Prolonged mild therapeutic hypothermia versus fever control with tight hemodynamic monitoring and slow rewarming in patients with severe traumatic brain injury: a randomized controlled trial.

Although mild therapeutic hypothermia is an effective neuroprotective strategy for cardiac arrest/resuscitated patients, and asphyxic newborns, recent randomized controlled trials (RCTs) have equally shown good neurological outcome between targeted temperature management at 33 °C versus 36 °C, and have not shown consistent benefits in patients with traumatic brain injury (TBI). We aimed to determine the effect of therapeutic hypothermia, while avoiding some limitations of earlier studies, which included patient selection based on Glasgow coma scale (GCS), delayed initiation of cooling, short duration of cooling, inter-center variation in patient care, and relatively rapid rewarming. We conducted a multicenter RCT in patients with severe TBI (GCS 4-8). Patients were randomly assigned (2:1 allocation ratio) to either therapeutic hypothermia (32-34 °C, n = 98) or fever control (35.5-37 °C, n = 50). Patients with therapeutic hypothermia were cooled as soon as possible for ≥ 72 h and rewarmed at a rate of <1 °C/day. All patients received tight hemodynamic monitoring under intensive neurological care. The Glasgow Outcome Scale was assessed at 6 months by physicians who were blinded to the treatment allocation. The overall rates of poor neurological outcomes were 53% and 48% in the therapeutic hypothermia and fever control groups, respectively. There were no significant differences in the likelihood of poor neurological outcome (relative risk [RR] 1.24, 95% confidence interval [CI] 0.62-2.48, p = 0.597) or mortality (RR 1.82, 95% CI 0.82-4.03, p = 0.180) between the two groups. We concluded that tight hemodynamic management and slow rewarming, together with prolonged therapeutic hypothermia (32-34 °C) for severe TBI, did not improve the neurological outcomes or risk of mortality compared with strict temperature control (35.5-37 °C).

Seizure suppression in amygdala-kindled mice by transplantation of neural stem/progenitor cells derived from mouse embryonic stem cells.

Embryonic stem cells (ES cells) differentiate into multiple cell lineages including neural cells. The present study optimized the method to induce differentiation of gamma-aminobutyric acid-producing neurons (GABAergic neurons) from ES cell-derived neural stem/progenitor cells (NS/PCs), and transplanted these ES cell-derived GABAergic neurons producing neural progenitors into kindled epileptic mice, and analyzed the morphological and functional recovery from epilepsy. The response of kindling was evaluated by the modified Racine scale. Following stage 5 kindling, the mice were divided into two groups. Group 1 received NS/PCs derived from the ES cells ubiquitously expressing green fluorescent protein transplanted into the dorsal hippocampal area. Group 2 received microinjections of only the medium. After transplantation, the recovery of seizures was evaluated by the modified Racine scale again. All mice were perfused and fixed for immunohistochemical analysis after finishing the kindling experiment. In Group 1, one mouse was classified as stage 0, five as stage 3, and one as stage 4 recovering from stage 5 at 6 weeks after transplantation. In Group 2, all mice remained in stage 5. The transplanted cells were examined immunohistochemically using neuronal and GABAergic markers. In the transplanted mice, substantial hippocampal GABAergic re-innervation and seizure-suppressing effects were observed. NS/PCs derived from ES cells have high potential for use in transplantation therapy for clinically intractable epilepsies.

Evaluation of human fetal neural stem/progenitor cells as a source for cell replacement therapy for neurological disorders: properties and tumorigenicity after long-term in vitro maintenance.

It is expected that human neural stem/progenitor cells (hNS/PCs) will some day be used in cell replacement therapies. However, their availability is limited because of ethical issues, so they have to be expanded to obtain sufficient amounts for clinical application. Moreover, in-vitro-maintained hNS/PCs may have a potential for tumorigenicity that could be manifested after transplantation in vivo. In the present study, we demonstrate the in vitro and in vivo properties of long-term-expanded hNS/PCs, including a 6-month bioluminescence imaging (BLI) study of their in vivo tumorigenicity. hNS/PCs cultured for approximately 250 days in vitro (hNS/PCs-250) exhibited a higher growth rate and greater neurogenic potential than those cultured for approximately 500 days in vitro (hNS/PCs-500), which showed greater gliogenic potential. In vivo, both hNS/PCs-250 and -500 differentiated into neurons and astrocytes 4 weeks after being transplanted into the striatum of immunodeficient mice, and hNS/PCs-250 exhibited better survival than hNS/PCs-500 at this time point. We also found that the grafted hNS/PCs-250 survived stably and differentiated properly into neurons and astrocytes even 6 months after the surgery. Moreover, during the 6-month observation period by BLI, we did not detect any evidence of rapid tumorigenic growth of the grafted hNS/PCs, and neither PCNA/Ki67-positive proliferating cells nor significant malignant invasive features were detected histologically. These findings support the idea that hNS/PCs may represent a nontumorigenic, safe, and appropriate cell source for regenerative therapies for neurological disorders.

Effect of delayed mild brain hypothermia on edema formation after intracerebral hemorrhage in rats.

Secondary consequences of intracerebral hemorrhage (ICH) including inflammation, edema, and oxidative damage all contribute to cell death after ICH. Brain hypothermia (BH) has been used as an effective neuroprotective treatment in experimental brain ischemia and traumatic brain injury. In this study, we first attempted to evaluate the effect of delayed mild BH (35 degrees C) on brain edema formation 48 hours after ICH. BH was started 3, 6, 12, and 24 hours after the induction of 100 muL of autologous blood into the basal ganglia (hypothermic [HT]; HT3: n = 4, HT6: n = 6, HT12: n = 11, HT24: n = 6) in rats. To examine the protective mechanism of BH, blood-brain barrier (BBB) permeability to Evans blue, accumulation of polymorphonuclear leukocyte, and oxidative DNA damage in the lesion were compared between normothermic (NT) (37 degrees C) and HT6 rats 48 hours after ICH. Finally, neurologic recovery was assessed using behavioral tests in NT and HT6 rats 48 hours after ICH. Brain water content in the ispilateral basal ganglia was significantly reduced with delayed BT compared with NT (n = 7, 81.8 +/- 0.7% v HT3: 78.9 +/- 0.8%, P < .01; HT6: 78.7 +/- 0.6%, P < .01; HT12: 79.4 +/- 1.1%, P < .01; HT24: 80.3 +/- 0.6%, P < .01). The BBB disruption to Evans blue was significantly reduced with BH (HT6: n = 6) compared with NT (n = 6) rats in the ipsilateral basal ganglia (23.0 +/- 5.2 v 42.3 +/- 4.0 ng/g wet tissue, P < .05). HT6 treatment (n = 6) significantly inhibited the accumulation of polymorphonuclear leukocyte compared with NT treatment (n = 6) (0.43 +/- 0.22 v 1.49 +/- 0.61 DeltaAbs/mg tissue, P < .05). HT6 treatment (n = 3) also significantly reduced oxidative DNA damage determined with 8-hydroxyl-2'-deoxyguanosine compared with NT treatment (n = 3) (92 +/- 18 v 40 +/- 7 pg 8-hydroxyl-2'-deoxyguanosine/mug DNA, P < .05). Furthermore, HT6 treatment (n = 5) significantly improved neurologic recovery assessed with forelimb placing score compared with NT treatment (42.0 +/- 5.8 v 12.0 +/- 3.7, P < .05). In conclusion, mild BH significantly reduces the brain edema formation after ICH, even when the BH is applied 24 hours after hematoma induction in rats. Several neuroprotective mechanisms, including reduced BBB disruption, inflammation and oxidative damage, are suggested in this study.

Targeting optimal biopsy location in basal ganglia germinoma using (11)C-methionine positron emission tomography.

BACKGROUND: Approximately 5% to 10% of intracranial germinomas arise from the basal ganglia or thalamus. Diagnosis is usually made by stereotactic biopsy, and precise location of the biopsy target is crucial because germinoma in these sites is potentially curable. We herein describe a case with germinoma in the basal ganglia that showed nonspecific clinical and radiological findings. The usefulness of MET-PET in locating an optimal biopsy target and monitoring treatment efficacy in this case is presented. CASE DESCRIPTION: A 9-year-old boy presented with a 4-month history of dystonia in his left upper extremity. Magnetic resonance imaging of the brain showed abnormal signal intensity in the right basal ganglia, internal capsule, and corona radiata without mass formation and enhancement effect. He had been treated as having multiple sclerosis without improvements on clinical and radiological findings. The MET-PET study showed increased tracer uptake in the areas of abnormal signal intensity on the MR images, and the MRI-PET co-registered images exhibited the highest tracer uptake in the anterior limb of the internal capsule. A stereotactic biopsy targeting the highest tracer uptake lesion was performed with histologic verification of germinoma. He was intensively treated with combined chemotherapy and radiotherapy according to the MR images and MET-PET findings. After the treatment, the area of abnormal signal intensity significantly reduced in size on the follow-up MRI and lesional tracer uptake was also decreased on MET-PET images. CONCLUSION: The MET-PET study is very useful for locating a precise biopsy target and provides useful information in monitoring treatment efficacy in the basal ganglia germinoma that showed nonspecific radiological findings.

Edaravone attenuates brain edema and neurologic deficits in a rat model of acute intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Our previous studies have demonstrated that oxidative DNA injury occurs in the brain after intracerebral hemorrhage (ICH). We therefore examined whether edaravone, a free-radical scavenger, could reduce ICH-induced brain injury. METHODS: These experiments used pentobarbital-anesthetized, male Sprague-Dawley rats that received an infusion of either 100 microL autologous whole blood (ICH), FeCl(2), or thrombin into the right basal ganglia. The rats were humanely killed 24 hours later. There were 4 sets of experiments. In the first, the dose-dependent effects of edaravone on ICH-induced brain injury were examined by measuring brain edema and neurologic deficits. In the second set, apurinic/apyrimidinic abasic sites and 8-hydroxyl-2'-deoxyguanosine, which are hallmarks of DNA oxidation, were investigated after treatment for ICH. In the third, the effect of delayed treatment with edaravone on ICH-induced injury was determined, whereas the fourth examined the effects of edaravone on iron- and thrombin-induced brain injury. RESULTS: Systemic administration of edaravone immediately or 2 hours after ICH reduced brain water content 24 hours after ICH compared with vehicle (P<0.05). Edaravone treatment immediately or 2 hours after ICH also ameliorated neurologic deficits (P<0.05). Edaravone also attenuated ICH-induced changes in apurinic/apyrimidinic abasic sites and 8-hydroxyl-2'-deoxyguanosine and reduced iron- and thrombin-induced brain injury. CONCLUSIONS: Edaravone attenuates ICH-induced brain edema, neurologic deficits, and oxidative injury. It also reduces iron- and thrombin-induced brain injury. These results suggest that edaravone is a potential therapeutic agent for ICH.

Hyperbaric oxygen therapy for consciousness disturbance following head injury in subacute phase.

BACKGROUND: Hyperbaric oxygen (HBO) therapy has been shown to improve outcome after brain injury, however its mechanisms are not understood. The purpose of the present study was to investigate the effect of hyperbaric oxygen (HBO) therapy on the cerebral circulation and metabolism of patients with disturbances in consciousness after head injury in the subacute phase. METHODS: Seven head injury patients underwent HBO treatment after leaving the intensive care unit. Oxygen (100% O2, 2.7 atm absolute) was delivered to patients in a hyperbaric chamber for 60 min every 24 h (total five treatments/patient). Cerebral circulation monitoring (mean flow velocity: mFV, and pulsatility index: PI at horizontal portion of middle cerebral artery by transcranial Doppler) and cerebral metabolism monitoring (arterio-jugular venous difference of oxygen: AJDO2 and jugular venous lactate: lac-JV) before and after the series of treatments were evaluated. FINDINGS: Both PI and lac-JV were significantly decreased after HBO theatment, while there were no significant changes in mFV and AJDO2. The decreased PI and lac-JV after HBO therapy might indicate that this treatment couples cerebral circulation and metabolism. CONCLUSIONS: The measurement of cerebral circulation and metabolism parameters, especially PI and lac-JV, is useful for estimation of effect of HBO therapy in patients with distubances in consciousness after head injury in the subacute phase.

Cerebral metabolism monitoring during hypothermia following resuscitation from cardiopulmonary arrest.

BACKGROUND: The aim of the present study was to evaluate cerebral metabolism monitoring during therapeutic hypothermia for global ischemic brain damage after cardiopulmonary resuscitation (CPR). METHODS: Jugular venous sampling and positron emission tomography (PET) were used. Seven comatose patients with cardiopulmonary arrest underwent hypothermia treatment as soon as possible after CPR. The body temperature of these patients was maintained at 34 degrees C for 72 h. Rewarming was performed at a rate of 1 degrees C/day. To monitor jugular venous saturation (SjO2) and lactate (lac-JV), a fiberoptic catheter was inserted into the jugular bulb. Oxygen extraction fraction (OEF) was calculated using the difference between arterial oxygen saturation (SaO2) and SjO2. 18F-fluorodeoxyglucose (FDG) PET was performed to investigate cerebral glucose metabolism at the end of therapeutic hypothermia. FINDINGS: The OEF was significantly increased at the end of hypothermia in four patients with favorable outcome on the Glasgow Outcome Scale (hypothermia onset 15.3 +/- 2.0% vs. hypothermia end 30.3 +/- 2.8%, P < 0.05). In three patients with unfavourable outcome (severe or worse on the Glasgow Outcome Scale), end hypothermia OEF tended to be low. There was also a reduction in FDG uptake in these three patients with unfavourable outcome. The lac-JV was significantly decreased at the end ofhypothermia treatment compared with hypothermia onset (27.7 +/- 7.4 vs. 6.0 +/- 3.0 mg/dL, P < 0.05). CONCLUSIONS: The measurement of cerebral metabolism parameters, especially OEF, might be useful for estimation of hypothermia therapy in patients with unconsciousness after resuscitation after cardiac arrest.

Metabolic disturbance without brain ischemia in traumatic brain injury: a positron emission tomography study.

BACKGROUND: Cerebral ischemia is believed to be an important mechanism of secondary neuronal injury in traumatic brain injury (TBI). METHODS: In this study, we performed 15O2 positron emission tomography (PET) studies to measure the cerebral blood flow (CBF) and oxygen metabolism (CMRO2) in the pericontusional region in a total of 15 patients (11 males, 4 females, aged 15-81 years) who sustained TBI with contusional hematoma. PET studies were performed a mean of 13.5 +/- 9.1 days (range 2-33 days) after TBI occurred. FINDINGS: The areas of pericontusional tissues located 10 mm away from the cerebral contusion exhibited mildly decreased CBF (89%) and severely suppressed CMRO2 (67%) when comparison was made with the remote cerebral cortex. Severely suppressed oxygen metabolism in the pericontusional tissue was observed not only in the acute stage, but also in the subacute stage after TBI, whereas blood flow was slightly recovered in the subacute stage. We also compared the PET findings obtained in the acute or subacute stage after TBI and structural abnormalities on late-stage MRI in 5 patients. The area of flow defect on the CBF-PET image developed into irreversible tissue damage (necrosis) in the chronic stage. The area of hypoperfusion surrounding the lesion partly resulted in tissue necrosis: however, a large part of the hypoperfused tissue survived in the chronic stage. Again, a significant portion of oxygen hypometabolism surrounding the lesion did not develop into tissue necrosis. CONCLUSIONS: We conclude that impaired cerebral blood flow and metabolism in the pericontusional region is observed even in the subacute stage after TBI and is unlikely to cause severe further neuronal damage.

Preoperative identification of subthalamic nucleus for deep brain stimulation using three-dimensional phase sensitive inversion recovery technique.

PURPOSE: We assessed the feasibility of utilizing three-dimensional (3D) phase sensitive inversion recovery (IR) images for preoperatively determining deep brain stimulator position. METHODS: We measured geometric distortion with a grid phantom and evaluated images of 3 volunteers to determine optimum imaging parameters for 3D phase sensitive IR. RESULTS: Geometric distortion measured less than 1.0%. Respective inversion and recovery times, which provided high T(1) contrast between the subthalamic nucleus and adjacent tissue, were 200 and 4000 ms. In studies of 3 volunteers and 2 patients, the subthalamic nucleus was clearly depicted in 3D phase sensitive IR images. The measured coordinates of the subthalamic nucleus agreed well with those calculated by conventional estimation from midpoint of the anterior and posterior commissure. CONCLUSION: Three-dimensional phase sensitive inversion recovery was useful in visualizing the subthalamic nucleus for effective deep brain stimulation.

Technetium-99m sestamibi single photon emission computed tomography findings correlated with P-glycoprotein expression in pituitary adenoma.

The aim of this study is to evaluate whether the technetium-99m sestamibi ((99m)Tc-MIBI) single photon emission computed tomography (SPECT) characteristics of pituitary adenomas might be correlated with cavernous sinus invasion, proliferative potential or the multidrug-resistance (MDR-1) gene product P-glycoprotein (Pgp) expression in pituitary adenomas. Fifteen patients with pituitary adenomas, including 10 nonfunctioning adenomas, two prolactinomas, two GH producing adenomas, and one ACTH producing adenomas was investigated for this study. SPECT images with (99m)Tc-MIBI were acquired 15 minutes (early) and 3 hours (delayed) after injection. The tumor-to-normal brain ratio was calculated both early (ER) and delayed (DR) images. Retention index (RI) was calculated using the following formula: (DR-ER)/ERx100%. The pituitary adenomas specimens were examined by immunohistochemistry using anti-Pgp and MIB-1 monoclonal antibodies.(99m)Tc-MIBI SPECT findings were not related to MIB-1 labeling index or cavernous sinus invasion. (99m)Tc-MIBI SPECT RI (-38.55+/-20.77) of the Pgp-positive group was significantly lower than that (-15.78+/-19.40) of Pgp-negative group (p=0.0494). No significant difference was observed in the ER and DR of (99m)Tc-MIBI SPECT between Pgp-positive and negative groups. Our study suggests that although (99m)Tc-MIBI SPECT is not useful to evaluate the proliferative potential or cavernous sinus invasion of pituitary adenomas. (99m)Tc-MIBI SPECT could predict anti-cancer drug resistance related to the expression of Pgp in pituitary adenomas.

Magnetic resonance imaging and positron emission tomography findings in status epilepticus following severe hypoglycemia.

We recently experienced a case with asymmetrical cortical abnormality on MRI with focal status epilepticus following severe hypoglycemia. The cerebral blood flow and metabolisms for oxygen and glucose were determined using positron emission tomography (PET) during focal status epilepticus following severe hypoglycemia and at the follow-up period. Prolonged seizure activity produced profound glucose hypermetabolism and mild hyperemia in the region of the presumed cortical focus of epilepsy and in structures anatomically remote from the focus, corresponding to the areas of abnormal signal intensity on the MRI. The patient remained comatose and exhibited a diffuse hypoperfusion/hypometabolism and symmetrical brain atrophy on the follow-up PET and MRI, respectively. Cytotoxic brain edema due to profound glucose metabolism without compensatory increase of the blood flow during status epilepticus may account for the brain abnormality observed on the early MRI. Simultaneous examination of the cerebral blood flow and metabolism using PET can provide useful information about the pathology in patients with status epilepticus.

Chiari I malformation accompanied by assimilation of the atlas, Klippel-Feil syndrome, and syringomyelia: case report.

BACKGROUND: Chiari I malformation, accompanied by superposed bony anomaly of the craniovertebral junction, is comparatively rare. We report a case of Chiari I malformation accompanied by assimilation of the atlas, Klippel-Feil syndrome, and syringomyelia. CASE DESCRIPTION: The patient was a 61-year-old woman demonstrating numbness of the extremities, sensory impairment, muscular weakness, and tendon hyper-reflexia. X-ray images and CT scans demonstrated assimilation of the atlas to the occipital bone, C2 and C3 fusion, abnormal passage of the vertebral arteries, and an anomalous bony mass on the right lateral mass of the atlas protruding into the spinal column. The odontoid process was also deviated to the left. Magnetic resonance images demonstrated bilateral descent of the cerebellar tonsils and syringomyelia extending from C6 to T8. Computed tomographic scans with the head rotated to the right demonstrated increased narrowing of the vertebral column caused by the right lateral mass of the atlas, and MR images confirmed exaggerated deformation of the spinal cord at the same region. This deformation manifested no neurologic symptoms, and we therefore performed foramen magnum decompression and duraplasty using Gore-Tex (W.L. Gore & Associates, Inc., Flagstaff, AZ). In the early postoperative period, neurologic symptoms improved. CONCLUSION: We believe it is important that a treatment plan for Chiari I malformation accompanied by bony anomaly of the craniovertebral junction be determined based on morphologic investigation of the region supplemented by dynamic imaging-based evaluation of instability, or a careful inspection for atypical passage of the vertebral arteries, a frequent site of complication.

Differences in the neuronal stem cells survival, neuronal differentiation and neurological improvement after transplantation of neural stem cells between mild and severe experimental traumatic brain injury.

We developed a novel protocol for generation and selective amplification of neural progenitor cells regionally specified to the rostral brain but not the spinal cord from mouse embryonic stem cells (ESCs). The neural progenitors could differentiate in vitro and in vivo into many cholinergic and a few GABAergic neurons but rarely into astrocytes. The transplanted neurospheres could survive in the hippocampus (CA3) of animals with mild traumatic brain injury (TBI). Twelve weeks after transplantation (a week after the behavioral test), we found significant cholinergic differentiation recognized as ChAT immunoreactivity in the eGFP+transplanted cells. Moreover, the grafts contained a few GAD67+cells. However, we barely found GFAP+astrocytes within the grafts. Furthermore, presynaptic formations of graft-derived neurons were recognized by immunohistochemistry of near the grafts around CA3. However, these findings were not observed in severe TBI group. So, we examined NGF, BDNF, and FGF-2 mRNA by RT-PCR in 12 mice including normal, mild TBI and severe TBI group. Increases in the neurotrophic factors' mRNA were evident in the hippocampus on the ipsilateral side in the mild TBI group. Statistical analysis revealed significant differences between the mild and severe TBI groups. The data also revealed significant differences between the mild TBI and normal groups. The transplanted neurospheres could survive in the mild TBI animals, but not in the severe TBI group.

Neural stem cells transplantation in cortex in a mouse model of Alzheimer's disease.

OBJECTIVE: The goal of this study was to elucidate the effect of neurospheres (NS) on dementia in the mouse model of nucleus basalis of Meynert (NBM) lesion. METHODS: Mouse embryonic stem cell (ES) derived neurospheres were transplanted into the frontal association cortex and barrel field of S1 cortex of C57BL/6 mice 4 weeks after including a lesion of NBM by ibotenic acid, while other healthy mice that received ES cells served as control. Behavioral tests by 8-arm radial maze were conducted 8 weeks after transplantation, and double staining of choline acetyltransferase (ChAT), serotonin, amyloid-beta protein (AP) and green fluorescent protein (GFP) 12 weeks after transplantation. We found that the neurospheres transplanted into the mouse cortex survived and produced many ChAT-positive neurons and a few serotonin-positive neurons in and around the grafts. The working memory error decreased significantly in the mice grafted with neurospheres. In contrast, the ES cells developed into teratomas in all of the control mice and expressed no neurons, and the working memory deteriorated remarkably. CONCLUSIONS: Transplantation of neurospheres, but not ES cells, into the prefrontal and parietal cortices, dramatically alleviated the cholinergic deficits and recent memory disruption in the NBM lesioned mice.

Prognostic implication of p27 expression in primary central nervous system lymphoma.

To clarify the role of p27/Kip1 (p27) in primary central nervous system lymphomas (PCNSLs), we examined p27 expression by immunohistochemical methods in a series of 22 patients with PCNSL. We attempted to correlate the expression of p27 with proliferation potential and prognosis. Although the MIB-1 labeling index (LI) was lower in tumors with low p27 expression (26.7% +/- 17.2% vs 38.1% +/- 16.3%), it was not significantly different from that of tumors with high p27 expression (P = 0.1253). Survival analysis revealed that high p27 expression was significantly associated with poorer overall prognosis (P = 0.0011); however, the MIB-1 LI were not associated with prognosis. Our results suggest p27 as a predictor of prognosis in patients with PCNSL.

Expression of matrix metalloproteinase-9 in thrombin-induced brain edema formation in rats.

Recent evidence has demonstrated that thrombin plays an important role in the development of brain edema by the blood-brain barrier disruption in intracerebral hemorrhage. Matrix metalloproteinases (MMPs), a family of proteolytic enzymes that degrade the extracellular matrix, are implicated in blood-brain barrier disruption. In this study, we examined whether thrombin injection into the brain parenchyma induces the MMP-9 expression in rats. Anesthetized adult rats received an injection of 10 U of thrombin into the basal ganglia. At 12, 24, and 72 hours after the thrombin injection, brain water content and the expression of MMP-9 messenger RNA (mRNA) and protein were determined. The effect of a specific thrombin inhibitor (hirudin) on MMP-9 expression and brain edema formation and general administration of synthetic MMPs inhibitor (GM6001) on brain edema formation were also examined for linking the injury and up-regulation of MMP-9. The brain water contents in the basal ganglia and overlying cortex were rapidly increased at 12 hours, maximized at 24 hours, and slightly decreased at 72 hours. The gelatinase activity of MMP-9 determined with gelatin zymography was detected in the basal ganglia and cortex at 12 hours, maximally expressed at 24 hours, and remained strong 72 hours after thrombin injection. The expression of MMP-9 mRNA in the cortex determined with reverse transcription-polymerase chain reaction was clearly seen at 12 and 24 hours, and became weak 72 hours after thrombin injection. Co-injection of thrombin and hirudin almost completely inhibited the brain edema formation and expressions of MMP-9 mRNA and protein. Administration of broad-spectrum metalloproteinase inhibitor GM6001 significantly reduced the brain edema formation in this model. These results indicate that intraparenchymal thrombin induces brain edema formation through MMP-9 expression in rats. Inhibition of MMPs activity may provide an approach to potentially reduce ongoing edema after intracerebral hemorrhage.

FDG-PET findings of the brain in lymphomatoid granulomatosis.

A 44-year-old man with a history of sudden onset short-term disorientation was admitted to our hospital. T2-weighted fast spin-echo MR images of the head showed increased signal intensity in the bilateral frontal and parietal white matter. Gadolinium-enhanced T1-weighted spin-echo images showed multiple areas with punctate and linear enhancement scattered in the bilateral frontal and parietal white matter. Although 18F-fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) did not display a significant increase in FDG accumulation in the bilateral frontal and parietal white matter, kinetic analysis of this scan showed increased hexokinase activity in the lesions compared to the unaffected occipital white matter. Diagnosis was made by open biopsy of the right frontal lobe and pathologic specimen was positive for lymphomatoid granulomatosis (LYG). The patient received high-dose methotrexate with CHOP (cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisolone) chemotherapy and follow-up MRI showed improvement of the lesions. [18F]FDG-PET study with kinetic analysis may be useful to diagnose LYG in the central nervous system.