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Stress and Other Psychosocial Characteristics of Patients With Psychogenic Nonepileptic Seizures
Stress and Other Psychosocial Characteristics of Patients With Psychogenic Nonepileptic Seizures TINA M. TOJEK, M.A., MARK LUMLEY, PH.D. GREGORY BARKLEY, M.D., GREGORY MAHR, M.D. ANDREA THOMAS, M.A.
Research on psychogenic nonepileptic seizures (PNES) has focused on childhood abuse, but less is known about other stressors and psychosocial risk factors. The authors compared 25 patients with PNES with 33 control subjects with epilepsy on stressful life events and other risk factors for somatoform disorders. Compared with control subjects, patients with PNES reported significantly more prevalent and stressful negative life events (including adulthood abuse) and more current rumination, stress-related diseases, somatic symptoms, bodily awareness, and marginally more anxiety and depression. However, the relationship of many of these variables to PNES was accounted for by life stress. Groups did not differ on illness worry, alexithymia, or psychotic symptoms. The results suggest that PNES are part of a larger pattern of somatic symptoms responses to a wide range of negative events, including stress in adulthood. (Psychosomatics 2000; 41:221–226)
P
sychogenic nonepileptic seizures (PNES) are events that resemble epileptic seizures behaviorally but demonstrate no coincident epileptiform activity during electroencephalographic recording. They occur in about 5%–20% of patients in epilepsy clinics with women representing about 75% of cases. The mean age of diagnosis is from 30 to 40 years.1 PNES can be further differentiated from veridical epileptic seizures in that PNES are more likely to demonstrate a gradual onset,2 atypical motor activity, emotional vocalizations, absence of self-injurious behavior,1 and longer average duration.3 Research has found an increased prevalence of childhood abuse in many cases of PNES.4–7 Also, patients with PNES frequently are diagnosed with conversion disorder.8 However, PNES occur as part of other somatoform disorders and may be manifestations of panic, dissociative, and factitious disorders, as well as malingering.1 Comorbid conditions include depression and anxiety as well as borderline and obsessive-compulsive personality traits.9–11 The available research on PNES has several limitaPsychosomatics 41:3, May-June 2000
tions, which we sought to redress in this study. First, many studies have compared PNES patients with healthy subjects, whereas fewer studies have used the more appropriate comparison group of epilepsy patients. When epileptic control subjects are studied, differences in the prevalence of psychiatric disorders decrease.4,10 Thus, we compared PNES patients with demographically comparable epilepsy patients. Second, research has focused on childhood abuse to the exclusion of other stressful events that may contribute to the development of PNES, including stress in adulthood. Also, studies have not examined the perceived stressfulness of negative events and whether patients have adequately Received June 25, 1999; revised September 29, 1999; accepted November 19, 1999. From Department of Psychology, Wayne State University, Detroit, MI; Department of Neurology and Department of Psychiatry and Behavioral Sciences, Henry Ford Hospital, Detroit, MI; and the Epilepsy Foundation of Michigan, Southfield, MI. Address reprint requests to Dr. Lumley, Department of Psychology, Wayne State University, 71 West Warren Avenue, Detroit, Michigan 48202; email: mlumley@ sun.science.wayne.edu Copyright 䉷 2000 The Academy of Psychosomatic Medicine.
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Nonepileptic Seizures coped with these events. Although not pathognomonic, continued rumination and thought intrusion about stressful experiences is considered one indicator of the failure to resolve or adapt to the experience.12 Thus, we surveyed a range of negative life events, their perceived stressfulness, and the frequency that patients continue to think about them. We hypothesized that PNES patients would report an increased prevalence and severity of a range of stressful events and would be less likely to have resolved the stress, as indicated by a greater frequency of ongoing rumination. Third, in addition to assessing anxious, depressive, and psychotic symptoms, we tested the hypotheses that PNES patients manifest elevations in a number of risk factors found in somatoform disorders but less frequently studied in PNES: general somatic symptoms, other stress-related physical disorders, illness worry, bodily awareness, and alexithymia.13,14 Finally, to develop a parsimonious model of psychosocial risk factors for PNES, we tested whether these other psychosocial risk factors are independent of, or coincide with, life stress in their relationship to PNES. METHOD Participants and Procedures Participants were 25 adults with PNES and 33 adults with epilepsy who were recruited from the Comprehensive Epilepsy Clinic of an urban hospital. The sample of PNES patients was obtained by identifying patients who had been evaluated during the past several years with the use of 24hour electroencephalogram (EEG) video monitoring and who demonstrated, during the evaluation, a behavioral event consistent with their reported spells but for which no ictal activity occurred. PNES patients were included only if they continued to experience at least occasional nonepileptic events at the time of the study. The comparison patients had confirmed epilepsy and were receiving ongoing medical care at the time of the study. Neither the PNES patients nor the patients with epilepsy had cognitive impairment (e.g., mental retardation or dementia), and to improve sample homogeneity, three patients with both epileptic and nonepileptic events were excluded. The two groups did not differ significantly on gender (PNES: 88% female, epilepsy: 90.9% female), age (PNES: meansⳲSD⳱43.56Ⳳ13.23 years old; epilepsy: meansⳲSD⳱39.60Ⳳ9.03), or education level (PNES: meansⳲSD⳱13.02Ⳳ2.71 years; epilepsy: meansⳲSD⳱ 13.75Ⳳ2.23). There also was no difference in annual family income. There was a trend (P⬍0.10), however, toward 222
more non-White members of the PNES group (52%; 12 African Americans and 1 Hispanic), compared with the epilepsy group (30.3%; all African Americans). Patients were recruited during a routine visit to the health center, where they provided fully informed consent; were interviewed for demographic, medical, and psychosocial history; and completed questionnaires. Measures Interview A structured interview inquired about seizure history, other medical problems, and health care utilization over the past 3 months. In addition, each patient was asked to rate the quality of the childhood relationship with his or her mother and father separately on 5-point scales (1⳱excellent, 5⳱very bad). Life Events Checklist Stressful life events were assessed with the Life Events Checklist (LEC), which measures the frequency and severity of 32 significant life stressors. The LEC was modified from the Life Experiences Survey15 by Kelley et al.16 First, patients indicated which events they had experienced during their lifetimes, and this yielded a frequency of stressful events score. Next, using a 4-point scale, patients rated the stressfulness of each event that they had experienced with respect to when the event occurred (0⳱not at all, 1⳱mildly, 2⳱moderately, 3⳱extremely). These ratings were averaged to provide a mean stress severity score, and a total stress score was generated by summing the stress ratings across all events that were experienced. Finally, patients reported the frequency that they currently thought about each experienced stressor on a 5point scale (0⳱rarely or never, 1⳱about once a month, 2⳱about once a week, 3⳱about once per day, 4⳱several times per day). Frequency ratings were averaged across events; higher scores indicated a greater average frequency of current thinking or ruminating about stressors. Brief Symptom Inventory Psychiatric symptoms were assessed with 4 subscales from the Brief Symptom Inventory (BSI).17 Patients rated depression, anxiety, somatic, and psychotic symptoms on a 5-point scale (0⳱not at all present; 4⳱extremely). Scale means were calculated. The BSI subscales have high internal consistencies and good convergent and divergent validities.17 Reliabilities of each subscale used in this study were acceptable (Cronbach’s alpha for anxiety, depression, somatization, and psychosis subscales, respectively⳱0.87, 0.88, 0.83, and 0.69). Psychosomatics 41:3, May-June 2000
Tojek et al. Illness Worry Scale Illness worry was assessed with the 9-item Illness Worry Scale (IWS).13,18 The IWS assesses concern about having or contracting a serious illness. Items were rated on a 5-point scale (0⳱extremely uncharacteristic; 4⳱extremely characteristic) and averaged; higher scores indicated greater illness worry. The IWS has demonstrated good reliability and validity.19 Internal consistency of the IWS in this study was good (alpha⳱0.83).
Private Body Consciousness Scale Bodily awareness was assessed with the 7-item Private Body Consciousness Scale (PBC),20 which assesses awareness of bodily sensations, such as temperature and hunger. Items were rated on a 5point scale (0⳱extremely uncharacteristic; 4⳱extremely characteristic) and averaged; higher scores indicate greater bodily awareness. This scale has shown moderate internal consistency (alpha⳱0.60)19 and good convergent and divergent validity.20,21 Internal consistency of the PBC scale in this sample was adequate (alpha⳱0.71).
Alexithymia Alexithymia was assessed with the Toronto Alexithymia Scale-20 (TAS-20).22 The TAS-20 assesses difficulty identifying feelings, difficulty communicating feelings, and externally oriented thinking. Patients rated each item on a 5-point scale (1⳱strongly disagree; 5⳱strongly agree). A total alexithymia score was calculated. The TAS-20 has been found to be reliable and valid,22 and in this study, it had adequate internal consistency (alpha⳱0.71).
RESULTS Approach to Data Analysis
The primary analyses used logistic regression to identify variables significantly related to group status (PNES vs. epilepsy patients). Because ethnicity was marginally different between the two groups, we statistically adjusted for ethnic group membership (White vs. non-White) in all analyses before testing the variables of interest. Subsequent logistic regressions tested for the continued significance of risk factors beyond the effects of life stress; these models adjusted for the total stress severity score in addition to ethnicity. For all analyses, a two-tailed alpha of 0.05 was considered significant, and a two-tailed alpha of 0.10 was considered marginally significant. Psychosomatics 41:3, May-June 2000
Group Comparisons on Seizure and General Medical Histories Table 1 presents medical and psychosocial history data for the two groups. After adjusting for ethnicity, PNES patients reported a later onset of events and were more likely to have a family member with a seizure history. In addition, PNES patients indicated a higher prevalence of hypertension and ulcers but not cardiac or pulmonary disease. PNES patients also made marginally more visits to their primary care physicians during the past 3 months than did the epilepsy patients, but the groups did not differ on emergency visits. Group Comparisons on Stress and Psychosocial Variables Table 2 presents the group data on stress variables, psychiatric symptoms, and other psychological variables. Adjusting for ethnicity, PNES patients reported a higher prevalence of stressful life events than epileptic patients, and PNES patients also had higher mean ratings of the stressfulness of the events; thus, the total stress score was significantly more elevated among PNES patients than epileptic patients. In addition, the PNES patients reported that they currently thought about stressful events more often than did epileptic patients. Next we examined specific stressful life events using the LEC. We found that 75% of the 32 specific events were more common among our sample of PNES patients than the epileptic patients, although only a few of these prevalence differences in specific events reached statistical significance. Although overall abuse (sexual or physical, child or adult) tended to be more common among PNES patients (PNES: 44%, epilepsy: 33.3%), it was physical abuse as an adult (P⳱0.03) rather than childhood abuse (P⳱0.35) that was significantly more common among PNES patients. Sexual abuse as an adult (P⳱0.10) was marginally more common among patients with PNES than epilepsy. In addition to abuse, PNES patients were significantly more likely to have experienced the serious illness or death of a close friend (P⳱0.05). They were marginally more likely than the epileptic patients to report marital discord or separation and divorce (P⳱0.08) or to have had a serious alcohol or drug problem (P⳱0.07). With respect to psychiatric symptoms, Table 2 shows that patients with PNES reported greater somatic symptoms and marginally greater anxiety and depression but no difference in psychotic symptoms than the epilepsy patients. PNES patients also reported greater bodily aware223
Nonepileptic Seizures ness. Groups did not differ on illness worry or alexithymia. Finally, as obtained on interview, patients with PNES reported having poorer childhood relationships with their fathers than did epileptic patients, but the groups did not differ in childhood relationships with their mothers. Because several variables in addition to total life stress were associated with PNES, we sought to determine if each would remain related to PNES, beyond the effects of life stress. Thus, we repeated the logistic regressions testing those risk factors that were at least marginally significant in the above analyses, adjusting for both ethnicity and total stress score. Later age at onset, having a family member with epilepsy, having hypertension, and having ulcers all remained significant correlates of PNES after controlling for the effects of life stress. Of the psychological variables in Table 2, none remained significantly related to PNES, although the somatic symptoms variable was marginally significant (P⳱0.057). Current thinking about stress (P⳱0.16), bodily awareness (P⳱0.76), and childhood re-
TABLE 1.
DISCUSSION Our results suggest that PNES occur in response to increased prevalence and stressfulness of negative life events throughout childhood and adulthood. These results also suggest that PNES is part of a larger pattern of somatization. Compared with a demographically comparable group of patients with epilepsy, patients with PNES reported experiencing more stressful events over the course of their lives and rated these events as more stressful. In addition, PNES patients also reported that they continued to think about stressful events more frequently, which suggests increased rumination and the failure to adequately resolve these stressful events.
Group differences in general medical history and health care utilization
Age at first seizure/event Family member with seizures Currently on disability because of seizures Hypertension Heart disease Lung disease Ulcers Primary care physician visits (past 3 months) Current # of medications
TABLE 2.
lationship with father (P⳱0.15) were no longer related to PNES. The marginally significant effects of depression and anxiety were completely accounted for by life stress (P⳱0.48 and P⳱0.60, respectively).
PNES Group (MeansⴣSD or n, %)
Epileptic Group (MeansⴣSD or n, %)
Wald’s Chi-Square
P-value
25.6Ⳳ17.1 11 (44) 11 (44) 9 (36) 1 (4) 3 (12) 10 (40) 2.48Ⳳ4.1 3.40Ⳳ3.25
15.1Ⳳ8.5 6 (18.2) 10 (30.3) 3 (9.1) 3 (9.1) 1 (6.1) 2 (6.1) 0.82Ⳳ1.3 2.73Ⳳ1.5
5.71 3.94 0.79 5.07 0.72 1.04 8.03 3.28 2.54
0.01 0.04 0.37 0.02 0.39 0.30 0.004 0.07 0.10
Group differences on dependent measures adjusting for ethnicity PNES MeansⴣSD
Epilepsy MeansⴣSD
Wald’s Chi-Square
P-value
Stressful Life Events Number of events Mean stress rating Total stress score Current stress thinking Childhood relationship w/father Childhood relationship w/mother
8.68Ⳳ4.75 2.65Ⳳ0.37 23.10Ⳳ12.9 1.60Ⳳ0.79 3.14Ⳳ1.28 2.27Ⳳ1.01
6.33Ⳳ3.27 2.21Ⳳ0.58 14.10Ⳳ8.6 1.12Ⳳ0.74 2.39Ⳳ0.95 2.25Ⳳ1.07
4.37 8.53 8.06 4.14 5.78 0.02
0.03 0.003 0.004 0.04 0.01 0.90
Symptoms Anxiety Depression Somatization Psychosis Illness Worry
8.57Ⳳ5.98 8.28Ⳳ6.58 11.24Ⳳ6.84 4.58Ⳳ4.50 15.48Ⳳ8.56
6.60Ⳳ4.84 6.31Ⳳ5.39 6.75Ⳳ4.44 4.23Ⳳ3.62 12.90Ⳳ7.78
3.29 3.44 7.44 0.18 1.36
0.07 0.06 0.006 0.67 0.24
Bodily awareness Alexithymia
19.98Ⳳ5.22 54.0Ⳳ11.9
16.90Ⳳ5.56 54.40Ⳳ10.4
3.93 0.14
0.04 0.70
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Psychosomatics 41:3, May-June 2000
Tojek et al. Many researchers have suggested that a history of psychological trauma often predates the onset of PNES;4,7 however, most research has focused specifically on sexual abuse,5,11,23 leaving unclear whether sexual abuse is a unique risk factor or if other stressful events are linked with PNES. Data from this study suggest that people with PNES are more likely to report a wide variety of stressful life events, including physical abuse during adulthood and the illness or death of a close friend. Our PNES patients were more likely to report troubled childhood relationships with their fathers and tended to experience a higher occurrence of marital difficulty. Thus, although few elements of family life have been systemically studied in PNES patients, our data support others’ findings7,10 that PNES patients experience a range of family and relationship problems, beginning in childhood and continuing through adulthood. The average onset of PNES in our sample occurred in adulthood at 25 years of age compared with 15 years of age for patients with epilepsy. This finding, along with our finding that PNES patients have higher rates of adult abuse, suggests that experiences during the adult years may be more closely tied to the occurrence of PNES than thought. Additionally, our patients with PNES were more likely to have a relative with epilepsy, suggesting that modeling may influence the development of PNES. That is, patients with increased stress may develop PNES after observing positive environmental consequences of a relative who had seizures. This observation also suggests that malingering may cause PNES. Malingering is the conscious creation and expression of symptoms to obtain secondary gain, such as relief from a difficult family experience or avoidance of certain responsibilities. This study also suggests that PNES is similar to other somatoform disorders and conditions that involve somatic manifestations of stress. For example, PNES patients reported more vague somatic symptoms than epileptic control subjects, and this effect tended to be independent of the overall life stress that patients had experienced. This is consistent with other studies that show a high incidence of physical symptom reports in PNES patients.24,25 In addition, PNES patients also had higher rates of hypertension and ulcers, both of which are exacerbated by stress.26,27 Also, consistent with previous findings,25 primary care utilization tended to be greater in PNES patients, again suggesting increased somatically focused behavior. Bodily awareness was greater among patients with PNES than those with epilepsy, suggesting further support for a somatization model. Body consciousness or awareness is linked to symptom reports in that people who are Psychosomatics 41:3, May-June 2000
preoccupied with bodily sensations are more likely to notice sensations, to attribute them to biological causes, and to report somatic symptoms.19,28 People with high bodily awareness also demonstrate more difficulty in problem solving than those with low bodily awareness.29 We found, however, that increased bodily awareness was no longer related to PNES after accounting for life stress, suggesting that stressful events may contribute to bodily awareness as well as physiological arousal, which is experienced, interpreted, and reported as physical symptoms. Although previous studies have found increased anxiety and depression among PNES patients,1,24 those studies typically were either uncontrolled or used healthy comparison subjects without epilepsy. Studies, including the current one, that have used epileptic control subjects have found little or no differences in negative affect. Indeed, we found that depression and anxiety were only marginally greater among PNES patients compared with epilepsy patients, suggesting that the increase in negative affect may be because of the presence of a chronic illness rather than uniquely related to PNES. Also, we found that marginal differences in depression and anxiety were completely eliminated after controlling for life stress. This suggests that any increase in negative affect associated with PNES is probably a consequence of life stress. Finally, the clear lack of a difference in psychotic symptoms between patients with PNES and patients with epilepsy confirms other findings1 that PNES is not typically part of a psychotic disorder. Contrary to our hypothesis, we found no difference in alexithymia between PNES and epilepsy patients. Yet, the mean alexithymia score in each group was elevated over community norms, and approximately 30% of both groups scored in the alexithymic range (TAS-20 scoreⱖ61), which is higher than found in healthy populations but fairly consistent with the elevated level of alexithymia found in other medical patient populations.30 Thus, alexithymia appears to be elevated in PNES but not greater than found in epilepsy. Several limitations of this study should be noted. First, our sample size, although large enough to detect a number of significant differences, was relatively small. A larger sample might have revealed significant differences in other variables, such as sexual abuse. Second, we used exclusively self-report measures, which present several potential problems, including response bias and unreliability because of situational reactivity and memory limitations. Third, our assumption that a lack of rumination about stress indicates adaptive resolution of an experience may be invalid for some patients. A subset of PNES patients may have a conversion disorder with repression of negative af225
Nonepileptic Seizures fect, which would serve to protect the person against unwanted thoughts. A lack of rumination may hide the patient’s failure to resolve the experience. Finally, we did not obtain formal psychiatric diagnoses, which would have been useful because different disorders may account for the heterogeneity among patients with PNES, and the diagnoses may be related to different etiologic mechanisms and treatment approaches. Future studies with this population should examine stress and psychosocial risk factors among subgroups of PNES patients, such as those who present with tonic-clonic events versus absence events1 and those with different psychiatric diagnoses. Assessment of factors related to secondary gain and malingering would be useful, as well as a
more systematic and in-depth assessment of stressful life events, to ensure the reliability of patient reports and clarify the types of events that precede PNES onset. Finally, because some reports have noted that PNES may subside after patients are given appropriately sensitive and validating diagnostic feedback or psychotherapeutic treatment,2,23,31,32 controlled studies of the effects of intervention need to be conducted. This study was based on the Masters thesis of the first author, under the direction of the second author. The authors thank Marcy Fivey and Barbara Raider-Gahry for their assistance.
References
1. Alper K: Non-epileptic seizures. Neurol Clin 1994; 12:153–171 2. Devinsky O, Thacker K: Non-epileptic seizures. Neurol Clin 1995; 13:299–318 3. Saygi S, Katz A, Marks DA, et al: Frontal lobe partial seizures and psychogenic seizures: comparison of clinical and ictal characteristics. Neurology 1992; 42:1274–1277 4. Arnold LM, Privitera MD: Psychopathology and trauma in epileptic and psychogenic seizure patients. Psychosomatics 1996; 37:438–443 5. Betts T, Boden S: Diagnosis, management, and prognosis of a group of 128 patients with non-epileptic attack disorder. Part II. Previous childhood sexual abuse in the etiology of these disorders. Seizure 1992; 1:27–32 6. Lesser RP: Psychogenic seizures. Neurology 1996; 46:1499–1507 7. Ramchandani D, Schindler B: Evaluation of pseudoseizures: a psychiatric perspective. Psychosomatics 1993; 34:70–79 8. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Washington, DC, American Psychiatric Association, 1994 9. Howell S, Owen L, Chadwick D: Pseudostatus epilepticus. Q J Med 1989; 71:504–519 10. Moore PM, Baker GA, McDade G, et al: Epilepsy, pseudoseizures, and perceived family characteristics: a controlled study. Epilepsy Res 1994; 18:75–83 11. Alper K, Devinsky O, Perrine K, et al: Non-epileptic seizures and childhood sexual and physical abuse. Neurology 1993; 43:1950– 1953 12. Horowitz M.J: Stress Response Syndromes, Second edition. Northvale, NJ, Jason Aronson, 1986 13. Kirmayer LJ, Robbins JM: Three forms of somatization in primary care: prevalence, co-occurrence, and sociodemographic characteristics. J Nerv Ment Dis 1991; 179:647–655 14. Lumley MA, Stettner L, Wehmer F: How are alexithymia and physical illness linked? A review and critique of pathways. J Psychosom Res 1996; 41:505–518 15. Sarason IG, Johnson JH, Siegel JM: Assessing the impact of life changes: development of the Life Experiences Survey. J Consult Clin Psychol 1978; 46:932–946 16. Kelley JE, Lumley MA, Leisen JC: Health effects of emotional disclosure in rheumatoid arthritis patients. Health Psychol 1997; 16:331–340
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17. Derogatis L: BSI Administration, Scoring and Procedure ManualII. Baltimore, MD, Clinical Psychometric Research, 1992 18. Pilowsky I, Spence ND: Manual for the Illness Behaviour Questionnaire: (IBQ). Adelaide, South Australia, University of Adelaide Press, 1983 19. Robbins JM, Kirmayer LJ, Kapusta MA: Illness worry and disability in fibromyalgia syndrome. Int J Psychiatry Med 1990; 20:49–63 20. Miller LC, Murphy R, Buss AH: Consciousness of body: private and public. J Pers Soc Psychol 1981; 41:397–406 21. Klein K, Barnes D: The relationship of life stress to problem solving: task complexity and individual differences. Soc Cog 1994; 12:187–204 22. Bagby RM, Parker JD, Taylor, GJ: The twenty-item Toronto Alexithymia Scale-I. Item selection and cross-validation of the factor structure. J Psychosom Res 1994; 38:23–32 23. Gumnit RJ, Gates JR: Psychogenic seizures. Epilepsia 1986; 27(suppl 2):S124-S129 24. Bowman ES, Markand ON: Psychodynamics and psychiatric diagnoses of pseudoseizure subjects. Am J Psychiatry 1996; 153:57– 63 25. Krahn LE, Reese MM, Rummans TA, et al: Health care utilization of patients with psychogenic non-epileptic seizures. Psychosomatics 1997; 38:535–542 26. Markovitz J, Raczynski JM, Wallace D, et al: Cardiovascular reactivity to video game predicts subsequent blood pressure increases in young men: the CARDIA study. Psychosom Med 1998; 60:186– 191 27. Fisher S: Psychological aspects of the treatment of duodenal ulcer. Stress Med 1994; 10:73–79 28. Robbins JM, Kirmayer LJ: Transient and persistent hypochondriacal worry in primary care. Psychol Med 1996; 26:575–589 29. Baradell J, Klein KW: The relationship of life stress and body consciousness to hypervigilant decision making. J Pers Soc Psychol 1993; 64:267–273 30. Taylor GJ, Bagby RM, Parker JDA: Disorders of Affect Regulation: Alexithymia in Medical and Psychiatric Illness. New York, Cambridge, 1997 31. Gates JR, Luciano D, Devinsky O: The classification and treatment of nonepileptic events, in Epilepsy and Behavior, edited by Devinski O, Theodore WA. New York, Wiley-Liss, 1991, pp 251–263 32. Aboukasm A, Mahr G, Gahry BR, et al: Retrospective analysis of the effects of psychotherapeutic interventions on outcomes of psychogenic nonepileptic seizures. Epilepsia 1998; 39:470–473
Psychosomatics 41:3, May-June 2000
Research on psychogenic nonepileptic seizures (PNES) has focused on childhood abuse, but less is known about other stressors and psychosocial risk factors. The authors compared 25 patients with PNES with 33 control subjects with epilepsy on stressful life events and other risk factors for somatoform disorders. Compared with control subjects, patients with PNES reported significantly more prevalent and stressful negative life events (including adulthood abuse) and more current rumination, stress-related diseases, somatic symptoms, bodily awareness, and marginally more anxiety and depression. However, the relationship of many of these variables to PNES was accounted for by life stress. Groups did not differ on illness worry, alexithymia, or psychotic symptoms. The results suggest that PNES are part of a larger pattern of somatic symptoms responses to a wide range of negative events, including stress in adulthood. (Psychosomatics 2000; 41:221–226)
P
sychogenic nonepileptic seizures (PNES) are events that resemble epileptic seizures behaviorally but demonstrate no coincident epileptiform activity during electroencephalographic recording. They occur in about 5%–20% of patients in epilepsy clinics with women representing about 75% of cases. The mean age of diagnosis is from 30 to 40 years.1 PNES can be further differentiated from veridical epileptic seizures in that PNES are more likely to demonstrate a gradual onset,2 atypical motor activity, emotional vocalizations, absence of self-injurious behavior,1 and longer average duration.3 Research has found an increased prevalence of childhood abuse in many cases of PNES.4–7 Also, patients with PNES frequently are diagnosed with conversion disorder.8 However, PNES occur as part of other somatoform disorders and may be manifestations of panic, dissociative, and factitious disorders, as well as malingering.1 Comorbid conditions include depression and anxiety as well as borderline and obsessive-compulsive personality traits.9–11 The available research on PNES has several limitaPsychosomatics 41:3, May-June 2000
tions, which we sought to redress in this study. First, many studies have compared PNES patients with healthy subjects, whereas fewer studies have used the more appropriate comparison group of epilepsy patients. When epileptic control subjects are studied, differences in the prevalence of psychiatric disorders decrease.4,10 Thus, we compared PNES patients with demographically comparable epilepsy patients. Second, research has focused on childhood abuse to the exclusion of other stressful events that may contribute to the development of PNES, including stress in adulthood. Also, studies have not examined the perceived stressfulness of negative events and whether patients have adequately Received June 25, 1999; revised September 29, 1999; accepted November 19, 1999. From Department of Psychology, Wayne State University, Detroit, MI; Department of Neurology and Department of Psychiatry and Behavioral Sciences, Henry Ford Hospital, Detroit, MI; and the Epilepsy Foundation of Michigan, Southfield, MI. Address reprint requests to Dr. Lumley, Department of Psychology, Wayne State University, 71 West Warren Avenue, Detroit, Michigan 48202; email: mlumley@ sun.science.wayne.edu Copyright 䉷 2000 The Academy of Psychosomatic Medicine.
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Nonepileptic Seizures coped with these events. Although not pathognomonic, continued rumination and thought intrusion about stressful experiences is considered one indicator of the failure to resolve or adapt to the experience.12 Thus, we surveyed a range of negative life events, their perceived stressfulness, and the frequency that patients continue to think about them. We hypothesized that PNES patients would report an increased prevalence and severity of a range of stressful events and would be less likely to have resolved the stress, as indicated by a greater frequency of ongoing rumination. Third, in addition to assessing anxious, depressive, and psychotic symptoms, we tested the hypotheses that PNES patients manifest elevations in a number of risk factors found in somatoform disorders but less frequently studied in PNES: general somatic symptoms, other stress-related physical disorders, illness worry, bodily awareness, and alexithymia.13,14 Finally, to develop a parsimonious model of psychosocial risk factors for PNES, we tested whether these other psychosocial risk factors are independent of, or coincide with, life stress in their relationship to PNES. METHOD Participants and Procedures Participants were 25 adults with PNES and 33 adults with epilepsy who were recruited from the Comprehensive Epilepsy Clinic of an urban hospital. The sample of PNES patients was obtained by identifying patients who had been evaluated during the past several years with the use of 24hour electroencephalogram (EEG) video monitoring and who demonstrated, during the evaluation, a behavioral event consistent with their reported spells but for which no ictal activity occurred. PNES patients were included only if they continued to experience at least occasional nonepileptic events at the time of the study. The comparison patients had confirmed epilepsy and were receiving ongoing medical care at the time of the study. Neither the PNES patients nor the patients with epilepsy had cognitive impairment (e.g., mental retardation or dementia), and to improve sample homogeneity, three patients with both epileptic and nonepileptic events were excluded. The two groups did not differ significantly on gender (PNES: 88% female, epilepsy: 90.9% female), age (PNES: meansⳲSD⳱43.56Ⳳ13.23 years old; epilepsy: meansⳲSD⳱39.60Ⳳ9.03), or education level (PNES: meansⳲSD⳱13.02Ⳳ2.71 years; epilepsy: meansⳲSD⳱ 13.75Ⳳ2.23). There also was no difference in annual family income. There was a trend (P⬍0.10), however, toward 222
more non-White members of the PNES group (52%; 12 African Americans and 1 Hispanic), compared with the epilepsy group (30.3%; all African Americans). Patients were recruited during a routine visit to the health center, where they provided fully informed consent; were interviewed for demographic, medical, and psychosocial history; and completed questionnaires. Measures Interview A structured interview inquired about seizure history, other medical problems, and health care utilization over the past 3 months. In addition, each patient was asked to rate the quality of the childhood relationship with his or her mother and father separately on 5-point scales (1⳱excellent, 5⳱very bad). Life Events Checklist Stressful life events were assessed with the Life Events Checklist (LEC), which measures the frequency and severity of 32 significant life stressors. The LEC was modified from the Life Experiences Survey15 by Kelley et al.16 First, patients indicated which events they had experienced during their lifetimes, and this yielded a frequency of stressful events score. Next, using a 4-point scale, patients rated the stressfulness of each event that they had experienced with respect to when the event occurred (0⳱not at all, 1⳱mildly, 2⳱moderately, 3⳱extremely). These ratings were averaged to provide a mean stress severity score, and a total stress score was generated by summing the stress ratings across all events that were experienced. Finally, patients reported the frequency that they currently thought about each experienced stressor on a 5point scale (0⳱rarely or never, 1⳱about once a month, 2⳱about once a week, 3⳱about once per day, 4⳱several times per day). Frequency ratings were averaged across events; higher scores indicated a greater average frequency of current thinking or ruminating about stressors. Brief Symptom Inventory Psychiatric symptoms were assessed with 4 subscales from the Brief Symptom Inventory (BSI).17 Patients rated depression, anxiety, somatic, and psychotic symptoms on a 5-point scale (0⳱not at all present; 4⳱extremely). Scale means were calculated. The BSI subscales have high internal consistencies and good convergent and divergent validities.17 Reliabilities of each subscale used in this study were acceptable (Cronbach’s alpha for anxiety, depression, somatization, and psychosis subscales, respectively⳱0.87, 0.88, 0.83, and 0.69). Psychosomatics 41:3, May-June 2000
Tojek et al. Illness Worry Scale Illness worry was assessed with the 9-item Illness Worry Scale (IWS).13,18 The IWS assesses concern about having or contracting a serious illness. Items were rated on a 5-point scale (0⳱extremely uncharacteristic; 4⳱extremely characteristic) and averaged; higher scores indicated greater illness worry. The IWS has demonstrated good reliability and validity.19 Internal consistency of the IWS in this study was good (alpha⳱0.83).
Private Body Consciousness Scale Bodily awareness was assessed with the 7-item Private Body Consciousness Scale (PBC),20 which assesses awareness of bodily sensations, such as temperature and hunger. Items were rated on a 5point scale (0⳱extremely uncharacteristic; 4⳱extremely characteristic) and averaged; higher scores indicate greater bodily awareness. This scale has shown moderate internal consistency (alpha⳱0.60)19 and good convergent and divergent validity.20,21 Internal consistency of the PBC scale in this sample was adequate (alpha⳱0.71).
Alexithymia Alexithymia was assessed with the Toronto Alexithymia Scale-20 (TAS-20).22 The TAS-20 assesses difficulty identifying feelings, difficulty communicating feelings, and externally oriented thinking. Patients rated each item on a 5-point scale (1⳱strongly disagree; 5⳱strongly agree). A total alexithymia score was calculated. The TAS-20 has been found to be reliable and valid,22 and in this study, it had adequate internal consistency (alpha⳱0.71).
RESULTS Approach to Data Analysis
The primary analyses used logistic regression to identify variables significantly related to group status (PNES vs. epilepsy patients). Because ethnicity was marginally different between the two groups, we statistically adjusted for ethnic group membership (White vs. non-White) in all analyses before testing the variables of interest. Subsequent logistic regressions tested for the continued significance of risk factors beyond the effects of life stress; these models adjusted for the total stress severity score in addition to ethnicity. For all analyses, a two-tailed alpha of 0.05 was considered significant, and a two-tailed alpha of 0.10 was considered marginally significant. Psychosomatics 41:3, May-June 2000
Group Comparisons on Seizure and General Medical Histories Table 1 presents medical and psychosocial history data for the two groups. After adjusting for ethnicity, PNES patients reported a later onset of events and were more likely to have a family member with a seizure history. In addition, PNES patients indicated a higher prevalence of hypertension and ulcers but not cardiac or pulmonary disease. PNES patients also made marginally more visits to their primary care physicians during the past 3 months than did the epilepsy patients, but the groups did not differ on emergency visits. Group Comparisons on Stress and Psychosocial Variables Table 2 presents the group data on stress variables, psychiatric symptoms, and other psychological variables. Adjusting for ethnicity, PNES patients reported a higher prevalence of stressful life events than epileptic patients, and PNES patients also had higher mean ratings of the stressfulness of the events; thus, the total stress score was significantly more elevated among PNES patients than epileptic patients. In addition, the PNES patients reported that they currently thought about stressful events more often than did epileptic patients. Next we examined specific stressful life events using the LEC. We found that 75% of the 32 specific events were more common among our sample of PNES patients than the epileptic patients, although only a few of these prevalence differences in specific events reached statistical significance. Although overall abuse (sexual or physical, child or adult) tended to be more common among PNES patients (PNES: 44%, epilepsy: 33.3%), it was physical abuse as an adult (P⳱0.03) rather than childhood abuse (P⳱0.35) that was significantly more common among PNES patients. Sexual abuse as an adult (P⳱0.10) was marginally more common among patients with PNES than epilepsy. In addition to abuse, PNES patients were significantly more likely to have experienced the serious illness or death of a close friend (P⳱0.05). They were marginally more likely than the epileptic patients to report marital discord or separation and divorce (P⳱0.08) or to have had a serious alcohol or drug problem (P⳱0.07). With respect to psychiatric symptoms, Table 2 shows that patients with PNES reported greater somatic symptoms and marginally greater anxiety and depression but no difference in psychotic symptoms than the epilepsy patients. PNES patients also reported greater bodily aware223
Nonepileptic Seizures ness. Groups did not differ on illness worry or alexithymia. Finally, as obtained on interview, patients with PNES reported having poorer childhood relationships with their fathers than did epileptic patients, but the groups did not differ in childhood relationships with their mothers. Because several variables in addition to total life stress were associated with PNES, we sought to determine if each would remain related to PNES, beyond the effects of life stress. Thus, we repeated the logistic regressions testing those risk factors that were at least marginally significant in the above analyses, adjusting for both ethnicity and total stress score. Later age at onset, having a family member with epilepsy, having hypertension, and having ulcers all remained significant correlates of PNES after controlling for the effects of life stress. Of the psychological variables in Table 2, none remained significantly related to PNES, although the somatic symptoms variable was marginally significant (P⳱0.057). Current thinking about stress (P⳱0.16), bodily awareness (P⳱0.76), and childhood re-
TABLE 1.
DISCUSSION Our results suggest that PNES occur in response to increased prevalence and stressfulness of negative life events throughout childhood and adulthood. These results also suggest that PNES is part of a larger pattern of somatization. Compared with a demographically comparable group of patients with epilepsy, patients with PNES reported experiencing more stressful events over the course of their lives and rated these events as more stressful. In addition, PNES patients also reported that they continued to think about stressful events more frequently, which suggests increased rumination and the failure to adequately resolve these stressful events.
Group differences in general medical history and health care utilization
Age at first seizure/event Family member with seizures Currently on disability because of seizures Hypertension Heart disease Lung disease Ulcers Primary care physician visits (past 3 months) Current # of medications
TABLE 2.
lationship with father (P⳱0.15) were no longer related to PNES. The marginally significant effects of depression and anxiety were completely accounted for by life stress (P⳱0.48 and P⳱0.60, respectively).
PNES Group (MeansⴣSD or n, %)
Epileptic Group (MeansⴣSD or n, %)
Wald’s Chi-Square
P-value
25.6Ⳳ17.1 11 (44) 11 (44) 9 (36) 1 (4) 3 (12) 10 (40) 2.48Ⳳ4.1 3.40Ⳳ3.25
15.1Ⳳ8.5 6 (18.2) 10 (30.3) 3 (9.1) 3 (9.1) 1 (6.1) 2 (6.1) 0.82Ⳳ1.3 2.73Ⳳ1.5
5.71 3.94 0.79 5.07 0.72 1.04 8.03 3.28 2.54
0.01 0.04 0.37 0.02 0.39 0.30 0.004 0.07 0.10
Group differences on dependent measures adjusting for ethnicity PNES MeansⴣSD
Epilepsy MeansⴣSD
Wald’s Chi-Square
P-value
Stressful Life Events Number of events Mean stress rating Total stress score Current stress thinking Childhood relationship w/father Childhood relationship w/mother
8.68Ⳳ4.75 2.65Ⳳ0.37 23.10Ⳳ12.9 1.60Ⳳ0.79 3.14Ⳳ1.28 2.27Ⳳ1.01
6.33Ⳳ3.27 2.21Ⳳ0.58 14.10Ⳳ8.6 1.12Ⳳ0.74 2.39Ⳳ0.95 2.25Ⳳ1.07
4.37 8.53 8.06 4.14 5.78 0.02
0.03 0.003 0.004 0.04 0.01 0.90
Symptoms Anxiety Depression Somatization Psychosis Illness Worry
8.57Ⳳ5.98 8.28Ⳳ6.58 11.24Ⳳ6.84 4.58Ⳳ4.50 15.48Ⳳ8.56
6.60Ⳳ4.84 6.31Ⳳ5.39 6.75Ⳳ4.44 4.23Ⳳ3.62 12.90Ⳳ7.78
3.29 3.44 7.44 0.18 1.36
0.07 0.06 0.006 0.67 0.24
Bodily awareness Alexithymia
19.98Ⳳ5.22 54.0Ⳳ11.9
16.90Ⳳ5.56 54.40Ⳳ10.4
3.93 0.14
0.04 0.70
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Tojek et al. Many researchers have suggested that a history of psychological trauma often predates the onset of PNES;4,7 however, most research has focused specifically on sexual abuse,5,11,23 leaving unclear whether sexual abuse is a unique risk factor or if other stressful events are linked with PNES. Data from this study suggest that people with PNES are more likely to report a wide variety of stressful life events, including physical abuse during adulthood and the illness or death of a close friend. Our PNES patients were more likely to report troubled childhood relationships with their fathers and tended to experience a higher occurrence of marital difficulty. Thus, although few elements of family life have been systemically studied in PNES patients, our data support others’ findings7,10 that PNES patients experience a range of family and relationship problems, beginning in childhood and continuing through adulthood. The average onset of PNES in our sample occurred in adulthood at 25 years of age compared with 15 years of age for patients with epilepsy. This finding, along with our finding that PNES patients have higher rates of adult abuse, suggests that experiences during the adult years may be more closely tied to the occurrence of PNES than thought. Additionally, our patients with PNES were more likely to have a relative with epilepsy, suggesting that modeling may influence the development of PNES. That is, patients with increased stress may develop PNES after observing positive environmental consequences of a relative who had seizures. This observation also suggests that malingering may cause PNES. Malingering is the conscious creation and expression of symptoms to obtain secondary gain, such as relief from a difficult family experience or avoidance of certain responsibilities. This study also suggests that PNES is similar to other somatoform disorders and conditions that involve somatic manifestations of stress. For example, PNES patients reported more vague somatic symptoms than epileptic control subjects, and this effect tended to be independent of the overall life stress that patients had experienced. This is consistent with other studies that show a high incidence of physical symptom reports in PNES patients.24,25 In addition, PNES patients also had higher rates of hypertension and ulcers, both of which are exacerbated by stress.26,27 Also, consistent with previous findings,25 primary care utilization tended to be greater in PNES patients, again suggesting increased somatically focused behavior. Bodily awareness was greater among patients with PNES than those with epilepsy, suggesting further support for a somatization model. Body consciousness or awareness is linked to symptom reports in that people who are Psychosomatics 41:3, May-June 2000
preoccupied with bodily sensations are more likely to notice sensations, to attribute them to biological causes, and to report somatic symptoms.19,28 People with high bodily awareness also demonstrate more difficulty in problem solving than those with low bodily awareness.29 We found, however, that increased bodily awareness was no longer related to PNES after accounting for life stress, suggesting that stressful events may contribute to bodily awareness as well as physiological arousal, which is experienced, interpreted, and reported as physical symptoms. Although previous studies have found increased anxiety and depression among PNES patients,1,24 those studies typically were either uncontrolled or used healthy comparison subjects without epilepsy. Studies, including the current one, that have used epileptic control subjects have found little or no differences in negative affect. Indeed, we found that depression and anxiety were only marginally greater among PNES patients compared with epilepsy patients, suggesting that the increase in negative affect may be because of the presence of a chronic illness rather than uniquely related to PNES. Also, we found that marginal differences in depression and anxiety were completely eliminated after controlling for life stress. This suggests that any increase in negative affect associated with PNES is probably a consequence of life stress. Finally, the clear lack of a difference in psychotic symptoms between patients with PNES and patients with epilepsy confirms other findings1 that PNES is not typically part of a psychotic disorder. Contrary to our hypothesis, we found no difference in alexithymia between PNES and epilepsy patients. Yet, the mean alexithymia score in each group was elevated over community norms, and approximately 30% of both groups scored in the alexithymic range (TAS-20 scoreⱖ61), which is higher than found in healthy populations but fairly consistent with the elevated level of alexithymia found in other medical patient populations.30 Thus, alexithymia appears to be elevated in PNES but not greater than found in epilepsy. Several limitations of this study should be noted. First, our sample size, although large enough to detect a number of significant differences, was relatively small. A larger sample might have revealed significant differences in other variables, such as sexual abuse. Second, we used exclusively self-report measures, which present several potential problems, including response bias and unreliability because of situational reactivity and memory limitations. Third, our assumption that a lack of rumination about stress indicates adaptive resolution of an experience may be invalid for some patients. A subset of PNES patients may have a conversion disorder with repression of negative af225
Nonepileptic Seizures fect, which would serve to protect the person against unwanted thoughts. A lack of rumination may hide the patient’s failure to resolve the experience. Finally, we did not obtain formal psychiatric diagnoses, which would have been useful because different disorders may account for the heterogeneity among patients with PNES, and the diagnoses may be related to different etiologic mechanisms and treatment approaches. Future studies with this population should examine stress and psychosocial risk factors among subgroups of PNES patients, such as those who present with tonic-clonic events versus absence events1 and those with different psychiatric diagnoses. Assessment of factors related to secondary gain and malingering would be useful, as well as a
more systematic and in-depth assessment of stressful life events, to ensure the reliability of patient reports and clarify the types of events that precede PNES onset. Finally, because some reports have noted that PNES may subside after patients are given appropriately sensitive and validating diagnostic feedback or psychotherapeutic treatment,2,23,31,32 controlled studies of the effects of intervention need to be conducted. This study was based on the Masters thesis of the first author, under the direction of the second author. The authors thank Marcy Fivey and Barbara Raider-Gahry for their assistance.
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