Hemifacial spasm induced by intracranial aneurysm is a rare clinical condition. A 45-year-old male patient presented with a 3-year history of progressive involuntary twitching movement on right face. On radiological study, a dilated vascular lesion compressing the brain stem was found at the junction of vertebral artery and posterior inferior cerebellar artery. On operative field, we found the posterior inferior cerebellar artery and the fusiform aneurysm compressing root exit zone of facial nerve. Microvascular decompression was performed and the facial symptom was relieved without complications.

Osteosarcoma of the skull is a very rare condition. Moreover, it is extremely rare for osteosarcoma to present as multiple lesions confined to the skull. A 58-year-old woman was admitted with two masses in the parietal area of the skull, accompanied by mild headache and tenderness. Imaging revealed two masses with a heterogeneous consistency in the cranial bones. Excision craniectomy was performed and the pathology was consistent with osteoblastic osteosarcoma. Two nodules in the heart were found on routine follow-up imaging while the patient was undergoing chemotherapy. The nodules were biopsied and found to be metastatic osteosarcoma.

In this study, Hydrologic regime alterations(magnitude, magnitude and duration of annual extreme, frequency and duration of high and low pulse, rate and frequency of water condition changes, Range of Variability Approach) were analyzed by using Indicators of Hydrologic Alterations at the 11 major multi-purpose dam. The analysis result of the magnitude of monthly water conditions during drought season, inflow was 6.38 ㎥/sec ～ 39.84 ㎥/sec and outflow was 20.36 ㎥/sec ～ 49.43 ㎥/sec, was increased 1.84 % ～ 200.98 %. The analysis result of the magnitude of monthly water conditions during flood season, inflow was from 79.06 ㎥/sec to 137.12 ㎥/sec and outflow was from 65.32 ㎥/sec to 80.16 ㎥/sec, was decreased from 18.19 % to 40.39 %. The analysis result of the magnitude and duration of annual extreme, 1-day minimum was increased 82.86 % ～ 2,950 %, but 1-day maximum was decreased 34.78 % ～ 83.96 %. The analysis result of the frequency and duration of high and low pulse, low pulse count was decreased 29.67 % ～ 99.07 % and high pulse count was also decreased 4.60 % ～ 92.35 % after dam operation. Hydrograph rise rate was decreased 15.84 % ～ 79.31 % and fall rate was 1.97 % ～ 107.10 %. RVA of 1-day minimum was increased 0.60 ～ 2.67, also RVA of 1-day maximum was decreased 0.50 ～ 1.00.