Although the cause of occipital neuralgia is mostly unknown, entrapment of the greater occipital nerve (GON) at its piercing point of the tendinous aponeurotic attachment of the trapezius at the superior nuchal line has been reported to be the most common cause. We report an occurrence of unilateral facial pain associated with continuous aching and stabbing headache in the frontotemporal and occipital regions in a patient whose occipital neuralgia has lasted for years. These symptoms were completely different from those of typical occipital neuralgia, making diagnosis very difficult. A 52-year-old male patient with a 6-year history of intermittent stabbing pain in his right suboccipital area presented with an unremitting continuous pain in his right frontotemporal and malar areas that lasted 5 months. The aching and stabling pain in his frontotemporal and malar areas developed suddenly 5 months prior to presentation. Although he was treated after visiting neurology, dentistry, opthalmology, ENT, and pain clinic, the pain was not controlled. It spread to right periorbital and right occipital areas. At 3 months following decompression of the right GON, he reported no more pain and was able to stop the medication. Until 12 months after the operation, his craniofacial pain did not recur.

Although entrapment of the greater occipital nerve (GON) is a well-known cause of occipital neuralgia, occurrence of referred hemifacial trigeminal pain involving V2 distribution from chronic occipital neuralgia is rare. A 67-year-old female patient with intermittent left-sided occipital neuralgia of 10-year duration presented with a new onset of left-sided hemifacial pain of 5-month duration. With aggravation of left-sided occipital neuralgia, continuous burning pain and paresthesia gradually developed in her left malar and periorbital area. They also spread to her left upper lip. Severe compression of the left GON by tendinous aponeurotic attachment of the trapezius was found intraoperatively. Decompression of the left GON from chronic entrapment resulted in immediate relief for her hemifacial pain and chronic occipital neuralgia. These findings provide clinical affirmation of the existence of trigeminal/cervical convergence and hypersensitivity. Chronic irritating afferent input of occipital neuralgia caused by entrapment of the GON seems to be associated with sensitization and hypersensitivity of the second-order neurons in the trigeminocervical complex receiving convergent input from dural and cervical structures. Referred trigeminal pain from chronic occipital neuralgia may extend to V2 in addition to V1 trigeminal distribution.

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Although the transgluteal approach splitting the gluteus maximus muscle has been reported as a posterior approach for sciatic nerve entrapment (piriformis syndrome), detailed descriptions of the surgical steps and intraoperative findings have not been published. Thus, the objective of this study was to present the transgluteal approach for decompression surgery of sciatic nerve entrapment in the subgluteal space. A method of circumferentially decompressing the sciatic nerve from the surrounding piriformis muscle was devised by decompressing it to the level of the sacrotuberous ligament, which was more proximal than the existing decompression range. Surgical findings are presented step-by-step in the stages of localization, exposure, and decompression of the sciatic nerve during surgery. We also emphasize the importance of intraoperative nerve monitoring to identify the sciatic nerve and its branches and the inferior gluteal nerve during surgery performed under general anesthesia. Our observations of intraoperative electromyographic responses by individual nerve stimulation are summarized and reported.

Background Lymphopenia frequently occurs after concomitant chemoradiation (CCRT) in patients with glioblastoma (GBM) and is associated with worse overall survival (OS). A few studies have tried to identify risk factors for lymphopenia; however, the results were not clear. We aimed to identify potential risk factors for lymphopenia, focusing on the use of dexamethasone to control cerebral edema in patients with GBM. Methods The electronic medical records of 186 patients with newly diagnosed GBM treated at our institution between 2009 and 2017 were retrospectively examined. Acute lymphopenia was defined as total lymphocyte count less than 1,000 cells/µL at 4 weeks after completion of CCRT. Multivariate logistic regression analysis was used to identify independent risk factors for lymphopenia, and Cox regression analysis was used to identify independent risk factors for OS. Results Of the 125 eligible patients, 40 patients (32.0%) developed acute lymphopenia. Female sex and median daily dexamethasone dose ≥2 mg after initiation of CCRT were independent risk factors for acute lymphopenia on multivariate analysis. Acute lymphopenia, extent of surgical resection, and performance status were associated with OS; however, dexamethasone use itself was not an independent risk factor for poor OS. Conclusion Female sex, median daily dexamethasone dose ≥2 mg after initiation of CCRT until 4 weeks after completion of CCRT may be associated with acute lymphopenia. However, dexamethasone use itself did not affect OS in patients newly diagnosed with GBM. These results should be validated by further prospective studies controlling for other confounding factors.

In this paper, a novel pulse transit time (PTT) measurement method which employs electrocardiography and bioimpedance measurement (ECG-BIM) is proposed. Unlike conventional method based on ECG and photoplethysmography (ECG-PPG), the proposed method offers a promising technique for continuous and portable monitoring of cardiovascular diseases, as it requires only electrical components that can be fully integrated in a low-power and low-cost silicon circuit. To verify the validity of the proposed ECG-BIM method, experiments have been conducted on a human body in various conditions, using both the ECG-PPG and the ECG-BIM methods which is implemented using discrete off-the-shelf components. Experimental results show that the PTT data achieved from ECG-PPG and ECG-BIM methods are highly correlated, with correlation coefficient of 0.93, hence indicating the validity of the proposed method which can offer high level of integration and low power consumption for portable continuous cardiovascular signal monitoring.

In the visual cortex, synaptic plasticity is very high during the early developmental stage known as the critical period and declines with development after the critical period. Changes in the properties of N-methyl-D-aspartate receptor (NMDAR) and γ-aminobutyric acid type A receptor (GABAA R) have been suggested to underlie the changes in the characteristics of plasticity. However, it is largely unknown how the changes in the two receptors interact to regulate synaptic plasticity. The present study investigates the changes in the properties of NMDAR and GABAA R from 3 to 5 weeks of age in layer 2/3 pyramidal neurons of the rat visual cortex. The impact of these changes on the characteristics of long-term potentiation (LTP) is also investigated. The amplitude and decay time constant of GABAA R-mediated currents increased during this period. However, the decay time constant of NMDAR-mediated currents decreased as a result of the decrease in the proportion of the GluN2B subunit-mediated component. Induction of NMDAR-dependent LTP at 3 weeks depended on the GluN2B subunit, but LTP at 5 weeks did not. Enhancement of GABAA R-mediated inhibition suppressed the induction of LTP only at 5 weeks. However, partial inhibition of the GluN2B subunit with a low concentration of ifenprodil allowed the GABAA R-mediated suppression of LTP at 3 weeks. These results suggest that changes in the properties of NMDAR- and GABAA R-mediated synaptic transmission interact to determine the characteristics of synaptic plasticity during the critical period in the visual cortex.

Although some surgeons utilize interictal spikes recorded via electrocorticography (ECoG) when planning extensive peritumoral resection in patients with tumor-related epilepsy, the association between interictal spikes and epileptogenesis has not been fully described. We investigated whether the resection of interictal spikes recorded by ECoG is associated with more favorable surgical outcomes in tumor-related epilepsy. Methods: Of 132 patients who underwent epilepsy surgery for tumor-related epilepsy from 2006 to 2013, seven patients who underwent extraoperative ECoG were included in this study. In each patient, ECoG interictal spike sources were localized using standardized low-resolution brain electromagnetic tomography and were co-registered into a reconstructed brain model. Correspondence to the resection volume was estimated by calculating the percentage of interictal spike sources in the resection volume. Results: All patients achieved gross total resection without oncological recurrence. Five patients achieved favorable surgical outcomes, whereas the surgical outcomes of two patients were unfavorable. Correspondence rates to the resection volume in the favorable and unfavorable surgical outcome groups were 44.6%±27.8% and 43.5%±22.8%, respectively (p=0.96). All patients had interictal spike source clusters outside the resection volume regardless of seizure outcome. Conclusions: In these cases of tumor-related epilepsy, the extent of the resection of ECoG interictal spikes was not associated with postoperative seizure outcomes. Furthermore, the presence of interictal spike sources outside of the resection area was not related to seizure outcomes. Instead, concentrating more on the complete removal of the brain tumor appears to be a rational approach. (2019;9:126-133