Cerebral Glucose Metabolism in Patients with Chronic Disorders of Consciousness.

OBJECTIVE: To measure regional cerebral metabolic rate of glucose (CMRGlu) in patients with chronic disorders of consciousness (DOCs) using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: This retrospective cohort study examined 50 patients (mean age: 40.9 ± 20.1 years) with traumatic brain injury (TBI)-induced chronic DOCs [minimally conscious state (MCS)+, n = 20; MCS-, n = 15 and vegetative state (VS), n = 15]. We measured FDG-PET-based CMRGlu values in 12 regions of both brain hemispheres and compared those among MCS+, MCS - and VS patients. RESULTS: In both hemispheres, the regional CMRGlu reduced with consciousness deterioration in 11 of 12 regions (91.7%). In seven right hemisphere regions, CMRGlu values were markedly higher in MCS+ patients than in MCS- patients. Furthermore, CMRGlu was suggestively higher in the left occipital region in MCS- patients than in VS patients. CONCLUSION: Functional preservation in the left occipital region in patients with chronic DOCs might reflect an awareness of external environments, whereas extensive functional preservation in the right cerebral hemisphere might reflect communication motivation.

Spastic muscle stiffness evaluated using ultrasound elastography and evoked electromyogram in patients following severe traumatic brain injury: an observational study.

OBJECTIVE: To determine the relationship between muscle stiffness assessed using ultrasound shear wave elastography, spinal motor neuron excitability assessed using the F wave, and clinical findings of spasticity in patients with spastic muscle overactivity following severe traumatic brain injury. METHODS: This study enrolled 17 inpatients with severe traumatic brain injury and 20 healthy volunteers. Biceps brachii muscle stiffness was then evaluated using ultrasound shear wave speed. Spinal motor neuron excitability was evaluated using the F/M ratio recorded from abductor pollicis brevis muscle. Clinical parameters, such as the modified Ashworth scale and modified Tardieu scale, were assessed in the patient with traumatic brain injury. RESULTS: The patients with traumatic brain injury group had a significantly higher shear wave speed and F/M ratio compared with the healthy group. A higher shear wave speed was correlated with higher clinical spastic severity in patients with traumatic brain injury. The F/M ratio was not significantly correlated with clinical spastic severity. CONCLUSION: Ultrasound shear wave elastography might be helpful for assessing muscle stiffness in patients with spastic muscle overactivity following severe traumatic brain injury. Further studies comprising larger cohorts are warranted.

Characteristics of time-activity curves obtained from dynamic 11C-methionine PET in common primary brain tumors.

PURPOSE: The aim of this study was to assess whether dynamic PET with 11C-methionine (MET) (MET-PET) is useful in the diagnosis of brain tumors. METHODS: One hundred sixty patients with brain tumors (139 gliomas, 9 meningiomas, 4 hemangioblastomas and 8 primary central nervous system lymphomas [PCNSL]) underwent dynamic MET-PET with a 3-dimensional acquisition mode, and the maximum tumor MET-standardized uptake value (MET-SUV) was measured consecutively to construct a time-activity curve (TAC). Furthermore, receiver operating characteristic (ROC) curves were generated from the time-to-peak (TTP) and the slope of the curve in the late phase (SLOPE). RESULTS: The TAC patterns of MET-SUVs (MET-TACs) could be divided into four characteristic types when MET dynamics were analyzed by dividing the MET-TAC into three phases. MET-SUVs were significantly higher in early and late phases in glioblastoma compared to anaplastic astrocytoma, diffuse astrocytoma and the normal frontal cortex (P < 0.05). The SLOPE in the late phase was significantly lower in tumors that included an oligodendroglial component compared to astrocytic tumors (P < 0.001). When we set the cutoff of the SLOPE in the late phase to - 0.04 h-1 for the differentiation of tumors that included an oligodendroglial component from astrocytic tumors, the diagnostic accuracy was 74.2% sensitivity and 64.9% specificity. The area under the ROC curve was 0.731. CONCLUSIONS: The results of this study show that quantification of the MET-TAC for each brain tumor identified by a dynamic MET-PET study could be helpful in the non-invasive discrimination of brain tumor subtypes, in particular gliomas.

A 1-year-old boy with long pauses caused by paroxysmal atrioventricular block and sinus arrest: Vagal reflex and effect of pacing.

Paroxysmal atrioventricular block (PAVB) is rare in children. A 1-year-old boy presented with PAVB and sinus arrest that resulted in refractory life-threatening symptomatic long pauses. Continuous heart rate variability analysis with high time resolution (wavelet analysis) revealed an abrupt increase in parasympathetic activity just before a long pause, which indicated a vagal reflex. Although a pacemaker is not always effective because of a concomitant vasodepressive response in such cases, the complete stabilization after pacemaker implantation in this case supports the necessity and usefulness of pacemaker implantation in patients with reflex-induced highly symptomatic bradycardia.

Diagnostic and prognostic factors for acute encephalopathy.

BACKGROUND: Acute encephalopathy has the possibility of sequelae. While early treatment is required to prevent the development of sequelae, differential diagnosis is of the utmost priority. The aim of this study was therefore to identify parameters that can facilitate early diagnosis and prediction of outcome of acute encephalopathy. METHODS: We reviewed the medical charts of inpatients from 2005 to 2011 and identified 33 patients with febrile status epilepticus. Subjects were classified into an acute encephalopathy group (n = 20) and a febrile convulsion group (n = 13), and the parameters serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), ammonia (NH3 ), cerebrospinal fluid (CSF) tau protein, and CSF interleukin-6 compared between them. Furthermore, the relationship between each parameter and prognosis was investigated in the encephalopathy group. RESULTS: Significant differences in serum AST, ALT, and LDH were observed between the febrile convulsion and acute encephalopathy group. Moreover, a significant difference in serum LDH was noted between the patients with and without developmental regression at the time of hospital discharge in the encephalopathy group. In particular, CSF tau protein was found to be highly likely to indicate progress, with CSF tau protein >1000 pg/dL associated with poor prognosis leading to developmental regression. CONCLUSION: Serum AST, ALT and LDH may be related to early diagnosis and prognosis, and should be carefully investigated in patients with encephalopathy. CSF tau protein could also be used as an indicator of poor prognosis in acute encephalopathy.

Bevacizumab treatment leads to observable morphological and metabolic changes in brain radiation necrosis.

We investigated morphological and metabolic changes of radiation necrosis (RN) of the brain following bevacizumab (BEV) treatment by using neuroimaging. Nine patients with symptomatic RN, who had already been treated with radiation therapy for malignant brain tumors (6 glioblastomas, 1 anaplastic oligodendroglioma, and 2 metastatic brain tumors), were enrolled in this prospective clinical study. RN diagnosis was neuroradiologically determined with Gd-enhanced MRI and 11C-methionine positron emission tomography (MET-PET). RN clinical and radiological changes in MRI, magnetic resonance spectroscopy (MRS) and PET were assessed following BEV therapy. Karnofsky performance status scores improved in seven patients (77.8 %). Both volumes of the Gd-enhanced area and FLAIR-high area from MRI decreased in all patients after BEV therapy and the mean size reduction rates of the lesions were 80.0 and 65.0 %, respectively. MRS, which was performed in three patients, showed a significant reduction in Cho/Cr ratio after BEV therapy. Lesion/normal tissue (L/N) ratios in MET- and 11C-choline positron emission tomography (CHO-PET) decreased in 8 (89 %) and 9 patients (100 %), respectively, and the mean L/N ratio reduction rates were 24.4 and 60.7 %, respectively. BEV-related adverse effects of grade 1 or 2 (anemia, neutropenia and lymphocytopenia) occurred in three patients. These results demonstrated that BEV therapy improved RN both clinically and radiologically. BEV therapeutic mechanisms on RN have been suggested to be related not only to the effect on vascular permeability reduction by repairing the blood-brain barrier, but also to the effect on suppression of tissue biological activity, such as immunoreactions and inflammation.

Brain activation by music in patients in a vegetative or minimally conscious state following diffuse brain injury.

OBJECTIVE: The aim of this study was to objectively evaluate the brain activity potential of patients with impaired consciousness in a chronic stage of diffuse brain injury (DBI) using functional MRI (fMRI) following music stimulation (MS). METHODS: Two patients in a minimally conscious state (MCS) and five patients in a vegetative state (VS) due to severe DBI were enrolled along with 21 healthy adults. This study examined the brain regions activated by music and assessed topographical differences of the MS-activated brain among healthy adults and these patients. RESULTS: MS was shown to activate the bilateral superior temporal gyri (STG) of both healthy adults and patients in an MCS. In four of five patients in a VS, however, no significant activation in STG could be induced by the same MS. The remaining patient in a VS displayed the same MS-induced brain activation in STG as healthy adults and patients in an MCS and this patient's status also improved to an MCS 4 months after the study. CONCLUSIONS: The presence of STG activation by MS may predict a possible improvement of patients in a VS to MCS and fMRI employing MS may be a useful modality to objectively evaluate consciousness in these patients.

The Impact of Listening to Background Music on Inhibition Control and Prefrontal Cortical Activation in Healthy Older Adults: A Study Using Functional Near-Infrared Spectroscopy.

Introduction Aging declines executive functions, including attentional function and inhibitory control, which is the ability to inhibit inappropriate or irrelevant responses. Certain types of background music are negatively correlated with cognitive function. The prefrontal network is correlated with task performance related to executive function. This study aimed to assess the impact of listening to background music on inhibition control and prefrontal cortical (PFC) activation measured using functional near-infrared spectroscopy (fNIRS) in healthy older people. Methods In total, 59 healthy volunteers, including 32 healthy older and 27 younger individuals (mean age ± standard deviation: 69 ± 7 and 32 ± 8 years, respectively), participated in this study. The participants completed the inhibition control task (the go/no-go task) and a similar task while listening to certain melodies of children's songs that are popular in Japan. Changes in cerebral blood flow in the PFC during each task were evaluated using multichannel fNIRS. The relative changes in oxygenated hemoglobin (oxy-Hb) levels during the no-go and go tasks under the music and no-music conditions were compared using a paired t-test. Among the channels with a significant difference in oxy-Hb levels during the go/no-go task between the music and no-music conditions in the older group, the correlation between changes in accuracy response and oxy-Hb levels was validated using Pearson's correlation test. Results The task accuracy was significantly reduced under the music condition compared with that under the no-music condition in the older group but not in the younger group. The accuracy reduction was significantly greater in the older group than in the younger group. In older people, the oxy-Hb levels in 20 channels located in the bilateral Broadman area (BA) 9 and BA46 in the dorsolateral prefrontal cortex and the bilateral BA10 in the frontal pole cortex significantly increased during the no-go tasks under the music condition. During the go/no-go task under the music condition, the decline in task accuracy was significantly correlated with increased oxy-Hb levels in six channels located in the bilateral BA10 in older people. Conclusion Background music induced the decline of inhibition control and increase of PFC activity in healthy older adults.

Evaluation of brain tumors using dynamic 11C-methionine-PET.

The aim of this study is to assess whether dynamic imaging of (11)C-methionine (MET) uptake on positron emission tomography (PET) is useful for the differential diagnosis of brain tumor histology. Regional MET uptake in static brain PET scans from three consecutive phases (5-15, 15-25, and 25-35 min) after intravenous injection were measured in 144 patients with brain tumors. Regions of interest (ROI) were placed in the pituitary gland, confluence, choroid plexus, coronal radiation, brainstem, frontal cortex, parietal cortex, cerebellum, and brain tumors. The standard uptake value (SUV) of the ROIs in the normal brain structures and brain tumors were measured, and the mean MET SUV region/normal frontal lobe cortex uptake ratio (R/N ratio) of the normal brain structures and the maximum MET SUV tumor/normal frontal cortex uptake ratio (T/N ratio) were evaluated semi-quantitatively. There were significant dynamic declines of the mean MET R/N ratio in the normal pituitary gland and confluence; however, there were significant dynamic increases in white matter. Significant dynamic decrease of the maximum MET T/N ratio was seen in meningiomas and oligodendrocytic tumors, whereas significant dynamic increase was seen in glioblastomas and malignant lymphomas. Dynamic changes of MET uptake vary significantly with the normal brain structures and brain tumor histology. These results suggest that MET-PET may be useful in the differential diagnosis of brain tumors.

A speech expression disorder in patients with severe diffuse brain injury who emerged from a vegetative or minimally conscious state.

OBJECTIVE: The purpose of this study was to highlight a speech expression disorder considered as a mixed speech apraxia (SA) and dysarthria syndrome in patients with chronic severe diffuse brain injury (DBI) and to determine its correlation with anatomical localizations of brain lesions using neuroimaging. METHODS: Among 140 patients with chronic severe DBI, eight showed this type of speech disorder. MRI (five patients) and FDG-PET (six patients) procedures were performed. RESULTS: Affected patients could comprehend verbally, read words silently and express words using a word board. Compared with SA, the disorder is characterized by similarities in regards to reduced phonation and marked facio-oral apraxia, but by distinct differences in terms of an accompanying dysphagia and pyramidal/extra-pyramidal symptoms that are similar to symptoms associated with dysarthria due to pseudobulbar palsy. Diffuse regions of the white matter including the left arcuate fasciculus (AF) were significantly decreased in fractional anisotropy value. However, there was no significant cortical metabolic damage in FDG-PET. CONCLUSIONS: The observed speech disorder in these patients is a characteristic entity related to dysfunction of speech expression and may be attributable to damage of not only the AF but also a number of fibres that are related to dysarthria, cognitive and emotional impairments and pyramidal/extra-pyramidal symptoms.

Computational approach to understand temporal and spatial tactile transmission processes from mechanical stimuli of the index fingertip to the primary somatosensory cortex.

Mechanisms of information transmission using tactile sense are one of major concerns in producing simulated experience in virtual or augmented reality as well as in compensating elderly or impaired people with diminished tactile sensory function. However, important mechanism of the difference of peak latency in the primary somatosensory cortex (SI) between electrical and mechanical stimulations of finger skin is not fully understood. We propose a computational approach to fuse a computational model to simulate temporal and spatial transmission processes from mechanical stimuli to the SI and experimental method using a magnetoencephalograph (MEG). In our model, a tactile model that combined a three-dimensional mechanical model of fingertip skin and a neurophysiological model of a slowly adapting type 1 (SA1) mechanoreceptor was integrated with a somatosensory evoked field (SEF) response model. Electrical and mechanical stimulations were applied to the same locations of the right or left index fingertips of three subjects using a MEG. By identifying parameters of the SEF response model using the electrical stimulation test data, predicted first peak latency due to a mechanical stimulus was identical to its average value obtained from the mechanical stimulation test data, while the spatial map predicted at the multiple SA1 receptors qualitatively corresponded to the MEG image map in the timings of peak latency. This suggests that mechanical change in the skin and neurophysiological responses generate the difference of peak latency in SI between electrical and mechanical stimulations. The computational approach has the potential for detailed investigation of mechanisms of tactile information transmission.

Osmotic Demyelination Syndrome due to Rhabdomyolysis and Hyperosmolar Hyperglycemic Syndrome following Cardiogenic Shock.

Osmotic demyelination syndrome (ODS) is a relatively rare disease that causes rapid demyelination, resulting in pontine and central nervous system damage with various symptoms, including impaired consciousness. It often occurs when hyponatremia is rapidly corrected. However, it can also occur when a normonatremic patient suddenly develops hypernatremia. A 51-year-old man developed cardiogenic shock with impaired consciousness, hyperCKemia, hypernatremia, and hyperglycemia. Osmotic demyelination syndrome secondary to rhabdomyolysis and hyperosmolar hyperglycemic syndrome was suspected. The patient's fluid volume decreased because of osmotic diuresis caused by hyperglycemia, and the blood sodium level increased rapidly. The latter resulted in ODS, which in turn resulted in a prolonged disturbance of consciousness, from which he has not yet recovered. ODS has been reported as a serious complication of rapid correction of hyponatremia, although it also occurs when normonatremia leads to hypernatremia. This disease is difficult to diagnose, as magnetic resonance imaging (MRI) of the brain is often unremarkable several weeks after its onset. This case of ODS occurred when normonatremia led to hypernatremia, as a result of rhabdomyolysis and hyperosmolar hyperglycemic syndrome. Diagnosis was made based on the MRI brain findings.

Investigation of dynamic deformation of the midbrain in rear-end collision using human brain FE model.

Mild traumatic brain injury (TBI), including concussions, can cause symptoms affecting physical or cognitive domains in the acute and chronic phases. In this study, we investigated the dynamic deformation of the brain stem, which might be important for these symptoms, using a human brain finite element model through reconstruction simulations of rear-end collisions in three different velocities. In all simulations, high maximum principal strain values were observed at the midbrain that were higher than those in the corpus callosum. These findings could provide some mechanical insights into brain disorders associated with mild TBI.

Splenic mass of uncertain etiology in a 15-year-old male patient: a case report.

BACKGROUND: There are few reports on spleen masses, and solitary splenic abscesses with abdominal pain have not been reported in younger age groups. We report a case of a splenic mass of uncertain etiology in a 15-year-old boy. CASE PRESENTATION: A 15-year-old boy visited the emergency department with abdominal pain. Abdominal ultrasonography revealed a thin-walled multilobular splenic cyst. Computed tomography revealed a cystic shadow and a septate structure in the spleen. Magnetic resonance imaging examination revealed a high-signal region on the T2-weighted image. The neutrophil ratio in the white blood cell count of 8,330/µL was high (80%), and splenic abscess could not be ruled out. Thus, therapy with 2 g/day fosfomycin was initiated. Abdominal pain disappeared on day 3 of hospital stay, and the patient was discharged on day 8. CONCLUSION: Antibiotic therapy can be effective against very acute onset splenic abscesses, although surgical treatment is usually carried out.

Acupuncture for Chronic Constipation in Patients with Chronic Disorders of Consciousness After Severe Traumatic Brain Injury.

Objective: Patients with chronic disorders of consciousness (DOC) frequently develop chronic constipation. This study evaluated the effects of acupuncture on bowel movements (BMs) in patients with DOC and chronic constipation resulting from severe traumatic brain injury (TBI). Materials and Methods: This retrospective observational study took place in the Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, of Kizawa Memorial Hospital, in Minokamo, Gifu, Japan. The study included 25 patients with chronic DOC resulting from TBI, who received acupuncture treatment. The patients received 2 sessions of acupuncture treatment per week. Information on frequency of defecation, number of days during which patients had BMs, and use of laxatives prior to the acupuncture treatment and after 10 weeks of treatment was extracted from medical records and compared. Results: The median (first quartile and third quartile) frequency of defecation increased significantly after 10 weeks of acupuncture from 3.0 (2.5, 3.5) to 3.5 (2.5, 4.5) times/week (P = 0.038). The number of days on which defecation occurred also increased significantly, from 2.0 (2.0, 2.5) to 2.5 (2.0, 3.5) days/week (P < 0.001). The use of bisacodyl suppositories decreased significantly from 1.5 (1.5, 2.0) to 1.5 (0.5, 2.0) times/week (P = 0.041). The mean ± standard error use of sodium picosulfate for 10 patients decreased significantly, from 20.4 ± 3.5 to 14.3 ± 3.3 drops/week (P = 0.004). Conclusions: Acupuncture treatment could be beneficial for chronic constipation in patients with DOC caused by TBI. A large prospective cohort study with a control group is warranted.

Cerebral Glucose Metabolism in Patients with Chronic Mental and Cognitive Sequelae after a Single Blunt Mild Traumatic Brain Injury without Visible Brain Lesions.

The aim of this study is to investigate glucose uptake on 18F-fluorodeoxyglucose positron emission tomography positron emission tomography (FDG-PET) in patients with chronic mental and cognitive symptoms following a single blunt mild traumatic brain injury (TBI) and without visible brain lesions on computed tomography (CT)/magnetic resonance imaging (MRI). Eighty-nine consecutive patients (mean age 43.8 ± 10.75 years) who had a single blunt mild TBI from a traffic accident and suffering from chronic mental and cognitive symptoms without visible brain lesions on CT/MRI were enrolled in the study. Patients underwent FDG-PET imaging, and the mean interval between the TBI and FDG-PET was 50.0 months. The Wechsler Adult Intelligence Scale version III (WAIS-III) testing was performed within 1 month of the FDG-PET. A control group consisting of 93 healthy adult volunteers (mean age 42.2 ± 14.3 years) also underwent FDG-PET. The glucose uptake pattern from FDG-PET in the patient group was compared with that from normal controls using statistical parametric mapping. Glucose uptake was significantly decreased in the bilateral prefrontal area and significantly increased around the limbic system in the patient group compared with normal controls. This topographical pattern of glucose uptake is different from that reported previously in patients with diffuse axonal injury (DAI), but may be similar to that seen in patients with major depression disorder. These results suggest that the pathological mechanism causing chronic mental and cognitive symptoms in patients with a single blunt mild TBI and without visible brain lesions might be different from that due to primary axonopathy in patients with DAI.

Dissociation Between 11C-Methionine-Positron Emission Tomography and Gadolinium-Enhanced Magnetic Resonance Imaging in Longitudinal Features of Glioblastoma After Postoperative Radiotherapy.

The aims of the present study were to compare the longitudinal changes of glioblastoma multiforme after radiotherapy (RT) between 11C-methionine positron emission tomography (MET-PET) and gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) and to clarify whether these changes were predictive of survival. We included 30 patients, who had undergone MET-PET and Gd-MRI before and every 3 months after RT. The lesion/normal brain uptake (L/N) ratio and contrast-enhancing lesion volume were examined. The L/N ratio was decreased until 9 months after RT with significance until 3 months. The contrast-enhancing lesion volume was decreased until 3 months and thereafter increased until 9 months with significance. The variation rates of the L/N ratio between pre-RT and 3 months differentiated survival of >23 months from ≤23 months. A dissociation could exist in the longitudinal changes of GBM after RT between MET-PET and Gd-MRI. The variation rate of the L/N ratio could be related to survival.

Usefulness of positron emission tomography for differentiating gliomas according to the 2016 World Health Organization classification of tumors of the central nervous system.

OBJECTIVE: Positron emission tomography (PET) is important in the noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 WHO classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification). Here, the authors investigated the relationship between uptake of 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) on PET imaging and isocitrate dehydrogenase (IDH) status (wild-type [IDH-wt] or mutant [IDH-mut]) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification. METHODS: In total, 105 patients with newly diagnosed cerebral gliomas (6 diffuse astrocytomas [DAs] with IDH-wt, 6 DAs with IDH-mut, 7 anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, 5 GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake value (SUV) of the tumor/mean SUV of normal cortex (T/N) ratios for MET, CHO, and FDG were calculated, and the mean T/N ratios of DA, AA, and GBM with IDH-wt and IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the 3 PET tracers. RESULTS: There were significant differences in the mean T/N ratios for all 3 PET tracers between the IDH-wt and IDH-mut groups of all histological classifications (p < 0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all 3 PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all 3 PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p < 0.01). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that in the IDH-mut group for both MET (p = 0.034) and CHO (p = 0.01). However, there was no significant difference in the ratio for FDG. CONCLUSIONS: PET imaging using MET, CHO, and FDG was suggested to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.

Disorder of Executive Function of the Brain after Head Injury and Mild Traumatic Brain Injury - Neuroimaging and Diagnostic Criteria for Implementation of Administrative Support in Japan.

The diagnotic criteria for disorder of the executive function of the brain (DEFB) as a syndrome of sequela were administratively established (ad-DEFB) in Japan in 2006 to support disabled patients whose impairment, limited to cognition (memory, attention, execution, and behavior), emerges after organic brain injuries regardless of physical deficits. However, some patients suffering from traumatic brain injury (TBI) have been excluded from receiving medico-social services. In particular, this tendency is more prominent in patients with mild TBI because no lesions are apparent on conventional computed tomography (CT) or magnetic resonance imaging (MRI) in the chronic phase. Recent development of new MRI neuroimaging modalities and positron emission tomography (PET) imaging makes it possible to detect regions of minute organic lesions and metabolic dysfunction in the brain where organic lesions may be absent or cannot be detected on conventional CT or MRI. In this review, we discuss diagnostic criteria for mild TBI and ad-DEFB, the relationship between the two disorders, characteristic neuroimaging [(MRI and 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)] of diffuse brain injury including cerebral concussion, which is the principal cause of mild TBI, and suggested pathological mechanisms of ad-DEFB in DBI.

Corrigendum to "Differences in Brain Metabolic Impairment between Chronic Mild/Moderate TBI Patients with and without Visible Brain Lesions Based on MRI".

[This corrects the article DOI: 10.1155/2016/3794029.].