Chun-Pi Chang, Yu-Min Chang, Chuang-Yen Huang, Hung-Shiang Fang, Chia-Hua Lin and Dueng-Yuan Hueng
Jiang Liu, Yue Yuan, Ying Fang, Li Zhang, Xiao-Li Xu, Hong-Ju Liu, Zhe Zhang and Yan-Bing Yu
Typical hemifacial spasm (HFS) commonly initiates from the orbicularis oculi muscle to the orbicularis oris muscle. Atypical HFS (AHFS) is different from typical HFS, in which the spasm of muscular orbicularis oris is the primary presenting symptom. The objective of this study was to analyze the sites of compression and the effectiveness of microvascular decompression (MVD) for AHFS.
The authors retrospectively analyzed the clinical data for 12 consecutive patients who underwent MVD for AHFS between July 2008 and July 2013.
Postoperatively, complete remission of facial spasm was found in 10 of the 12 patients, which gradually disappeared after 2 months in 2 patients. No recurrence of spasm was observed during follow-up. Immediate postoperative facial paralysis accompanied by hearing loss occurred in 1 patient and temporary hearing loss with tinnitus in 2. All 3 patients with complications had gradual improvement during the follow-up period.
The authors conclude that most cases of AHFS were caused by neurovascular compression on the posterior/rostral side of the facial nerve distal to the root entry zones. MVD is a safe treatment for AHFS, but the incidence of postoperative complications, such as facial paralysis and decrease in hearing, remains high.
Fang-Chen Liu, Yin-Hsien Liao, Che-Hsien Chang, Chao-Ming Chang, Yu-Chi Tsai and Dueng-Yuan Hueng
Zhong Yang, Yuan Xue, Qin Dai, Chao Zhang, H. Fang Zhou, J. Feng Pan and Dan Sheng
The authors introduce a novel technique to treat thoracic myelopathy caused by ossification of the ligamentum flavum (OLF): upper facet joint en bloc resection. This surgical procedure avoids surgery to the most heavily compressed cord surface, contact with the cord, and cord injury. The epidural venous plexus bleeding point can be directly seen and easily controlled during the decompression.
Between January 2007 and January 2009, thoracic myelopathy caused by OLF was diagnosed in 38 patients using plain radiography, CT, and MRI, and diagnoses were confirmed by postoperative pathological examination. All upper facet joint en bloc resection procedures were performed in 2 steps. First, the bony structures above the upper facet joint surfaces were resected and the upper facet joints were isolated. Second, en bloc resection of the upper facet joint was performed by dissection of the junction between the pedicle and upper facet joint. Intraoperative neurological monitoring was performed in all cases. The modified Japanese Orthopaedic Association (mJOA) scoring system was used to assess neurological status. The degree of postoperative expansion of the spinal cord was calculated on axial MR images. The pre- and postdecompression Cobb angle was applied to assess the magnitude of local kyphosis.
Of the 38 cases of OLF, 6 were single level, 12 were double level, and 20 were multilevel. Of the 92 ossified segments in this study, 23 (25.0%) were located in the upper thoracic spine (T1–4), 13 (14.1%) were located in the midthoracic spine (T5–8), and 56 (60.9%) were located in the lower thoracic spine (T9–L1). The mean intraoperative blood loss was 340 ± 54 ml. The neurological status improved during follow-up (mean 46.1 months) from a preoperative mean mJOA score of 5.39 ± 1.52 to 8.97 ± 1.22 points (t = 18.39, p < 0.05). The neurological function recovery rate ranged from 28.6% to 100%. The mean increase in pre- and postoperative kyphosis of the involved vertebrae was only 1.3° ± 1.6°. The increase in the cross-sectional area of the dural sac at the level of maximum compression suggested that decompression was complete.
Upper facet joint en bloc resection is effective and may be a reasonable alternative treatment choice for thoracic myelopathy caused by OLF.
Yuan Zhu, Qun Wu, Jin-Fang Xu, Dorothea Miller, I. Erol Sandalcioglu, Jian-Min Zhang and Ulrich Sure
Loss-of-function mutations in CCM genes are frequently detected in familial cerebral cavernous malformations (CCMs). However, the current functional studies of the CCM genes in vitro have been performed mostly in commercially purchased normal cell lines and the results appeared discrepant. The fact that the cerebral vascular defects are rarely observed in CCM gene-deficient animals suggests the requirement of additional pathological background for the formation of vascular lesions. Consistent with these data, the authors assumed that silencing CCM genes in the endothelium derived from CCMs (CCM-ECs) serves as a unique and valuable model for investigating the function of the CCM genes in the pathogenesis of CCMs. To this end, the authors investigated the role and signaling of CCM2 and CCM3 in the key steps of angiogenesis using CCM-ECs.
Endothelial cells (ECs) derived from CCMs were isolated, purified, and cultured from the fresh operative specimens of sporadic CCMs (31 cases). The CCM2 and CCM3 genes were silenced by the specific short interfering RNAs in CCM-ECs and in control cultures (human brain microvascular ECs and human umbilical vein ECs). The efficiency of gene silencing was proven by real-time reverse transcriptase polymerase chain reaction. Cell proliferation and apoptosis, migration, tube formation, and the expression of phosphor-p38, phosphor-Akt, and phosphor-extracellular signal-regulated kinase–1 and 2 (ERK1/2) were analyzed under CCM2 and CCM3 silenced conditions in CCM-ECs.
The CCM3 silencing significantly promoted proliferation and reduced apoptosis in all 3 types of endothelium, but accelerated cell migration exclusively in CCM-ECs. Interestingly, CCM2 siRNA influenced neither cell proliferation nor migration. Silencing of CCM3, and to a lesser extent CCM2, stimulated the growth and extension of sprouts selectively in CCM-ECs. Loss of CCM2 or CCM3 did not significantly influence the formation of the tubelike structure. However, the maintenance of tube stability was largely impaired by CCM2, but not CCM3, silencing. Western blot analysis revealed that CCM2 and CCM3 silencing commonly activated p38, Akt, and ERK1/2 in CCM-ECs.
The unique response of CCM-ECs to CCM2 or CCM3 siRNA indicates that silencing CCM genes in CCM-ECs is valuable for further studies on the pathogenesis of CCMs. Using this model system, the authors demonstrate a distinct role of CCM2 and CCM3 in modulating the different processes of angiogenesis. The stimulation of endothelial proliferation, migration, and massively growing and branching angiogenic sprouts after CCM3 silencing may potentially contribute to the formation of enriched capillary-like immature vessels in CCM lesions. The severe impairment of the tube integrity by CCM2, but not CCM3, silencing is associated with the different intracranial hemorrhage rate observed from CCM2 and CCM3 mutation carriers. The activation of p38, ERK1/2, and Akt signal proteins in CCM2- or CCM3-silenced CCM-ECs suggests a possible involvement of these common pathways in the pathogenesis of CCMs. However, the specific signaling mediating the distinct function of CCM genes in the pathogenesis of CCMs needs to be further elucidated.