Functional Connectivity Pattern Using Resting-state fMRI as an Assessment Tool for Spatial Neglect during the Recovery Stage of Stroke: A Pilot Study.

PURPOSE: To determine if functional connectivity measured with resting-state functional MRI could be used as a tool to assess unilateral spatial neglect during stroke recovery. METHODS: Resting-state functional MRI was performed on 13 stroke patients with lesions in the right cerebral hemisphere and 31 healthy subjects. The functional connectivity score was defined as a correlation of a target region with the right inferior parietal lobule. Spatial neglect was measured with a behavioral inattention test. RESULTS: First, the functional connectivity scores between the right inferior parietal lobule and right inferior frontal gyrus, including the opercular and triangular parts, were significantly decreased in stroke patients with unilateral spatial neglect compared with patients without unilateral spatial neglect and were significantly correlated with the behavioral inattention test score. Second, the functional connectivity scores between the bilateral inferior parietal lobules were also significantly decreased in patients with unilateral spatial neglect compared with patients without unilateral spatial neglect and were significantly correlated with the behavioral inattention test score. Third, negative functional connectivity scores between the right inferior parietal lobule and bilateral medial orbitofrontal cortexes, which are related to the default mode network, were detected in patients without unilateral spatial neglect in contrast to a reduction of this negative tendency in patients with unilateral spatial neglect. The functional connectivity scores between these regions were significantly different between patients with and without unilateral spatial neglect and were negatively correlated with the behavioral inattention test score. CONCLUSION: Though still in the pilot research stage and using a small number of cases, our findings are consistent with the hypothesis that functional connectivity maps generated with resting-state functional MRI may be used as a tool to evaluate unilateral spatial neglect during stroke recovery.

Impact of a Rehabilitation Protocol and a Dedicated Therapist in the Intensive Care Unit on Physical Function and Activities of Daily Living.

OBJECTIVES: The goal of this study was to determine the effects of an intensive care unit (ICU) rehabilitation protocol with dedicated therapists on the physical function and activities of daily living (ADL) of patients on discharge from the ICU. METHODS: This retrospective study included patients who started rehabilitation during their ICU stay. Patients were divided into three groups: the Usual Care group (before the introduction of the rehabilitation protocol), the Protocol group (after the introduction of the rehabilitation protocol), and the PT + Protocol group (with a dedicated therapist in addition to the rehabilitation protocol). The standard interventions in the Protocol group and the PT + Protocol group were set according to the protocol based on the level of consciousness and strength of each individual patient. Patients' age, APACHE II score, length of ICU stay, length of hospital stay, and the Functional Status Score for the ICU (FSS-ICU) and Medical Research Council score (MRC score) on discharge from the ICU were compared among the three groups. RESULTS: There were no significant differences among the three groups in age and APACHE II score. The MRC and FSS-ICU scores were significantly higher in the PT + Protocol and Protocol groups than in the Usual Care group. Furthermore, the lengths of ICU stay and hospital stay were lower in the PT + Protocol group than in the Usual Care group. CONCLUSIONS: Introduction of the rehabilitation protocol improved the limb strength and ADL of patients. Moreover, the presence of dedicated therapists in addition to the protocol reduced the lengths of ICU and hospital stays.

Evaluation of skeletal muscle mass indices, assessed by bioelectrical impedance, as indicators of insulin resistance in patients with type 2 diabetes.

[Purpose] This study aimed to investigate the association between two skeletal muscle mass indices and insulin resistance, and to determine the skeletal muscle mass index that is beneficial in evaluating insulin resistance in patients with type 2 diabetes mellitus. [Participants and Methods] This study evaluated 136 male and 100 female patients with type 2 diabetes mellitus. The skeletal muscle mass was evaluated by bioelectrical impedance analysis. Two skeletal muscle mass indices were investigated as the appendicular skeletal muscle mass index (appendicular skeletal muscle mass divided by the square of height) and relative total skeletal muscle mass (total skeletal muscle mass as a percent of body weight). The homeostasis model assessment of insulin resistance was used as a marker of insulin resistance. Associations were investigated by grouping the participants according to gender and age (<60 or ≥60 years). [Results] The appendicular skeletal muscle mass index was positively associated with the homeostasis model assessment of insulin resistance, except in male patients aged ≥60 years, whereas the relative total skeletal muscle mass was significantly inversely associated with the homeostasis model assessment of insulin resistance, in all patient groups. The cutoff values of the relative total skeletal muscle mass for the presence of insulin resistance were 37.9% and 32.5% in male and female patients, respectively. [Conclusion] This finding suggests that relative total skeletal muscle mass may be a better indicator of insulin resistance than appendicular skeletal muscle mass index is, in patients with type 2 diabetes mellitus.

Abscess formation within a cerebellar metastasis: Case report and literature review.

INTRODUCTION: The managements of brain abscesses and brain tumors including brain metastases differ greatly, especially in terms of surgical procedures. Therefore, differentiating between the two is essential for assuring optimal treatment. However, on rare occasion, these two lesions coexist. Only five cases with both a brain tumor and an abscess have thus, far been reported. We experienced a patient with a brain abscess within a cerebellar metastasis. CASE PRESENTATION: A middle-aged man receiving treatment for bile duct cancer presented with headache and nausea. Computed tomography (CT) and magnetic resonance (MR) imaging revealed two lesions, one in each cerebellar hemisphere. Although these lesions appeared to be brain metastases, the right lesion showed high intensity on diffusion-weighted images (DWI), and magnetic resonance spectroscopy (MRS) findings suggested an abscess. Surgical puncture of the lesion identified it as a brain abscess histologically, and we thus, administered antibiotics. However, since the lesion grew, we performed a second surgery for removal, which histopathologically the lesion to be a well-differentiated adenocarcinoma. The final diagnosis was an abscess within a cerebellar metastasis. DISCUSSION/CONCLUSION: Modern diagnostic tools such as DWI and MRS are reportedly reliable for differentiating brain tumors from brain abscesses, though they are not specific in cases with both lesions. The present case highlights the importance of considering coexisting diseases prior to surgery when we encounter a lesion which has the imaging characteristics of both a tumor and an abscess. The patient may have a better outcome if, preoperatively, surgeons take into consideration the possibility of the coexistence of a brain tumor and a brain abscess.

Ruptured intracranial aneurysm during pregnancy with false-negative computed tomography angiography findings: a case report.

A 34-year-old female was admitted at 34 weeks of gestation with sudden onset of a severe headache accompanied by vomiting. Neurological examination revealed neck rigidity, and computed tomography (CT) of the brain revealed a subarachnoid hemorrhage (SAH). Although the hemorrhage was located primarily in the left Sylvian fissure, computed tomography angiography (CTA) performed immediately after CT did not reveal any obvious vascular abnormalities such as an intracranial aneurysm. An emergency cesarean section was performed, and a healthy infant was delivered. Cerebral digital subtraction angiography (DSA) was performed the day following surgery, which revealed a saccular aneurysm measuring 4.3 mm × 2.4 mm in the left middle cerebral artery. Left craniotomy and clipping of the aneurysm were performed. The clot around the aneurysm was relatively solid. This case report is of significance given that initial CTA was negative for SAH during pregnancy, suggesting the requirement for immediate DSA or another CTA in such cases. There are many previous reports on false-negative CTA findings or disappearance and reappearance of aneurysms in SAH patients, and various biophysical and dynamic parameters are suggested to cause such phenomena. However, there are no reports on similar occurrences during pregnancy. Although the precise cause remains unclear, multiple factors associated with homeostasis during pregnancy were possibly associated with the transient disappearance in this patient.

Diffusion-weighted line-scan echo-planar spectroscopic imaging technique to reduce motion artifacts in metabolite diffusion imaging.

Metabolite diffusion is expected to provide more specific microstructural and functional information than water diffusion. However, highly accurate measurement techniques have still not been developed, especially for reducing motion artifacts caused by cardiac pulsation and respiration. We developed a diffusion-weighted line-scan echo-planar spectroscopic imaging (DW-LSEPSI) technique to reduce such motion artifacts in measuring diffusion-weighted images (DWI) of metabolites. Our technique uses line-scan and echo-planar techniques to reduce phase errors induced by such motion during diffusion time. The phase errors are corrected using residual water signals in water suppression for each acquisition and at each spatial pixel specified by combining the line-scan and echo-planar techniques. We apply this technique to a moving phantom and a rat brain in vivo to demonstrate the reduction of motion artifacts in DWI and apparent diffusion coefficient (ADC) maps of metabolites. DW-LSEPSI will be useful for investigating a cellular diffusion environment using metabolites as probes.

A surgical case of cerebral hemorrhage in a patient with factor XI deficiency.

A 63-year-old man suddenly presented with right hemiplegia and was taken to our hospital. Computed tomography (CT) scan revealed subcortical hemorrhage of the left parietal lobe. He had no medical history except hypertension; thus, it initially appeared to be a typical hypertensive hemorrhage. However, blood analysis showed an abnormally elevated activated partial thromboplastin time. One hour after admission, his Glasgow Coma Scale fell from 14 to 11. We performed an echo-guided stereotaxic removal of the hematoma. He improved immediately and was diagnosed with congenital factor XI (FXI) deficiency a few days after surgery. FXI deficiency, described as hemophilic syndrome C, rarely manifests as spontaneous bleeding, but surgical intervention has been known to manifest as bleeding. This case highlights the importance of evaluation of coagulopathies in patients with intracerebral hemorrhage before surgery, and, in cases wherein blood analysis results suggest coexisting coagulation disorders, less invasive surgical methods would likely lead to good outcomes.

Detection of necrotic neural response in super-acute cerebral ischemia using activity-induced manganese-enhanced (AIM) MRI.

Immediate and certain determination of the treatable area is important for choosing risky treatments such as thrombolysis for brain ischemia, especially in the super-acute phase. Although it has been suggested that the mismatch between regions displaying 'large abnormal perfusion' and 'small abnormal diffusion' indicates a treatable area on an MRI, it has also been reported that the mismatch region is an imperfect approximation of the treatable region named the 'penumbra'. Manganese accumulation reflecting calcium influx into cells was reported previously in a middle cerebral artery occlusion (MCAO) model using activity-induced manganese-enhanced (AIM) MRI. However, in the super-acute phase, there have been no reports about mismatches between areas showing changes to the apparent diffusion coefficient (ADC) and regions that are enhanced in AIM MRI. It is expected that the AIM signal can be enhanced immediately after cerebral ischemia in the necrotic core region due to calcium influx. In this study, a remote embolic rat model, created using titanium-oxide macrospheres, was used to observe necrotic neural responses in the super-acute phase after ischemia. In addition, images were evaluated by comparison between ADC, AIM MRI, and histology. The signal enhancement in AIM MRI was detected at 2 min after the cerebral infarction using a remote embolic method. The enhanced area on the AIM MRI was significantly smaller than that on the ADC map. The tissue degeneration highlighted by histological analysis corresponded more closely to the enhanced area on the AIM MRI than that on the ADC map. Thus, the manganese-enhanced region in brain ischemia might indicate 'necrotic' irreversible tissue that underwent calcium influx.

Multiple brain abscesses in neonate caused by Edwardsiella tarda: case report.

A neonate presented with multiple brain abscesses caused by very unusual infection with the Gram-negative bacterium, Edwardsiella tarda. Serial changes in magnetic resonance imaging findings including diffusion-weighted imaging demonstrated the development from the late cerebritis to late capsule stages. The patient was successfully treated by external drainage, and has since reached normal development milestones. Early diagnosis with computed tomography, magnetic resonance imaging, and ultrasound tomography, and prompt external drainage were essential to the good outcome of this case.

[Primary intracerebral hemorrhage due to probable cerebral amyloid angiopathy complicated by brain abscess: case report].

Cerebral amyloid angiopathy (CAA), in which deposition of amyloid within the arterial media and adventitia is the remarkable feature, causes spontaneous lober cerebral hemorrhage in elderly person, and some reports show the quite high occurrence rate of this entity among intracerebral hemorrhage in patents above 70 years old. Brain abscess resulting from intracerebral hemorrhage is rare. To our knowledge, no report of such hemorrhage which is caused by CAA has been published so far. We report a case of brain abscess, from which Stenotrophomonas maltophilia was isolated, following spontaneous non-hypertensive intracerebral hemorrhage caused by probable CAA, with a review of the relevant literature.

Neuroprotective effects of an immunosuppressant agent on diffusion/perfusion mismatch in transient focal ischemia.

The immunosuppressant FK506 (tacrolimus) exerts potent neuroprotection following focal ischemia in animals; however, the separate effects of FK506 on the ischemic core and penumbra have not been reported. The ischemic penumbra is clinically defined as the difference between a large abnormal area on perfusion-weighted imaging (PWI) and a smaller lesion on diffusion-weighted imaging (DWI). The goal of this study was to determine the effect of FK506 on DWI/PWI match and mismatch areas in transient focal ischemia in rats. Twelve rats were subjected to 1 hr of transient middle cerebral artery (MCA) occlusion, and given an intravenous injection of a placebo (N = 6) or 1 mg/kg FK506 (N = 6) immediately before reperfusion. Magnetic resonance imaging (MRI) was performed during MCA occlusion, and 0.5, 1, and 24 hr after reperfusion. FK506 significantly protected the ischemic brain only in the mismatch cortex where the initial apparent diffusion coefficient (ADC) was normal and there was a mild reduction of cerebral blood flow (CBF). This is the first report to describe the protective effects of FK506 on ischemic penumbra, as measured by DWI/PWI mismatch. The findings provide direct evidence for the utility of DWI/PWI mismatch as a guideline for therapeutic intervention with FK506.

Interindividual and interspecies variations of the extrastriate visual cortex.

Functional homology between human and macaque visual cortices has provided an important cue to functional subdivisions of the human visual cortex, but it is unclear beyond V1. We estimated the sizes and the visual field eccentricity functions of the extrastriate visual areas of human brains using MRI and fMRI measurements to analyze the interindividual and interspecies variations. We found distinctive features of the area fraction values relative to V1 and the visual field eccentricity functions beyond V2 between the human and the macaque visual cortices. This suggests that selection on color-form and stereoscopic vision, associated with processing and manipulating socio-visual stimuli, may generate variations of the architecture of the extrastriate visual cortex beyond V2.

Detection of the anoxic depolarization of focal ischemia using manganese-enhanced MRI.

Mismatch between diffusion- and perfusion-weighted MRI was used to indicate a treatable area following focal ischemia, called the penumbra. Activity-induced manganese contrast MRI has been reported as a new visualization method for neural activation using manganese ions as a depolarization-dependent contrast agent. It is well known that energy failure induced by cerebral ischemia produces anoxic depolarization. The purpose of this study was to detect manganese accumulation caused by permanent middle cerebral artery occlusion (MCAO) of rat brain and to compare regional differences between manganese accumulation and decreased apparent diffusion coefficient (ADC). The ratios of signal intensity of manganese-enhanced MRI in the ipsilateral cortex to that in the contralateral cortex were 171.0 +/- 17.5% in MCAO group and 108.4 +/- 13.2% in the sham group. In addition, the enhanced region was much smaller than the area which was detected as having a reduced ADC.

Dynamic activity-induced manganese-dependent contrast magnetic resonance imaging (DAIM MRI).

Activity-induced manganese-dependent contrast (AIM) MRI is a hemodynamic-independent functional MRI method that used manganese ion as an MR-detectable contrast agent. In AIM, MnCl(2) is infused intra-arterially after the blood-brain barrier (BBB) is opened with a hyperosmolar agent. Upon functional stimulation of the brain, Mn(2+) accumulates in the active region(s) by entering active cells through voltage-gated Ca(2+) channels, causing local signal increases in T(1)-weighted images. The contrast of AIM MRI depends strongly on the depth of anesthesia, and the low levels used in somatosensory stimulation studies can lead to significant nonspecific accumulation of manganese ion throughout the brain. The purpose of this study was to produce an AIM functional map of somatosensory stimulation, which separates the stimulation-specific signal increase from the nonspecific activation due to light anesthesia. A dynamic AIM (DAIM) paradigm was developed, which used sequential MR scans during MnCl(2) infusion, prior to and following functional stimulation of the brain. Stimulation-specific functional maps were produced using time-course analysis. The new method was tested during glutamate administration and electric stimulation of the rat forepaw. It was shown that DAIM maps are better confined to the specific region of brain activated by somatosensory stimulation as compared to AIM MRI.