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Childhood Family Dysfunction and Associated Abuse in Patients With Nonepileptic Seizures: Towards a Causal Model

From the Departments of Clinical Psychology and Neurosciences, University of Liverpool, Liverpool, England.

Address reprint requests to: Peter Salmon, DPhil, University of Liverpool, Department of Clinical Psychology, The Quadrangle, Brownlow Hill, Liverpool, L69 3GB, England. Email: psalmon{at}liv.ac.uk

Received for publication July 3, 2002; revision received October 25, 2002.

	ABSTRACT

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OBJECTIVE: A history of childhood sexual abuse is thought to characterize patients with nonepileptic seizures (NES). We tested the hypotheses: 1) that history of sexual abuse is more prevalent in patients with NES than in controls with epilepsy; 2) that such abuse is associated with NES, not directly but because it is a marker of family dysfunction; and 3) that family dysfunction and abuse are, in turn, linked to NES because they increase a general tendency to somatize.

METHODS: We compared 81 patients with NES with 81 case-matched epilepsy patients, using questionnaires to elicit recollections of sexual, physical, and psychological abuse and family atmosphere and to quantify current somatization.

RESULTS: Although each form of abuse was more prevalent in NES patients, only child psychological abuse uniquely distinguished NES from epilepsy. However, its association with NES was explained by family dysfunction. A general tendency to somatize explained part of the relationship of abuse to NES.

CONCLUSIONS: Abuse therefore seems to be a marker for aspects of family dysfunction that are associated with – and may therefore cause – somatization and, specifically, NES.

Key Words: epilepsy, • nonepileptic seizures, • somatization, • abuse, • family dysfunction.

Abbreviations: CFI = comparative fit index;; CI = confidence interval;; EEG = electroencephalogram;; NES = nonepileptic seizures;; OR = odds ratio.

	INTRODUCTION

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In neurology clinics, many patients present with behavioral indications of epileptic seizures that, on investigation, lack the EEG correlates that characterize epilepsy. They are said to have nonepileptic seizures (NES) and have been estimated to account for 5 to 37% of patients who consult neurologists with seizures (1–3). Many are misdiagnosed with epilepsy and therefore receive iatrogenic treatment with antiepileptic drugs (4, 5).

Although a minority of NES are explained by physical problems other than epilepsy, most are not (4). A long-standing and influential explanation for unexplained physical symptoms in general has been to attribute them to psychological distress, particularly depression (6, 7). Consistent with this view, many patients with NES have previous or current psychiatric problems, including depression, anxiety, and somatization (8–13). However, although patients with NES somatize more than patients with epileptic seizures (14–16) and, within a group of patients with NES, depression predicted recurrence of seizures after diagnosis (17), depression and anxiety are not consistently greater in NES than in epilepsy (15, 18, 19). Moreover, the causal role of psychological distress in unexplained symptoms may have been overstated in the past. Although distress is, on average, elevated in groups of patients with unexplained symptoms, many patients are not abnormally distressed and, in those who are, distress might be secondary to symptoms (20–23).

A less ambiguous clue to psychological causation of NES is the evidence of sexual abuse in the childhood histories of adult patients with NES. By following numerous case studies that linked NES to a history of sexual assault (24–29), uncontrolled studies found that around one-third to one-half of NES patients recalled childhood or lifetime sexual abuse (8, 10–12). Comparisons with epilepsy patients have confirmed higher levels of lifetime or childhood sexual abuse in NES patients (15, 16, 30–32) . However, these studies used small (15, 32) or exclusively female samples (30), did not match for age or gender (15, 16, 31, 32), or obtained information about sexual abuse clinically rather than by standardized assessments (30, 31). Therefore, the first aim of the present study was to confirm, in a large sample, that sexual abuse is more common in NES patients than in matched epilepsy patients that controlled for history of medical management and possible effects of seizure activity to increase vulnerability to abuse.

The focus in previous literature on sexual abuse may, however, be premature. A high prevalence of physical abuse has also been reported in NES patients (10–12). Moreover, a recent comparison with epilepsy found higher rates of both physical and psychological abuse in NES (15). Different forms of abuse tend to affect the same individuals and are associated with poor parental care and family dysfunction (33). Moreover, current and childhood family dysfunction have been reported in NES (9, 10, 13, 19, 34, 35) and NES patients describe more dysfunctional and less supportive families than do epilepsy patients (18, 19). The association of childhood sexual abuse with NES might therefore arise not because it is causally implicated in NES but because it is a marker for other damaging childhood experiences. Therefore our second aim was to identify which forms of childhood adversity were uniquely associated with NES. In addition, rather than assume that only abuse as a child is implicated in NES, we also recorded abuse as an adult.

Finally, although anxiety and depression are not clearly elevated in NES patients, reports of greater somatization (14–16) suggest the hypothesis that abuse leads to NES because, as is already known, it increases a general tendency to experience physical symptoms (33, 36, 37). Therefore we sought to confirm that NES patients somatize more than epilepsy patients and to test the prediction that this difference could explain why abuse is associated with NES.

	METHODS

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Patients
Consecutive patients with a diagnosis of NES (N = 99) who were referred to one of two consultant neurologists with expertise in epilepsy were invited to participate. For each consenting patient, the first patient of the same gender and within 5 years of the same age who had a diagnosis of epilepsy was recruited from that or subsequent clinics (93 were approached in total). Epilepsy and NES were each diagnosed on the basis of clinical presentation, EEG recordings, and, where necessary, ambulatory EEG and video monitoring. Excluded patients were those: under 16 years old; with insufficient use of English to consent or complete questionnaires; or with diagnoses of both NES and epilepsy.

Patients were asked individually by the female researcher after consultation to help with research into "the previous life experiences of people with physical problems." They were assured of anonymity before completing the questionnaire in a private room; 11 NES and 12 epilepsy patients, respectively, declined before reading the questionnaire; 7 NES patients failed to complete it and were excluded from the analysis. Therefore, 81 patients (56 females and 25 males) were recruited into each group. Where occasional items were omitted from otherwise completed questionnaires, degrees of freedom were adjusted in the data analysis as appropriate.

Questionnaires
A frontsheet gathered demographic information (education was coded as none vs. one or more school-leaving exams, trade or professional qualification).

Psychosocial Dysfunction
Anxiety and depression were measured by the Hospital Anxiety and Depression Scale (HADS) (38) which excludes physical symptoms of depression. The tendency to somatize was measured by the Somatization subscale of the Hopkins Symptom Checklist (39), which records respondents’ experience of common physical symptoms of the kind that are not usually associated with disease.

Abuse and Family Dysfunction
Recalled childhood abuse was assessed by the Medical History Questionnaire of Drossman et al. (40) because this has previously proven to be acceptable in medical settings (15, 37, 40). In keeping with most previous literature, sexual abuse was defined as a positive response to one or more of the following questions (15, 37): "Has anyone ever threatened to have sex with you when you didn’t want this?" "Has anyone ever touched the sex organs of your body when you didn’t want this?" "Has anyone ever made you touch the sex organs of their body when you didn’t want this?" "Has anyone ever tried forcefully or succeeded to have sex with you when you didn’t want this?" A single question assessed physical abuse: "When you were a child did an older person punch, hit, or kick you?" Patients choosing "occasionally" or "often" rather than "never" or "seldom" were regarded as abused. A single question addressed psychological abuse: "When you were a child did an older person insult, humiliate, or try to make you feel guilty?" Once again, responses "occasionally" or "often" indicated abuse. Questions were written separately for childhood (13 years) and adulthood (>13 years), yielding six categories of abuse: sexual, physical, and psychological, each as a child or adult. The Parental Bonding Instrument (PBI) (41–43) is widely used in research to indicate the aspects of parental care that form the context for abuse. It provided separate scores for parental care and overcontrol recalled before age 16. Patients also reported the broader functioning of the family of origin, using subscales from the Family Environment Scale (FES) (44) indicating: cohesion, expressiveness, conflict, independence, and control.

Statistical Analysis
Interrelationships of different forms of abuse, and the relationship of each to patient gender, were examined by ². The proportion of educated patients differed between NES and epilepsy groups and education was associated with several other variables. Therefore, education was used as a covariate in relevant analyses. The relationship of abuse to diagnosis was tested by multiple logistic regression and ². After confirming that continuous variables approximated a normal distribution, NES and epilepsy groups were compared on these by multivariate analysis of covariance, including gender as a factor and education as a covariate; significant multivariate effects were followed by univariate analysis of covariance. Similarly, multivariate and univariate analyses of covariance related questionnaire scores to each form of abuse. Multiple hierarchical logistic regression analysis was used to determine whether the relationship of abuse to NES could be accounted for by recalled parental care or family dysfunction or by current psychological disturbance. Analyses were preceded by tests of multicollinearity. Sets of predictor variables were then entered in sequence. Where entry of a set of variables was stepwise (see below), p to enter = .05 and p to remove = .10. Significant reduction in -2 log-likelihood ² confirmed that a set of variables was collectively significant; the Wald test showed the significance of individual variables. Odds ratios (OR) and 95% confidence intervals (CI) are provided from final models.

The results of the separate regression analyses were used to build a path model involving key variables; clinical group was included as a binary variable. Relevant paths identified in the regression analyses were included and tested for significance. The fit of the model was tested using robust statistics (45) to protect against distributional limitations. Criteria for fit were: nonsignificant Satorra-Bentler scaled ² and robust comparative fit index (CFI) > 0.90.

Analyses were performed using SPSS 10.0 for Windows and EQS 5.7b. The criterion for significance was p < .05.

	RESULTS

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Samples
The samples are described in Table 1. The 81 NES and epilepsy patients were, as intended, matched on age and gender, although each group was predominantly female. The groups were similar sociodemographically except that fewer NES patients had educational qualifications.

View larger version (22K): [in this window] [in a new window]   Fig. 1. Number of patients recalling each form of abuse.

Separate logistic regression analyses found no evidence that the relationship of abuse to group differed between males and females.

Psychological Characteristics of NES and Epilepsy Patients
Multivariate analysis confirmed that the groups differed (F(11,147) = 3.55, p < .001) and that gender and the interaction of gender with group were not significant. In the univariate analyses, detailed in Table 5, NES patients were no more anxious or depressed than epilepsy patients but they somatized more. They reported more parental overprotection and less expression and more control in the family (FES).

Finally, we examined whether the relationship of family dysfunction to NES could be accounted for by somatization. In a hierarchical multiple logistic regression analysis, somatization was entered in block 2. When family control was then entered in block 3, it still reached significance (² = 9.73, p < .01; OR = 1.28, 95% CI = 1.06–1.54 (associated with unit increase in score)).

Results of the regression analyses were included in a path model in which paths linked family control to NES directly and indirectly through somatization (Figure 2). All paths indicated by those analyses were significant. The model fitted excellently (² = 5.56, df = 4, p = .26; CFI = 0.98) without further modification.

View larger version (11K): [in this window] [in a new window]   Fig. 2. Results of path analysis. Significant standardized path coefficients are shown. Single-headed arrows represent hypothesized causal paths; double-headed arrows represent covariances. All paths are significant. Dependent variable is membership of the nonepileptic seizure (NES) group vs. epilepsy.

	DISCUSSION

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However, the association of childhood psychological abuse with NES was itself explained by the relationship of each to childhood family dysfunction. Specifically, NES patients recalled more control by the family and less emotional expression, and control was the critical variable in linking abuse to NES. It was previously reported that, although child sexual abuse was associated with NES, this association was explained by child physical abuse (15). Inconsistent findings about whether the relationship of sexual abuse to NES is accounted for by associated physical or psychological abuse might be expected if, as the present findings indicate, abuse is a marker for more important influences within family dysfunction. Although continued emphasis on the role of sexual abuse in nonepileptic seizures helps researchers and clinicians make sense of this perplexing clinical problem (46), our findings support a previous warning that this emphasis is too narrow and potentially damaging if it diverts clinical concern from more important causal factors (47).

NES patients were no more depressed or anxious than those with epilepsy, which is consistent with some previous reports (18, 19) , but they somatized more than epilepsy patients, also as described previously (14–16); that is, they reported more physical symptoms of the kinds that typically are not explained by physical disease. Moreover, somatization was related to both family dysfunction and NES, and these relationships overlapped partly. That is, although somatization was the greater influence on NES in our path analysis, it mediated part of the relationship of family dysfunction to NES. This is consistent with a growing view that apparently distinct functional syndromes such as chronic fatigue or irritable bowel have much in common and that distinctions between them often reflect iatrogenic effects of medical specialization more than underlying differences between patients (22, 23, 48–50). Indeed, patients with NES and irritable bowel syndrome were shown in one report to be indistinguishable in their psychological profile and history of abuse (15). Nevertheless, our analyses showed that family dysfunction also had a specific relationship to NES. The key element was control: the predominance of rules over individual interests and needs. Nonepileptic seizures might be a way in which an individual learns to exert control compellingly in such an environment.

Prospective designs are rare in studying the adult effects of childhood abuse, and information about childhood history is normally retrospective. Cross-sectional designs such as ours cannot prove the direction of causation. However, such designs can be used to develop and test models about the specific contributions of putative causal factors. Therefore, our findings have research and clinical implications. First, although our sample was large by comparison with previous research, even larger samples are necessary to test and develop the model that we have proposed. Secondly, alternative assessment procedures are needed. Although questionnaires about abuse are relatively unintrusive and acceptable in medical settings, allowing patients to disclose traumatic events that they have not disclosed previously, abuse is known to be underreported (51). Moreover, our assessment of abuse was insensitive to severity and frequency of abuse and to the patients’ relationship with the abuser, each of which needs further investigation before abuse can be conclusively regarded as only a marker of other factors. Our assessment of family functioning was limited to patients’ recollections using one questionnaire. Therefore, future research could use interview assessments of abuse and record additional family members’ perspectives on family functioning. Finally, the present findings indicate that, although sexual abuse was more common in females, the critical variables of psychological abuse and family dysfunction were similar in males and females. Therefore, alternative explanations are needed for why NES is also more common in females.

Clinically, our findings suggest that family dysfunction is a significant factor in understanding the development of NES and should therefore be a focus of treatment (19, 35). However, therapy should address mechanisms related to family dysfunction in general, rather than the trauma of abuse specifically. Studies of the effects of such treatments would provide a way to test the causal relationships suggested in this paper on the basis of cross-sectional evidence.

	ACKNOWLEDGMENTS

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The authors are indebted to Professor D. Chadwick and Dr. D. Smith for their cooperation in inpatient recruitment.

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