Reversible splenial lesion after surgery for distant arteriovenous malformation: a case report.

Isolated lesions of the corpus callosum are rare and may represent permanent but also transient responses to various pathology termed "reversible splenial lesion syndrome" (RESLES) when in light of relevant clinical presentation. We present the first case of the RESLES after elective surgery for distant arteriovenous malformation (AVM), followed by a slight speech disturbance and MRI verified small, oval, well-circumscribed area of apparent cytotoxic edema in the center of the corpus callosum splenium, which completely resolved within 15 days. Surgery for AVM is followed by the complex adaptation to a new vascular pattern, RESLES might develop, and should be suspected.

Effects of diltiazem on sympathetic activity in patients with aneurysmal subarachnoid hemorrhage.

This study evaluated the effect of diltiazem, a calcium antagonist, on sympathetic activity in patients with aneurysmal subarachnoid hemorrhage (SAH) during the hyperacute stage. Of patients with aneurysmal SAH who underwent aneurysm repair between August 2008 and June 2011, 119 consecutive patients were enrolled in this prospective study. On admission, patients were assigned to an antihypertensive treatment receiving continuous infusion of diltiazem (67 patients) or nicardipine (52 patients). Plasma levels of adrenaline (AD), noradrenaline (NA), and dopamine (DP) were repeatedly measured using high-performance liquid chromatography (HPLC). There were no significant differences in patient characteristics or aneurysm topography between the two groups. In all patients, acute surge of catecholamines was observed with mutual correlation. However, patients receiving diltiazem exhibited a significantly lower plasma concentration of DP than those receiving nicardipine, 3 and 6 h after admission. A similar trend was observed for NA, but the difference was not significant at 6 h. Conversely, the concentration of AD was similar between the two groups. Diltiazem may suppress sympathetic activity in the hyperacute stage of aneurysmal SAH. Further studies are needed to verify the beneficial effect of diltiazem in patients with SAH.

Subdural and intracerebral hemorrhage caused by spontaneous bleeding in the middle meningeal artery after coil embolization of a cerebral aneurysm.

Nontraumatic acute subdural hemorrhage (SDH) with intracerebral hemorrhage (ICH) is rare and is usually caused by severe bleeding from aneurysms or arteriovenous fistulas. We encountered a very rare case of spontaneous bleeding from the middle meningeal artery (MMA), which caused hemorrhage in the temporal lobe and subdural space 2 weeks after coil embolization of an ipsilateral, unruptured internal cerebral artery aneurysm in the cavernous portion. At onset, the distribution of hematoma on a computed tomography scan led us to believe that the treated intracavernous aneurysm could bleed into the intradural space. Emergency craniotomy revealed that the dura of the middle fossa was intact except for the point at the foramen spinosum where the exposed MMA was bleeding. Retrospectively, angiography just before and after embolization of the aneurysm did not show any aberrations in the MMA. Although the MMA usually courses on the outer surface of the dura and is unlikely to rupture without an external force, physicians should be aware that the MMA may bleed spontaneously and cause SDH and ICH.

Influence of Perioperative Three-Dimensional Computed Tomography (CT) Angiography and Surgical Clipping for Unruptured Cerebral Aneurysms on Renal Function in Patients with Chronic Kidney Disease.

BACKROUND: Surgical clipping is a valuable treatment option for unruptured intracranial aneurysms in patients with chronic kidney disease (CKD). However, the comprehensive impact of clipping and perioperative three-dimensional computed tomography angiography (3D-CTA) on renal function remains unclear. This study aimed to evaluate the effects of perioperative 3D-CTA and surgical clipping on renal function in patients with CKD. METHODS: We retrospectively analyzed 529 patients who underwent surgical clipping and perioperative 3D-CTA. An estimated glomerular filtration rate (eGFR) < 60 was defined as CKD. Patients were stratified according to their renal function (group 1: eGFR ≥60, group 2: 45 ≤ eGFR <60, group 3: 30 ≤ eGFR <45, group 4: eGFR <30 ml/min/1.73 m2), and eGFR was assessed preoperatively and 1 week and several months postoperatively. RESULTS: Of the 529 patients, 442 did not have CKD and 87 had CKD. Hypertension, hyperlipidemia, and hyperuricemia were significantly more common in those with CKD. After the surgery and perioperative series of 3D-CTA, renal function deterioration was not observed in any group, whether in the acute or chronic postoperative period. Notably, eGFR significantly increased in groups 2 (66.7 ± 10.1, P < 0.01) and 3 (48.9 ± 9.2, P = 0.02) 1 week postoperatively, despite the CKD. CONCLUSIONS: Surgical clipping of unruptured intracranial aneurysms and perioperative 3D-CTA with normal-dose contrast media did not impair renal function in patients with CKD. These results could be valuable in determining treatment strategies for those with CKD and intracranial aneurysms.

Frontal Sinus Mucosa Bacteriological Features: Evaluation after Unintentional Opening in Neurosurgery.

Objectives The bacteriological features of the frontal sinus mucosa may impose significant complications in neurosurgery, when breached unintentionally. This study aimed to investigate the bacterial flora in patients undergoing frontal craniotomy for cerebrovascular substrate surgery. Design This is a single-center prospective study. Setting When mucosal laceration occurred, the patients underwent frontal sinus reconstruction with mucosa reconstruction, preserving the nasofrontal duct. Participants We enrolled eight consecutive patients who underwent bifrontal craniotomy associated with frontal sinus mucosa laceration. Main Outcome Measures A portion of the mucosa was extracted during the reconstructive procedure and was sent for microbiological analysis. Results None of the patients presented with the bacterial flora in the mucosal cultures. No patient experienced postoperative cerebrospinal fluid leakage or meningitis. One patient with a clinical history of chronic maxillary sinusitis presented with a subcutaneous abscess around the forehead at 9 months postoperatively. The patient rapidly recovered after receiving oral administration of antibiotics. Conclusions Our findings demonstrated that the frontal sinuses were maintained in an aseptic environment in all cases. The results may encourage the development and wider use of transfrontal sinus approaches.

Effect of revascularization surgery on cerebral hemodynamics in adult moyamoya disease.

OBJECTIVE: Few studies have reported local hemodynamic changes after revascularization surgery. This study aimed to identify regional hemodynamic changes after combined revascularization surgery for moyamoya disease using single-photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine. METHODS: A total of 46 adults with moyamoya disease who underwent combined revascularization surgery from August 2009 to July 2021 at our facility were enrolled. The combined bypass procedure comprised a single direct bypass to the motor area and encephalo-duro-arterio-myo-synangiosis. The preoperative and postoperative cerebral blood flow (CBF) and cerebral vascular reserve (CVR) in the genu; precentral, central, parietal, angular, temporal, and posterior regions; splenium; hippocampus; and cerebellum were measured. To modify the examination variability, the cerebral-to-cerebellar activity ratio (CCR) was calculated by dividing the counts in the region by those in the cerebellum (CBF-CCR and CVR-CCR). RESULTS: Postoperatively, asymptomatic cerebral infarction occurred in three (6.5%) patients. The CBF-CCR and CVR-CCR improved in the precentral, parietal, and temporal regions and in the overall middle cerebral artery (MCA) territory. Sub-analysis of anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territory hemodynamics revealed that patients with normal preoperative hemodynamics showed no changes in the CBF-CCR and CVR-CCR postoperatively, whereas patients with preoperative perfusion impairment exhibited improved CVR-CCR in the ACA territory (0.13-0.3, p=0.019) and CBF-CCR in the PCA territory (0.93-0.96, p=0.0039). CONCLUSION: Combined revascularization surgery with single bypass to the motor area improved hemodynamics in the primary targeted MCA territory and in the ACA and PCA territories among patients with preoperative hemodynamic impairment.

Another cause of treatable dementia: rapid cognitive improvement after carotid endarterectomy. Illustrative case.

BACKGROUND: Revascularization techniques in cervical internal carotid artery (ICA) stenosis are indicated to prevent the onset or recurrence of ischemic events in the setting of atherosclerotic carotid artery disease. Recent reports, case series, and comparative studies have suggested that revascularization techniques may also improve cognitive outcome in both symptomatic and asymptomatic patients, thus raising the question of whether another surgically treatable dementia has presented itself. OBSERVATIONS: A 70-year-old right-handed female with a history of hypertension, diabetes, and bilateral silent cerebral infarcts was evaluated for progressive cognitive impairment over a 1-year period, which was associated with a severe left cervical ICA stenosis. Carotid endarterectomy (CEA) was indicated as a revascularization technique, and the patient showed significant neurocognitive improvement as early as one month postoperatively, consistent with blood flow restoration to the left hemisphere on control imaging. LESSONS: This case serves as a reminder that CEA may improve the cognitive outcome of patients previously impaired by uncomplicated severe cervical ICA atherosclerotic disease, which can be another cause of treatable dementia. Further prospective studies may help to assess this potential benefit.

Recovery of Oculomotor Nerve Palsy After Surgical and Endovascular Repair of Unruptured Internal Carotid-Posterior Communicating Artery Aneurysms.

OBJECTIVE: Unruptured posterior communicating artery (Pcom) aneurysms cause oculomotor nerve palsy (ONP). However, the time course of recovery after aneurysm repair remains unclear. We aimed to evaluate the ONP course after clipping and coiling for unruptured Pcom aneurysms. METHODS: We retrospectively reviewed the medical records of 25 consecutive patients with ONP due to unruptured Pcom aneurysms, undergoing aneurysm repair at our institution during 2010-2022. We analyzed the clinical data, angiographic results, and surgical complications. The time to ONP recovery was evaluated using the Kaplan-Meier method. RESULTS: This study included 14 patients undergoing surgical clipping and 11 undergoing endovascular coiling. The two groups exhibited no significant differences in complete or partial ONP percentage or in symptom presentation (ptosis, diplopia, ocular paralysis, pupillary light reflex disorder, or mydriasis). All patients achieved complete or partial recovery during the follow-up period. The median time to partial or complete improvement in ONP was significantly shorter for clipping compared to coiling (2 days vs. 33 days; P = 0.009). Preoperative partial and complete ONP were stratified; clipping improved significantly earlier than coiling in the complete ONP group (P = 0.010). In the early treatment group (based on the median duration of treatment), clipping resulted in earlier improvement than coiling (P = 0.014). In the small aneurysm group (based on the median of the aneurysm maximum diameter), clipping resulted in earlier improvement than coiling (P = 0.005). CONCLUSION: In ONP caused by an unruptured Pcom aneurysm, clipping may provide faster recovery than coiling, particularly in cases of early onset, complete palsy, and small aneurysms.

Intracranial mycotic aneurysm rupture following cupping therapy.

Background: Cupping therapy is an alternative treatment that uses a small glass cup to suck the skin with a needle and has been used to manage skin problems and pain. However, serious complications have been reported. Herein, we describe a case of intracranial mycotic aneurysm rupture after cupping therapy. Case Description: A 25-year-old male patient presented with a headache and fever after cupping therapy for atopic dermatitis. He was diagnosed with infective endocarditis, and antibiotic therapy was initiated. After that, he suddenly lost consciousness, and head imaging revealed a cerebral hemorrhage due to a ruptured intracranial mycotic aneurysm. He underwent craniotomy, which was successful, and he was transferred to a rehabilitation center with a modified Rankin scale score of 2 at three months post-stroke. Conclusion: This case serves as a reminder of life-threatening infectious complication risks after cupping therapy. A patient who has a compromised skin barrier may experience serious adverse effects, especially when cupping is performed without implementing suitable infection prevention measures.

A technique for reconstruction of a giant extracranial internal carotid artery aneurysm: A technical note.

Background: Surgery is effective for extracranial internal carotid artery (EICA) aneurysms. However, the risk of cranial nerve injury associated with surgical repair, such as graft-assisted resection and extracranial-intracranial bypass techniques, is relatively high. Here, we report two cases of surgical treatment for EICA aneurysms and describe the surgical techniques and strategies to avoid cranial nerve injury. Methods: Two patients presented to our facility with an increasing cervical pulsatile mass and no neurological symptoms. Angiography showed a large aneurysm in the cervical internal carotid artery. Surgical treatment was performed to prevent rupture of the aneurysm. In both patients, the aneurysm was strongly attached to the vagus nerve. The aneurysm and vagus nerve were carefully dissected using a low-power bipolar (20 Malis; 3 watts), leaving connective tissue on the vagus nerve side. Results: The aneurysm was detached from the vagus nerve without injury. Based on intraoperative findings, one patient underwent clipping, and the other underwent aneurysmectomy and primary closure for aneurysm obliteration and angioplasty. Both patients were discharged without any cranial nerve dysfunction. Conclusion: The selection of a strategy based on intraoperative findings and low-power bipolar cutting is important for the treatment of extracranial carotid artery aneurysms to preserve cranial nerves.

Disappearance of hemichorea as the initial presentation of moyamoya disease after revascularization surgery regardless of residual hypoperfusion evaluated by quantitative N-isopropyl-p-123I-iodoamphetamine SPECT.

BACKGROUND AND IMPORTANCE: Although hypoperfusion of the basal ganglia or the frontal subcortical matter is suspected, the pathology of chorea in moyamoya disease remains unclarified. Herein, we report a case of moyamoya disease presenting with hemichorea and evaluate pre- and postoperative perfusion using single photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine (123I-IMP SPECT). CLINICAL PRESENTATION: An 18-year-old woman presented with choreic movement of her left limbs. Magnetic resonance imaging revealed an ivy sign, and 123I-IMP SPECT demonstrated decreased cerebral blood flow (CBF) and cerebral vascular reserve (CVR) values in the right hemisphere. The patient underwent direct and indirect revascularization surgery to improve cerebral hemodynamic impairment. The choreic movements entirely resolved immediately after surgery. Although CBF and CVR values in the ipsilateral hemisphere demonstrated by quantitative SPECT increased, these did not reach the normal values threshold. CONCLUSION: Choreic movement in moyamoya disease may be related to cerebral hemodynamic impairment. Further studies are required to elucidate its pathophysiological mechanisms.

Association of antithrombotic therapy with postoperative rebleeding in patients with cerebral amyloid angiopathy.

BACKGROUND: Cerebral amyloid angiopathy is a common cause of subcortical hemorrhage in older adults. Although open hematoma removal may be performed for severe subcortical hemorrhage, its safety in patients with cerebral amyloid angiopathy has not been established, and postoperative rebleeding may occur. Therefore, this study aimed to investigate factors associated with postoperative rebleeding. METHODS: Out of 145 consecutive patients who had undergone craniotomy for surgical removal of subcortical intracerebral hemorrhage between April 2010 and August 2019 at a single institution in Japan, we examined 109 patients with subcortical hemorrhage who met the inclusion criteria. After excluding 30 patients whose tissue samples were unsuitable for the study, the final study cohort comprised 79 patients. RESULTS: Of the 79 patients, 50 (63%) were diagnosed with cerebral amyloid angiopathy (cerebral amyloid angiopathy group) and 29 (37%) were not diagnosed with noncerebral amyloid angiopathy (noncerebral amyloid angiopathy group). Postoperative rebleeding occurred in 12 patients (24%) in the cerebral amyloid angiopathy group and in 2 patients (7%) in the noncerebral amyloid angiopathy group. Preoperative prothrombin time-international normalized ratio and intraoperative bleeding volume were significantly associated with postoperative rebleeding in the cerebral amyloid angiopathy group (odds ratio = 42.4, 95% confidence interval = 1.14-1578; p = 0.042 and odds ratio = 1.005, 95% confidence interval = 1.001-1.008; p = 0.007, respectively). CONCLUSIONS: Patients with cerebral amyloid angiopathy-related cerebral hemorrhage who are receiving antithrombotic therapy, particularly warfarin therapy, are at a high risk of postoperative rebleeding. TRIAL REGISTRATION: Registry and Registration Number of the study: 19-220, 2019/12/23, retrospectively registered.

Facet joint thickness and lumbar instability documented on myelo-computed tomography studies in patients with lumbar degenerative disease.

Background: Various indicators of vertebral instability in patients with lumbar degenerative disease can be identified in myelo-computed tomography (CT) studies. Methods: Of 120 patients, 45 with lumbar degenerative spondylolisthesis (LDS; 53 lumbar lesions) and 75 with lumbar spinal stenosis alone (LSS; 105 lesions) (2015-2019) myelo-CT studies and surgery confirmed the presence of lumbar instability. Myelo-CT findings indicative of instability included facet joint thickness (FJT), fluid in the facet joint, facet tropism, and air in the facet and/or disc. Results: For the 120 study patients, FJT was significantly elevated in both the LDS and LSS groups. Conclusion: FJT on myelo-CT is more specific for lumbar instability than other imaging parameters when evaluating LDS. An increase in FJT suggests vertebral instability likely warranting fusion.

Study of certain easily available biochemical markers in prognostication in severe traumatic brain injury requiring surgery.

Background: This study aimed to identify easily available prognostic factors in severe traumatic brain injury (TBI) patients undergoing craniotomy. Methods: We retrospectively analyzed the clinical characteristics (age, sex, Glasgow coma scale score, cause of TBI, and oral antithrombotic drug use), laboratory parameters (hemoglobin, sodium, C-reactive protein, D-dimer, activated partial thromboplastin time, prothrombin time-international normalized ratio, and glucose-potassium [GP] ratio), and neuroradiological findings of 132 patients who underwent craniotomy for severe TBI in our hospital between January 2015 and December 2021. The patients were divided into two groups: Those with fatal clinical outcomes and those with non-fatal clinical outcomes, and compared between the two groups. Results: The patients comprised 79 (59.8%) male and 53 (40.2%) female patients. Their mean age was 67 ± 17 years (range, 16-94 years). Computed tomography revealed acute subdural hematoma in 108 (81.8%) patients, acute epidural hematoma in 31 (23.5%), traumatic brain contusion in 39 (29.5%), and traumatic subarachnoid hemorrhage in 62 (47.0%). All 132 patients underwent craniotomy, and 41 eventually died. There were significant differences in the D-dimer, GP ratio, and optic nerve sheath diameter between the groups (all P < 0.01). Multivariate logistic regression analysis showed elevated GP ratio and D-dimer were associated with the death group (P < 0.01, P < 0.01, respectively). A GP ratio of >42 was the optimal cutoff value for the prediction of a fatal outcome of TBI (sensitivity, 85.4%; specificity, 51.1%). Conclusion: The GP ratio and D-dimer were significantly associated with poor outcomes of TBI. A GP ratio of >42 could be a predictor of a fatal outcome of TBI.

Clinical Features of Ruptured Very Small Intracranial Aneurysms (<3 mm) in Patients with Subarachnoid Hemorrhage.

OBJECTIVE: Although small unruptured aneurysms rarely rupture, many patients with subarachnoid hemorrhage (SAH) have ruptured small, especially very small intracranial aneurysms (VSIAs; <3 mm) in clinical practice. We aimed to clarify the proportion and clinical features of patients with SAH with ruptured VSIAs. METHODS: 609 patients with ruptured intracranial aneurysms diagnosed at our institution from January 2012 to December 2018 were retrospectively analyzed. We classified patients into 2 groups based on ruptured aneurysm size: VSIAs or non-VSIAs (≥3 mm). We analyzed age, sex, location of aneurysms, World Federation of Neurological Surgeons grade on admission, treatment modality, and outcome at discharge. RESULTS: Among 609 patients, 103 had ruptured VSIAs. The proportion of young patients (age <40 years) was greater in the VSIA group than the non-VSIA group (10.7% vs. 3.6%, P = 0.002). The proportions of VSIAs located in the middle cerebral and vertebrobasilar arteries were relatively low and high, respectively (P = 0.002, 0.005). Significantly more patients with VSIAs than those with non-VSIAs were classified under World Federation of Neurological Surgeons grade I-III (70.9% vs. 56.3%, P = 0.006). Coil embolization was preferred for VSIAs (68.0% vs. 32.0%, P = 0.006). Outcomes were more favorable in the VSIA group than in the non-VSIA group. CONCLUSIONS: Small unruptured aneurysms rarely rupture; however, many patients with SAH have ruptured VSIAs in clinical practice. We observed that VSIA rates among ruptured aneurysms were fairly high. Age, posterior circulation location, and preferable outcome may be important clinical characteristics of ruptured VSIAs.

Predictors of Ischemic Complication in Anterior Choroidal Artery Aneurysm Repair.

BACKGROUND: Treatment of anterior choroidal artery (AchoA) aneurysms is challenging because of the risk of artery injury. The objective of the study was to evaluate the incidence and predictors of AchoA infarction in patients who underwent surgical or endovascular procedure. METHODS: We included 123 patients with AchoA aneurysms treated by surgical clipping (n = 62; 50.4%) or endovascular coiling, including flow diverter placement (n = 61; 49.6%). The clinical and radiological data were retrospectively analyzed. AchoA infarction was defined as the presence of a hyperintense signal on diffusion-weighted imaging in the area of AchoA, including the posterior limb of the internal capsule. RESULTS: AchoA infarction was detected in 8 cases (6.5%), with similar incidence in both groups (6.5% [4/62] vs. 6.6% [4/61]). It occurred in ruptured aneurysms more frequently than in unruptured aneurysms (14.3% [6/42] vs. 2.5% [2/81], P = 0.019). In the surgical group, all 4 affected patients had a non-proximal type AchoA, whereas in the non-infarction group, 9 patients (15.5%) had a non-proximal type AchoA (P = 0.001). In the endovascular group, the incidence was higher in patients with ruptured aneurysms (17.3% [4/23] vs. 0% [0/38], P = 0.017) and lower in patients with pre-admission antiplatelet therapy (0% [0/39] vs. 18.8% [4/22], P = 0.014). CONCLUSIONS: Repair of an AchoA aneurysm is associated with the risk of incurring post-procedural AchoA infarction. Surgical clipping and endovascular coiling have similar complication rates, but risk factors specific to each intervention exist. Careful surgical planning to avoid these risk factors in each therapeutic modality may improve patient outcomes.

Prevention of symptomatic vasospasm by continuous cisternal irrigation with mock-CSF containing ascorbic acid and Mg(2+).

BACKGROUND: Symptomatic vasospasm (SVS) is still a major cause of poor outcome in cases undergoing early surgical intervention for ruptured intracranial aneurysm. Among the numbers of therapeutic trials to prevent and ameliorate neurological deterioration due to SVS, removal or quenching of oxy-hemoglobin (OxyHb) from subarachnoid colts and administration of Mg(2+) (Mg) have especially been expected to be effective. In this report the authors investigated the effect of continuous cisternal irrigation (CCI) with mock CSF containing ascorbic acid (ASA) and Mg, performed after early surgery for ruptured aneurysm. METHOD: Sixty-three cases which had received CCI were retrospectively compared with 40 control cases as to the incidence of SVS and outcome. FINDINGS: Incidence of SVS was significantly less frequent (P < 0.05) in the CCI group (11%) than in the control group (25%). Severe and definitive SVS requiring additional specific treatment occurred only in 3.2% of the CCI group, while 22.5% in the control (P < 0.01). Overall outcome at discharge was significantly better in the CCI group than in the control (P < 0.01). CONCLUSIONS: Postoperative CCI with ASA and Mg was definitively effective in preventing SVS and in lessening severity of SVS if it occurs.

Simultaneous measurement of changes in light absorption due to the reduction of cytochrome c oxidase and light scattering in rat brains during loss of tissue viability.

We performed the simultaneous measurement of intrinsic optical signals (IOSs) related to metabolic activity and cellular and subcellular morphological characteristics, i.e., light scattering for a rat global ischemic brain model made by rapidly removing blood by saline infusion. The signals were measured on the basis of multiwavelength diffuse reflectances in which 605 and 830 nm were used to detect the IOSs that are thought to be dominantly affected by redox changes of heme aa(3) and CuA in cytochrome c oxidase (CcO), respectively. For measuring the scattering signal, the wavelength that was found to be most insensitive to the absorption changes, e.g., approximately 620 nm, was used. The measurements suggested that an increase in the absorption due to reduction of heme aa(3) occurred soon after blood clearance, and this was followed by a large triphasic change in light scattering, during which time a decrease in the absorption due to reduction of CuA occurred. Through the triphasic scattering change, scattering signals increased by 5.2 +/- 1.5% (n = 5), and the increase in light scattering showed significant correlation with both the reflectance intensity changes at 605 and 830 nm. This suggests that morphological changes in cells correlate with reductions of heme aa(3) and CuA. Histological analysis of tissue after the triphasic scattering change showed no alteration in either the nuclei or the cytoskeleton, but electron microscopic observation revealed deformed, enlarged mitochondria and expanded dendrites. These findings suggest that the simultaneous measurement of absorption signals related to the redox changes in the CcO and the scattering signal is useful for monitoring tissue viability in the brain.

Up-regulation of L type amino acid transporter 1 after spinal cord injury in rats.

BACKGROUND: L-type amino acid transporter 1 (LAT1) is proposed to be a major nutrient transporter at the blood brain barrier. LAT1 requires the heavy chain of 4F2 cell surface antigen (4F2hc) for functional expression. METHODS: We investigated the expression of this heterodimeric transporter after traumatic spinal cord injury in rat by using immunohistochemical and western blot analyses. FINDINGS: LAT1 immunoreactivities were up-regulated in the capillary endothelia in close to the injury epicenter 24 hours after injury. It reached a peak at 48 hours after injury, and thereafter decreased. 4F2hc was abundant and unchanged all through the time course after SCI. Western blot analysis under reductive and non-reductive conditions showed that LAT1 and 4F2hc were conjugated as a heterodimeric transporter and the functional regulation was dependent on the light chain, LAT1. CONCLUSIONS: We suggest that LAT1 may be transiently upregulated as part of the tissue-repair process after traumatic contusion injury in the spinal cord.

Role of the activated extracellular signal-regulated kinase pathway on histological and behavioral outcome after traumatic brain injury in rats.

The extracellular signal-regulated kinase (ERK) pathway, which modulates the activity of many transcriptional factors leading to the proliferation of various cells, is activated in lesions in regions of selective vulnerability after traumatic brain injury (TBI). In the present study, using the ERK inhibitor U0126, we investigated the role of the ERK pathway in histopathological and behavioral outcomes after TBI. Adult male Sprague-Dawley rats, weighing 300-400 g were subjected to lateral fluid percussion brain injury. The ERK inhibitor U0126 was injected intravenously before injury at 100, 200 and 400 microg/kg. The severity of CA3 neuronal damage was evaluated by the number of surviving CA3 neurons 7 days after injury. The contusional lesion volume 72 h after injury was analysed using a computer-assisted analysis system. Three different motor skill tasks were measured on days 1-5, 7, 14 and 21 after injury. Pretreatment with U0126 significantly reduced both CA3 neuronal damage and contusional lesion volume after injury. In addition, administration of U0126 ameliorated motor function recovery on days 3, 4 and 5 after injury. Therefore, inhibition of ERK phosphorylation could be a potentially effective therapeutic target after TBI.