Postoperation chemotherapy with S1 and docetaxel in curatively resected gastric cancer of stage III (POST trial)

TPS4142

Background: Complete surgical resections remains the only chance for cure in patients with gastric cancer, but approximately from 40% to 80% of patients still have recurrences and most patients ultimately die from their disease. The recent adjuvant trials in gastric cancer showed significantly improved survival in patients with adjuvant chemotherapy than those with surgery alone. However, further studies need for the effect of adjuvant chemotherapy following D2 dissected gastric cancer patients, especially in advanced gastric cancer. S-1 is an oral anticancer drug, a prodrug of fluorouracil, very effective in gastric cancer. Docetaxel is the first drug that showed survival benefits when added to the two drugs in advanced gastric cancer patients. And docetaxel is also synergistic anti-cancer effect with S-1 in advanced gastric cancer. Base on this background, the aim of this study is to detect a significant increase in 3 –year disease free survival (DFS) of adjuvant chemotherapy with docetaxel and S-1(DS) relative to those with S-1 and cisplatin (SP) in patients with stage III gastric cancer Methods: This study is an open-label, phase 3, randomized controlled trial, multicenter in South Korea. Patients with stage III (AJCC 7th edition) gastric cancer who had had curative D2 gastrectomy is randomly assigned to receive adjuvant chemotherapy of eight 3-week cycles of intravenous docetaxel (35 mg/m2 on day 1 and 8 of each cycle) plus oral S-1 (35 mg/m2 twice daily on days 1 to 14 of each cycle) for 6 months (DS) or chemotherapy of eight 3-week cycles of oral S1 plus intravenous cisplatin (60 mg/m2). After satisfying the screening criteria, patients have been randomized to the SD or SP arm in a 1:1 ratio. The randomization is stratified by institution and stage of disease (IIIA vs. IIIB vs. IIIC). The each stratum has been randomized by using the method of randomly permuted block. The primary endpoint is 3 year DFS, will analyze by intention to treat. A total of 290 patients will be enrolled, 67 patients have been treated to day, with continuing accrual. The trial is registered at ClinicalTrials.gov (NCT01283217).

Which is your choice? Neoadjuvant doxorubicin hydrochloride and doxetaxel (AD) versus doxorubicin hydrochloride, cyclophosphamide, and paclitaxel (AC-T) in locally advanced breast cancer

e11559

Background: It is well known that neoadjuvnat chemotherapy is acceptable for women with locally advanced breast cancer. However, it is not achieving consensus that what kind of regimen is most effective and tolerable, although lots of regimens and dosages were clinically used. Methods: We compared the patients who were received adriamycine and doxetaxel (AD) and adriamycin, cyclophosphamide followed by paclitaxel (AC-T) as neoadjuvant chemotherapy and then received operation from 1 January 2006 to 30 September 2011. The group of AD regimen was scheduled for 3 cycles of AD (50mg/m2 and 75mg/m2, respectively) with 3 weeks interval and then completes resection. The group of AC-T was scheduled for 4 cycles of AC regimen (50mg/m2 and 500mg/m2, respectively) and then 4 cycles of paclitaxel(175mg/m2) with 3 weeks interval and then completes resection. Results: The patients who were enrolled in this study were totally 78(AD and AC-T were equally 38.) The significant differences of patients’ characteristics between two groups were not observed. However, the significant differences were identified in hematologic toxicity including neutropenia more than grade 3 p<0.001), neutropenic fever p<0.001), dose reduction rate due to hematologic toxicity (p=0.012) and chemotherapy induced anemia (p=0.012)), although chemotherapy induced thrombocytopenia (p=1.0) was not different between two groups. No differences were identified in non-hematologic toxicity including hepatic toxicity, gastrointestinal toxicity and peripheral neuropathy. The response of chemotherapy was no difference between two groups, which was estimated by conversion rate of breast conserving surgery, clinical response of chemotherapy (p=0.148), clinically downstaging rate (p=0.464) and pathologic complete response rate (p=1.0). There is no factor to predicting pathologic complete response or conversion to breast conservation in this study. Conclusions: The neoadjuvant AC-T regimen is more tolerable with similar clinical outcome compared to AD regimen.

A phase III, multicenter, randomized trial of maintenance versus observation after achieving clinical response in patients with metastatic breast cancer who received six cycles of gemcitabine plus paclitaxel as first-line chemotherapy (KCSG-BR 0702, NCT00561119)

1003

Background: Chemotherapy provides a survival benefit in patients with metastatic breast cancer (MBC), but the optimal duration of chemotherapy remains controversial. Primary purpose of the study was to evaluate whether the maintenance chemotherapy with gemcitabine/paclitaxel (GP), which is one of the two regimens which showed a survival gain from a randomized trial, is superior to observation in terms of progression free survival (PFS) in responding patients with MBC after 6 cycles of GP as first-line treatment. Methods: This study is a prospective, randomized, multi-center, phase III study. Patients who achieved response (CR+PR+SD) following 6 cycles of GP chemotherapy (gemcitabine 1250 mg/m2 on day 1 and 8 plus paclitaxel 175 mg/m2 on day 1 every 3 weeks) randomized to maintenance till progression or observation arm. The trial was conducted by the Korean Cancer Study Group (KCSG). Results: Among total 324 patients enrolled between 2007 and 2010 from 10 centers, 231 responding patients to were randomly assigned to maintenance chemotherapy (n=116) or observation (n=115). Median age was 49 (range 28-76). The numbers of hormone receptor (HR)+ve and HR-ve patients were 172 (74.5%) and 59 (25.5%), respectively. The median No. of chemotherapy cycles in maintenance group was 12 (range 6-32). During median 33 months of follow-up, median PFS was superior in maintenance than in observation (12.0 vs. 8.3 months, p=0.030). Patients < age 50 years (hazard ratio 0.50, p=0.001) and HR-ve patients (hazard ratio 0.52, p=0.019) received more benefit from maintenance chemotherapy in terms of PFS. Median OS was superior in maintenance than in observation (36.8 vs 28.0 months, p=0.047). Neurotoxicity (≥ grade 2) was more common in maintenance than in observation without statistical significance (41.7% vs 33.3%, p=0.210). Serial assessment of Quality of Life (QoL) did not show any significant difference between two groups. Conclusions: Maintenance GP chemotherapy for responding patients with MBC showed clinical benefit in terms of PFS and OS without impairment of QoL.

Differential diagnosis in idiopathic granulomatous mastitis and tuberculous mastitis

PURPOSE

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory disease of unknown etiology. The diagnosis of IGM requires that other granulomatous lesions in the breast be excluded. Tuberculous mastitis (TM) is also an uncommon disease that is often difficult to differentiate from IGM. The purpose of this study is to develop a new algorithm for the differential diagnosis and treatment of IGM and TM.

METHODS

Medical records of 68 patients (58 with IGM and 10 with TM) between July 1999 and February 2009 were retrospectively reviewed.

RESULTS

The mean age of the patients was 33.5 (IGM) and 40 (TM) years (p=0.018). The median follow-up was 84 months. Of the total 10 patients with TM, 5 patients had a history of pulmonary tuberculosis. The most common symptoms of the diseases were breast lump and pain. However, axillary lymphadenopathy was more seen in TM (50%) compared to IGM (20.6%) (p=0.048). TM showed more cancer-mimicking findings on radiologic study (p=0.028). In IGM, 48 patients (82.7%) underwent surgical wide excision and 21 patients (36.2%) were managed with corticosteroid therapy and antibiotics. All of the TM patients received anti-tuberculosis medications and 9 patients (90%) underwent wide excision. The mean treatment duration was 2.8 months in IGM and 8.4 months in TM. Recurrence developed in 5 patients (8.6%) in IGM and 1 patient (10%) in TM.

CONCLUSION

This study shows different characteristics between IGM and TM. The IGM patients were younger and had more mastalgia symptoms than the TM patients. Axillary lymphadenopathy was seen more often in TM patients. Half of the TM patients had pulmonary tuberculosis or tuberculosis lymphadenitis. Surgical wide excision might be both therapeutic and useful for providing an exact diagnosis.

A novel algorithm for detection of adverse drug reaction signals using a hospital electronic medical record database

PURPOSE

Quantitative analytic methods are being increasingly used in postmarketing surveillance. However, currently existing methods are limited to spontaneous reporting data and are inapplicable to hospital electronic medical record (EMR) data. The principal objectives of this study were to propose a novel algorithm for detecting the signals of adverse drug reactions using EMR data focused on laboratory abnormalities after treatment with medication, and to evaluate the potential use of this method as a signal detection tool.

METHODS

We developed an algorithm referred to as the Comparison on Extreme Laboratory Test results, which takes an extreme representative value pair according to the types of laboratory abnormalities on the basis of each patient's medication point. We used 10 years' EMR data from a tertiary teaching hospital, containing 32,033,710 prescriptions and 115,241,147 laboratory tests for 530,829 individual patients. Ten drugs were selected randomly for analysis, and 51 laboratory values were matched. The sensitivity, specificity, positive predictive value, and negative predictive value of the algorithm were calculated.

RESULTS

The mean number of detected laboratory abnormality signals for each drug was 27 (±7.5). The sensitivity, specificity, positive predictive value, and negative predictive value of the algorithm were 64-100%, 22-76%, 22-75%, and 54-100%, respectively.

CONCLUSION

The results of this study demonstrated that the Comparison on Extreme Laboratory Test results algorithm described herein was extremely effective in detecting the signals characteristic of adverse drug reactions. This algorithm can be regarded as a useful signal detection tool, which can be routinely applied to EMR data.

Helicobacter pylori infection as an independent prognostic factor for locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection

A few studies reported the association between negative Helicobacter pylori infection and poor clinical outcome in resected gastric cancer patients. We investigated the H. pylori infection status and its association with the clinical outcome in 274 locally advanced gastric cancer patients (American Joint Committee on Cancer stage IB: 25, II: 82, IIIA: 80, IIIB: 39 and IV: 48) who underwent adjuvant chemotherapy after curative resection (≥ D2 dissection). H. pylori infection status in hematoxylin and eosin stained corporal and antral mucosa of non-tumor tissue was graded according to the updated Sydney System and categorized as H. pylori negative (normal or mild infection) and H. pylori positive (moderate or marked infection). Eighty-one patients received 5-fluorouracil (5-FU) and doxorubicin-based chemotherapy, while 193 patients underwent 5-FU, mitomycin-C and polysaccharide-K chemotherapy. The median follow-up duration of survivors was 144 (120-184) months. In univariate analysis, patients with H. pylori negative status (108 patients) demonstrated significantly poor 10-year overall survival (OS) compared to those with H. pylori-positive status (166 patients; 21.3% vs. 71.1%, p < 0.0001). H. pylori negative status was associated with poor outcome in all stages except stage IIIB. In multivariate analysis, H. pylori-negative status was the most significant independent prognostic factor of poor OS (hazard ratio: 3.45, 95% confidence interval: 2.43-4.89, p < 0.0001) followed by old age (>54 years, p < 0.0001), advanced stage (stage III or IV, p = 0.001), and Borrmann type IV (p = 0.027). H. pylori infection status seems to have strong prognostic significance in locally advanced gastric cancer. H. pylori-negative patients may need careful follow-up after curative resection.

Deuterium nuclear magnetic resonance investigation of the effects of proteins and polypeptides on hydrocarbon chain order in model membrane systems

Deuterium Fourier-transform nuclear magnetic resonance spectra have been obtained of 1-myristoyl 2-(14,14,14-trideutero)myristoyl phosphatidylcholine bilayers at 34.1 MHz by using the quadrupole echo pulse technique. Thereby, we have investigated the effects upon the deuterated dimyristoyl phosphatidylcholine bilayers of the following proteins and polypeptides: gramicidin A, bacteriophage f1 coat protein, beef brain myelin proteolipid apoprotein, cytochrome b(5), and cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1). Above T(c), the transition temperature between the gel and liquid crystal phases, the quadrupole splitting of the deuterium-labeled methyl group is reduced or collapsed in the presence of protein or polypeptide. No evidence has been found for ordered "boundary lipid." Below T(c), the spectra show that the hydrocarbon chains are prevented from crystallizing by the protein (or polypeptide) incorporated in the membrane. Similar disordering effects above T(c) are also seen when an unsaturated lipid, 1-(16,16,16-trideutero)palmitoyl 2-palmitoleyl phosphatidylcholine is complexed with cytochrome oxidase.

A case of donor-derived granulocytic sarcoma after allogeneic hematopoietic stem cell transplantation

The occurrence of granulocytic sarcoma as a pattern of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. In this paper, we report a rare case of acute myeloid leukemia (AML) relapsed as a granulocytic sarcoma of the donor type. The patient was diagnosed as having AML and underwent an allo-HSCT from his matched sibling donor. Fifty-seven months after allo-HSCT, he developed granulocytic sarcomas of duodenum, jejunum, and left sterno-cleido-mastoid muscle. The bone marrow was normal with 100% donor chimerism. A Y chromosome PCR was performed on the patient's duodenum specimen as well as bone marrow aspirate in order to check the patient-origin cells. The duodenal specimen was found to contain 41.2% SRY-positive cells (from the donor). Repeat endoscopy on day 2 of chemotherapy showed that the granulocytic sarcoma had shrunk dramatically. The patient died of sepsis during the nadir state 35 days after starting salvage chemotherapy.

High expression of excision repair cross-complementation group 1 protein predicts poor outcome in patients with nasopharyngeal cancer

We evaluated the prognostic significance of excision repair cross-complementation group 1 protein (ERCC1) and thymidylate synthase (TS) in patients with nasopharyngeal cancer (NPC) treated with concurrent chemoradiotherapy (CCRT). Pre-treatment tumor biopsy specimens from 41 patients with locally advanced NPC (stage I: 1, II: 10, III: 9, IV: 21 patients) were analyzed for ERCC1 and TS expression by immunohistochemistry. All patients were treated with one cycle of induction chemotherapy (5-fluorouracil 1000 mg/m(2)/day and cisplatin 20mg/m(2)/day, days 1-4) followed by CCRT starting on day 22. CCRT consisted of radiotherapy (70 Gy/35 fractions for 7 weeks) with cisplatin 20mg/m(2)/day for 4 days on weeks 1, 4, and 7 of radiotherapy. High expression of ERCC1 and TS was observed in 25 (60%) and 21 (51%) patients, respectively. High expression of ERCC1 was associated with WHO type 1 or 2 histology (p=0.045). With a median follow-up duration of 106 months (32-152 months) in survivors, the 5-year overall survival (OS) of all patients was 53%. In univariate analysis, 5-year OS (73% versus 39%, p=0.005) was significantly inferior in patients with high expression of ERCC1, while high expression of TS was not correlated with patient outcome. In multivariate analysis, high expression of ERCC1 was a significant independent prognostic factor for poor OS (p=0.029) along with WHO type 1 or 2 histology. High expression of ERCC1 protein may be a useful prognostic factor for poor outcome in patients with locally advanced NPC treated with CCRT.

Three point method to characterize low-pressure electronegative discharges using electrostatic probe

Electrostatic probe measurements for low-pressure inductively coupled SF(6) plasmas are performed. From the current-voltage (I-V) curves of probe, the saturation currents of the positive ions and electrons and the electron temperature are measured. The electronegativity and the negative ion density are deduced by using the ratios of these parameters at three adjacent pressure points. The positive ion density is calculated by the orbital-motion-limited theory, and the electron temperatures are given either by the slope of the I-V curves or by the electron energy distribution function with the second derivative of I-V curves. The variations in the charged species density with pressure and power are investigated.

Low expression of Bax predicts poor prognosis in resected non-small cell lung cancer patients with non-squamous histology

Objective

The present study evaluated the prognostic significance of apoptosis-related proteins p53, Bax and galectin-3 in patients with non-small cell lung cancer (NSCLC) treated with surgical resection.

Methods

We investigated the expression of these proteins and their association with clinicopathologic characteristics including disease-free survival (DFS) and overall survival (OS) in 205 NSCLC patients who underwent surgical resection (Stage I, 97; II, 46; IIIA, 45; IIIB, 17) using immunohistochemistry. Eighty-eight patients (43%) received adjuvant treatment (chemotherapy: 8, radiotherapy: 24, both: 56).

Results

High expressions of Bax, p53 and galectin-3 were observed in 48 (23%), 81 (40%) and 105 (51%) patients, respectively. Low expression of Bax was significantly associated with male gender, squamous cell histology and low expression of galectin-3. Five-year DFS and OS of total patients were 37 and 46%, respectively. High expressions of p53 and galectin-3 were not associated with poor DFS or OS, and no significant correlation existed between low expression of Bax and outcome of patients. However, in patients with non-squamous histology (108 patients), low expression of Bax was a significant independent predictor of poor DFS (P = 0.017) and OS (P = 0.037). In addition, in patients with Stage II or III disease, low expression of Bax significantly correlated with poor DFS (P = 0.004). It was also the most significant independent poor prognostic factor second only to a large primary tumor size in Stage II or III patients with non-squamous histology.

Conclusions

Low expression of Bax was significantly associated with poor prognosis in resected NSCLC patients with non-squamous histology.

Expression of excision repair cross-complementation group 1 protein predicts poor outcome in patients with small cell lung cancer

BACKGROUND

Alterations in apoptosis-related proteins and DNA damage repair proteins are associated with resistance to chemotherapy or radiotherapy, which is the most important cause of treatment failure in small cell lung cancer (SCLC).

PATIENTS AND METHODS

Pretreatment tumor biopsy specimens from 77 patients with SCLC (limited stage: 40, extensive stage: 37) were analyzed for p53, bcl-2, bax and ERCC1 expression by immunohistochemistry. All patients were treated with platinum-based doublets. The most commonly used regimen was etoposide/cisplatin (50 patients). In patients with limited stage SCLC, thoracic irradiation was performed either concurrently with chemotherapy or sequentially.

RESULTS

High expression of p53, bcl-2, bax and ERCC1 was observed in 40 (52%), 72 (94%), 38 (49%) and 13 (17%) patients, respectively. High expression of ERCC1 was associated with poor OS (1-year, 23% vs. 53%; p=0.026). When grouped according to stage, a significant correlation between high expression of ERCC1 and poor outcome was observed only in patients with limited stage SCLC (p=0.017). High expression of p53, bcl-2 and bax was not correlated with patient outcome. Multivariate analysis showed that extensive stage (p=0.006) and male gender (p=0.009) were independent predictors of poor OS, while high expression of ERCC1 failed to reach statistical significance despite a trend (p=0.057). In limited stage patients, high expression of ERCC1 was an independent prognostic factor for poor OS (p=0.046), along with male gender (p=0.033).

CONCLUSIONS

High expression of ERCC1 protein may be a useful predictor of poor outcome in SCLC patients treated with chemotherapy with or without radiotherapy, especially in limited stage SCLC.

Low expression of Bax predicts poor prognosis in patients with locally advanced esophageal cancer treated with definitive chemoradiotherapy

PURPOSE

The present study evaluated the prognostic significance of apoptosis-related proteins, p53, Bcl-2, Bax, and galectin-3 in patients with locally advanced esophageal cancer treated with definitive chemoradiotherapy.

EXPERIMENTAL DESIGN

A total of 63 patients with locally advanced esophageal cancer (squamous cell carcinoma: 62; adenocarcinoma: 1; stages II-IV) were treated with definitive chemoradiotherapy using 5-fluorouracil and cisplatin combined with radiotherapy. Pretreatment tumor biopsy specimens were analyzed for p53, Bcl-2, Bax, and galectin-3 expression by immunohistochemistry.

RESULTS

High expression of Bax, p53, Bcl-2, and galectin-3 was observed in 67%, 47%, 24%, and 29% of patients, respectively. The median overall survival (OS) of total patients was 14 months with 16% of 3-year OS. High expression of p53, Bcl-2, and galectin-3 did not show correlation with clinicopathologic characteristics, including patient outcome. Low expression of Bax was significantly correlated with lack of clinical complete response (P=0.023). Low expression of Bax was also associated with poor OS (median, 8 months versus 16 months; P=0.0008) in univariate analysis. In multivariate analysis, low expression of Bax was the most significant independent predictor of poor OS (P=0.009), followed by low dose intensity of cisplatin and lack of clinical complete response.

CONCLUSIONS

Low expression of Bax was significantly associated with the poor survival of patients with locally advanced esophageal cancer treated with chemoradiotherapy using 5-fluorouracil and cisplatin. Immunohistochemical staining for Bax with a pretreatment biopsy specimen might be useful to select the optimal treatment options for these patients.

The origin of the triploid in Paragonimus westermani on the basis of variable regions in the mitochondrial DNA

Triploid, parthenogenetic forms of the lungfluke, Paragonimus westermani, occur in Japan, Korea and China. The origin(s) of triploidy has been debated over the years. Sequences of two regions in the mitochondrial DNA, i.e. partial lrRNA (16S), and a portion of the non-coding region, were obtained from natural populations of P. westermani. All triploid individuals (Japan, Korea, China) and a single tetraploid individual (China) had identical sequences in the 16S region studied. Some sequence variation was observed among diploids, with those from Taiwan being distinct from the remainder. Both neighbour joining and parsimony trees using the 16S region placed diploid individuals from southwestern Japan close to the triploids and the tetraploid. The fragment amplified from the mitochondrial non-coding region showed dimorphism. One form (type A) consisted of 239 bp comprising two identical tracts of 70 bp separated by a tract of 93 bp. The second form (Type B) consisted of only a single 70 bp tract. All diploid individuals from Taiwan, China and Korea possessed type A, while those from Japan were polymorphic; individuals from Oita and Hyogo had type B, those from Chiba had type A, but both types were found in Mie. On the other hand, all of the triploid individuals and two tetraploid individuals possessed type B. Both the form present in the non-coding region and the 16S sequence suggest an affinity between a south-eastern group of diploid populations in Japan and the triploid form. A possible mechanism responsible for the origin of the triploid is discussed.

Comparative study on biologic and immunologic characteristics of the pancreas islet cell between 24 degrees C and 37 degrees C culture in the rat

The aim of this study was to investigate the effect of culture at 24 degrees C on cell viability, cellular function, immunogenicity, and cytokine profiles of rat pancreatic islets. Pancreatic islets were isolated from Lewis rats and cultured at either 24 degrees C or 37 degrees C for 14 days. Islet recovery was counted as islet equivalents; islet viability was examined with fluorescent vital staining. Islet function was measured with a glucose stimulation test. Annexin V, and MHC class I and II expression were measured using flow cytometric assay for apoptosis and immunogenicity, respectively. Lymphocyte cell proliferation was examined with WST-1 proliferation assay. Cytokine profiles were analyzed with quantitative real time RT-PCR. All these parameters were measured on 1, 3, 5, 7 and 14 culture days after islet isolation. Islet recovery was higher in islets cultured at 24 degrees C than 37 degrees C without a change in viability. Insulin secretion after glucose stimulation was more effective in 24 degrees C culture conditions. Decreased apoptotic cell death was demonstrated in 24 degrees C cultured islets. Both MHC class I and II expression on islets and lymphocyte proliferation upon coculture with islets were less prominent in 24 degrees C cultured islets. TNF-alpha expression was lower in islets cultured at 24 degrees C than in islets cultured at 37 degrees C. Both IL-1beta and IL-10 cytokine expressions were similar under both culture conditions. This study demonstrated that cell recovery and function are increased in islets cultured at 24 degrees C than those at 37 degrees C with decreased antigenicity and proinflammatory cytokine expression.

Concurrent chemoradiotherapy in patients with nasopharyngeal cancer: prognostic significance of low expression of bax

A randomized trial has demonstrated that concurrent chemoradiotherapy (CRT) is superior to radiotherapy (RT) alone in locally advanced nasopharyngeal cancer (NPC). Our study comprise 35 patients with locally advanced NPC (stage I: 1, II: 12, III: 7, IV: 15) with 1 cycle of induction chemotherapy (5-fluorouracil 1,000 mg/m(2)/day and cisplatin 20 mg/m(2)/day, days 1- 4) followed by concurrent CRT starting on day 22. Concurrent CRT consisted of RT (70 Gy/35 fractions for 7 weeks) with cisplatin 20 mg/m(2)/day for 4 days on weeks 1, 4, 7 of RT. Complete response (CR) was achieved in 33 patients (94%). Four-year progression-free survival (PFS) and overall survival (OS) of all patients were 57% and 65%, respectively. In analysis of prognostic factors, low expression of bax was the most significant independent predictor of poor prognosis in both PFS (p=0.002) and OS (p=0.008). In conclusion, the outcome of patients treated with this combined therapeutical modality appears to be comparable with that of Intergroup 0099 trial with high CR rate. Low expression of bax was significantly associated with poor PFS and OS.

Corticospinal disinhibition in paroxysmal kinesigenic dyskinesia

OBJECTIVE

To investigate the underlying mechanism responsible for paroxysmal kinesigenic dyskinesia (PKD).

METHODS

We performed a transcranial magnetic stimulation (TMS) study in 12 drug-naïve patients with PKD and 10 healthy volunteers. TMS parameters included resting motor threshold, recruitment curve of motor evoked potential amplitudes, short intracortical inhibition and facilitation, long intracortical inhibition (LICI), and silent period. We also measured compound muscle action potential.

RESULTS

LICI, representing GABA-mediated inhibition, was significantly reduced in the patients (P = 0.033), while results for all other TMS parameters tested were comparable between the two groups.

CONCLUSIONS AND SIGNIFICANCE

These results suggest that a specific type of corticospinal inhibitory mechanism is impaired in patients with PKD.