Optogenetic Inhibition of Glutamatergic Neurons in the Dysgranular Posterior Insular Cortex Modulates Trigeminal Neuropathic Pain in CCI-ION Rat.

In individuals with chronic neuropathic pain, the posterior insular cortex (PIC) has been found to exhibit increased glutamatergic activity, and the dysgranular portion of PIC (DPIC) has been investigated as a novel cortical target for pain modulation. However, the role of DPIC glutamatergic neurons (DPICg) in trigeminal neuropathic pain (TNP) remains unclear. Here, we examined the outcomes of DPICg inhibition in a rat model of chronic constriction injury of the infraorbital nerve (CCI-ION). Animals were randomly divided into TNP, sham, and control groups. TNP animals underwent CCI-ION surgery. Either optogenetic or null viruses were delivered to the contralateral DPICg of TNP and sham animals. In vivo single-unit extracellular recordings from the ipsilateral spinal trigeminal nucleus caudalis (TNC) and contralateral ventral posteromedial (VPM) thalamus were obtained under both "ON" and "OFF" stimulation states. Behavioral responses during the stimulation-OFF and stimulation-ON phases were examined. Expression of c-Fos, pERK, and CREB immunopositive neurons were also observed. Optogenetic inhibition of contralateral DPICg decreased the neural firing rate in both TNC and VPM thalamus, the expression of sensory-responsive cell bodies, and transcriptional factors in the DPIC of TNP group. Improvements in hyperalgesia, allodynia, and anxiety-like responses in TNP animals were also observed during stimulation-ON condition. In fine, descending pain processing is influenced by neuroanatomical projections from the DPIC to the pain matrix areas, and DPICg could play a necessary role in this neural circuitry. Therefore, the antinociceptive effect of DPICg inhibition in this study may provide evidence for the therapeutic potential of DPICg in TNP.

Implications of Mechanical Endovascular Thrombectomy for Acute Basilar and Posterior Cerebral Artery Occlusion.

OBJECTIVE: Protocols for posterior circulation ischemic stroke have not been established by randomized clinical trials. Mechanical endovascular thrombectomy (MET) devices are evolving, and many of these devices already developed or in development are suitable for posterior circulation MET. MATERIALS AND METHODS: We investigated the medical records of patients who underwent MET for posterior circulation ischemic stroke from January 2012 to August 2016. Fifteen patients were included. MET was performed in patients with or without injected intravenous tissue plasminogen activator. MET was considered in patients with a National Institute of Health Stroke Scale score of 4 or more, older than 18 years, with definite occlusion of the basilar artery or posterior cerebral artery (PCA), and who arrived at the hospital within 24 hours from onset. RESULTS: The direct catheter aspiration technique was used in five cases, and the stent retrieval technique was used in seven cases. The stent retrieval technique with the direct aspiration technique was used in three cases. Recanalization failed in two cases. Basilar occlusion without PCA involvement is the only effective factor of successful recanalization (p = 0.03). Successful recanalization (p = 0.005) and the presence of a posterior communicating artery (p = 0.005) affected the good outcome at discharge. CONCLUSION: An early diagnosis and active MET may improve the patient outcome. MET may help recanalization and good flow restoration and the potential for a good outcome.

Intraventricular hemorrhage long after successful encephaloduroarterio synangiosis in moyamoya patient.

Intraventricular hemorrhage long after successful encephaloduroarterio synangiosis (EDAS) is very rare. The effect of revascularization surgery for preventing hemorrhagic event of moyamoya disease remains controversial. We report a 17-year-old female with intracerebral hemorrhage and intraventricular hemorrahge 10 years after successful EDAS. Even though cerebral vessels angiography showed good collateral circulations without specific weak points, a cerebral hemorrhage could occur in patient with ischemic type of moyamoya disease long after successful indirect bypass operations. Good collateralization of cerebral angiography or magnetic resonance perfusion image after indirect bypass surgery would ensure against ischemic symptoms, not a hemorrhage. And, thus a life-time follow-up strategy might be necessary even if a good collateral circulation has been established.