Gating In Patients Research Articles

Blink reflex and prepulse inhibition in fibromyalgia

Patients with fibromyalgia syndrome (FMS) show increased sensory processing of nociceptive and non-nociceptive stimuli. They perceive somatosensory stimuli differently and show altered cortical sensory representation maps following peripheral stimulation. Altered sensory gating may play a causal role. Blink reflex, blink reflex excitability recovery, and prepulse inhibition of the blink reflex – representing brainstem excitability – were assessed in 10 female patients with FMS and 26 female healthy controls. Unconditioned blink reflex characteristics (R1 latency and amplitude, R2 and R2c latency and area-under-the-curve) did not differ significantly between patients and controls. However, blink reflex excitability recovery was enhanced in patients versus controls at all intervals tested. Prepulses significantly suppressed R2 area and increased R2 latency in patients and controls, but patients showed significantly less R2 area suppression than controls (patients: to 80.0 ± 28.9%, controls: to 47.8 ± 21.7%). The general pattern of corresponding changes in R2c was similar. Blink reflex is normal, whereas blink reflex excitability recovery is enhanced, and blink reflex prepulse inhibition is reduced, in patients with FMS, suggesting functional changes at the brainstem level in FMS. Reduced blink reflex prepulse inhibition concurs with altered sensory gating in patients with FMS.

P50 sensory gating in patients with vaginismus

Objective: P50 sensory gating was investigated in patients with primary vaginismus (PV) with the hypothesis that interpreting coping capacities as a stress factor during sexual intercourse by perceiving unrelated stimuli and an impairment of the sensory information processing may be associated with fear/anxiety related to a possible pain in vulvovagina. Methods: A total of 35 patients who were diagnosed with PV and 29 healthy volunteers matched for age and gender underwent P50 recording in the neurophysiology laboratory and the results were compared. Results: The PV group's P50 gating ratio and S1 amplitude were statistically significantly lower than in the control group. Conclusion: Sensory gating is required for filtering the stimuli coming to the brain and developing an appropriate behavioral response. The reduced formation of an appropriate behavioral response in the PV group can lead to a perception of excessive and unrelated stimuli coming from internal and external environments and interpreting these as a stress factor exceeding the capacity to cope. Our study is the first to evaluate sensory gating in PV patients and new studies with larger patient groups are required.

Information processing and brain metabolic characteristics in patients at ultra-high risk for endogenous psychosis

Functional and structural brain abnormalities in people at high risk for psychosis is a subject of intensive studies in biological psychiatry over the last decades. We studied correlations between neurophysiological and neuroimaging parameters in ultra-high risk patients. Fifty-six patients, aged 17-25 years, with nonpsychotic mental disorders were examined. The control group included 30 age- and sex-matched healthy people. Neurophysiological study measured sensory gating. Proton MR-spectroscopy was used to study metabolic processes in the brain (index for glutamate/glutamine, N-acetylaspartate and choline containing compounds in the dorsolateral prefrontal cortex and thalamus of both hemispheres as well as in the genu and splenium of the corpus callosum). We found the abnormality of sensory gating in patients at ultra-high risk for endogenous psychosis that was not correlated with the metabolic parameters. The latter were normal or were normalized during treatment.

방사선 누설선량 조사를 통한 방어시설과 누설선량 평가방법에 대한 문제점 연구 : 부산, 경남 지역 CT실을 중심으로

이 연구는 CT(computed tomography)검사 중 발생하는 방사선 누설선량(radiation leakage)으로부터 종사자 및 일반인의 피폭을 최소화하기 위한 것이다. 부산, 경남에 위치한 대학병원 7곳과 종합전문요양병원 4곳의 CT실을 대상으로 하였다. 누설선량 측정 장소로는 1) 조정실 내 감시창 벽면의 지면으로부터 3m 높이 2) 조정실 내 특정 지점 3) 조정실 내 종사자 출입문 4) 환자 출입문을 선정하였다. 그 결과 M병원의 종사자 출입문에서 가장 높은 누설선량이 나타났다. 각각의 측정값은 고전적 방법에 의한 주당 최대 누설선량으로 환산하였다. 그 결과 1) <TEX>$5.97{\pm}0.23$</TEX>, 2) <TEX>$0.50{\pm}0.02$</TEX>, 3) <TEX>$10.00{\pm}0.11$</TEX>, 4) <TEX>$2.37{\pm}0.47$</TEX> mR/week로 주당 최대 누설선량 허용치(<100 mR/week)이하였다. 하지만 측정 최대 누설선량을 기록한 M병원의 조정실 내 종사자 출입문을 실험적 방법으로 계산한 결과 <TEX>$118.31{\pm}17.72$</TEX> mR/week(>100 mR/week)로 나타났다. 조정실 지면으로부터 3 m 이상의 높이에서의 누설선량은 조정실내부에 영향을 끼쳤다(p<0.05). 따라서, 누설선량의 피해를 줄이기 위해, 주당 최대 누설선량 산출 방법에 대한 개선과, 조정실 차폐벽의 차폐체를 3 m 이상으로 할 것을 제안 한다. The purpose of this study is to minimize radiation exposure to the workers and public members during CT examination. The objects are seven of the CT rooms in university hospitals and four of the CT rooms in clinics located in Busan and Gyung-nam area. The places of measurement for radiation leakage are 1) 3 m above the ground of shielding wall in the control room 2) particular space in the control room 3) worker's gate in the control room 4) the patient gate. Its values were calculated maximum leakage radiation per week(MLRW). As a result, the worker's gate of M clinic displayed the highest dose. When it was calculated by MLRW in classic method, it showed 1) <TEX>$5.97{\pm}0.23$</TEX>, 2) <TEX>$0.50{\pm}0.02$</TEX>, 3) <TEX>$10.00{\pm}0.11$</TEX>, 4) <TEX>$2.37{\pm}0.47$</TEX> mR/week. All of them did not exceed limit for maximum permissible dose per week(MPDW). However, When MLRW of M clinic was calculated by empirical method, its value displayed <TEX>$118.31{\pm}17.72$</TEX> mR/week.(MPDW>100 mR/week). Radiation leakage influenced in the control room(p<0.05). Therefore, The way of calculating MLRW must be developed and shielding wall in control room is designed 3 m above the ground for reducing dangerous of leakage radiation.

Clonidine Normalizes Levels of P50 Gating in Patients With Schizophrenia on Stable Medication

Sensory gating deficits are among the core features of schizophrenia. Recently, we reported significantly increased sensorimotor gating following additional administration of single dosages of clonidine to the treatment of stably medicated patients with schizophrenia who, in spite of their medication, showed gating deficits. In the current study, we investigated whether this result is generalizable to filtering of sensory information as a whole, by examining clonidine's effect on P50 suppression in the same group of patients. In a double-blind, placebo-controlled, randomized yet balanced cross-over design, 20 male schizophrenia patients on stable medication were assessed in a psychophysiological test battery, including a sensory gating paradigm on 5 occasions: once after oral administration of placebo and after single doses of 25, 50, 75, and 150 µg of clonidine. Their results were compared with 20 age-matched healthy male volunteers, who received no treatment. Patients showed significantly reduced levels of P50 suppression in the placebo session compared with controls. All dosages of clonidine significantly diminished these deficits to such levels that they no longer differed significantly from the healthy controls (except the highest dose). This is the first study to show that even a single low dose of clonidine administered to stably medicated patients with schizophrenia not only significantly increases their levels of P50 suppression but also normalizes them. The results indicate that α2-noradrenergic agonists are capable of normalizing levels of P50 gating, which has a potentially high clinical relevance for the medical treatment of schizophrenia.

Alterations in excitatory and inhibitory brainstem interneuronal circuits in fibromyalgia: Evidence of brainstem dysfunction

ObjectivePatients with fibromyalgia syndrome (FMS) perceive stimuli differently and show altered cortical sensory representation maps following peripheral stimulation. Altered sensory gating may play a causal role. MethodsBlink reflex, blink reflex excitability recovery, and prepulse inhibition of the blink reflex – representing brainstem excitability – were assessed in 10 female patients with FMS and 26 female healthy controls. ResultsUnconditioned blink reflex characteristics (R1 latency and amplitude, R2 and R2c latency and area-under-the-curve) did not differ significantly between patients and controls. Blink reflex excitability recovery was enhanced in patients versus controls at all intervals tested. Prepulses significantly suppressed R2 area and increased R2 latency in patients and controls. However, R2 area suppression was significantly less in patients than in controls (patients: to 80.0±28.9%, controls: to 47.8±21.7%). The general pattern of corresponding changes in R2c was similar. ConclusionsBlink reflex is normal, whereas blink reflex excitability recovery is enhanced and blink reflex prepulse inhibition is reduced in patients with FMS, suggesting functional changes at the brainstem level in FMS. SignificanceReduced blink reflex prepulse inhibition concurs with altered sensory gating in patients with FMS.

Prospective study of partial breast irradiation (PBI) with stereotactic body radiation therapy (SBRT) with Exactrac Adaptive Gating in patients with breast cancer of very good prognosis (VGP)

Prospective study of partial breast irradiation (PBI) with stereotactic body radiation therapy (SBRT) with Exactrac Adaptive Gating in patients with breast cancer of very good prognosis (VGP)

Coronary CT Angiography Incorporating Doppler-Guided Prospective ECG Gating in Patients with High Heart Rate: Comparison with Results of Traditional Prospective ECG Gating

PurposeAs Doppler ultrasound has been proven to be an effective tool to predict and compress the optimal pulsing windows, we evaluated the effective dose and diagnostic accuracy of coronary CT angiography (CTA) incorporating Doppler-guided prospective electrocardiograph (ECG) gating, which presets pulsing windows according to Doppler analysis, in patients with a heart rate >65 bpm.Materials and Methods119 patients with a heart rate >65 bpm who were scheduled for invasive coronary angiography were prospectively studied, and patients were randomly divided into traditional prospective (n = 61) and Doppler-guided prospective (n = 58) ECG gating groups. The exposure window of traditional prospective ECG gating was set at 30%–80% of the cardiac cycle. For the Doppler group, the length of diastasis was analyzed by Doppler. For lengths greater than 90 ms, the pulsing window was preset during diastole (during 60%–80%); otherwise, the optimal pulsing intervals were moved from diastole to systole (during 30%–50%).ResultsThe mean heart rates of the traditional ECG and the Doppler-guided group during CT scanning were 75.0±7.7 bpm (range, 66–96 bpm) and 76.5±5.4 bpm (range: 66–105 bpm), respectively. The results indicated that whereas the image quality showed no significant difference between the traditional and Doppler groups (P = 0.42), the radiation dose of the Doppler group was significantly lower than that of the traditional group (5.2±3.4mSv vs. 9.3±4.5mSv, P<0.001). The sensitivities of CTA applying traditional and Doppler-guided prospective ECG gating to diagnose stenosis on a segment level were 95.5% and 94.3%, respectively; specificities 98.0% and 97.1%, respectively; positive predictive values 90.7% and 88.2%, respectively; negative predictive values 99.0% and 98.7%, respectively. There was no statistical difference in concordance between the traditional and Doppler groups (P = 0.22).ConclusionDoppler-guided prospective ECG gating represents an improved method in patients with a high heart rate to reduce effective radiation doses, while maintaining high diagnostic accuracy.

Auditory verbal hallucinations in schizophrenia correlate with P50 gating

ObjectiveWhile auditory verbal hallucinations (AVHs) are a common symptom of schizophrenia, the underlying mechanisms behind these perceptual anomalies and their effects on auditory processing are not fully understood. Patients suffering from schizophrenia have been shown to exhibit impaired sensory gating of acoustic stimuli, evidenced by a failure to inhibit the auditory P50 scalp recorded middle latency evoked potential response to the second of two paired auditory “clicks” (S1–S2). MethodsBecause abnormal activation of auditory pathways is associated with a general AVH trait of schizophrenia patients, this study correlated the hallucinatory trait subscale of the Psychotic Symptoms Ratings Scale (PSYRATS) scores of 16 actively hallucinating patients with their P50 responses to S1 and S2 as well as sensory gating indices. P50 gating in patients was also compared to twenty one healthy controls. ResultsControl S1 amplitudes were significantly greater than those of patients. There was a negative correlation between PSYRATS scores and gating difference score as well as with S1 amplitude, and a positive correlation with gating ratio, indicating the global trait of hallucinating schizophrenia patients may be associated with deficiencies in the processing of auditory stimuli. No significant correlation was found when the same analysis was applied to a state-dependent hallucination ratings scale. SignificanceResults suggest the relationship between auditory hallucinations and auditory processing dysfunction measured by P50 response is more trait than state dependent in schizophrenia.

The neuropsychological and neurophysiological profile of women with pseudoseizure

ObjectiveOur aim in this study was to compare the assessments of neuropsychological tests and the p50 neurophysiological test of patients with seizure diagnosed as conversion disorder and healthy control subjects, and to investigate the neurological status in conversion disorder with pseudoseizure. MethodsA total of 22 female conversion disorder patients with convulsions diagnosed according to SCID-I/CV and 22 healthy women were included in the assessment. The participants were administered WMS-R, the cancellation test, and the Stroop test as neuropsychological tests and p50 was assessed as a neurophysiological test. ResultsThe patient's results for the neuropsychological tests were found to be significantly low compared to the control group. The p50 sensory gating ratios of the patient group were statistically significantly lower than the controls. There was no significant correlation between the neuropsychological test scores and gating ratios of the patient and control groups. ConclusionsThis study is the first to check sensory gating in conversion disorder patients with pseudoseizure and its most important result is finding reduced p50 sensory gating in patients. Our results suggest that these patients have a neurological tendency to this disease due to functional neurophysiological features.

Neuropsychological correlates of P50 sensory gating in patients with schizophrenia

Impaired inhibition of P50 cerebral evoked response is one of the best validated endophenotypes in schizophrenia. There are controversial data on the relationship between P50 evoked potential deficit and measures of cognitive function in schizophrenia. A comprehensive clinical and neurocognitive assessment plus an evaluation of P50 sensory gating was performed in 160 schizophrenia patients and 64 controls. Neurocognitive scores from each cognitive domain were converted to demographically-adjusted T-scores (age, gender, and years of education) for all study participants. The relationship between P50 and neurocognitive variables was assessed via parametric and nonparametric correlations and categorical strategies: we compared neuropsychological test scores in patients and controls in the lowest P50 quartile vs. the highest. Controls had better performance than schizophrenia patients in all cognitive domains. Schizophrenia patients had significantly higher P50 ratios than controls, and no significant correlation was found between P50 gating measures and neuropsychological test scores in schizophrenia patients or healthy controls. Moreover, no differences in neurocognitive performance were found between subjects in the lowest P50 ratio quartile vs. the highest in healthy controls or patients with schizophrenia. We concluded that there is no evidence of an association between P50 ratio and cognitive measures in schizophrenia patients, and this seems to be also the case in healthy controls.

Poster #199 EFFECT OF MEDICATION IN COGNITION AND INSIGHT IN PSYCHOTIC PATIENTS

While auditory verbal hallucinations (AVHs) are a common symptom of schizophrenia, the underlying mechanisms behind these perceptual anomalies and their effects on auditory processing are not fully understood. Patients suffering from schizophrenia have been shown to exhibit impaired sensory gating of acoustic stimuli, evidenced by a failure to inhibit the auditory P50 scalp recorded middle latency evoked potential response to the second of two paired auditory “clicks” (S1–S2).Because abnormal activation of auditory pathways is associated with a general AVH trait of schizophrenia patients, this study correlated the hallucinatory trait subscale of the Psychotic Symptoms Ratings Scale (PSYRATS) scores of 16 actively hallucinating patients with their P50 responses to S1 and S2 as well as sensory gating indices. P50 gating in patients was also compared to twenty one healthy controls.Control S1 amplitudes were significantly greater than those of patients. There was a negative correlation between PSYRATS scores and gating difference score as well as with S1 amplitude, and a positive correlation with gating ratio, indicating the global trait of hallucinating schizophrenia patients may be associated with deficiencies in the processing of auditory stimuli. No significant correlation was found when the same analysis was applied to a state-dependent hallucination ratings scale.Results suggest the relationship between auditory hallucinations and auditory processing dysfunction measured by P50 response is more trait than state dependent in schizophrenia.

Event-related potential studies of post-traumatic stress disorder: a critical review and synthesis

Despite the sparseness of the currently available data, there is accumulating evidence of information processing impairment in post-traumatic stress disorder (PTSD). Studies of event-related potentials (ERPs) are the main tool in real time examination of information processing. In this paper, we sought to critically review the ERP evidence of information processing abnormalities in patients with PTSD. We also examined the evidence supporting the existence of a relationship between ERP abnormalities and symptom profiles or severity in PTSD patients. An extensive Medline search was performed. Keywords included PTSD or post-traumatic stress disorder, electrophysiology or EEG, electrophysiology, P50, P100, N100, P2, P200, P3, P300, sensory gating, CNV (contingent negative variation) and MMN (mismatch negativity). We limited the review to ERP adult human studies with control groups which were reported in the English language. After applying our inclusion-exclusion review criteria, 36 studies were included. Subjects exposed to wide ranges of military and civilian traumas were studied in these reports. Presented stimuli were both auditory and visual. The most widely studied components included P300, P50 gating, N100 and P200. Most of the studies reported increased P300 response to trauma-related stimuli in PTSD patients. A smaller group of studies reported dampening of responses or no change in responses to trauma-related and/or unrelated stimuli. P50 studies were strongly suggestive of impaired gating in patients with PTSD. In conclusion, the majority of reports support evidence of information processing abnormalities in patients with PTSD diagnosis. The predominance of evidence suggests presence of mid-latency and late ERP components differences in PTSD patients in comparison to healthy controls. Heterogeneity of assessment methods used contributes to difficulties in reaching firm conclusions regarding the nature of these differences. We suggest that future ERP-PTSD studies utilize standardized assessment scales that provide detailed information regarding the symptom clusters and the degree of symptom severity. This would allow assessment of electrophysiological indices-clinical symptoms relationships. Based on the available data, we suggest that ERP abnormalities in PTSD are possibly affected by the level of illness severity. If supported by future research, ERP studies may be used for both initial assessment and treatment follow-up.

Cannabis use and sensorimotor gating in patients with schizophrenia and healthy controls

Schizophrenia patients and healthy cannabis users show different attention-dependant alterations in prepulse inhibition (PPI). It is of interest then to examine PPI in patients with schizophrenia who use cannabis, given the hypothesized association between cannabis use and schizophrenia. Prepulse inhibition was measured in 34 healthy cannabis users, 32 healthy non-using controls, 20 patients with schizophrenia who were current cannabis users, and 44 non-using patients with schizophrenia. PPI was measured across a range of startling stimulus intensities, during two attention set conditions. Curves of best fit were fitted to the startle magnitudes, across the stimulus intensities. A number of reflex parameters were extracted from these logistic functions. Similar to healthy cannabis users, cannabis-using patients showed altered PPI of Threshold, only when instructed to sustain attention to the auditory stimuli. Conversely, non-using patients with schizophrenia showed reduced PP of R(MAX) only when instructed to ignore the auditory stimuli. Cannabis use in patients with schizophrenia is associated with a similar pattern of attention-dependant alterations in PPI to that observed in healthy cannabis users. This is different to those observed in patients with schizophrenia who do not use cannabis and may be as a result of a dysfunction of sustained attention.

Impairment of Phosphatidylinositol 3-Kinase Signaling in Schizophrenia: State or Trait?

Back to table of contents Previous article Next article Letter to the EditorFull AccessImpairment of Phosphatidylinositol 3-Kinase Signaling in Schizophrenia: State or Trait?Undine E. Lang, M.D., Ph.D.Undine E. LangSearch for more papers by this author, M.D., Ph.D.Published Online:1 Jun 2010https://doi.org/10.1176/appi.ajp.2010.10010103AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: In their article, published in the April 2010 issue of the Journal, Szabolcs Kéri, M.D., Ph.D., D.Sc., et al. (1) showed that neuregulin 1-dependent activation of phosphatidylinositol 3-kinase signaling was impaired in schizophrenia patients, which was connected to P50-evoked response and thereby influenced sensory gating in patients with first-episode schizophrenia. Phosphatidylinositol 3-kinase and phosphoinositide-dependent protein kinase-1 signaling inhibit glycogen synthase kinase-3β. Our workgroup found increased anxiety behavior in phosphoinositide-dependent protein kinase 1 hypomorphic mice (2) and stress-resistant behavior in glycogen synthase kinase-3β knock-in mice, supporting the role of phosphatidylinositol 3-kinase signaling in anxiety and stress (3). However, Dr. Kéri et al. did not examine the influence of neuroleptic treatment on phosphatidylinositol 3-kinase activity. The highly effective atypical antipsychotics olanzapine and clozapine in contrast to haloperidol have been shown to activate the protein kinase B (AKT) glycogen synthase kinase-3β axis (4). These effects might explain heterogenous findings on the P50-evoked response in schizophrenia patients, which seems to normalize after treatment with clozapine and olanzapine but not after typical drugs (5).Berlin, GermanyThe author reports no financial relationships with commercial interests.References1 Kéri S , Beniczky S , Kelemen O : Suppression of the P50 evoked response and neuregulin 1-induced AKT phosphorylation in first-episode schizophrenia. Am J Psychiatry 2010; 167:444–450 Link, Google Scholar2 Ackermann TF , Hörtnagl H , Wolfer DP , Colacicco G , Sohr R , Lang F , Hellweg R , Lang UE : Phosphatidylinositide dependent kinase deficiency increases anxiety and decreases GABA and serotonin abundance in the amygdala. Cell Physiol Biochem 2008; 22:735–744 Crossref, Medline, Google Scholar3 Ackermann TF , Kempe DS , Lang F , Lang UE : Hyperactivity and enhanced curiosity of mice expressing PKB/SGK-resistant glycogen synthase kinase-3 (GSK–3). Cell Physiol Biochem 2010 (in press) Crossref, Google Scholar4 Aubry JM , Schwald M , Ballmann E , Karege F : Early effects of mood stabilizers on the Akt/GSK-3beta signaling pathway and on cell survival and proliferation. Psychopharmacology 2009; 205:419–429 Crossref, Medline, Google Scholar5 Light GA , Geyer MA , Clementz BA , Cadenhead KS , Braff DL : Normal P50 suppression in schizophrenia patients treated with atypical antipsychotic medications. Am J Psychiatry 2000; 157:767–771 Link, Google Scholar FiguresReferencesCited byDetailsCited ByProgress in Neuro-Psychopharmacology and Biological Psychiatry, Vol. 64Reduced Brain-Derived Neurotrophic Factor Serum Concentrations in Acute Schizophrenic Patients Increase During Antipsychotic TreatmentJournal of Clinical Psychopharmacology, Vol. 31, No. 3 Volume 167Issue 6 June 2010Pages 719-719 Metrics PDF download History Accepted 1 March 2010 Published online 1 June 2010 Published in print 1 June 2010

Antipsychotic effects on auditory sensory gating in schizophrenia patients

P50 sensory gating deficit has repeatedly been demonstrated in schizophrenia. Studies have produced inconsistent findings with respect to normalization of P50 gating in patients with schizophrenia receiving treatment with different antipsychotics. The current study was designed to determine whether there is a difference in P50 gating in schizophrenia patients treated with first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs), including clozapine. P50 evoked potential recordings were obtained from 160 patients with schizophrenia and 77 healthy comparison subjects. Forty-three patients were being treated with clozapine, sixty-eight were taking SGAs (33 risperidone, 21 olanzapine, 11 aripiprazole, and 3 combinations of SGAs) and 49 were being treated with FGAs. Schizophrenia patients exhibited significantly higher P50 ratios than healthy subjects. When patients treated with different antipsychotics were compared, there were no differences in any of the neurophysiological findings. Second-generation antipsychotics were not related to more normal sensory gating in this population of patients with chronic schizophrenia.

Radiotherapy for breast cancer: Can the heart be protected with respiratory gating in patients with left-sided breast cancer?

e11572 Background: Because there are hints for an increased risk of cardiovascular diseases after radiotherapy of the left chest wall the dose to the heart should be reduced as far as possible. With respiratory gating technique irradiation can be restricted only in the inspiratory plateau phase and so the distance between heart and chest wall will be increased. As a result the dose to the heart, in particular to the anterior wall, can be reduced. We investigated in all patients with left sided breast cancer dose reduction to the heart when treated only in the inspiration phase compared with not gated treatments. Methods: Between September 2004 and March 2008 97 pat. with left sided breast cancer were treated with respiratory gating technique. We irradiate only in maximum inspiration with a range between 10% - 20%. For the investigation of real dose reduction to the heart we performed for all of these patients a normal and a respiratory gated planning CT. DVH for the entire heart and the anterior wall of the left ventricle wall were calculated. 96/97 of these pat. were treated with 2 Gy single dose to a total dose of 50 Gy to the entire left breast, 1 pat with 1.8 Gy single dose to 50.4 Gy. 72 pat. had an additional boost of 10 Gy. The PTV was in 75 pat. after breast conserving surgery the left breast, in 22 pat. after mastectomy the left chest wall. Results: To median dose to the anterior ventricle wall was 2.3 Gy (0.5 Gy - 7.9 Gy) without and 1.3 Gy (0.1 Gy - 5.6 Gy) with respiratory gating (p = 0.001). The median maximal dose to the anterior wall was 45.2 Gy (5.5 Gy - 52.3 Gy) without and 4.5 Gy (0.9Gy - 50.6 Gy) with respiratory gating (p = 0.000). In 72 pat. the maximal dose reduction to the anterior wall was &gt; 20 Gy. In this pat. the mean movement of the diaphragma was 26mm against 16 mm for pat. with dose reduction &lt;20 Gy (p = 0.000). The mean up and down movements ot the chest wall were 7.9mm (&gt;20 Gy) and 5.2 mm (&gt;20Gy) (p = 0.05). Conclusions: Respiratory gating and irradiation only in the inspiratory phase reduce radiation dose to the heart and especially to the anterior wall of the heart significantly. Pat breathing with diaphragm seems to profite mostly from treating only in inspiratory phase. No significant financial relationships to disclose.

Neuroleptic effects on P50 sensory gating in patients with first-episode never-medicated schizophrenia

Sensory gating deficit, as reflected by P50 suppression, has been demonstrated in schizophrenia. Despite extensive evidence of the irreversible effects of typical neuroleptics on this deficit, recent studies of atypical neuroleptics have produced inconsistent findings on the reversibility of P50 suppression in schizophrenia. As the majority of these studies were limited by either their cross-sectional design or the recruitment of patients on multiple medications, the current study was designed to examine the effects of different neuroleptic medications on the P50 sensory gating index in patients with first-episode, never-medicated schizophrenia. P50-evoked potential recordings were obtained from 62 normal controls when they entered the study and from 65 patients with first-episode, never-medicated schizophrenia at baseline and after six weeks of different neuroleptic treatments (sulpiride [n=24], risperidone [n=24] and clozapine [n=17]). The first-episode, never-medicated schizophrenia patients had impaired sensory gating relative to the normal controls (mean=94.19% [SD=61.31%] versus mean=41.22% [SD=33.82%]). The test amplitude S2 was significantly higher in the schizophrenia patients than in the normal controls. The conditioning amplitude S1 and the positive symptom scores were related to the P50 gating ratios in schizophrenia at baseline. There was no change in P50 sensory gating (P>0.10) and a significant improvement in the clinical ratings (P>0.10) after six-week neuroleptic treatment for schizophrenia. P50 sensory gating was not significant for the patients who received sulpiride, risperidone or clozapine at baseline (F=1.074, df=2, 62, P=0.348) or at endpoint (F=0.441, df=2, 62, p=0.646). Our findings indicate that there is P50 sensory gating impairment in first-episode, never-medicated schizophrenia and that treatment with typical and atypical antipsychotics has no significant impact on such gating in this illness.

P50 gating at acute and post-acute phases of first-episode schizophrenia

Deficit in P50 sensory gating has repeatedly been shown in schizophrenia. In order to determine the contribution of trait and/or state features to P50 gating deficit in schizophrenia we evaluated the P50 gating in patients with first-episode schizophrenia (FES) at acute and post-acute phases. Subject groups comprised 16 patients with FES and 24 healthy controls. Patients were tested at the acute phase of the illness and retested at the post-acute phase when their positive symptoms improved. During the testing at the acute phase five patients were neuroleptic-naive and the others were taking atypical antipsychotics which were started recently in order to control the acute excitation. Patients were receiving risperidone, olanzapine or quetiapine treatment at the post-acute phase. P50 gating was impaired in patients at the acute phase compared to controls. However, at the post-acute phase P50 gating was increased compared to the acute phase, reaching to the gating values of controls. P50 gating improvement might be emerged from atypical antipsychotic medication, although this can only be definitively determined by randomized studies including different antipsychotics.

P50 gating at acute and post-acute phases of schizophrenia

Event Abstract Back to Event P50 gating at acute and post-acute phases of schizophrenia Alp Üçok1*, Müge Devrim-Üçok2 and H. Keskin-Ergen2 1 University of Istanbul, Istanbul Medical Faculty, Department of Psychiatry, Turkey 2 University of Istanbul, Istanbul Medical Faculty, Department of Physiology, Turkey Deficit in P50 sensory gating has repeatedly been shown in schizophrenia. In order to determine the contribution of trait and/or state features to P50 gating deficit in schizophrenia we evaluated the P50 gating in patients with first-episode schizophrenia (FES) at acute and post-acute phases. Paired clicks (S1 and S2) were presented 500 ms apart. P50 gating was quantified both by S2/S1 ratio (P50 amplitude to S2 divided by the P50 amplitude to S1) and S1-S2 difference (difference between the P50 amplitude to S1 and S2). Subject groups comprised 16 patients with FES and 24 age-, gender- and education-matched healthy controls. Patients were tested at the acute phase of the illness and retested at the post-acute phase when their positive symptoms improved. Mean inter-test interval was 2.65+/-2.42 months. Patients were on atypical antipsychotic treatment (risperidone, olanzapine or quetiapine) at the post-acute phase. P50 gating was impaired in patients at the acute phase compared to controls (S2/S1 ratio, p=0.024; S1-S2 difference, p=0.05). However, at the post-acute phase P50 gating was increased compared to the acute phase (S2/S1 ratio, p=0.021; S1-S2 difference, p=0.04), reaching to the gating values of controls. No correlation was found between P50 gating and clinical severity measures. P50 gating improvement might be emerged from atypical antipsychotic medication. However, there is little evidence in the extant literature that other than the clozapine atypical antipsychotics exert a restorative effect on sensory gating. This controversy could be explained by the fact that previous studies evaluated chronic or recent-onset schizophrenia patients; however, all patients had a FES in our study. Randomized studies which include placebo and different antipsychotics in a large sample are needed to determine the effects of individual atypical antipsychotics on P50 gating in first-episode patients. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Poster Presentation Topic: Neuropsychiatric Disorders Citation: Üçok A, Devrim-Üçok M and Keskin-Ergen H (2008). P50 gating at acute and post-acute phases of schizophrenia. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.378 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 16 Dec 2008; Published Online: 16 Dec 2008. * Correspondence: Alp Üçok, University of Istanbul, Istanbul Medical Faculty, Department of Psychiatry, Istanbul, Turkey, alpucok@superonline.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Alp Üçok Müge Devrim-Üçok H. Keskin-Ergen Google Alp Üçok Müge Devrim-Üçok H. Keskin-Ergen Google Scholar Alp Üçok Müge Devrim-Üçok H. Keskin-Ergen PubMed Alp Üçok Müge Devrim-Üçok H. Keskin-Ergen Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.