Does alexithymia differentiate between patients with nonepileptic seizures, patients with epilepsy, and nonpatient controls?

Abstract

Considering the evidence of an association between alexithymia and somatization, this study aimed to discover whether alexithymia could distinguish patients with psychogenic nonepileptic seizures (NES) from those with epilepsy (ES) and nonpatient controls (C). Toronto Alexithymia Scale (TAS-20) scores were obtained from 21 matched participants from each of these groups, together with measures of anxiety and depression. Overall TAS-20 scores did not differentiate the three groups after controlling for anxiety and depression, but scores on certain subscales of the TAS-20 differed significantly between the patient groups and the controls. Although alexithymia could not discriminate individuals with NES from those with organic manifestations, whether the etiology of alexithymia may differ according to patient group was discussed. Given that 90.5% of NES patients were identified as alexithymic, treatment approaches used for individuals with alexithymia may be usefully applied to those with NES.

Introduction

Individuals with psychogenic nonepileptic seizures (NES) present with seizures that resemble, and are frequently mistaken for, epileptic seizures (ES), but lack the characteristic electrophysiological changes in the brain that accompany an epileptic seizure [1]. NES have been reported to differ from those of organic origin in a number of ways. For example, patients with NES generally retain consciousness during an attack [2] and tend not to experience postepisode drowsiness, incontinence, or tongue biting [3]. However, it is not clear which psychiatric variables, if any, help in distinguishing individuals with NES from those with ES.

A history of psychological trauma often predates the onset of NES, and current psychological explanations argue that the seizure serves as a coping mechanism to put conflict out of awareness and can be seen as the individual’s way of communicating psychological distress. For this reason, it is a popular notion that NES episodes are an expression of the broader syndrome of somatization. Research into the prevalence of emotionally traumatic events in the lives of patients with NES has reported high rates for sexual abuse [1], [4], physical abuse [4], bereavement, and relationship problems [5]. NES patients have also been found to exceed the general population with respect to the prevalence of affective disorders [4].

While patients with epilepsy have also been shown to demonstrate elevated levels of affective disorders compared with the general population [1], [6], those with NES have been found to be more anxious and depressed than those with ES [7], although no difference was found between these two patient groups in another study [8]. Patients with NES report a poorer quality of life and, more long-term health problems [9], and describe more dysfunctional and less supportive families than do patients with ES [8]. They have also been found to have experienced higher rates of sexual, physical, and psychological abuse than epilepsy patients [10], [11], and to have a history of past suicide attempts and psychiatric treatment [12]. A recent study, however, found no difference between women with NES and women with ES in histories of childhood sexual abuse and posttraumatic stress disorder [13].

The concept of alexithymia has been developed from clinical observations of patients with classic psychosomatic disorders. Individuals with alexithymia demonstrate difficulty in verbal expressions of affect and often communicate inner psychic distress in the form of physical complaints, experiencing emotions as physiological reactions as opposed to feelings [14]. Individuals with stress-related illnesses and somatization have consistently been shown to demonstrate elevated levels of alexithymia in comparison to other patient groups and normal controls [15], [16]. Alexithymia is also considered to be a possible risk factor in a variety of disorders including anorexia nervosa, obsessive–compulsive disorder, posttraumatic stress disorder, substance abuse disorders, and depression [17], [18].

Despite the prominent role of somatization in the clinical description of alexithymia, some authors argue there is little evidence that it correlates with somatic complaints at all when negative affect is controlled for [19]. Saarijarvi et al. [20] acknowledge that emotional suppression and decreased verbal ability to communicate feelings are common to both alexithymia and depression, and positive correlations have been reported between depression, anxiety (state and trait), and alexithymia [21]. Nonetheless, alexithymia has been found to make an independent contribution to somatic symptoms beyond that related to negative affect [22], [23].

A variety of etiologies have been proposed for the development of alexithymia, including psychological factors and neurologic deficits. From the neurobiological perspective, a review by Larsen et al. indicates that alexithymia could result from brain dysfunction located in the corpus callosum, right hemisphere, or frontal lobe [24]. Alexithymia arising from such causes would be expected to take the form of a long-term trait. Alternatively, psychological explanations support the idea that alexithymia is essentially a secondary phenomenon that develops as a coping response to severe psychological trauma. For example, victims of childhood sexual abuse have reported an inclination to use emotional suppression as a coping strategy [25], and rape victims have been shown to be more alexithymic than controls, with those who had been victimized more than once being more alexithymic than single-rape victims [26]. From this perspective, alexithymia may be considered as a temporary state as opposed to a dispositional trait, acting more as a denial of emotion as opposed to a complete absence of feelings.

As far as the present authors are aware, only two studies to date have investigated levels of alexithymia in patients with NES compared with those with ES. Stewart et al. used Rorschach data to assess alexithymia, and found a trend for patients with epilepsy to be classified as alexithymic more frequently than patients with NES or patients exhibiting both ES and NES [27]. However, the sample size in this study was small, with none of the patient groups exceeding 11 for the alexithymia analyses. Using the 20-item Toronto Alexithymia Scale (TAS-20) [28], Tojek et al. found that while levels of alexithymia were elevated in both NES and ES patients compared with community norms, the two patient groups did not differ significantly from each other on this dimension [29]. This study reported only the results arising from overall TAS-20 scores however, with no examination of the three subscales constituting this measure (i.e., difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking). Furthermore, the NES patients were also reported to have higher levels of anxiety and depression than the ES patients, and the potentially confounding effect of this for the alexithymia finding was not explored. Neither study employed a nonpatient control group.

Identifying NES and distinguishing them from organic seizures is essential to avoiding a variety of potential iatrogenic hazards including inappropriate treatment with antiepileptic drugs. Betts claims that as many as 20% of individuals who classify themselves as being “epileptic” may not actually have the condition [12]. Given the limitations of the two studies described above [27], [29] and the evidence of an association between alexithymic characteristics and somatization, the potential ability of alexithymia to distinguish between these two patient groups would seem to merit further attention. The aim of this study is to investigate levels of alexithymia in patients with NES, patients with ES, and a nonpatient control group. Based on clinical experience that most NES patients have experienced some form of trauma, loss, or abuse and on the basis that alexithymia may develop as a coping response to severe trauma, it was predicted that levels of alexithymia would be significantly elevated in the NES group in comparison to both the ES group and the nonpatient control group (C) and that this difference would remain after controlling for anxiety and depression as covariates. Given that the literature consistently indicates a markedly higher incidence of psychopathology in patients with epilepsy compared with the normal population [6], it was also predicted that alexithymia would be significantly higher in the epilepsy than in the control group. These intergroup differences will be expected for both overall TAS-20 scores and scores on each of the three subscales constituting this measure.