Covariation of the anxious-depressed syndrome during adolescence: Separating fact from artifact.

Nosological (symptom overlap) and methodological (informant) artifact in the covariation of an empirically derived syndrome of anxious-depressed symptoms with 7 other syndromes of emotional and behavior problems was examined in reports by parents, teachers, and adolescents on a nationally representative sample of 908 adolescents. Although minor symptom overlap was observed and the effects of informant were significant, the anxious-depressed syndrome covaried significantly with all other syndromes after controlling for these effects. Indices of covariation controlling for informant effects were all significant and ranged for all syndromes except for delinquent behavior from .619 to .681, reflecting significant covariation of the anxious-depressed syndrome with both externalizing and internalizing syndromes. Covariation of the anxious-depressed syndrome and delinquent behavior was .470. Implications for research on the comorbidity-covariation of depressive syndromes during childhood and adolescence are highlighted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increasing the impact of cluster analysis research: The case of psychiatric classification.

The publication of the DSM-III by the American Psychiatric Association has fueled interest among psychologists in developing alternative classifications. A popular approach is to use multivariate methods known as cluster analysis to identify clinical syndromes. Empirical clustering techniques offer potential for making diagnoses more objective, reliable, and predictive of outcome from differential treatment. However, problems exist at the interface between this statistical technology and psychiatric classification. To date, cluster-analytic studies have had limited impact on psychiatric nomenclature, and clinicians have not found the cluster-derived syndromes to be relevant to everyday practice. The present authors discuss reasons that underlie the lack of impact and describe directions for upgrading both the scientific quality and clinical acceptance of cluster-analysis research. It is concluded that more emphasis must be placed on fostering the clinical use of empirically derived classifications. (69 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-cultural generalizability of the Child Behavior Checklist cross-informant syndromes.

Principal factor analysis followed by promax rotations were performed on Child Behavior Checklist (CBCL) scores of 2,339 children randomly drawn from a sample of 4,674 clinically referred Dutch children, aged 4–18 years. Dutch syndromes were very similar in item composition to the 8 CBCL cross-informant syndromes derived by T. M. Achenbach (1991), except for the Social Problems syndrome. Cross-national correlations ranged from .82 for the Social Problems syndrome to .99 for the Somatic Complaints and Anxious/Depressed syndromes. Confirmatory factor analysis of the Dutch and American syndromes in a cross-validation sample of the remaining 2,335 Dutch children supported both the Dutch and the American scales to the same degree. Exploratory and confirmatory results both strongly supported the cross-cultural generalizability of the CBCL cross-informant syndromes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intuitive and empirical prototypes in childhood psychopathology.

This study examines the validity of intuitive classifications of experienced diagnosticians, that is, the empirical foundation of their intuitive prototypes. Intuitive prototypes of 10 experienced diagnosticians were collected in two tasks and were compared with the empirically based assessment system of T. M. Achenbach (T. M. Achenbach, K. C. Conners, H. C. Quay, F. C. Verhulst, & C. T. Howell, 1989). Results show that the intuitive prototypes correspond very poorly with the empirical core syndromes, instead consisting of different groups of symptoms from various core syndromes. The study also showed a low similarity between behaviors that clinicians judge as co- occurring with an incompletely specified syndrome and behaviors that empirically co-occur with that syndrome. Reasons for the difference between intuitive prototypes and empirically derived classification structures are discussed, as are consequences for diagnostic practice. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

ILAE-defined epilepsy syndromes in children: correlation with quantitative MRI

PURPOSE: The role of quantitative magnetic resonance imaging (MRI) in evaluation of childhood epilepsy remains poorly defined, with minimal published data. Previous work from our center questioned the specificity of hippocampal asymmetry (HA) in an outpatient group whose epilepsy was defined by using clinical and interictal data only. By using childhood volunteer controls and defining epilepsy syndromes using video-EEG monitoring, we readdressed the utility of HA in differentiating mesial temporal lobe epilepsy (MTLE) from other partial and generalized epileptic syndromes in children. METHODS: Seventy children were enrolled; entry criteria were age younger than 18 years with predominant seizure type recorded on video-EEG telemetry with volumetric MRI in all cases. Thirty healthy child volunteers had volumetric MRI. Epilepsy syndrome classification was according to ILAE. RESULTS: Control data revealed symmetric hippocampi, mean smaller/larger ratio of 0.96 (0.95-0.97, 95% CI) with no gender or right/left predominance. Overall 23% of patients had significant HA. Mean hippocampal ratio for MTLE was 0.78 (95% CI, 0.70-0.86), significantly lower than controls and from all other epilepsy syndromes. HA was highly specific (85%) to the syndrome of MTLE. Other potential epileptogenic lesions were found in 27 (39%) patients, lowest yield in frontal and mesial temporal syndromes. Dual pathology was present in 10% of patients. There was no significant association between HA and risk factors. CONCLUSIONS: In this study, we found that HA in children with a well-defined epilepsy syndrome is highly sensitive and specific for MTLE. Whether this will correlate with surgical outcome, as in adults, is the subject of ongoing study.     

Inhibitors of spasmogen-induced Ca2+ channel suppression in smooth muscle cells from small intestine

OBJECTIVE: To examine relationships between anti-beta2-glycoprotein (beta2-GPI) antibodies and other antiphospholipid antibody (aPL) tests (aPL ELISA and the lupus anticoagulant or LAC) and the associations of each of these aPL tests with individual clinical manifestations of the antiphospholipid antibody syndrome (APS). METHODS: IgG and IgM anti-beta2-GPI antibodies were determined by ELISA in 281 patients with SLE, primary APS, or other connective tissue diseases. Frequencies, sensitivities, specificities, and predictive values and correlations of anti-beta2-GPI were compared to the aPL ELISA (IgG and IgM) and LAC for individual (and combined) features of APS. RESULTS: Among 139 patients with positive aPL ELISA and/or LAC tests, 57 (41%) had anti-beta2-GPI antibodies (IgG and/or IgM) compared to 11% of patients with SLE negative for these tests (p = 0.00001). In 130 patients with APS, anti-beta2-GPI occurred in 42% and tended to be more specific but less sensitive than the aPL ELISA or LAC. When all 3 aPL tests were combined, the best sensitivities and negative predictive values were achieved; however, specificity and positive predictive values remained low. Anti-beta2-GPI antibodies occurred more frequently in primary APS (58%) vs secondary antiphospholipid syndromes (33%) (p = 0.008, OR = 2.9). Among 79 patients with SLE negative by both aPL ELISA and LAC, 9 (11 %) were positive for anti-beta2-GPI, 7 of whom had clinical features consistent with APS (representing 5% of all with APS). Stepwise multiple logistic regression analysis revealed beta2-GPI to be most strongly associated with neurological syndromes other than stroke, deep venous thrombosis, and recurrent fetal loss, while LAC was most strongly correlated with stroke and thrombocytopenia. IgM aPL antibodies also were independently associated with neurological syndromes and recurrent fetal loss. CONCLUSION: Testing for beta2-GPI antibodies may be clinically useful in the diagnosis of APS but cannot supplant other aPL ELISA or LAC. Multivariate analyses suggest that anti-beta2-GPI antibodies may play a more central role in certain clinical manifestations of APS than antibodies detected by the aPL ELISA or LAC.     

Quantitative MRI in outpatient childhood epilepsy

PURPOSE: In adult studies, MRI volumetrics is a proven technique in presurgical assessment of epilepsy. Hippocampal volume loss is maximal in the syndrome of mesial temporal lobe epilepsy. We aimed (a) to validate this methodology in a pediatric outpatient epilepsy population (b) to determine the relationship of hippocampal asymmetry (HA) to epileptic syndromes and risk factors. METHODS: Two neurologists classified the epileptic syndrome in 79 pediatric outpatients, according to the International Classification of Epilepsies and Epileptic Syndromes (ILAE). Hippocampal volumetrics were performed in all patients. HA was defined according to adult control values. RESULTS: Inter-rater variability on measurement of HA was very small (Correlation of test retest of 0.97 on 17 children <3 years old). The rate of HA was 44/79 (57%). In 21 patients, (27%) potentially epileptogenic lesions (other than HA) were identified (cerebral dysgenesis n = 11). HA was present in 9/15 (60%) of temporal lobe epilepsy and in 15/28 (54%) extratemporal onset epilepsy and 5/11 (46%) of generalized symptomatic epilepsy. Analysis confined to <13 years also showed HA was not specific for epileptic syndrome. There was no significant association of febrile convulsions (13%) with HA or temporal lobe epilepsy. CONCLUSIONS: There is a high incidence of HA in childhood epilepsy. HA was not confined to clinically defined temporal lobe epilepsy. The poor correlation of epileptic syndrome to quantitative MRI findings may be due to the inadequacies of epilepsy classification in the younger child, with the clinical semiology providing misleading localizing information. Normative childhood data for hippocampal volumes and symmetry is needed.     

Prevalence, classification, and severity of epilepsy and epileptic syndromes in children

PURPOSE: To determine the point prevalence of active childhood epilepsy in a defined area and evaluate the usefulness of ILAE classification of seizures, and epilepsies/syndromes with special interest in severe epilepsies. METHODS: By using the latest ILAE International Classification of Epileptic Seizures (ICES, 1981) and Epilepsies and Epileptic Syndromes (ICE, 1989), we determined the age- and sex-specific prevalence rates of epilepsy, type of seizures, epilepsies, and recognizable epileptic syndromes, as well as the proportion of severe cases in each seizure/epilepsy/syndrome category in all children 0-15 years of age from a geographically defined area in Finland. All medical records, neurophysiological recordings and available clinical data were reviewed retrospectively. RESULTS: Point prevalence of active epilepsy on December 12, 1992 was 3.94 per 1,000. According to ICES/ICE, we were able to classify 96% of seizures and 90% of epilepsies and syndromes. Generalized seizure and epilepsy/syndrome types were more prevalent in children 0-6 years of age and partial/localization-related in children 6-15 years of age. Epilepsy was intractable in 17% of all cases and correlated significantly with symptomatic etiology and early onset of epilepsy, as well as with additional neuroimpairments. CONCLUSIONS: A considerable number of cases fell into the nonspecific categories of ICE, which limits the value of present epilepsy/syndrome classification in terms of prognosis, prediction, and indication for special investigations in individual cases. A number of intractable cases was relatively low, indicating good prognosis in many childhood epilepsies, especially when additional neuroimpairments are absent.     

Typical absence status in adults: diagnostic and syndromic considerations

PURPOSE: To study the electroclinical features of typical absence status (TAS) in adults with syndromes of idiopathic generalized epilepsies (IGEs). METHODS: Twenty-one patients with one or more spells of TAS were identified among 136 consecutive adult patients with IGEs. All patients with TAS had comprehensive electroclinical investigations and EEG or video-EEG recorded absences. RESULTS: TAS occurred in 24.4% of 86 patients who had IGEs with typical absences alone or in combination with other seizures presisting in adult life. The prevalence of TAS appeared to be syndrome related, ranging from as high as 57.1% in perioral myoclonia with absences and 46.2% in "phantom" absences with GTCS to as low as 6.7% in juvenile myoclonic epilepsy. A varying degree of impairment of cognition was the cardinal clinical symptom shared in all TAS, but corresponding syndromes of IGE were often betrayed by other symptoms such as eyelid or perioral myoclonia. In phantom absences with GTCS, TAS was more numerous (p < or = 0.05) and more frequently the first overt seizure type (p = 0.006) than in any other IGE. Only in the syndrome of eyelid myoclonia with absences, TAS was always situation related, mainly as a result of antiepileptic drug discontinuation. CONCLUSIONS: The clinical EEG semiology and prevalence of TAS appear to be syndrome related with the highest prevalence in the syndromes of perioral myoclonia with absences and phantom absences with GTCS (p = 0.0024).     

The Youth Self-Report inventory: A study of its measurements fidelity.

Evaluated the measurement fidelity (i.e., reliability, factor structure, and validity) of T. M. Achenbach's (1966, 1991) Youth Self-Report (YSR) scale. Data from hospitalized psychiatric adolescents were used to test the unidimensionality of each narrow band syndrome and to conduct confirmatory factor analysis on broadband syndromes. Three competing models regarding broadband syndromes were constructed and compared with the structure reported by Achenbach (1991). The results partly support Achenbach's findings in that 4 of the 7 narrowband syndromes were found to be valid. However, meaningful subdimensions were obtained for the other 3 narrowband syndromes. Confirmatory factor analysis revealed that internalizing and externalizing were valid broadband syndromes. However, 3 narrowband syndromes (Social Problems, Thought Problems, and Attention Problems) cross-loaded on both broadband syndromes. Important differences in broadband syndromes were found between boys and girls. Supplemental analyses on Time 2 data demonstrated the stability of these findings. Implications for future refinement of the YSR are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the results of cleft lip and palate surgical treatment: preliminary report

We have analysed randomized controlled studies which reported the incidence of postoperative nausea and vomiting (PONV) after propofol anaesthesia compared with other anaesthetics (control). Cumulative data of early (0-6 h) and late (0-48 h) PONV were recorded as occurrence or non-occurrence of nausea or vomiting. Combined odds ratio and number-needed-to-treat were calculated for propofol as an induction or maintenance regimen, early or late outcomes, and different emetic events. This was performed for all control event rates and within a range of 20-60% control event rates. We analysed 84 studies involving 6069 patients. The effect of propofol on PONV was dependent mainly on the method of administration, time of measurement and range of control event rates. When all studies were included the number-needed-to-treat to prevent PONV with propofol was more than 9 when used for induction of anaesthesia and at best 6 when used for maintenance. Within the 20-60% control event rate range, best results were achieved with propofol maintenance to prevent early PONV: the number-needed-to-treat to prevent early nausea was 4.7 (95% confidence interval 3.8-6.3), vomiting 4.9 (4-6.1) and any emetic event 4.9 (3.7-7.1). Within the 20-60% control event rate, of five patients treated with propofol for maintenance of anaesthesia, one will not vomit or be nauseated in the immediate postoperative period who would otherwise have vomited or been nauseated. This may be clinically relevant. In all other situations the difference between propofol and control may have reached statistical significance but was of doubtful clinical relevance. Treatment efficacy should be established within a defined range of control event rates for meaningful estimates of efficacy and for comparisons.     

Course of psychiatric and substance abuse syndromes co-occurring with bipolar disorder after a first psychiatric hospitalization

BACKGROUND: Patients with bipolar disorder frequently meet criteria for other psychiatric and substance abuse diagnoses. To clarify relationships among these disorders, the authors examined the course of syndromes co-occurring with bipolar disorder for 12 months after a first hospitalization. METHOD: Seventy-seven patients were recruited from consecutive inpatient admissions who met DSM-III-R criteria for bipolar disorder, manic or mixed with psychosis. The 12-month syndromal course of co-occurring DSM-III-R alcohol and drug abuse disorders, posttraumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and other anxiety disorders were longitudinally recorded. RESULTS: The rates of all syndromes, except other anxiety disorders, were elevated. OCD demonstrated an interval course that frequently mirrored the course of the bipolar disorder. The courses of PTSD and substance abuse syndromes were separate from that of the bipolar disorder in many of those with both syndromes. Alcohol and drug abuse syndromes were strongly correlated. CONCLUSION: The obsessive-compulsive syndrome may represent an alternative expression of bipolar disorder in some patients. In contrast, PTSD appears to represent a truly separate disorder, which is possibly more prevalent in bipolar patients due to a shared risk factor. Substance abuse does not appear to simply result from attempts at self-medication or from the impulsivity of mania. These results suggest that future studies examining the course of syndromes co-occurring with bipolar disorder are warranted.     

Syndromes, antecedents, and outcomes of psychosis: A cluster-analytic study.

Sought mental illness definitions through the use of the bc try computer system and 1,099 patient records of a modern mental health center. Results of other investigations that had used objective syndrome finding techniques were utilized as the hypotheses, and 8 of 9 predicted syndromes were discovered. Altogether, 11 replicated syndromes appeared. The attempt to relate a set of illness outcome variables to the syndromes, including some variables describing conditions antecedent to hospitalization, was less successful. Findings are discussed in terms of relationships between the syndrome and the feasibility of using record system data for research. (36 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variability of the clinical picture and the classification of progressive systemic scleroderma

Fiftythree patients with progressive systemic sclerosis were studied. Four of them (3 males) had the diffuse form of the disease. The skin manifestation of this clinical picture is characterized by diffuse progression of the cutaneous sclerosis over almost the whole body surface, except for the hands where it eventually may appear late. The prognosis for these patients it especially poor. Fortyfive patients (44 females) had acrosclerosis in the widest sence. Twentyseven of these ("acrosclerosis stricto sensu") had cutaneous sclerosis of the hands, face, and often other parts of the body, but not on the abdomen, arms or thighs. The remaining 18 patients had sclerotic alterations on these surfaces also. In this syndrome (which the authors call "the intermediary syndrome"), i.e. where the abdomen, arms, and thighs also are affected, certain internal organs and the joints are more involved than in "acrosclerosis stricto sensu". With rare exceptions, a symptomatic tetrade (REST-syndrome) occurred in acrosclerosis and all the intermediary syndromes. This consisted of Raynaud's syndrome (R), esophagopathy (E), cutaneous sclerosis (S), and telangectasia (T). Fifty % of the patients in addition had calcinosis (C), either subcutaneous or para-articular. The tetrade "REST syndrome" becomes in these cases the pentade "CREST syndrome". The addition of calcinosis to the other four phenomena of the REST syndrome does not alter the frequency of internal organ involvement or the prognosis of the disease. The term "REST syndrome" and its variant "CREST syndrome" should replace the conservative term "acrosclerosis" because they add to the purely cutaneous phenomena other characteristic manifestations of the disease. Two patients could neither be classified under the REST syndrome nor the progressive diffuse syndromes. Two other patients had no cutaneous phenomena ("scleroderma sine scleroderma").     

Psychometric properties of the Geriatric Depression Scale among the institutionalized aged.

Validity and reliability of the Geriatric Depression Scale (GDS) were examined among 806 nursing home and congregate apartment residents (mean age 84 years). The scale was highly internally consistent and, although a clean factor structure emerged, basically unidimensional. Test-retest reliability at 1 mo was good, but correlations with staff-rated depression were only moderate. GDS-based classifications of respondents as suffering possible major, minor, or no depression were fairly consistent with those based on a symptom checklist and with clinical diagnoses. However, both the GDS and the checklist yielded high false negative rates vis à vis clinically diagnosed minor depression. There were no differences in reliability or validity for cognitively impaired and intact groups. GDS responses did not vary with age or length of institutionalization, but there was a positive correlation with functional disability and ill health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paraneoplastic syndromes affecting the nervous system

Paraneoplastic syndromes can affect virtually any portion of the nervous system. Most paraneoplastic syndromes are believed to be caused by an autoimmune reaction to an "onconeural" antigen shared by the cancer and the nervous system. The immune reaction may retard growth of the cancer, but it also damages the nervous system. Specific autoantibodies found in some individual paraneoplastic syndromes are usually associated with specific tumors. Neurological disorders, clinically and pathologically identical to paraneoplastic syndromes, may occur in some patients without cancer, but paraneoplastic antibodies are not found in these patients. The diagnosis of a paraneoplastic syndrome is based on its increased incidence in patients with cancer, the occasional response of the neurological syndrome to treatment of the underlying cancer, or the presence of specific autoantibodies. Some paraneoplastic syndromes respond to treatment of the underlying cancer or to immunosuppression but, for most syndromes, no effective treatment exists.     

The classification of child psychopathology: A review and analysis of empirical efforts.

Reviews empirically derived syndromes of child behavior problems, and identifies those having counterparts in 2 or more studies. A distinction between broad-band and narrow-band syndromes was made. Broad-band undercontrolled and overcontrolled syndromes and narrow-band aggressive, delinquent, hyperactive, schizoid, anxious, depressed, somatic, and withdrawn syndromes were found in diverse samples of disturbed children. Two other broad-band and 6 other narrow-band syndromes were found in a few studies. Test–retest reliabilities and stabilities of syndrome scores were more adequate than interrater reliabilities. Cross-instrument and cross-population consistencies corroborated some empirically derived syndromes but the lack of independent criteria for categorizing disturbed children made it difficult to establish criterion-referenced validity. Because categorization of children by syndromes has been limited primarily to the broad-band undercontrolled–overcontrolled dichotomy, it is suggested that more efforts are needed to translate syndromes into categories for use by practitioners and researchers. It is concluded that further work in this area should be systematically linked to the existing mental health system and to efforts at reforming this system. (98 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Beck Depression Inventory and Research Diagnostic Criteria: Congruence in an Older Population.

This study examined the congruence between conventional cutoff scores on the Beck Depression Inventory (BDI) and selected diagnostic classifications of the Research Diagnostic Criteria in a sample of 102 elders seeking psychological treatment. Only 16.67% were misclassified by customary BDI cutoff scores. Minor Depressive Disorders were less clearly identified than Major Depressive Disorders or nondepressed status. Similar results were obtained in a second sample of elders not seeking treatment. Findings support the utility of the BDI as a screening instrument for identification of clinically depressed elders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in crystallinity by sterilization and processing of ultrahigh molecular polyethylene used in endoprosthetics]

Research in animals shows that the levels of neuropathic pain expression is genetically associated with a characteristic response profile to sensory stimuli. The aim of the present investigation was to examine if pressure algometry can identify a specific pain sensitivity profile in patients with complex regional pain syndrome, Type I (reflex sympathetic dystrophy), and to distinguish complex regional pain syndromes from other chronic pain dysfunction syndromes. Pressure pain threshold and pain tolerance measured at the sternum in 17 patients with complex regional pain syndrome, Type I (reflex sympathetic dystrophy), were compared with values obtained in 13 patients suffering from other chronic pain dysfunction syndromes and in a control group of 24 pain-free volunteers. The pressure algometer consisted of a force displacement transducer with a 0.25 cm2 tip connected to a recorder. The rate of force application was 1 kg/0.25 cm2/s. The difference between threshold and tolerance was defined as the pain sensitivity range. Young patients with complex regional pain syndrome (<40 yr) demonstrated a significantly higher mean pain sensitivity range compared with young subjects who had chronic pain or who were pain-free. Mean threshold and tolerance values were significantly lower in patients with complex regional pain syndrome (2.7+/-1.0 kg (mean +/- standard deviation) and 5.4+/-2.0 kg, respectively) and in patients suffering from other chronic pain syndromes (2.6+/-1.1 and 4.6+/-1.7 kg) than in healthy subjects (5.4+/-2.3 and 8.4+/-2.6 kg). Women in the chronic pain group exhibited a significantly lower pressure pain threshold than all other subgroups. Regardless of group, women exhibited lower pressure pain tolerance than men. In conclusion, the study contained herein shows a specific pain sensitivity profile to experimental stimuli behavior in young patients with complex regional pain syndrome expressed by a large pressure pain sensitivity range, at a location away from the painful area. However, one single pressure pain measurement over the sternum is insufficient for differentiation of patients with complex regional pain syndrome from those with chronic pain because of intersubject variation.     

Response of melanocortin-4 receptor-deficient mice to anorectic and orexigenic peptides

Whether P/Q-type voltage-gated calcium channel (VGCC) antibodies are present in the serum of patients with paraneoplastic syndromes other than the Lambert-Eaton myasthenic syndrome (LEMS) and tumors other than small-cell lung cancer (SCLC) is controversial. Using a commercially available radioimmunoprecipitation assay kit, we examined the sera of 93 patients with paraneoplastic syndromes of the central nervous system (CNS), including 27 patients with paraneoplastic cerebellar degeneration (PCD) associated with tumors other than SCLC and 66 SCLC patients with paraneoplastic encephalomyelitis and sensory neuronopathy (PEM/SN). All PCD sera from patients with tumors other than SCLC were negative for P/Q-type VGCC antibodies. Eight of 66 (12%) SCLC patients with PEM/SN had P/Q-type VGCC antibodies; 4 had LEMS and the other 4 had no symptoms of LEMS or they were overlooked and, therefore, not examined electrophysiologically. In patients with paraneoplastic syndromes of the CNS, the detection of P/Q-type VGCC antibodies supports the diagnosis of LEMS; in our series, only 6% of patients with SCLC and PEM/SN may have had a false positive antibody result, or undiagnosed LEMS.