Near-infrared spectroscopy-mediated neurofeedback enhances efficacy of motor imagery-based training in poststroke victims: a pilot study.

BACKGROUND AND PURPOSE: Despite the findings that motor imagery and execution are supposed to share common neural networks, previous studies using imagery-based rehabilitation have revealed inconsistent results. In the present study, we investigated whether feedback of cortical activities (neurofeedback) using near-infrared spectroscopy could enhance the efficacy of imagery-based rehabilitation in stroke patients. METHODS: Twenty hemiplegic patients with subcortical stroke received 6 sessions of mental practice with motor imagery of the distal upper limb in addition to standard rehabilitation. Subjects were randomly allocated to REAL and SHAM groups. In the REAL group, cortical hemoglobin signals detected by near-infrared spectroscopy were fed back during imagery. In the SHAM group, irrelevant randomized signals were fed back. Upper limb function was assessed using the finger and arm subscales of the Fugl-Meyer assessment and the Action Research Arm Test. RESULTS: The hand/finger subscale of the Fugl-Meyer assessment showed greater functional gain in the REAL group, with a significant interaction between time and group (F(2,36)=15.5; P<0.001). A significant effect of neurofeedback was revealed even in severely impaired subjects. Imagery-related cortical activation in the premotor area was significantly greater in the REAL group than in the SHAM group (T(58)=2.4; P<0.05). CONCLUSIONS: Our results suggest that near-infrared spectroscopy-mediated neurofeedback may enhance the efficacy of mental practice with motor imagery and augment motor recovery in poststroke patients with severe hemiparesis.

[Subcortical calcification on CT in Borden type III intracranial dural arteriovenous fistula].

We herein report a 67-year-old female who presented with progressive dementia and disturbance of consciousness. Brain CT showed multiple subcortical calcifications with edema. Enhanced CT showed multiple abnormal vessels in the left hemisphere. Electroencephalography indicated diffuse spike and slow wave complex, so non-convulsive status epilepticus was diagnosed. Cerebral angiography revealed several feeder arteries with retrograde leptomeningeal venous drainage. We diagnosed her with Borden type III cerebral dural arteriovenous fistulas. Trans-arterial embolization with n-butyl-2-cyanoacrylate was performed, and she has experienced no epileptic attacks for at least ten months. Calcification changes are sometimes seen in Borden type II dural arteriovenous fistulas but not in aggressive types, such as Borden type III. It is important to suspect dural arteriovenous fistulas when we encounter patients with progressive dementia or/and epilepsy with cerebral calcification lesions, as this may be a treatable disease condition.

Escape from the interferon response associated with RNA interference using vectors that encode long modified hairpin-RNA.

In mammalian cells, siRNAs have been used to induce RNA interference (RNAi) in an attempt to prevent nonspecific effects (including the interferon (IFN) response) which are caused by long double-stranded RNAs (dsRNAs) of more than 30 bp. In this report, we describe a novel and simple strategy for avoiding activation of the IFN response by dsRNA. We show that modified hairpin-RNAs (mhRNAs) of more than 100 bp, with multiple specific point-mutations within the sense strand and transcribed from the U6 or tRNA(Val) promoters, can cause RNAi without inducing the IFN pathway genes. Moreover, we demonstrate that the 50-bp mhRNA vector could effectively suppress the replication of multiple hepatitis C viruses (the genomes of which differ slightly, thus the 21-bp siRNA vector failed to suppress one of them). Our findings should enhance the exploitation of RNAi in mammalian cells, especially in the field of RNAi therapy against pathogenic viruses.

[Bilateral medial medullary infarction presented with monoplegia of the lower limb, followed by paraplegia and finally by tetraplegia].

A 69-year-old Japanese man suddenly developed monoplegia of left lower extremity, followed by paraplegia and finally by tetraplegia. MRI revealed an infarction in bilateral medial medulla extending from the cervicomedullary junction up to the upper limit of the medulla. Both hypoglossal nerve palsy and sensory disturbance were absent. At the pyramidal decussation, fibers to the lower extremities cross caudal to the fibers going to the upper extremities, therefore right below the decussation, fibers to the lower extremities run medial side of the fibers to the upper extremities, but later the former run lateral side of the latter. In this patient, the authors considered that the lesion initially damaged the pyramidal decussation at a slightly lower level, involving the tract to left lower extremity, and then extended to right lower extremity, to the left upper extremity, finally to the right upper extremity. Bilateral medial medullary infarction must be considered in the clinical course seen as in this patient.

Bacteremia caused by Desulfovibrio fairfieldensis.

Desulfovibrio species are anaerobic gram-negative, pleomorphic bacilli rarely causing infection in humans. In the present report, we describe a case of bacteremia caused by Desulfovibrio fairfieldensis. The patient, for whom biapenem was administered, rapidly improved without any sequelae. As far as we know, this is the first case report of infection by Desulfovibrio species in Japan.

In vivo delivery of small interfering RNA targeting brain capillary endothelial cells.

Brain capillary endothelial cells (BCECs) play an important role in blood-brain barrier (BBB) functions and pathophysiologic mechanisms in brain ischemia and inflammation. We try to suppress gene expression in BCECs by intravenous application of small interfering RNA (siRNA). After injection of large dose siRNA with hydrodynamic technique to mouse, suppression of endogenous protein and the BBB function of BCECs was investigated. The brain-to-blood transport function of organic anion transporter 3 (OAT3) that expressed in BCECs was evaluated by Brain Efflux Index method in mouse. The siRNA could be delivered to BCECs and efficiently inhibited endogenously expressed protein of BCECs. The suppression effect of siRNA to OAT3 is enough to reduce the brain-to-blood transport of OAT3 substrate, benzylpenicillin at BBB. The in vivo siRNA-silencing method with hydrodynamic technique may be useful for the study of BBB function and gene therapy targeting BCECs.

Motor cortical disinhibition in the unaffected hemisphere after unilateral cortical stroke.

Following a hemispheric stroke, various degrees of neuronal reorganization around the lesion occur immediately after disease onset and thereafter up to several months. These include transcallosal excitability, changes of the intact motor cortex and ipsilateral motor responses after transcranial magnetic stimulation (TMS) on the intact hemisphere. To elucidate the relationship between lesion localization and motor cortex excitability (intracortical inhibition; ICI) in the intact hemisphere, we applied a paired conditioning-test TMS paradigm in 12 patients with unilateral cortical stroke (cortical group) and nine patients with subcortical stroke caudal to the corpus callosum (subcortical group), with interstimulus intervals varying from 1 to 10 ms. All patients exhibited unilateral complete hand palsy. ICI was significantly less in the cortical group than in age-matched healthy control subjects. It was especially more marked in the cortical group patients with a disease duration of less than 4 months after onset. Patients in the cortical group with a duration longer than 4 months showed a tendency for ICI to be normalized, and there was a significant correlation between ICI and disease duration. Patients in the subcortical group showed normal excitability curves. All patients in the cortical group showed no transcallosal inhibition (TCI) in the active unaffected hand muscle after TMS of the affected motor cortex, whereas all the subcortical patients showed some TCI. No ipsilateral motor responses were elicited in the paretic hand in any of the patients. The reduced ICI in the cortical group might have been a result of disruption of TCI. The normalization of ICI in the patients with longer disease duration and the normal ICI in the subcortical group patients do not support the functional significance of motor cortex hyperexcitability in the unaffected hemisphere, at least in a patient population with poor motor recovery.

siRNA-based inhibition specific for mutant SOD1 with single nucleotide alternation in familial ALS, compared with ribozyme and DNA enzyme.

In many of autosomal dominant diseases such as familial amyotrophic lateral sclerosis (ALS) with SOD1 mutation, a missense point mutation may induce the disease by its gain of adverse property. Reduction of such a mutant protein expression is expected to improve the disease phenotype. Duplex of 21-nt RNA, known as siRNA, has recently emerged as a powerful tool to silence gene, but the sequence specificity and efficacies have not been fully studied in comparison with ribozyme and DNA enzyme. We could make the siRNA which recognized even a single nucleotide alternation and selectively suppress G93A SOD1 expression leaving wild-type SOD1 intact. In mammalian cells, the siRNA much more efficiently suppressed the expression of mutant SOD1 than ribozyme or DNA enzyme. Furthermore, these siRNAs could suppress cell death of Neuro2a induced by over-expression of mutant SOD1s with stress of proteasome inhibition. Our results support the feasibility of utilizing siRNA-based gene therapy of familial ALS with mutant SOD1.