATERIALS AND METHODS: hUCB-derived MSCs were activated by interleukin-2, interleukin-15, granulocyte macrophage colony-stimulating factor, and combinations. The hUCB-derived MSCs and activated hUCB-derived MSCs were effector cells. The cytotoxicity of the unactivated hUCB-derived MSCs and activated hUCB-derived MSCs against the target cells (human malignant glioma cells) was estimated via visual survival cell assays and transwell inserts. Phenotypic changes occurring in these hUCB-derived MSCs before and after cytokine activation were determined via flow cytometry. The secreted proteins from these effector cells were estimated via enzyme-linked immunosorbent assays. RESULTS: We noted a significant cytotoxicity of hUCB-derived MSCs against malignant glioma cells. In addition, the hUCB-derived MSCs activated with cytokines evidenced significantly higher cytotoxicity than that observed with unactivated hUCB-derived MSCs. Differentiated immune effectors cells from the hUCB-derived MSCs after cytokine activation were not shown to have increased in number. However, the activated hUCB-derived MSCs secreted more immune response-related proteins (interleukin 4, interferon-gamma) than did the unactivated hUCB-derived MSCs. CONCLUSION: The data collected herein confirm for the first time that hUCB-derived MSCs, with or without activation, evidence significant cytotoxicity against human malignant glioma cells, and the immune response-related proteins secreted in this process may perform relevant functions.

Pituitary abscess in a pregnant woman.

Pituitary abscess is a rare and potentially lethal condition. Pituitary abscess in a pregnant woman has not been previously described. A 38-year-old pregnant woman (34 weeks gestation) with a pituitary mass complained of a progressive headache and sudden visual impairment. She was afebrile and had no inflammatory symptoms on admission. On MRI, the preoperative diagnosis was pituitary adenoma with sphenoid sinusitis. She underwent an uncomplicated transsphenoidal procedure for removal of the pituitary mass. The next day, labor commenced and a healthy preterm baby was delivered. Pathologic examination of the intrasellar mass showed polymorphonuclear cells, debris and no tumor cells. The sellar contents were cultured and Streptococcus viridans was grown. To our knowledge this is the first case of pituitary abscess reported during pregnancy. Although the patient was pregnant, the transsphenoidal approach was safe for the mother and the fetus. Surgical drainage and antibiotic therapy are required for the definitive treatment of this condition.

Simple excision and periosteal reattachment for the treatment of calcified cephalhematoma. Technical note.

Until now, calcified cephalhematoma has been treated by excision of the lesion and the use of an onlay autograft. The authors report their use of a less complicated alternative, simple excision and periosteal reattachment, in a 3-month-old male infant. They excised the calcified cap of cephalhematoma and reattached the periosteum to the exposed bone surface instead of using an onlay autograft technique. A follow-up CT scan demonstrated a smooth skull contour and good cosmetic appearance. The authors note that this is the first report of the successful use of simple excision and periosteal reattachment for the treatment of a case of calcified cephalhematoma in which there was a depressed area after the calcified cap was removed. They conclude that in cases of calcified cephalhematoma it may be unnecessary to perform a complicated cranioplasty with bone harvested from the top of the calcification.

Surgical results in pediatric moyamoya disease: angiographic revascularization and the clinical results.

OBJECTIVE: We retrospectively reviewed the pediatric patients with moyamoya disease (MMD) who underwent bypass surgery at our institution to compare the surgical results according to the surgical procedures. PATIENTS AND METHODS: There were 24 total patients (age range: 2-15 years; mean age: 8.2 years). Twelve patients underwent encephalo-duro-arterio-synangiosis (EDAS) on 16 sides, 5 patients underwent encephalo-duro-arterio-myo-synangiosis (EDAMS) on 8 sides and 7 patients underwent combined superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis with EDAMS (STA-MCA-EDAMS) on 12 sides. The postoperative results were evaluated between 4 months and 5 years following surgery in terms of the angiographic revascularization and the clinical outcome. RESULTS: EDAMS, regardless of the combined STA-MCA anastomosis, was significantly effective for achieving a good extent of the postoperative angiographic revascularization as compared with simple EDAS (P<0.05). STA-MCA-EDAMS tended to be better with respective to the relief of preoperative ischemic symptoms as compared with simple EDAS, although there was no significant statistical difference. CONCLUSION: These results suggest that EDAMS with or without the combination of STA-MCA anastomosis was very useful for the formation of collateral circulation in comparison with simple EDAS for treating the pediatric patients with MMD, although these findings were not well correlated with the clinical outcomes.

Intracranial atherosclerotic disease; current options for surgical or medical treatment.

Recently, intracranial atherosclerosis has become a major cause of ischemic stroke, appearing more frequently in Koreans than Caucasians. Symptomatic or asymptomatic intracranial atherosclerosis is a disease that could recur readily even during the treatment with anti-platelet agents. When the symptoms develop, ischemic stroke can not be recovered readily. Therefore, aggressive treatments such as endovascular therapy and bypass surgery are required in addition to medical treatment for the intracranial artery stenosis. Recent intracranial stenting and drug eluting stenting have shown as very advanced effective therapeutic modalities. Nevertheless, until now, a randomized controlled study has not been conducted. Regarding bypass surgery, since the failed EC-IC bypass surgery study performed 20 years ago, extensive studies on its efficacy has not been conducted yet, and thus it has to be performed strictly only in hemodynamically compromised patients. Unless breakthrough drugs that suppress the progression of intracranial atherosclerosis and the formation of thrombi, and facilitate the regression of the arterial stenosis, the treatment concept of the recovery of the blood flow of stenotic arterial territory by mechanical recanalization or bypass surgery would be remained for the prevention as well as treatment of ischemic stroke caused by intracranial atherosclerosis.

Combined direct anastomosis and encephaloduroarteriogaleosynangiosis using inverted superficial temporal artery-galeal flap and superficial temporal artery-galeal pedicle in adult moyamoya disease.

BACKGROUND: We evaluated the efficacy of combined STA-MCA anastomosis and EDAGS using inverted STAGF and STAGP for the treatment of adult MMD. METHODS: This study included 8 patients with nonhemorrhagic MMD. There were 6 women and 2 men who were between 23 and 62 years old (mean = 37.8 years) in the sample. The combined surgery was performed on 12 sides in the 8 patients. The surgical results were assessed for clinical outcome, angiographic revascularization, and hemodynamic change on HMPAO brain SPECT. The follow-up period ranged from 6 to 62 months (mean = 27 months). RESULTS: Clinical symptoms and signs were improved or stabilized, and the extent of revascularization evident on external carotid angiograms was excellent in all 8 patients. The CBF on HMPAO SPECT also improved in all 12 sides that were operated on with the combined surgery, except for the preexisting infarcted area, on the basal as well as Diamox stimulation studies. One patient had a transient speech disturbance after surgery, and another patient had delayed wound healing. CONCLUSIONS: The combined STA-MCA anastomosis and EDAGS using inverted STAGF/P seems to be one of the most effective surgical modalities for the treatment of nonhemorrhagic MMD in adults.

Inductin of neuron-derived orphan receptor-1 in the dentate gyrus of the hippocampal formation following transient global ischemia in the rat.

Neuron-derived orphan receptor (NOR-1) is a member of the thyroid/steroid receptor superfamily that was originally identified in forebrain neuronal cells undergoing apoptosis. In addition to apoptotic stimuli, activation of several signal transduction pathways including direct neuronal depolarization regulates the expression of NOR-1. In this study we tested whether the expression of NOR-1 is changed following transient ischemic injury in the adult rat brain. NOR-1 mRNA increased rapidly in the dentate gyrus of the hippocampal formation and piriform cortex 3 h after transient global ischemia and returned to basal level at 6 h. On the other hand, oxygen-glucose deprivation of cultured cerebral cortical neurons did not alter the expression of NOR-1. These results suggest that expression of NOR-1 is differentially regulated in different brain regions in response to globally applied brain ischemia, but that hypoxia is not sufficient to induce its expression.

Diagnostic method for differentiating external hydrocephalus from simple subdural hygroma.

OBJECT: The various terms used to describe subdural fluid collection--"external hydrocephalus", "subdural hygroma", "subdural effusion", "benign subdural collection", and "extraventricular obstructive hydrocephalus"-reflect the confusion surrounding the diagnoses of these diseases. Differentiating external hydrocephalus from simple subdural hygroma may be difficult, but the former appears to be a distinct clinical entity separate from the latter. In this report, the authors present a diagnostic method for differentiating external hydrocephalus from simple subdural hygroma, based on their clinical experience in treating subdural fluid collection after mild head trauma. METHODS: Twenty patients with subdural fluid collection after mild head trauma were included in this study. Ventricle size was measured using a modified frontal horn index (mFHI); that is, the largest width of the frontal horns divided by the bicortical distance in the same plane, instead of the inner table distance. Bur hole trephination was performed on the appearance of a subdural fluid collection thicker than 15 mm on computed tomography (CT), persistent (longer than 4 weeks) or increasing in size, and accompanied by neurological symptoms (confusion or memory impairment). During the procedure, subdural pressure was measured using a manometer before opening the dura mater. Subdural pressure varied among the patients, ranging from 3 to 27.5 cm H2O. Four patients with a subdural pressure greater than 15 cm H2O had hydrocephalus after surgery (p < 0.05). Hydrocephalus developed in a pediatric patient (2 years old) with a subdural pressure of 12 cm H2O. All of the patients in whom hydrocephalus developed after bur hole trephination had had enlarged ventricles (mFHI > 33%) on preoperative CT scans. CONCLUSIONS: Monitoring subdural pressure may be a valuable tool for differentiating subdural hygroma from external hydrocephalus in patients with mild head trauma. Additionally, the mFHI reflects the nature of the subdural collection more accurately than the standard frontal horn index.