Hypertension, cerebral Amyloid, aGe Associated Known neuroimaging markers of cerebral small vessel disease Undertaken with stroke REgistry (HAGAKURE) prospective cohort study: Baseline characteristics and association of cerebral small vessel disease with prognosis in an ischemic stroke cohort.

Introduction: Cerebral small vessel disease (SVD) is one of the leading causes of stroke; each neuroimaging marker of SVD is correlated with vascular risk factors and associated with poor prognosis after stroke. However, longitudinal studies investigating the association between comprehensive SVD burden scoring system, "total SVD score" - which encompasses the established neuroimaging markers of lacunae, cerebral microbleeds (CMBs), white matter hyperintensities (WMH) including periventricular hyperintensities, and perivascular spaces in basal ganglia- and clinical outcomes are limited. The aim of this study is to determine the association between SVD burden and long-term prognosis in patients with ischemic stroke. Methods and design: This prospective, single-center, observational study enrolled patients with acute ischemic stroke, including cerebral infarction and transient ischemic attack. Magnetic resonance imaging scans were performed, and then total SVD score (range, 0-4) was calculated. We recorded baseline characteristics and evaluated the relationships of long-term outcomes to SVD neuroimaging markers and total SVD score. Stroke recurrence was thought as primary outcome. Hazard ratios (HRs) of events during follow-up were calculated using Cox proportional hazards modeling with adjustments for age, sex, hypertension, dyslipidemia, diabetes mellitus, atrial fibrillation, and smoking. Cumulative event rates were estimated using the Kaplan-Meier method. Results: Consecutive 564 acute ischemic stroke patients were enrolled according to inclusion and exclusion criteria. A total of 467 participants with first-ever ischemic stroke were analyzed (median age 75.0 [interquartile range, 64.0-83.0] years, 59.3% male). Total SVD score was 0 point in 47 individuals (12.0%), 1 point in 83 (21.2%), 2 points in 103 (26.3%), 3 points in 85 (21.7%), and 4 points in 73 (18.7%). Twenty-eight recurrent stroke events were identified during follow-up. Total SVD score ≥ 2, presence of CMBs, and moderate-to-severe WMH were associated with increased risk of recurrent stroke events (HR 9.31, 95% confidence interval [CI] 2.33-64.23; HR 2.81, 95% CI 1.08-7.30; HR 2.90, 95% CI 1.22-6.88, respectively). Conclusion: The accumulation of SVD biomarkers as determined by total SVD score offered a reliable predictor of stroke recurrence. This study established a firm understanding of SVD prognosis in clinical settings.

Three-dimensional organization of local excitatory and inhibitory inputs to neurons in laminae III-IV of the spinal dorsal horn.

Laser scanning photostimulation was used to map the distribution of the synaptic input zones (sites that give local synaptic inputs) for dorsal horn laminae III-IV neurons, in parasagittal and transverse slices of the rat lumbar spinal cord, and examine how these inputs differed for neurons of different morphologies. All neurons received local excitatory and inhibitory synaptic inputs from within laminae III-IV, while a subset of neurons also received excitatory input from the superficial laminae, especially lamina IIi, as well as the II/III border region. Two anatomical properties were found to be predictive of the dorsoventral position of a neuron's input zone relative to its soma: (1) both excitatory and inhibitory input zones were more dorsal for neurons with longer dorsal dendrites, and (2) excitatory, but not inhibitory, input zones were more dorsal (relative to the soma) for more ventral neurons, with the transition between the dorsal input zones of laminae III-IV neurons and the ventral input zones of lamina II neurons occurring at the II/III border. The observed morphophysiological correlations support the idea that interlaminar connectivity is mediated via translaminar dendritic extensions and that, more generally, local connectivity within the dorsal horn is governed by rules relating the position of a neuron's soma and dendrites to the position of the local presynaptic neurons from which it receives inputs, which are specific to the axis and direction (dorsal vs. ventral), whether the input is excitatory or inhibitory, and the laminar position of the postsynaptic neuron.

Subpopulation-specific patterns of intrinsic connectivity in mouse superficial dorsal horn as revealed by laser scanning photostimulation.

The primary goal of this study was to map the transverse distribution of local excitatory and inhibitory synaptic inputs to mouse lamina I spinal dorsal horn neurons, using laser scanning photostimulation. A sample of lamina II neurons was also studied for comparison. Lamina I neurons received excitatory synaptic input from both laminae I-II and the outer part of III-IV, especially the II/III border region, while the inhibitory input zones were mostly confined within I-II. The excitatory synaptic input zones showed a pronounced medial asymmetry, which was correlated with a matching asymmetry in the dendritic fields of the neurons. Inhibitory input from laminae III-IV was found in a subpopulation of neurons occupying a highly restricted zone, essentially one cell layer thick, immediately below the lamina I/II border, with morphological and physiological properties that were distinct from other laminar populations in the superficial dorsal horn, and that suggest a critical role in interlaminar communication. This subpopulation also received excitatory input from laminae III-IV. Within this subpopulation, inhibitory III-IV input was correlated with the presence of long ventral dendrites. Correlations between the distribution of synaptic input zones and dendritic fields support the concept that interlaminar communication is mediated in part via contacts made onto ventrally extending dendrites of superficial laminae neurons. The results point to the presence of cell type specificity in dorsal horn circuitry, and show how the study of connectivity can itself help identify previously unrecognized neuronal populations.

Cavernous sinus thrombophlebitis related to dental infection--two case reports.

Two cases of cavernous sinus thrombophlebitis (CST) caused by dental infection are described. A 64-year-old woman presented with palsies of the left oculomotor and trochlear nerves after tooth extraction for dental caries in the left maxilla. A 54-year-old man presented with palsy of the left trochlear nerve, sensory disturbance in the ophthalmic and maxillary divisions of the left trigeminal nerve, ptosis, proptosis, and chemosis after dental treatment for caries and periodontitis in the left maxilla. In both patients, computed tomography and magnetic resonance imaging with contrast medium showed non-enhanced lesions within the left cavernous sinus and dilation of the superior ophthalmic veins, which indicated CST. These conditions were resolved by administration of broad-spectrum antibiotics. CST is rare but lethal, so prompt diagnosis is crucial, and immediate appropriate treatment is essential.

Separate inhibitory and excitatory components underlying receptive field organization in superficial medullary dorsal horn neurons.

Extracellular recording has shown that dorsal horn neurons can have an inhibitory surround outside their excitatory receptive field, but cannot reveal inhibitory inputs within the excitatory field, or show the underlying excitatory and inhibitory synaptic inputs that determine net output. To study the underlying components of receptive field organization, in vivo patch-clamp recording was used to compare the size and distribution of subthreshold, suprathreshold, and inhibitory fields, in neurons in the mouse superficial medullary dorsal horn that were characterized by their responses to noxious and innocuous mechanical facial stimulation. Subthreshold excitatory fields typically extended some distance beyond the borders of the suprathreshold field, and also commonly exhibited broader stimulus selectivity, in that the majority of nociceptive-specific neurons exhibited subthreshold responses to brush. Separate voltage-clamp recording of excitatory and inhibitory inputs using different holding potentials revealed that inhibition could be evoked from both within and outside the excitatory field. In nociceptive neurons, inhibition tended to be maximal at the excitatory receptive field center, and was usually greater for pinch than brush, although the selectivity for pinch versus brush was not as great as with excitatory responses. Based on current data on dorsal horn organization, we propose that the localized peak of inhibition at the excitatory field center could be mediated by local interneurons, while the more widespread surrounding inhibition may depend on supraspinal circuitry.

Organization of intralaminar and translaminar neuronal connectivity in the superficial spinal dorsal horn.

The spinal dorsal horn exhibits a high degree of intrinsic connectivity that is critical to its role in the processing of nociceptive information. To examine the spatial organization of this intrinsic connectivity, we used laser-scanning photostimulation in parasagittal and transverse slices of lumbar spinal cord to stimulate presynaptic neurons by glutamate uncaging, and mapped the location of sites that provide excitatory and inhibitory synaptic input to neurons of the superficial laminae. Excitatory interneuronal connectivity within lamina II exhibited a pronounced sagittal orientation, in keeping with the somatotopic organization present in the pattern of primary afferent projections. Excitatory inputs to all classes of lamina II neurons arose from a wider rostrocaudal area than inhibitory inputs, whereas both excitatory and inhibitory input zones were restricted mediolaterally. Lamina I-II neurons exhibited cell type-specific patterns in the laminar distribution of their excitatory inputs that were related to their dorsoventral dendritic expanse. All cell types received excitatory input predominantly from positions ventral to that of their soma, but in lamina I neurons and lamina II vertical cells this ventral displacement of the excitatory input zone was greater than in the other cell types, resulting in a more pronounced translaminar input pattern. A previously unknown excitatory input to the superficial dorsal horn from lamina III-IV was identified in a subset of the vertical cell population. These results reveal a specific three-dimensional organization in the local patterns of excitatory and inhibitory connectivity that has implications for the processing of information related to both somatotopy and sensory modality.

Incidence and clinical significances of human T-cell lymphotropic virus type I-associated myelopathy with T2 hyperintensity on spinal magnetic resonance images.

OBJECTIVE: To clarify the incidence and clinical significance of HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) showing T2 hyperintensity in the spinal cord on magnetic resonance images (MRI). PATIENTS AND METHODS: We reviewed the spinal cord MRI of 38 HAM/TSP patients and analyzed them in relation to clinical and laboratory findings. Analyzed data were: age at onset, disease duration, disability status, responsiveness to interferon therapy, brain abnormalities on MRI, serum anti-HTLV-I titers, and cerebrospinal fluid (CSF) findings. RESULTS: MRI findings of the spinal cord were classified into 3 types, "normal" (n=22, 57.9%), "atrophy" (n=13, 34.2%) and "T2-hyperintensity" (n=3, 7.9%). Patients in the normal and atrophy types showed slowly progressive paraparesis. Significant differences were not found between the normal and atrophy types in any clinical or laboratory data, including disease duration, disability status and responsiveness to interferon-alpha therapy. Meanwhile, all patients showing T2-hyperintensity had severe paraparesis of a rapid progressive nature, with CSF IgG elevation. CONCLUSION: HAM/TSP with T2-hyperintensity on spinal MRI shows a rapid progressive clinical course with severe motor impairment. The incidence of this malignant form of HAM/TSP is estimated to be around 7.9%.

[Clinical characteristics, diagnostic criteria and treatment of progressive multifocal leukoencephalopathy].

The clinical characteristics, diagnostic criteria and treatment of progressive multifocal leukoencephalopathy (PML) are reviewed. PML is characterized by rapid progression and poor outcome, and therefore requires the diagnosis and treatment as early as possible. Diffusion-weighted and diffusion tensor MRI were reported to be useful for the evaluation of disease activity of PML. The detection of JCV-DNA in the cerebrospinal fluid by PCR has replaced the brain biopsy. Highly active antiretroviral therapy has improved both the survival rate and the neurological functions in HIV-associated PML. However, the treatment for immune reconstitution inflammatory syndrome, which often deteriorates neurological functions, has never been solved.

Activation of TRPA1 channel facilitates excitatory synaptic transmission in substantia gelatinosa neurons of the adult rat spinal cord.

TRPA1 is expressed in primary sensory neurons and hair cells, and it is proposed to be activated by cold stimuli, mechanical stimuli, or pungent ingredients. However, its role in regulating synaptic transmission has never been documented yet. In the present study, we examined whether activation of the TRPA1 channels affects synaptic transmission in substantia gelatinosa (SG) neurons of adult rat spinal cord slices by using the whole-cell patch-clamp technique. A chief ingredient of mustard oil, allyl isothiocyanate (AITC), superfused for 2 min markedly increased the frequency and amplitude of spontaneous EPSCs (sEPSCs), which was accompanied by an inward current. Similar actions were produced by cinnamaldehyde and allicin. The AITC-induced increases in sEPSC frequency and amplitude were resistant to tetrodotoxin (TTX) and La3+, whereas being significantly reduced in extent in a Ca2+-free bath solution. In the presence of glutamate receptor antagonists CNQX and AP5, AITC did not generate any synaptic activities. The AITC-induced increases in sEPSC frequency and amplitude were reduced by ruthenium red, whereas being unaffected by capsazepine. AITC also increased the frequency and amplitude of spontaneous inhibitory postsynaptic currents; this AITC action was abolished in the presence of TTX or glutamate receptor antagonists. These results indicate that TRPA1 appears to be localized not only at presynaptic terminals on SG neurons to enhance glutamate release, but also in terminals of primary afferents innervating onto spinal inhibitory interneurons, which make synapses with SG neurons. This central modulation of sensory signals may be associated with physiological and pathological pain sensations.

Diffuse cranial nerve and cauda equina lesions associated with breast cancer.

We report on the case of a patient with breast cancer with diffuse cranial nerve and cauda equina lesions. Magnetic resonance imaging of the patient's brain and spinal cord showed diffuse abnormal enhancement and slight enlargement of the cranial nerves and cauda equina. Although the results of subsequent testing for two antineural antibodies were negative, paraneoplastic sensorimotor neuropathy associated with breast cancer was considered to be the most likely clinical diagnosis.

Four mutations of the spastin gene in Japanese families with spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a group of genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower limbs. HSP is caused by failure of development or selective degeneration of the corticospinal tracts, which contain the longest axons in humans. The most common form of HSP is caused by mutations of the spastin gene (SPAST), located on chromosome 2p21-p22, which encodes spastin, one of the ATPases associated with diverse cellular activities (AAA). In this study, we detected four causative mutations of SPAST among 14 unrelated patients with spastic paraplegia. Two missense mutations (1447A-->G, 1207C-->G) and two deletion mutations (1465delT, 1475-1476delAA) were located in the AAA cassette region. Three of these four mutations were novel. Previous reports and our results suggest that the frequency of SPAST mutations is higher among Japanese patients with autosomal dominant HSP, although SPAST mutations are also observed in patients with sporadic spastic paraplegia.