Facilitation of distinct inhibitory synaptic inputs by chemical anoxia in neurons in the oculomotor, facial and hypoglossal motor nuclei of the rat.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective loss of motor neurons in the brainstem and spinal cord. Clinical studies have indicated that there is a distinct region-dependent difference in the vulnerability of motor neurons. For example, the motor neurons in the facial and hypoglossal nuclei are more susceptible to neuronal death than those in the oculomotor nucleus. To understand the mechanism underlying the differential susceptibility to cell death of the neurons in different motor nuclei, we compared the effects of chemical anoxia on the membrane currents and postsynaptic currents in different motor nuclei. The membrane currents were recorded from neurons in the oculomotor, facial and hypoglossal nuclei in brain slices of juvenile Wistar rats by using whole-cell recording in the presence of tetrodotoxin that prevents action potential-dependent synaptic transmission. NaCN consistently induced an inward current and a significant increase in the frequency of spontaneous synaptic inputs in neurons from these three nuclei. However, this increase in the synaptic input frequency was abolished by strychnine, a glycine receptor antagonist, but not by picrotoxin in neurons from the hypoglossal and facial nuclei, whereas that in neurons from the oculomotor nucleus was abolished by picrotoxin, but not by strychnine. Blocking ionotropic glutamate receptors did not significantly affect the NaCN-induced release facilitation in any of the three motor nuclei. These results suggest that anoxia selectively facilitates glycine release in the hypoglossal and facial nuclei and GABA release in the oculomotor nucleus. The region-dependent differences in the neurotransmitters involved in the anoxia-triggered release facilitation might provide a basis for the selective vulnerability of motor neurons in the neurodegeneration associated with ALS.

Olfactory function combined with morphology distinguishes Parkinson's disease.

OBJECTIVE: This study aimed to examine whether the volume of the olfactory bulbs and tracts (OB & T) on magnetic resonance imaging (MRI) is useful for differentiating Parkinson's disease (PD) from PD-related disorders. METHODS: The study group comprised 13 patients with PD, 11 with multiple system atrophy (MSA), five with progressive supranuclear palsy, and five with corticobasal degeneration (PSP/CBD). All patients were evaluated using the odor stick identification test for Japanese (OSIT-J), (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy, and brain MRI. OB & T areas on 1-mm-thick coronal images were measured and summed for volumes. We examined relationships between olfactory function and volume, and cardiovascular dysautonomia. We defined the cut-off values for OSIT-J score or MIBG uptake and OB & T volume to discriminate PD from PD-related disorders and calculated the proportional rate of PD in four categorized groups. RESULTS: OB & T volume was smaller in PD than in MSA or PSP/CBD (p < 0.05 each). The cut-off for detecting PD patients was OSIT-J score <8, heart/mediastinum ratio <1.6, and OB & T volume <270 mm(3). In the group with OSIT-J score <8 and OB & T volume <270 mm(3), the proportion of PD patients among all patients with PD-related disorders was 91%. The rate of probable PD gradually increased as OSIT-J score and OB & T volume decreased (p < 0.001). CONCLUSIONS: Although preliminary, these data obtained from a combined morphological and functional evaluation of OB or cardiovascular dysautonomia could be useful for further differential of PD and other PD-related disorders.

Clinical characteristics associated with corticospinal tract hyperintensity on magnetic resonance imaging in patients with amyotrophic lateral sclerosis.

OBJECTIVE: The usefulness of conventional magnetic resonance imaging (C-MRI) for diagnosing amyotrophic lateral sclerosis (ALS) remains controversial. The aim of this study was to investigate the utility of C-MRI in identifying ALS, specifically the association between corticospinal tract (CST) hyperintensity on C-MRI and clinical characteristics in patients with ALS. METHODS: Between June 2008 and April 2012, we retrospectively enrolled consecutive patients diagnosed with sporadic ALS who underwent C-MRI. Patients with ALS were classified as definite-phase ALS (D-ALS) and indefinite-phase ALS (ID-ALS). We focused on the hyperintensity of T2-weighted images in the CST in patients with ALS. Based on the MRI results, we divided patients into two groups: a positive CST group showing CST hyperintensity; and a negative CST group with no such findings. Clinical characteristics of the two groups were compared. RESULTS: Seventeen patients (median age, 62 years; 8 women, 9 men) were enrolled in this study, with D-ALS in eight (47%) and ID-ALS in nine (53%). Eight patients (47%) showed CST positivity. The rate of CST positivity was higher in patients with D-ALS (75%) than in patients with ID-ALS (22%, p=0.03). CONCLUSIONS: CST positivity appears significantly increased in D-ALS patients. C-MRI can play an important role in diagnosing ALS.

¹¹C-PiB PET imaging of encephalopathy associated with cerebral amyloid angiopathy.

We herein report that the clinical, laboratory, and radiographic features and positron emission tomography (PET) imaging may provide valuable clues to the pathogenesis of cerebral amyloid angiopathy (CAA)-associated encephalopathy, which currently remains unclear. We herein describe two cases of encephalopathy with CAA, with an emphasis on PET imaging with (11)C-Pittsburgh compound B ((11)C-PiB) and (18)F-fluorodeoxyglucose ((18)F-FDG). One case of Alzheimer's disease for which a brain biopsy was performed showed CAA-related inflammation. Another case that had developed sudden sensory aphasia presented with posterior reversible encephalopathy syndrome-like vasogenic edema in the left temporal region with (11)C-PiB uptake and microhemorrhages. (11)C-PiB and (18)F-FDG PET are useful for detecting CAA-associated encephalopathy, including atypical CAA cases.

[A case of neuro-Behçet disease presenting with a longitudinal spinal cord lesion without pain].

A 64-year-old man had transverse myelopathy that rapidly progressed without pain over the course of 1 day. The cerebrospinal fluid interleukin-6 (CSF IL-6) level was extremely high (1,120 pg/dl). Spinal cord magnetic resonance imaging (MRI) showed a longitudinal extensive lesion extending from Th8 to the conus medullaris. Despite treatment with steroids and cyclophosphamide, the symptoms worsened, and the range of sensory disturbance spread. MRI showed that the lesion expanded to Th3 over the course of 2 months. Neuro-Behçet disease (NBD) was diagnosed on basis of the high CSF IL-6 level and HLA-B51 positivity, and treatment with infliximab was begun. The sensory disturbance improved slightly, and the CSF IL-6 level fell to the normal range (7.0 pg/ml). It is important to include NBD, which rarely presents with extensive spinal cord lesion, in the differential diagnosis when patients present with acute transverse myelopathy without pain.

Intensive lipid lowering therapy with titrated rosuvastatin yields greater atherosclerotic aortic plaque regression: Serial magnetic resonance imaging observations from RAPID study.

OBJECTIVE: Although previous randomized clinical trials established a basis for lipid guidelines worldwide, they employed fixed doses of statins throughout trials (fire-and-forget approach). In the real clinical setting, however, statin doses are titrated to achieve target low-density lipoprotein cholesterol (LDL-C) levels (treat-to-target approach). The major objective was to investigate whether intensive lipid-lowering therapy using the treat-to-target approach yielded greater regression of aortic plaques. METHODS: We therefore performed a prospective, randomized trial comparing the effects of standard (achieve LDL-C levels recommended by the Japanese guidelines) and intensive (achieve 30% lower LDL-C levels than standard) rosuvastatin therapy for 1 year in 60 hypercholesterolemic patients with a primary endpoint of aortic atherosclerotic plaques evaluated by non-invasive magnetic resonance imaging (MRI). RESULTS: Average doses were 2.9 ± 3.1 and 6.5 ± 5.1 mg/day for standard (n = 29) and intensive therapy group (n = 31), respectively. Although both therapies significantly reduced LDL-C and high-sensitivity C-reactive protein (hsCRP) levels, LDL-C reduction was significantly greater in the intensive group (-46 vs. -34%). MRI study showed that thoracic aortic plaques were significantly regressed in both groups, with greater regression of thoracic plaque in the intensive group (-9.1 vs. -3.2%, p = 0.01). Multivariate analyses revealed that thoracic plaque regression was significantly correlated with hsCRP reduction, but not with changes in serum lipids, endothelial function, or doses of rosuvastatin. CONCLUSION: Intensive statin therapy with titration targeting lower LDL-C levels resulted in greater thoracic aortic plaque regression compared to standard therapy, which was correlated with hsCRP reduction, suggesting that intensive statin therapy could provide better clinical outcomes.

Clinical characteristics associated with abnormal diffusion-weighted images in patients with transient cerebral ischemic attack.

BACKGROUND: Precise associations between clinical characteristics of transient ischemic attack (TIA) patients and diffusion-weighted imaging (DWI) positivity are still controversial. Thus, the purposes of this were to investigate the clinical characteristics associated with DWI positivity in patients with TIA and to develop a risk score for the prediction of DWI positivity in TIA. METHODS: Between April 2008 and June 2011, we retrospectively enrolled consecutive patients, who were admitted to our hospital with TIA and underwent DWI within 24 hours of admission. Patients were divided into a DWI-positive or DWI-negative group. The clinical characteristics of the 2 groups were compared, and a DWI positivity score was determined for each patient. We calculated the DWI positivity score by assigning a point value of 1 to the following factors: blood urea nitrogen to serum creatinine (BUN/Cr) ratio greater than 17.5, glucose greater than 161 mg/dL, and brain natriuretic peptide (BNP) greater than 55.4 pg/dL. Values below these cutoffs were given a value of 0, and the 3 point values were summed to obtain the final DWI positivity score (from 0 to 3). RESULTS: A total of 41 patients (median age = 62 years; 8 women) were enrolled in this study. There were 14 (35%) patients with DWI positivity. The median of the BUN/Cr ratio, blood glucose, and BNP were significantly higher in the DWI-positive than that in the DWI-negative group. As the DWI positivity score increased, there was an increased rate of DWI positivity. CONCLUSIONS: Our data indicate that seminal scores that included BUN/Cr ratio, glucose, and BNP contributed to DWI positivity in TIA patients.

[An advanced case of myopathy and dementia with a new mutation in the valosin-containing protein gene].

We report a 51-year-old man with myopathy and dementia probably caused by a novel mutation of the valosin-containing protein (VCP) gene, in the form of a p.Ala439Pro substitution. At 43 years old, he presented at least 2-year history of weakness of right ankle dorsiflexion. Findings from muscle biopsy suggested distal myopathy with rimmed vacuoles. However, no mutation in the GNE gene was identified. He complained of giving way of the knee, and muscle imaging study showed adipose tissue infiltration in the quadriceps. Ten years later, he was confined to a wheelchair and became reticent and antisocial with slightly impaired memory. A muscle CT revealed atrophy or replacement by adipose tissue in the muscles of neck, trunks and extremities muscles with laterality and variation of the degree. The magnetic resonance imaging of the brain showed bilateral frontal and temporal lobe atrophy with left dominance. Findings were compatible with inclusion body myopathy with Paget's disease of bone and frontotemporal dementia.

Multifocal conduction block in a patient with sarcoid neuropathy: successful treatment with intravenous immunoglobulin.

A 54-year-old-woman with sarcoidosis presented with progressive symmetric, predominantly distal weakness and sensory dysfunction with areflexia in all four limbs. Nerve conduction studies showed multifocal conduction blocks in several nerves. Oral steroids were ineffective; however, intravenous immunoglobulin (IVIG) therapy rapidly and repeatedly improved the patient's neurologic symptoms with a resolution of the conduction blocks. Multifocal conduction blocks are not frequently reported in patients with sarcoid neuropathy, but they may respond to early treatment with IVIG.

Stroke patients with cerebral microbleeds on MRI scans have arteriolosclerosis as well as systemic atherosclerosis.

Cerebral microbleeds (CMBs) are recognized as a manifestation of arteriolosclerosis in cerebral small vessels. However, little is known regarding whether stroke patients with CMBs often have systemic atherosclerosis. The aim of the present study was to elucidate this issue using the cardio-ankle vascular index (CAVI), a new index of systemic atherosclerosis, in acute ischemic stroke patients. We prospectively studied 105 patients (71 males, median age=70.0 years) with acute ischemic stroke. All of the patients were examined using T2*-weighted gradient echo magnetic resonance imaging (MRI) to look for and assess the CMBs and using fluid-attenuated inversion recovery to evaluate white matter hyperintensity (WMH). We assigned the patients into CMB and non-CMB groups and compared the clinical characteristics of these groups. The factors associated with CMBs were investigated using multivariate logistic regression analysis. T2*-weighted gradient echo MRI revealed CMBs in 47 patients (44.8%) and no CMBs in 58 patients (55.2%). The CAVI was significantly higher in the CMBs group (10.5 vs. 8.6, P<0.001). In the multivariate logistic regression analysis, CAVI per one point increase (odds ratio (OR), 1.50; 95% confidence interval (CI), 1.12-2.00; P=0.006), advanced WMH (OR, 4.78; 95% CI, 1.55-14.74; P=0.006) and impaired kidney function (OR, 3.31; 95% CI, 1.16-9.81; P=0.031) were independent factors associated with the presence of CMBs. A high CAVI was independently associated with CMBs in patients with acute ischemic stroke. Our results indicated that ischemic stroke patients with CMBs may have cerebral arteriolosclerosis as well as systemic atherosclerosis.

[A case of limbic encephalitis associated with leucine-rich glioma-inactivated 1 antibody].

We report a 55-year-old woman with limbic encephalitis associated with leucine-rich glioma-inactivated 1 (LGI1) antibody. She first developed a generalized seizure, following by consciousness loss. Although anticonvulant was initially effective, she began to present frequently with seizure and memory impairment. After eleven months from onset, she was admitted due to generalized seizure. Neurological examination after recovering from the treatment with anesthetic agent demonstrated disorientation and memory impairment. Cerebrospinal fluid analysis was unremarkable. MR brain FLAIR imaging demonstrated high intensity lesions in the medial parts of the both temporal lobes, suggesting limbic encephalitis. There were no signs of malignant tumor detected on systemic examination. LGI1 antibody was positive in the cerebrospinal fluid and we finally diagnosed this patient as having limbic encephalitis associated with LGI1 antibody. She demonstrated a good response to steroid therapy and was discharged after one month.

[Beneficial effects of rituximab in a case of anti-myelin antibody-associated neuropathy].

We report here in a 61-year-old woman in whom sensory disturbance predominantly affecting the distal portion of the limbs progressed over the course of 1 year. Blood tests showed IgM monoclonal gammopathy as well as the presence of anti-myelin-associated glycoprotein (MAG) antibody. Nerve conduction studies revealed significant prolongation of distal latency, and sural nerve biopsy showed IgM deposition on the myelin sheath. She was diagnosed as suffering anti-MAG neuropathy. High-dose intravenous immunoglobulin therapy proved to be ineffective and her symptoms progressed. Therefore, rituximab was administered and the sensory disturbance improved. Although no detailed studies on rituximab therapy for anti-MAG neuropathy have been reported in Japan, the present findings suggest that rituximab may be more effective than immunoglobulin therapy and other conventional therapies that have been used for autoimmune neuropathies.

Reduced cardiac 123I-MIBG uptake reflects cardiac sympathetic dysfunction in de novo Parkinson's disease.

It remains unclear whether cardiac iodine-123-labeled metaiodobenzylguanidine ((123)I-MIBG) uptake is clinically related to autonomic dysfunction on conventional autonomic function testing in de novo Parkinson's disease (PD). We therefore studied the relation between cardiac (123)I-MIBG uptake and cardiovascular autonomic dysfunction in patients with de novo PD. The subjects were 26 patients with de novo PD. The ratio of the average pixel count in the heart to that in the mediastinum was calculated to derive the cardiac (123)I-MIBG uptake. Cardiovascular autonomic function was evaluated on the basis of cardiovascular autonomic response on the Valsalva maneuver (VM), and systolic blood pressure response (SBP) on head-up tilt-table testing (HUT). Patients with de novo PD had significantly reduced cardiac (123)I-MIBG uptake as compared with controls (1.58 ± 0.43 vs. 2.25 ± 0.34, p = 0.0001) and cardiovascular autonomic response on the VM. No significant difference in the fall in SBP on HUT was found between patients with de novo PD and the controls. Cardiac (123)I-MIBG uptake in de novo PD was not significantly related to vasomotor sympathetic function, baroreceptor reflex gain, cardiac parasympathetic function, or the changes in SBP on HUT. Cardiac (123)I-MIBG uptake was, however, significantly related to the blood pressure overshoot in phase IV of the VM (r = 0.648, p = 0.0003). Cardiac (123)I-MIBG uptake began to decrease in association with the reduction in the overshoot of phase IV on the VM. Cardiac (123)I-MIBG uptake clinically reflects cardiac sympathetic dysfunction in de novo PD.

Corticospinal tract fibers cross the ephrin-B3-negative part of the midline of the spinal cord after brain injury.

The fibers of corticospinal tract (CST), which control fine motor function, predominantly project to the contralateral spinal cord, not recross to the ipsilateral side. Ephrin-B3, which is expressed in the midline of the spinal cord, and its receptor, EphA4, are crucial for preventing CST fibers from recrossing the midline in the developing spinal cord. However, these fibers can cross the midline to the denervated side after a unilateral CST or cortical injury. We determined the reason CST fibers can cross the midline after a cortical injury and the changes in ephrin-B3-EphA4 signaling associated with such a crossing. We first examined axonal sprouting from CST fibers after unilateral ablation of the motor cortex in postnatal and adult mice. CST fibers crossed the midline of the spinal cord after cortical ablation, especially when conducted during the early postnatal period. These fibers were well associated with functional recovery after the injury. We next assessed the mRNA expression of ephrin-B3 and EphA4 before and after the ablation. Surprisingly, no changes were detected in the expression patterns. We found, however, that ephrin-B3 expression in the ventral part of the midline disappeared after postnatal day 9 (P9), but was pronounced along the entire midline before P6. Most of the CST fibers crossed the midline through the ventral region, where ephrin-B3 expression was absent. Our results suggest that ephrin-B3 is not expressed along the entire midline of the spinal cord, and sprouting axons can cross the midline at ephrin-B3-negative areas.

Genetic deletion of paired immunoglobulin-like receptor B does not promote axonal plasticity or functional recovery after traumatic brain injury.

The rewiring of neural networks is a fundamental step in recovering behavioral functions after brain injury. However, there is limited potential for axonal plasticity in the adult CNS. The myelin-associated proteins Nogo, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein (OMgp) are known to inhibit axonal plasticity, and thus targeting the inhibitory pathways they participate in is a potential means of promoting plasticity and functional recovery. Each of Nogo, MAG, and OMgp interacts with both the Nogo receptor (NgR) and paired immunoglobulin-like receptor B (PirB). Here, we determined whether blocking PirB activity enhances axonal reorganization and functional recovery after cortical injury. We found that axons of the contralesional corticospinal tract sprouted into the denervated side of the cervical spinal cord after unilateral injury of the motor cortex. The extent to which this axonal reorganization occurred was far greater in mice lesioned during early postnatal days than in mice lesioned at an age when myelin had begun to form. This suggests that myelin-associated proteins might limit axonal remodeling in vivo. However, the number of sprouting fibers within either the corticospinal or corticorubral tract was not enhanced in PirB(-/-) mice. Blocking PirB signaling also failed to enhance functional recovery with three motor tests. Our results suggest that blocking the function of PirB is not sufficient to promote axonal reorganization or functional recovery after cortical injury.

Are hypersegmented neutrophils a characteristic of Boucher-Neuhäuser syndrome?

We report a family with Boucher-Neuhäuser syndrome (BNS). All 3 patients with BNS had hypersegmented neutrophils on peripheral-blood films. Our findings indicate that hypersegmented neutrophils are a characteristic of BNS. Blood films should therefore be examined in patients with a suspected diagnosis of BNS.