Acute Spontaneous Subdural Hematoma of Arterial Origin

Acute spontaneous subdural hematoma (SDH) of arterial origin is very rare. We report a case of acute spontaneous SDH that showed contrast media extravasation from cortical artery on angiograms. A 58-year-old male patient developed sudden onset headache and right hemiparesis. Brain CT scan demonstrated acute SDH at left convexity. The patient was drowsy mentality on admission. He had no history of head trauma. Cerebral angiography was performed and revealed a localized extravasation of the contrast media from distal cortical MCA branch. After angiography, the patient deteriorated to comatose mentality. Decompressive craniectomy for removal of SDH was performed. We verified the arterial origin of the bleeding and coagulated the bleeding focus. The histological diagnosis was aneurysmal artery. He recovered after surgery with mild disability. In a case of acute spontaneous SDH, the possibility of a cortical artery origin should be considered

Differences in Cervical Sagittal Alignment Changes in Patients Undergoing Laminoplasty and Anterior Cervical Discectomy and Fusion

Objective Anterior cervical discectomy and fusion (ACDF) and laminoplasty (LP) are the most commonly performed procedures for degenerative cervical spondylosis. Cervical sagittal alignment (CSA) has recently been studied as an important predictor of clinical and radiological outcomes. The data from previous studies are insufficient for analysis using the recently designed CSA parameters, T1 slope (T1s), and T1s minus cervical angle (T1sCA). Methods We retrospectively collected data from patients who underwent ACDF and LP from January 2013 to May 2016. The CSA parameters included CA, sagittal vertical axis, T1s, and T1sCA. T1sCA values were used to evaluate the preoperative cervical balance (T1sCA>20°: imbalance). Clinical results were evaluated using the neck disability index (NDI) and recovery rate (RR) according to the Japanese Orthopedic Association scoring system. Results We analyzed the data of 72 patients (ACDF, n=39; LP, n=33). Imbalance on ACDF was associated with an increase in CA (balance: preoperative [PRE], 15.64° → follow-up [F/U], 15.74°, p=0.953; imbalance: PRE, −1.14° → F/U, 8.045°, p=0.008), whereas balance on LP was associated with a significant decrease in CA (balance: PRE, 16.26°→ F/U, 11.59°, p=0.009; imbalance: PRE, 5.36°→ F/U, 2.38°, p=0.249). No significant difference was found in the RR and NDI changes in the ACDF group based on balance, but a significant difference was found in RR in the LP group (balance: 61.65%±19.88%, imbalance: 46.90%±15.71%, p=0.046). Conclusion We found a significant difference in postoperative alignment in cases of ACDF and LP according to preoperative cervical sagittal balance. The postoperative clinical results of the LP group were more affected by F/U alignment than by the degree of alignment change

Group-Based Channel Access Scheme for a V2I Communication System using Smart Antenna

We propose a vehicle-to-infrastructure (V2I) communication system that utilizes a smart antenna technology to increase service coverage and system throughput. During contention-based channel access, a collision occurs when more than one vehicle selects the same minislot to transmit an access signal to an infrastructure. To solve this problem, we propose a group-based channel access scheme. Numerical analysis and simulation results show that the proposed scheme can help to reduce the number of collisions that occur during channel access. © 2011 IEEE.