In recent years, several radiotracers that selectively bind to pathological tau proteins have been developed. Evidence is emerging that binding patterns of in vivo tau positron emission tomography (PET) studies in Alzheimer's disease (AD) patients closely resemble the distribution patterns of known neurofibrillary tangle pathology, with the extent of tracer binding reflecting the clinical and pathological progression of AD. In Lewy body diseases (LBD), tau PET imaging has clearly revealed cortical tau burden with a distribution pattern distinct from AD and increased cortical binding within the LBD spectrum. In progressive supranuclear palsy, the globus pallidus and midbrain have shown increased binding most prominently. Tau PET patterns in patients with corticobasal syndrome are characterized by asymmetrical uptake in the motor cortex and underlying white matter, as well as in the basal ganglia. Even in the patients with multiple system atrophy, which is basically a synucleinopathy, ¹⁸F-flortaucipir, a widely used tau PET tracer, also binds to the atrophic posterior putamen, possibly due to off-target binding. These distinct patterns of tau-selective radiotracer binding in the various degenerative parkinsonisms suggest its utility as a potential imaging biomarker for the differential diagnosis of parkinsonisms.
Alzheimer Disease ; Basal Ganglia ; Diagnosis, Differential ; Electrons ; Globus Pallidus ; Humans ; Lewy Bodies ; Mesencephalon ; Motor Cortex ; Multiple System Atrophy ; Neurofibrillary Tangles ; Parkinsonian Disorders ; Pathology ; Positron-Emission Tomography ; Putamen ; Supranuclear Palsy, Progressive ; tau Proteins ; White Matter

Traumatic brain injury (TBI) is associated with poor neurological outcome, including necrosis and brain edema. In this study, we investigated whether agmatine treatment reduces edema and apoptotic cell death after TBI. TBI was produced by cold injury to the cerebral primary motor cortex of rats. Agmatine was administered 30 min after injury and once daily until the end of the experiment. Animals were sacrificed for analysis at 1, 2, or 7 days after the injury. Various neurological analyses were performed to investigate disruption of the blood-brain barrier (BBB) and neurological dysfunction after TBI. To examine the extent of brain edema after TBI, the expression of aquaporins (AQPs), phosphorylation of mitogen-activated protein kinases (MAPKs), and nuclear translocation of nuclear factor-kappaB (NF-kappaB) were investigated. Our findings demonstrated that agmatine treatment significantly reduces brain edema after TBI by suppressing the expression of AQP1, 4, and 9. In addition, agmatine treatment significantly reduced apoptotic cell death by suppressing the phosphorylation of MAPKs and by increasing the nuclear translocation of NF-kappaB after TBI. These results suggest that agmatine treatment may have therapeutic potential for brain edema and neural cell death in various central nervous system diseases.
Active Transport, Cell Nucleus/drug effects ; Agmatine/*therapeutic use ; Animals ; Apoptosis/*drug effects ; Aquaporins/metabolism ; Blood-Brain Barrier/physiopathology ; Brain Edema/*drug therapy ; Brain Injuries/*pathology ; Male ; Mitogen-Activated Protein Kinases/metabolism ; Motor Cortex/*pathology ; NF-kappa B/metabolism ; Phosphorylation/drug effects ; Rats ; Rats, Sprague-Dawley

BACKGROUND AND PURPOSE: Involvement of the corpus callosum (CC) is reported to be a consistent feature of amyotrophic lateral sclerosis (ALS). We examined the CC pathology using diffusion tensor tractography analysis to identify precisely which fiber bundles are involved in ALS. METHODS: Diffusion tensor imaging was performed in 14 sporadic ALS patients and 16 age-matched healthy controls. Whole brain tractography was performed using the multiple-region of interest (ROI) approach, and CC fiber bundles were extracted in two ways based on functional and structural relevance: (i) cortical ROI selection based on Brodmann areas (BAs), and (ii) the sulcal-gyral pattern of cortical gray matter using FreeSurfer software, respectively. RESULTS: The mean fractional anisotropy (FA) values of the CC fibers interconnecting the primary motor (BA4), supplementary motor (BA6), and dorsolateral prefrontal cortex (BA9/46) were significantly lower in ALS patients than in controls, whereas those of the primary sensory cortex (BA1, BA2, BA3), Broca's area (BA44/45), and the orbitofrontal cortex (BA11/47) did not differ significantly between the two groups. The FreeSurfer ROI approach revealed a very similar pattern of abnormalities. In addition, a significant correlation was found between the mean FA value of the CC fibers interconnecting the primary motor area and disease severity, as assessed using the revised Amyotrophic Lateral Sclerosis Functional Rating Scale, and the clinical extent of upper motor neuron signs. CONCLUSIONS: Our findings suggest that there is some degree of selectivity or a gradient in the CC pathology in ALS. The CC fibers interconnecting the primary motor and dorsolateral prefrontal cortices may be preferentially involved in ALS.
Amyotrophic Lateral Sclerosis* ; Anisotropy ; Brain ; Corpus Callosum* ; Diffusion Tensor Imaging ; Diffusion* ; Humans ; Motor Neuron Disease ; Motor Neurons ; Pathology ; Prefrontal Cortex

BACKGROUNDTumor surgery in brain motor functional areas remains challenging. Novel techniques are being developed to gain maximal and safe resection for brain tumor surgery. Herein, we assessed the magnetic resonance diffusion tensor imaging (MR-DTI) and fluorescein sodium dyeing (FLS) guiding technique for surgery of glioma located in brain motor functional areas.

METHODSTotally 83 patients were enrolled according to our inclusion and exclusion criteria (56 patients in experimental group, 27 patients in control group). In the experimental group, the surgical approach was designed by DTI imaging, which showed the relationship between the tumor and motor tract. The range of resection in the operation was determined using the FLS-stained area, which recognized the tumor and its infiltrated tissue. The traditional routine method was used in the control group. Postoperatively, all patients underwent enhanced brain MRI within 72 hours to ascertain the extent of resection. Patients were followed in our outpatient clinic over 6 - 24 months. Neurological deficits and Karnofsky scoring (KPS) were evaluated.

RESULTSThere were no significant differences in balance test indexes of preoperative data (sex, age, lesion location and volume, and neurological deficits before operation) and diagnosis of histopathology between the two groups. There was a trend in the experimental group for greater rates of gross total resection (80.4% vs. 40.7%), and the paralysis rate caused by surgery was lower in experimental (25.0%) vs. control (66.7%) groups (P < 0.05). The 6-month KPS in the low-grade and high-grade gliomas was 91 ± 11 and 73 ± 26, respectively, in the experimental group vs. 82 ± 9 and 43 ± 27, respectively, in the control group (P < 0.05 for both).

CONCLUSIONSMR-DTI and FLS dye guiding for surgery of glioma located in brain motor functional areas can increase the gross total resection rate, decrease the paralysis rate caused by surgery, and improve patient quality of life compared with traditional glioma surgery.

Adolescent ; Adult ; Aged ; Brain Neoplasms ; pathology ; psychology ; surgery ; Diffusion Tensor Imaging ; methods ; Female ; Fluorescein ; Glioma ; pathology ; psychology ; surgery ; Humans ; Male ; Middle Aged ; Motor Cortex ; pathology ; Muscle Strength ; Prognosis

Transcranial direct current stimulation (tDCS) is associated with enhancement or weakening of the NMDA receptor activity and change of the cortical blood flow. Therefore, repeated tDCS of the brain with cerebrovascular injury will induce the functional and histologic changes. Sixty-one Sprague-Dawley rats with cerebrovascular injury were used. Twenty rats died during the experimental course. The 41 rats that survived were allocated to the exercise group, the anodal stimulation group, the cathodal stimulation group, or the control group according to the initial motor function. Two-week treatment schedules started from 2 days postoperatively. Garcia, modified foot fault, and rota-rod performance scores were checked at 2, 9, and 16 days postoperatively. After the experiments, rats were sacrificed for the evaluation of histologic changes (changes of the white matter axon and infarct volume). The anodal stimulation and exercise groups showed improvement of Garcia's and modified foot fault scores at 16 days postoperatively. No significant change of the infarct volume happened after exercise and tDCS. Neuronal axons at the internal capsule of infarct hemispheres showed better preserved axons in the anodal stimulation group. From these results, repeated tDCS might have a neuroprotective effect on neuronal axons in rat stroke model.
Animals ; Axons/pathology ; Cerebral Cortex/physiology ; Disease Models, Animal ; Electric Stimulation ; Motor Activity/physiology ; Rats ; Rats, Sprague-Dawley ; Stroke/metabolism/*pathology/physiopathology

BACKGROUNDBlood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) plays an important role in identifying functional cortical areas of the brain, especially in patients with gliomas. This study aimed to assess the value of fMRI in presurgical planning and functional outcome of patients with gliomas in the motor cortical areas.

METHODSTwenty-six patients with gliomas in the motor cortex were recruited in the study. Before operation, fMRI was performed in each patient to obtain the mapping of bilateral hands area on the primary sensorimotor cortex. This examination was performed on a 3.0T scanner with a bilateral hands movement paradigm. During microsurgery under awake anesthesia, the motor area was identified using direct electrical stimulation and compared with preoperative mapping. Finally the tumor was resected as much as possible with the motor cortex preserved in each patient. Karnofsky performance status (KPS) was evaluated in all patients before and after operation.

RESULTSTwenty-three patients showed a successful fMRI mapping. Among them, 19 were classified to be grade III; 4, grade II; 3, grade I. The operation time was about 7 hours in the 23 patients, 8.5 hours in the other 3. The pre- and postoperative KPS score was 82.3 +/- 8.6 and 94.2 +/- 8.1, respectively.

CONCLUSIONSPreoperative fMRI of the hand motor area shows a high consistency with intraoperative cortical electronic stimulation. Combined use of the two methods shows a maximum benefit in surgical treatment.

Adult ; Brain Neoplasms ; pathology ; surgery ; Female ; Glioma ; pathology ; surgery ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Motor Cortex ; pathology ; Oxygen ; blood

OBJECTIVE: To explore the geomorphological performance, the characteristics of volume, and the largest signal intension of blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) in brain tumors located in or closed to the central area. METHODS: We recruited 13 normal volunteers and 31(13 benign tumors and 18 malignant tumors) patients with brain tumor located in or closed to the central area, to examine both side hand motor and tactile function by BOLD-fMRI and obtained the activation map and its superposition image with T1 imaging, the volume, and the largest signal intension of the functional area by SPM software which manipulated the raw data in the off-line work station. The volume and the largest signal intension data of the functional area were statistically analyzed by SPSS 13.0. RESULTS: The volume and the largest signal intension of the activation map in the normal functional area had hemisphere advantage. There was difference in the activated signal pixel number and the largest signal intension of the functional area between the benign brain tumors, malignant brain tumors, and the normal volunteers (P < 0.05). The shape, anatomic location, the volume, and the largest signal intension of the functional area were changed in the patients with brain tumors. CONCLUSION BOLD-fMRI is a valid method to assess the pre-surgical risk of patients with brain tumors, which can get the volume, the largest signal intension, the basic shape,and the anatomic location of the functional area.
Adolescent ; Adult ; Aged ; Brain Neoplasms ; blood ; physiopathology ; Female ; Hand ; physiopathology ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Motor Cortex ; pathology ; physiopathology ; Oxygen ; blood ; Somatosensory Cortex ; pathology ; physiopathology

This study is to observe the effect of salvianolic acid B (Sal B) on neural cells damage and neurogenesis in sub-granular zone (SGZ) and sub-ventricular zone (SVZ) after brain ischemia-reperfusion (I/R) in rats. A modified middle cerebral artery occlusion (MCAO) model of focal cerebral ischemia-reperfusion was used. The rats were divided into four groups: sham control group, ischemia-reperfusion group, Sal B 1 and 10 mg x kg(-1) groups. Sal B was consecutively administrated once a day by ip injection after MCAO. The neurogenesis in SGZ and SVZ was investigated by BrdU method 7 days after MCAO. The Nissl staining for neurons in the hippocampal CA1 and cerebral cortex was performed 14 days after MCAO. A beam-walking test was used to monitor the motor function recovery. We found that brain ischemia resulted in an increase of BrdU positive cells both in ipsilateral SGZ and SVZ at 7th day after MCAO. Sal B (10 mg x kg(-1)) significantly increased further the number of BrdU positive cells both in SGZ and SVZ (P < 0.01). Ipsilateral hippocampal neuron damage occurred and CA1 almost lost 14 days after MCAO. Sal B (10 mg x kg(-1)) obviously attenuated the neuron damage and increased the number of neuron both in ipsilateral CA1 and cerebral cortex (P < 0.01). We also observed an obvious improvement of motor function recovery when Sal B (10 mg x kg(-1)) administrated. From the results above we concluded that Sal B stimulated neurogenesis process both in SGZ and SVZ after brain ischemia, and also alleviated neural cells loss and improved motor function recovery after brain ischemia in rats.
Animals ; Benzofurans ; isolation & purification ; pharmacology ; Cell Count ; Cerebral Cortex ; pathology ; Cerebral Ventricles ; pathology ; Dentate Gyrus ; pathology ; Hippocampus ; pathology ; Infarction, Middle Cerebral Artery ; complications ; Male ; Motor Activity ; drug effects ; Neurogenesis ; drug effects ; Neurons ; drug effects ; pathology ; Plants, Medicinal ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; etiology ; pathology ; physiopathology ; Salvia miltiorrhiza ; chemistry

OBJECTIVEFunctional magnetic resonance imaging (fMRI) was used to detect the cerebral cortical somatotopy during maximum voluntary clenching with and without soft splint in patients with hemimasticatory spasms (HMS) and the central mechanisms of HMS and the rule of the splint therapy.

METHODSFour HMS patients were selected and the spasms sides were right in two cases and left in the other two cases. FMRI images were obtained on Elscint/GE 2.0 Tesla MR system. Block design was used and the movement pattern was the onset of spasms after maximum voluntary clenching with and without soft splint. The fMRI data were analyzed by SPM99 software.

RESULTSWith the onset of spasms after maximum voluntary clenching, the activation of motor cortex in 3 HMS patients was found lateral dominance on the left side, and the other one showed bilateral activation. All the 4 patients were found activation in cingulate area. With the onset of spasms after maximum clenching wearing soft splints, the activation of motor cortex showed no lateral dominance on the left side, and 3 patients were not found activation in cingulate area.

CONCLUSIONSThe changes of the activation in motor cortex and cingulate area during the onset of spasms after clenching with and without soft splint might be the central mechanisms of the rule of splint therapy, through which the soft splint might function in alleviating muscle pain.

Brain ; physiopathology ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Masticatory Muscles ; pathology ; physiopathology ; Middle Aged ; Motor Cortex ; physiopathology ; Mouth Protectors ; Muscle Spasticity ; pathology ; physiopathology

OBJECTIVETo compare the relation between the preoperative functional magnetic resonance imaging (fMRI) with blood oxygen level dependent (BOLD) technique and intraoperative motor evoked potential (MEP) monitoring for cortical mapping of primary motor cortex in patients with tumors near the central area. And to determine whether non-invasive preoperative fMRI can provide results equivalent to those achieved with the invasive neurosurgical "gold standard".

METHODSA prospective study of 16 patients with various pathological tumors of the central area was conducted. Preoperative fMRI scans using the BOLD contrast technique in each patient were performed. An activation scan was achieved by using a motor task paradigm, which consisted of simple flexion-extension finger movements and finger-to-thumb touching in a repeating pattern. The anatomical structure was delineated by the T(1)-weighted three-dimensional fast spoiled gradient recalled sequence (3D/FSPGR) immediately afterward. The BOLD images were overlaid on the T(1)-weighted 3D/FSPGR images, and then co-registered to the neuronavigation system. The fMRI activations were documented by using a neuronavigation system in sequence, and compared to standardized intraoperative MEP monitoring, which included direct cortical electrical stimulation (DCES) or transcranial cortical electrical stimulation (TCES) or their combination. The compound muscle action potentials of forearm flexor and hand muscle responses were recorded during either TCES or DCES. Two techniques were compared to determine the accuracy for cortical mapping of primary motor areas with fMRI.

RESULTSOverall, the intraoperative MEP monitoring showed good correlation with fMRI activation in 92.3% of cases. The coincidence rate, however, was 100.0% between TCES and fMRI, and 66.7% between DCES and fMRI respectively. There was no statistically difference between two cortical mapping techniques, chi-square test of paired comparison of enumeration data, P < 0.01.

CONCLUSIONBOLD fMRI was a high sensitive and reliable technique to locate the position of the primary motor areas and their spatial relation with adjacent tumor, especially for the presurgical planning in patients with central area brain tumor.

Adolescent ; Adult ; Brain Neoplasms ; pathology ; physiopathology ; surgery ; Child ; Evoked Potentials, Motor ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Monitoring, Intraoperative ; Motor Cortex ; pathology ; physiology ; Neuronavigation ; Oximetry ; Prospective Studies ; Transcranial Magnetic Stimulation ; methods