Long-Term Changes in Thecal Sac Compression and Decreased Cerebrospinal Fluid Space Following Paddle Lead Spinal Cord Stimulation at T9: A Long-Term Follow-Up via Three-Dimensional Myelographic Computed Tomography.

OBJECTIVES: To investigate the long-term changes in thecal sac compression following T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography (CT). MATERIALS AND METHODS: Seventeen patients with five-column paddle lead SCS at T9 underwent three-dimensional myelographic CT scans preoperatively, immediately after surgery, and after an average of 11 months. The cross-sectional areas of thecal sac and spinal cord and the widths of anterior and posterior cerebrospinal fluid (CSF) spaces were repeatedly measured and compared. The contact angle of the lead with long-term pain relief was assessed. RESULTS: The cross-sectional areas of thecal sac and spinal cord decreased significantly after lead placement (30.47 ± 9.21% and 4.71 ± 9.84%, respectively). Even after 11 months, a significant reduction was found with the preoperative values (17.97 ± 12.32% and 2.88 ± 7.09%). The widths of anterior and posterior CSF spaces decreased significantly after surgery (43.53 ± 13.17% and 57.13 ± 13.17%, respectively) and the severe decrease persisted long-term (29.13 ± 21.54% and 50.99 ± 16.07%). The average pain relief was 42.27 ± 17.50% with no correlation between the rate of reduction in cross-sectional areas of thecal sac and the widths of CSF spaces. CONCLUSIONS: Significant early reduction and late partial restoration occurred in the thecal sac and spinal cord and the width of the anterior and posterior CSF spaces in the T9 5-column paddle lead SCS. Thecal sac compromise was expected to some extent after paddle lead implantation, but the degree is significant, and the cross-sectional area of the spinal cord as well as the thecal sac is affected. Fortunately, these anatomical changes did not cause any clinical problems except for intercostal root irritation. The shape and flat contours of the five-column paddle leads clearly affected the results.

Blood lead concentration and exposure related factors in Korea from the National Environmental Health Survey (KoNEHS) II (2012-2014).

This study evaluated lead concentrations in blood and related factors among the South Korean population based on data from the Korea National Environmental Health Survey (KoNEHS) II (2012-2014) conducted by the National Institute of Environmental Research and the Ministry of Environment. Personal data were obtained from non-institutionalized civilian Korean individuals in an interview with trained community surveyors using a structured questionnaire (n = 6,455, aged 19 or older, mean age 49.7 years). The lead concentrations in whole blood were analyzed by atomic absorption spectrophotometry (AAS) with a Zeeman-effect-based background corrector. The precision and accuracy of the analytical methods were verified by internal and external quality controls (G-EQUAS, Germany). Statistical analysis was performed using weighted KoNEHS II data separated by sex, and the lead concentration was expressed as a geometric mean (GM). Multiple linear regression was performed using the SPSS 23.0 software package (SPSS Inc., Chicago, IL, USA). The total GM of lead concentrations was 19.5 µg/L. Lead concentrations increased with age and were higher in males (22.8 µg/L) than in females (16.6 µg/L). Smokers and drinkers had higher concentrations than non-smokers and non-drinkers of both sexes. People who used herbal medications had higher concentrations than those who did not among females. People of both sexes living in rural areas had higher lead concentrations than those in urban areas. Lead concentrations also varied with educational level, total family income, the type of water regularly consumed, and occupation. The average lead concentration of the general adult population in Korea has rapidly decreased over time from 45.8 µg/L (1999) to 19.45 µg/L (2012-2014); however, it remains higher than that of the United States, Germany, and Canada. The factors significantly related to lead concentration in South Korea were age, sex, smoking and alcohol drinking status, herbal medication usage by females, residential area, drinking water at home, and occupation. These factors could be used to improve occupational and environmental hygiene among the Korean population.

Intraoperative monitoring of Z-L response (ZLR) and abnormal muscle response (AMR) during microvascular decompression for hemifacial spasm. Interpreting the role of ZLR.

BACKGROUND: Z-L response (ZLR) has been suggested to a new electromyographic (EMG) potential recorded from the facial muscle of patient with hemifacial spasm (HFS) during microvascular decompression (MVD). Although ZLR has been suggested to be useful, experience of ZLR monitoring is limited and its significance during MVD is still unclear. METHODS: To investigate the significance of ZLR, both ZLR and abnormal muscle response (AMR) were simultaneously recorded before and after decompression of root exit zone (REZ) in 20 consecutive patients with HFS. RESULTS: All 19 AMRs elicited before REZ decompression disappeared immediately after decompression of REZ. ZLRs were also observed before decompression of REZ in 19 (95%) of 20 patients. Despite negative conversion of AMR after decompression in 19 patients, ZLR disappeared in only 13 (68.4%) of 19 patients. Among six sustained ZLRs, three showed reduction in the intensity of ZLRs while the other three remained unchanged. There were nine cases featuring attachment of the distal, non-offending portion of offending vessels to the distal course of the facial nerve in addition to attachment to REZ. Negative ZLR conversion and presence of peripheral contact of offending vessels to distal facial nerves showed significant correlations (p < 0.05). ZLR could be elicited by electrical stimulation at non-REZ-offending portion of the offending arterial wall, attached to the distal course of the facial nerve. HFS disappeared immediately in all 20 patients. CONCLUSIONS: Although ZLR might be helpful in cases with multiple offenders, interpretation of ZLR needs caution for non-specific transmission of electric current through vessel wall to facial nerve.

Intraoperative Neurophysiological Monitoring (Motor and Somatosensory Evoked Potentials) in Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion Pain.

AIMS: To address the feasibility and importance of intraoperative neurophysiological monitoring (IONM) in dorsal root entry zone (DREZ) lesioning for brachial plexus avulsion pain. METHODS: Muscle motor evoked potential (mMEP) and somatosensory evoked potential (SSEP) were applied during DREZ lesioning for brachial plexus avulsion pain. RESULTS: IONM of mMEPs and SSEPs was feasible for monitoring of the spinal cord during DREZ lesioning. With the exception of 3 unrecordable mMEPs in ipsilateral arms, mMEPs were preserved and referenced to look for changes according to lesioning in 6 upper extremities (66.6%) and 8 lower extremities. All 3 patients with >50% reduction in baseline mMEP amplitude after lesioning in either the ipsilateral upper or lower extremities showed postoperative ataxia and weakness of the lower extremities (100%). Only 2 out of 9 patients (22.2%) with brachial plexus avulsion pain had discernible baseline SSEPs in the ipsilateral upper extremities. One of 2 patients with discernible SSEPs in the upper extremities showed significant SSEP events during the DREZ lesioning and experienced postoperative ataxia and weakness in the legs despite the absence of a SSEP event in the lower extremities. CONCLUSION: Significant events on IONM were common during DREZ lesioning for brachial plexus avulsion pain and were closely related to the occurrence of postoperative neurological deficits.

Cardiovascular autonomic dysfunctions in elderly patients with essential tremor: comparison with healthy controls.

Questionnaire-based analyses show that patients with essential tremor (ET) may have several autonomic dysfunctions, especially in the cardiovascular and genitourinary domains; yet the laboratory correlates of autonomic dysfunction in ET are unknown and have not been studied. Herein, we explored whether sympathetic and parasympathetic functions differed between control subjects and patients with ET. Seventy-five elderly patients with ET were enrolled in this study, along with 25 age-matched controls. Orthostatic vital signs, ambulatory 24-h blood pressure monitoring and 24-h Holter monitoring values were recorded and metaiodobenzylguanidine (MIBG) uptake was assessed using the heart-to-mediastinum ratio (H/M ratio). The frequencies of orthostatic hypotension, supine hypertension, nocturnal hypertension and non-dipping were not different between the ET patients and the controls, although ET patients had more episodes of orthostatic intolerance. The ET group also had similar heart rate variations as the control group for all the time-domains. The mean H/M ratios for the ET group were not statistically different from that of the control group. This result proves that the autonomic control of the cardiovascular system is normal in ET.

Relationship between Postoperative EEG Driving Response and Lead Location in Deep Brain Stimulation of the Anterior Nucleus of the Thalamus for Refractory Epilepsy.

OBJECTIVES: Interpreting the postoperative electroencephalographic (EEG) driving response (DR) as an indicator of electrode placement within the thalamic nucleus in deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) for refractory epilepsy is controversial. MATERIALS AND METHODS: We retrospectively investigated the relationship between postoperative EEG DR and the location of 11 electrodes in 6 patients who underwent ANT DBS for refractory epilepsy. RESULTS: Cerebral synchronizing EEG DR was observed in 10 electrodes. However, 9 of the 11 electrodes were located within the ANT. For the 2 electrodes that missed the ANT, DR was observed in 1 misplaced electrode facing the anterior surface of the ANT within the third ventricle. The other misplaced electrode without DR elicitation showed a DR after electrode repositioning. CONCLUSIONS: The diagnostic significance of DR as indirect evidence of electrodes being within thalamic nuclei is limited. If DR is not elicited, it should be regarded as a misplacement. Even if DR is elicited, it may not be interpreted as a sound indicator of proper electrode placement within the thalamus. A sophisticated, postoperative imaging study is warranted in every case of ANT DBS.

Clinical Outcome of Patients with Deep Brain Stimulation of the Centromedian Thalamic Nucleus for Refractory Epilepsy and Location of the Active Contacts.

OBJECTIVES: To investigate the clinical outcome of patients treated with chronic deep brain stimulation (DBS) of the centromedian nucleus (CM) for refractory epilepsy and to determine the location of active contacts. METHODS: The outcome of CM stimulation was evaluated as percent seizure reduction compared to the baseline 3 months. To establish the location of active contacts, 27 leads were studied in 14 patients with refractory epilepsy. An analysis was conducted to reveal whether any coordinates of the center of the active contacts predicted percent seizure reduction. RESULTS: With an average follow-up of 18.2 ± 5.6 months, the mean percent seizure reduction (n = 14) was 68 ± 22.4% (25-100%). Eleven of the 14 patients (78.6%) achieved >50% improvement in seizure frequency. Specifically, all 4 patients (100%) with generalized epilepsy (Lennox-Gastaut syndrome) and 7 of 10 patients (70%) with multilobar epilepsy showed >50% reduction in seizure frequency. The mean coordinates of the center of the active contact were located in the superior part of the anterior ventrolateral CM. The calculated coordinates of laterality from midline (x), anterior-posterior (y) and height (z) from the posterior commissure did not correlate with seizure outcome measured by percent seizure reduction. However, the locations of active contacts used during chronic CM stimulation in multilobar epilepsy were identified more dorsal to those used in generalized epilepsy. CONCLUSIONS: Chronic CM stimulation is a safe and effective means in the treatment of refractory epilepsy.

Phantom Remodeling Effect of Dorsal Root Entry Zone Lesioning in Phantom Limb Pain Caused by Brachial Plexus Avulsion.

BACKGROUND: Dorsal root entry zone (DREZ) lesioning has been reported to be effective for phantom limb pain caused by brachial plexus avulsion pain. Most reports on DREZ lesioning for brachial plexus avulsion pain have focused on the results of pain relief without a detailed description of phantom sensations following DREZ lesioning. MATERIALS AND METHODS: Two patients (1 with amputation and the other nonamputated) with chronic intractable phantom limb pain caused by brachial plexus avulsion underwent DREZ lesioning on the avulsed segments of the cervical spinal cords. Changes of the phantom limb were observed. RESULTS: Immediately following DREZ lesioning, the phantom limb pain disappeared in the amputee, the phantom arm was shortened and the phantom hand disappeared. The other patient with the nonamputated arm reported an immediate 50% reduction in the size of the phantom hand, and pain relief was up to 70% of the preoperative phantom limb pain. There was no further change in the phantom arm and hand during the follow-up of 1.5-2 years. CONCLUSIONS: The phantom arms and hands showed a prompt shortening and reduction in size, rather than a disappearance, following successful DREZ lesioning in patients with chronic phantom limb pain caused by brachial plexus avulsion.

Multimodal, Intraoperative Monitoring during Paddle Lead Placement for Cervicothoracic Spinal Cord Stimulation.

BACKGROUND AND OBJECTIVE: We investigated the efficacy of combined somatosensory evoked potentials (SSEP) and electromyography monitoring during paddle lead placement through cervicothoracic laminectomy under general anesthesia in a retrospective review of data from 25 patients. METHODS: Muscle motor evoked potentials (MEP) recordings and SSEP monitoring were used for surveillance of the spinal cord. Collision testing of SSEP and threshold amplitudes of compound muscle action potentials (CMAP) in the bilateral upper and lower extremities evoked by electrode contacts of the paddle lead were checked to determine the laterality of the lead in the mediolateral direction. RESULTS: A significant decrease in amplitudes of muscle MEP in spite of stable SSEP occurred in 2 patients: 1 patient with a retrograde C1-C2 insertion and another patient with an anterograde C4/C5 insertion. Repositioning of leads based on significantly asymmetrical collision testing of SSEP and thresholds of CMAP in bilateral extremities was needed in 6 and 8 patients, respectively. In 22 patients, paresthesia coverage of the painful area was consistently located in the painful side, either unilaterally or bilaterally. There was no episode of revision for suboptimal lead placement. CONCLUSIONS: Intraoperative neurophysiological guidance using SSEP and muscle MEP was useful for the safe and accurate placement of paddle leads for cervicothoracic SCS.

Long-term results of motor cortex stimulation in the treatment of chronic, intractable neuropathic pain.

BACKGROUND/OBJECTIVES: Although motor cortex stimulation (MCS) has been used for more than 20 years in the treatment of chronic neuropathic pain, there is still a debate about the efficacy of MCS. METHODS: To investigate the long-term results and the factors associated with the long-term success of chronic MCS, 21 patients who underwent MCS trial were classified as having central poststroke pain, central pain after spinal cord injury (SCI) and peripheral neuropathic pain, and we investigated the clinical factors associated with long-term success and degree of pain relief. RESULTS: Of the 21 patients, 16 (76.2%) had a successful trial and underwent chronic MCS. In the long-term follow-up (53 ± 39 months), only the diagnosis (central poststroke pain and peripheral neuropathic pain) was associated with long-term success defined as >30% pain relief compared with baseline (p < 0.05, χ(2) test). The difference in pain relief was not significant in patients having SCI pain (p > 0.05, 1-way ANOVA). The other variables did not show any significant influence in the long-term success and degree of pain relief (p > 0.05, 1-way ANOVA). CONCLUSIONS: MCS was more effective in the treatment of chronic neuropathic pain of central poststroke pain and peripheral neuropathic pain types than in the treatment of SCI pain in the long-term follow-up.

Simultaneous trial of deep brain and motor cortex stimulation in chronic intractable neuropathic pain.

BACKGROUND/OBJECTIVES: Both motor cortex stimulation (MCS) and deep brain stimulation (DBS) of the ventralis caudalis (Vc) thalamus have been shown to be effective in chronic neuropathic pain, and the modulation of thalamic and thalamocortical activity is regarded as a possible mechanism. Although Vc DBS and MCS have a common analgesic mechanism, the application of MCS and DBS is still considered empirical, and there is no consensus on which method is better. METHODS: We performed a simultaneous trial of thalamic Vc DBS and MCS in 9 patients with chronic neuropathic pain and investigated the results of the stimulation trial and long-term pain relief. RESULTS: Of the 9 patients initially implanted with both DBS and MCS electrodes, 8 (89%) had a successful trial; 6 of these 8 patients (75%) responded to MCS, and the remaining 2 responded to Vc DBS. During the long-term follow-up, the mean numeric rating scale score decreased significantly (p < 0.05). The percentages of pain relief in the chronic MCS group and the chronic DBS group were 37.9 ± 16.5 and 37.5%, respectively, and there was no statistically significant difference (p = 0.157). CONCLUSION: Considering the initial success rate and the less invasive nature of epidural MCS compared with DBS, we think that MCS would be a more reasonable initial means of treatment for chronic intractable neuropathic pain.

Dorsal rhizotomy for pain from neoplastic lumbosacral plexopathy in advanced pelvic cancer.

BACKGROUND: Pain from neoplastic lumbosacral plexopathy is resistant to conventional pain treatment. According to a recent review of destructive procedures for cancer pain, only cordotomy has been reported to play an important role in the treatment of cancer pain. To date, the effectiveness of dorsal rhizotomy, which selectively interrupts pain transmission, has not been shown in neoplastic lumbosacral plexopathy. OBJECTIVES: The present study seeks to find out the effectiveness of selective dorsal rhizotomies for intractable pain from neoplastic lumbosacral plexopathy in terminal pelvic cancer patients. METHODS: Dorsal rhizotomies of the involved segments were performed on 6 cancer patients in whom neuropathic pain from lumbosacral plexus involvement in terminal pelvic cancer had been refractory to other therapies. Clinical efficacy of the procedure was assessed by comparing patient pain ratings and narcotic usage before and after dorsal rhizotomy. RESULTS: Examination of the results indicated a significant reduction in pain ratings as well as a significant reduction in daily narcotic use. No adverse neurological effects were observed and no recurrence of pain from neoplastic lumbosacral plexopathy was noted. CONCLUSIONS: These findings provide corroborating clinical evidence for the effectiveness of selective dorsal root rhizotomy for the intractable pain from lumbosacral plexopathy in terminal pelvic cancer patients.

Secondhand smoke exposure and urine cotinine concentrations by occupation among Korean workers: results from the 2008 Korea National Survey for Environmental Pollutants in the Human Body.

This study aimed to estimate the status of secondhand smoke (SHS) exposure through urine cotinine analysis among nonsmoking workers in Korea and to analyze factors affecting urine cotinine concentrations. Data were based on "The 2008 Korea National Survey for Environmental Pollutants in the Human Body," a cross-sectional study of the National Institute of Environmental Research of Korea. We selected 1448 nonsmoking adult workers from 200 localities to participate in this survey. Urine cotinine concentrations were analyzed using a gas chromatograph-mass selective detector. We calculated separate covariate-adjusted geometric means for socio-demographic variables for males, females, and total subjects by analysis of covariance (ANCOVA). Statistical analyses were performed using SPSS version 18.0 (SPSS Inc., Chicago, Ill.). The prevalence of self-reported exposure to SHS was 36.9%. The geometric mean (95% confidence interval) of urine cotinine concentrations among all participants was 16.50 (14.48-18.80) µg/L. Gender, living area, education, and SHS exposure showed significant differences in urine cotinine concentrations. The urine cotinine concentrations of farmworkers and blue-collar workers such as skilled agricultural, forestry, and fishery workers, and elementary occupations were higher than those of white-collar workers such as clerical support workers, technicians, and associate professionals. Such a high proportion of the population having high urine cotinine levels indicates widespread exposure to SHS among nonsmoking workers in Korea. Furthermore, the urine cotinine levels among nonsmoking workers exposed to SHS varied by occupation. The measured urine cotinine concentration is suggested to be a valuable indication of SHS exposure in Korea.

Importance of Sacrotuberous Ligament in Transgluteal Approach for Sciatic Nerve Entrapment in the Greater Sciatic Notch (Piriformis Syndrome).

OBJECTIVE: The efficacy of sciatic nerve decompression via transgluteal approach for entrapment of the sciatic nerve at the greater sciatic notch, called piriformis syndrome, and factors affecting the surgical outcome were analyzed. METHODS: The outcome of pain reduction was analyzed in 81 patients with sciatic nerve entrapment who underwent decompression through a transgluteal approach. The patients were followed up for at least 6 months. The degree of pain reduction was analyzed using a numerical rating scale-11 (NRS-11) score and percent pain relief before and after last follow-up following surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. In addition, demographic characteristics, anatomical variations, and variations in surgical technique involving sacrotuberous ligamentectomy were analyzed as factors that affect the surgical outcome. RESULTS: At a follow-up of 17.5±12.5 months, sciatic nerve decompression was successful in 50 of 81 patients (61.7%), and the pain relief rate was 43.9±34.17. Subjective improvement based on a 10-point Likert scale was 4.90±3.43. Among the factors that affect the surgical outcome, only additional division of the sacrotuberous ligament during piriformis muscle resection played a significant role. The success rate was higher in the scarotuberous ligementectomy group (79.4%) than in the non-resection group (42.6%), resulting in statistically significant difference based on average NRS-11 score, percent pain relief, and subjective improvement (p<0.05, independent t-test). CONCLUSION: Sciatic nerve decompression is effective in pain relief in chronic sciatica due to sciatic nerve entrapment at the greater sciatic notch. Its effect was further enhanced by circumferential dissection of the sciatic nerve based on the compartment formed by the piriformis muscle and the sacrotuberous ligament in the greater sciatic notch.

Generalized Extension of Referred Trigeminal Pain due to Greater Occipital Nerve Entrapment.

We report a very rare case of referred pain caused by greater occipital nerve (GON) entrapment, inducing spontaneous pain in the whole body as well as in the trigeminal nerve region of the face and head. It has already been reported that entrapment of the GON can induce referred pain in the ipsilateral limb as well as the ipsilateral hemiface. A 42-year-old female patient presented with chronic pain in her gums, jaw angle, submandibular region, retro-auricular suboccipital, and temporo-occipital vertex that had been ongoing for four years. As the patient's head pain and facial pain became severe, severe spontaneous pain occurred in the arm, waist, and both lower extremities. This patient's pain in the occipital and neck, spontaneous pain in the face, jaw, and whole body improved with decompression of the GON. Anatomical basis of pain referral to the facial trigeminal area caused by chronic GON entrapment is convergence of nociceptive inflow from high cervical C1-C3 structures and trigeminal orofacial area in the dorsal horn of the cervical spinal cord from the C2 segment up to the medullary dorsal horn (MDH). The major afferent contribution among the suboccipital and high cervical structure is mediated by spinal root C2 that is peripherally represented by the GON. Chronic noxious input from GON entrapment can cause sensitization and hypersensitivity in second order neurons in the trigeminocervical complex (TCC) and MDH in the caudal trigeminal nucleus and high cervical cord. Generalized extension of referred pain due to GON entrapment is thought to involve two possible pathophysiologies. One is the possibility that generalized pain is caused by sensitization of third-order nociceptive neurons in the thalamus. Another speculation is that spontaneous pain may occur throughout the body due to dysfunction of the descending brain stem pain-modulating pathway by sensitization and hyperexcitation of the MDH and trigeminal brainstem sensory nuclear complex (TBSNC).

Increase in Trigeminal Nerve Cross-Sectional Area on Immediate Postoperative MRI Predicts Favorable Outcome After Microvascular Decompression for Classical Trigeminal Neuralgia.

BACKGROUND: Although distortion or indentation of a trigeminal nerve due to neurovascular compression (NVC) is associated with classical trigeminal neuralgia, whether morphological change in the trigeminal nerve is relieved by eliminating NVC has not been studied. OBJECTIVE: To estimate morphological change in the trigeminal nerve after microvascular decompression (MVD). METHODS: Fifty patients with classical trigeminal neuralgia who underwent MVD were included. Using coronal images in both preoperative and postoperative MRI, the trigeminal nerve cross-sectional area (CSA) was measured at 4 mm anterior to the nerve entry into the pons. Clinical outcomes were assessed using the Barrow Neurological Institute Pain Intensity Scale (BNI-PS) at the patient's latest follow-up. RESULTS: Forty-one patients achieved favorable outcomes without medication (BNI-PS I or II), and 9 patients had residual pain (BNI-PS ≥ 3A). The mean symptomatic trigeminal nerve CSA was increased by 51.47% after MVD in the favorable outcome group (preoperative: 4.37 ± 1.64 mm 2 vs postoperative: 6.26 ± 1.76 mm 2 , P < .01), whereas it was not significantly changed in the unfavorable outcome group (preoperative: 4.20 ± 1.19 mm 2 vs postoperative: 4.43 ± 1.24 mm 2 , P = .69). Kaplan-Meier survival analysis showed that the 3-year probability of maintaining a favorable outcome was 92.3 ± 7.4% and 56.1 ± 11.9%, for those whose symptomatic trigeminal nerve CSA was increased by over 20% and less than 20%, respectively ( P < .01). CONCLUSION: Morphological changes in the trigeminal nerve due to NVC could be recovered by MVD, and increases in the trigeminal nerve CSA predicted favorable outcomes.

E-cadherin as a predictive marker of brain metastasis in non-small-cell lung cancer, and its regulation by pioglitazone in a preclinical model.

It remains unclear whether patients with non-small-cell lung cancer (NSCLC) develop brain metastasis during or after standard therapy. We attempted to identify biological markers that predict brain metastasis, and investigated how to modulate expression of such markers. A case-control study of patients who were newly diagnosed with NSCLC and who had developed brain metastasis during follow-up was conducted between 2004 and 2009. These patients were compared with a control group of patients who had NSCLC but no evidence of brain metastasis. Immunohistochemical analysis of expression of Ki-67, p53, Bcl-2, Bax, vascular endothelial growth factor, epidermal growth factor receptor, caspase-3, and E-cadherin was conducted. The methylation status of the genes for O(6)-methylguanine-DNA-methyltransferase, tissue inhibitor of matrix metalloproteinase (TIMP)-2, TIMP-3, and death-associated protein-kinase was also determined, by use of a methylation-specific polymerase chain reaction. A significantly increased risk of developing brain metastasis was associated with the presence of primary tumors with low E-cadherin expression in patients with NSCLC. We also investigated the effects of pioglitazone, a peroxisome proliferator-activated receptor γ-activating drug, in tumor-bearing mouse models. We found that E-cadherin expression was proportional to pioglitazone exposure time. Interestingly, pioglitazone pretreatment before cancer cell inoculation prevented loss of E-cadherin expression and reduced expression of MMP9 and fibronectin, compared with the control group. E-cadherin expression could be a predictor of brain metastasis in patients with NSCLC. Preventive treatment with pioglitazone may be useful for modulating E-cadherin expression.

Occipital nerve stimulation for medically refractory hypnic headache.

OBJECTIVE: Hypnic headache is a rare, primary headache disorder that exclusively occurs regularly during sleep. We present a case of hypnic headache successfully managed with occipital nerve stimulation. MATERIALS AND METHODS: A 64-year-old female presented with a four-year history of a right occipital headache that regularly awakened her from sleep. The headache, which was dull and throbbing, would awaken her regularly at 4:00 am, five hours after bedtime at 11:00 pm. No photophobia, nausea or vomiting, lacrimation, or other autonomic symptoms were present. The headache was refractory to various medical treatments, including indomethacin, flunarizine, propranolol. She underwent a trial of occipital nerve stimulation with a lead electrode using a medial approach. RESULTS: During the ten-day trial stimulation, she reported almost complete relief from hypnic headache. Chronic occipital nerve stimulation replicated the trial results. The attacks of hypnic headache recurred in one year with loss of stimulation-induced paresthesia; a subsequent x-ray showed electrode migration. After revision of the electrode to the original location, the effectiveness of the occipital nerve stimulation against hypnic headache was achieved again, and this effect has been consistent through 36 months of follow-up. CONCLUSION: Occipital nerve stimulation was effective in a patient with chronic, refractory hypnic headache.

Transaxillary subpectoral implantation of implantable pulse generator for deep brain stimulation.

OBJECTIVES: Deep brain stimulation (DBS) is an effective modality of treating cardinal motor symptoms of several movement disorders such as Parkinson's disease, essential tremor, and dystonia. Although hardware-related complications of DBS have been reported, the cosmetic satisfaction and discomfort associated with infraclavicular subcutaneous implantation of the pulse generator has not been described. The authors adopted a technique of transaxillary subpectoral implantable pulse generator (IPG) placement and investigated the difference in the discomfort, cosmetic satisfaction, mean operation time for IPG implantation, and severity of postoperative pain between infraclavicular subcutaneous placement and transaxillary subpectoral implantation of IPG. MATERIALS AND METHODS: 25 patients who underwent bilateral, infraclavicular subcutaneous IPG placement for DBS and 15 patients who had bilateral, transaxillary subpectoral IPG placement were investigated. RESULTS: The differences in cosmetic satisfaction and discomfort between the two groups were significant. The cosmetic satisfaction was higher and discomfort was less in the subpectoral IPG implantation group (p = 0.002 and p = 0.000). However, more time was needed for IPG implantation, and the postoperative pain was more severe after subpectoral IPG implantation (p = 0.002 and p = 0.000). There was no difference in cosmetic satisfaction according to sex (p = 0.907). There was one transient intercostobrachial nerve injury in the subpectoral IPG implantation group and two infections which needed removal of one side of the DBS hardware in the infraclavicular IPG implantation group. CONCLUSIONS: These results demonstrated that subpectoral transaxillary IPG implantation can provide better cosmetic satisfaction in patients undergoing DBS, with less discomfort and morbidity related to erosion and infection.

Decompression of the Greater Occipital Nerve for Occipital Neuralgia and Chronic Occipital Headache Caused by Entrapment of the Greater Occipital Nerve.

BACKGROUND: Chronic entrapment of the greater occipital nerve (GON) can not only manifest in typical stabbing pain of occipital neuralgia (ON) but also lead to continuous ache and pressure-like pain in the occipital and temporal areas. However, the effect of GON decompression on these symptoms has yet to be established. We report the follow-up results of GON decompression in typical cases of ON and chronic occipital headache due to GON entrapment (COHGONE). METHODS: A 1-year follow-up study of GON decompression was conducted on 11 patients with typical ON and 39 COHGONE patients with GON entrapment. The degree of pain reduction was analyzed using the numerical rating scale-11 (NRS-11) score and percent pain relief before and 1 year after surgery. A success was defined by at least a 50% reduction in pain measured via NRS-11 during the 12-month follow-up. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Postoperative outcome was also evaluated using the Barrow Neurological Institute (BNI) pain intensity score. The difference in GON decompression between the patients with typical ON and those with COHGONE was studied. RESULTS: GON decompression was successful in 43 of 50 patients (86.0%) and percent pain relief was 72.99 ± 25.53. Subjective improvement based on a 10-point Likert scale was 7.9 ± 2.42 and the BNI grade was 2.06 ± 1.04. It was effective in both the ON and COHGONE groups, but the success rate was higher in the ON group (90.9%) than in the COHGONE group (84.6%), showing statistically significant differences in the results based on average NRS-11 score, percent pain relief, subjective improvement, and BNI grades (p < 0.05, independent t-test). CONCLUSION: GON decompression is effective in chronic occipital headache and in ON symptoms induced by GON entrapment.