Psychiatric Outcome of Temporal Lobectomy for Epilepsy: Incidence and Treatment of Psychiatric Complications

Summary: Purpose: To determine the incidence of psychiatric disorders before and after surgical treatment for partial epilepsy and to document the effectiveness of their treatment.
Methods: Fifty consecutive patients treated surgically for focal epilepsy (44 temporal and six frontal) were evaluated by established neuropsychiatric methods before surgery and over a mean period of 2 years after surgery. The patients with interictal dysphoric disorders, with or without psychotic episodes, were treated with tricyclic antidepressant medication alone or combined with serotonin selective reuptake inhibitors and, if necessary, with the addition of risperidone.
Results: Before surgery, 25 (57%) of the 44 patients with temporal lobe epilepsy had dysphoric disorders. After surgery, 17 (39%) of the 44 patients experienced either de novo psychiatric complications (six psychotic episodes, six dysphoric disorders, and two depressive episodes) or exacerbation of preoperative dysphoric disorder (three patients). Eight previously intact patients of the 19 (42%) developed dysphoric disorders after surgery that were significantly related to recurrence of seizures. All psychiatric complications occurred in the first 2 months after surgery, except for the six patients intact before surgery, who had a recurrence of seizures. A significant predictor of ultimate excellent psychiatric outcome was complete absence of seizures after surgery. All postoperative psychiatric complications remitted on treatment with psychotropic medication in the compliant patients.
Conclusions: An exceptional psychiatric morbidity is associated with the months after temporal lobectomy. Possible pathogenetic mechanisms are discussed. Antidepressant drugs are very effective in treating the psychiatric disorders of chronic epilepsy; their use in conjunction with the surgical treatment of epilepsy appears to be crucial for the overall positive outcome of a significant number of patients.     

Treatment of the interictal psychoses

BACKGROUND: The interictal "schizophrenia-like" psychoses of epilepsy conventionally are treated with antipsychotic medication with uncertain results. In patients with these psychoses, a preceding and concomitant dysphoric disorder usually can be documented. Effectiveness of the pharmacologic treatment by the combination of drugs that is effective for severe interictal dysphoric disorders is demonstrated in a series of patients with interictal psychosis. METHOD: Patients were treated with the combination of a tricyclic antidepressant and a selective serotonin reuptake inhibitor, enhanced if necessary by a small amount of the atypical neuroleptic risperidone. The series consisted of 8 consecutive patients with interictal psychosis seen over a 20-month period. Two additional patients seen over the past 10 years who required a different therapeutic intervention were also included. RESULTS: Five of the 8 consecutive patients achieved full remission of their psychosis; 3 patients could not be reached for the full treatment effort. One patient with a malignant psychosis had been treated successfully (prior to the series reported) by surgical removal of a left frontal epileptogenic zone; a second patient (treated after the series) recovered only upon elimination of the antiepileptic drug that had suppressed clinical seizures but had resulted in an alternating psychosis. CONCLUSION: Interictal psychoses can be viewed as severe interictal dysphoric disorders with psychotic features. The same combination of psychotropic medication that is effective for severe interictal dysphoric disorders serves as the primary therapy for interictal psychoses. The interictal psychiatric disorders presumably result from seizure-suppressing mechanisms that are the targets of the proconvulsant drugs. Upon suppression of seizures, some patients with interictal psychosis may require modification of the antiepileptic medication responsible for excessive inhibition. Complete surgical removal of the epileptogenic zone can eliminate a chronic interictal psychosis upon postoperative fading of inhibitory mechanisms.     

The interictal dysphoric disorder: recognition, pathogenesis, and treatment of the major psychiatric disorder of epilepsy

The unawareness of psychiatrists about the importance of epilepsy dates back half a century, when epilepsy became considered an ordinary neurologic disorder. Epileptic seizures, however, can be provoked in every human being. Epilepsy is an extraordinary disorder that, beyond its well-known neurologic complexities, tends to become complicated with a wide range of specific psychiatric changes; they occur on the establishment of a temporal-limbic focus of intermittent excessive neuronal excitatory activity that produces increasingly inhibitory responses. These changes are distinct from those related to the two major psychiatric spheres for which a genetic basis is established, i.e., the manic-depressive and schizophrenic disorders, and represent a genetic sphere of its own. Apart from more subtle personality changes and the serious late complications of interictal psychoses and suicidal episodes, the key psychiatric syndrome associated with epilepsy consists of the interictal dysphoric disorder, with its characteristic intermittent and pleomorphic symptomatology. This disorder was clearly identified about a century ago by Kraepelin, when he established a comprehensive basis for the modern classification of the psychiatric disorders, at a time when epilepsy represented an area of major interest to psychiatrists. A practical method of recognizing the dysphoric disorder is reported. The disorder tends to be very treatable by combining psychotropic (chiefly antidepressant) with antiepileptic medication. The variations in treatment approach required are discussed and illustrated by representative case studies. Psychiatrists must become familiar with the psychiatric aspects of epilepsy to be able to assist the neurologists who focus on the neural complexities of the illness. They also must become able to recognize, among their own patients, the presence of a subictal dysphoric disorder that requires the same treatment as the interictal dysphoric disorder; combined treatment with antidepressant and antiepileptic medication is likewise indicated for the premenstrual dysphoric disorder, a condition that appears to belong to the spectrum of epilepsy-related psychiatric disorders. Furthermore, they must learn how an ignored population in their care, epilepsy patients confined to state hospitals, can be properly treated. Of particular importance is the need for psychiatrists to become familiar with the role of the paroxysmal affects in the general human condition, with their basic conflict to be intermittently angry and irascible yet otherwise good-natured, helpful, and religious--a conflict that tends to be particularly accentuated among patients with the "Sacred Disease."     

Suicide in epilepsy: psychopathology,pathogenesis, and prevention

OBJECTIVE: Death by suicide among patients with epilepsy has found scant psychiatric attention, yet it may occur at the rate reported among patients with manic-depressive illness. We aim to clarify the psychopathology and pathogenesis of suicide in epilepsy and to document an effective method of prevention.METHOD: A total of 10,739 patients with epilepsy were seen at the Epi-Care Center in Memphis from 1987 to 1999. The patients with significant psychiatric complications were evaluated systematically and treated with an increasingly effective psychopharmacologic approach.RESULTS: Five suicides were registered during the 12-year period. All occurred in patients with longstanding complex partial seizures and dysphoric disorder a short time after full control of the seizures was achieved. During the last 8years of the 12-year period, more effective pharmacotherapy of the psychiatric complications of epilepsy was used (augmented antidepressant medication), and the two suicides that still occurred had eluded this treatment. Review of earlier series confirms that suicide tends to occur particularly among patients with chronic epilepsy who have obtained good control of their seizures; suicide may occur during interictal dysphoric episodes with or without psychotic features or in a state of postictal depression.CONCLUSIONS: Suppression of seizures in longstanding epilepsy may be associated with suicidal risk. The psychotoxic effect of predominant inhibitory mechanisms appears to be the crucial pathogenetic factor in all suicides. The number of suicides in our series is a fraction of that expected based on previous reports and indicates that prevention by psychopharmacologic treatment is available.     

Dysphoric disorders and paroxysmal affects: recognition and treatment of epilepsy-related psychiatric disorders

Interictal dysphoric disorder is an intermittent and pleiomorphic affective-somatoform disorder that presumably occurs as a result of inhibitory mechanisms in chronic mesial temporal lobe epilepsy. Treatment with antidepressant medication, enhanced if necessary with small doses of an atypical antipsychotic, tends to be highly effective. The dysphoric disorder also occurs in the absence of epilepsy in a subictal variation, particularly in patients with brain lesions and as premenstrual dysphoric disorder. The paroxysmal affects, ranging from irritability through anger to rage, play a major role in interictal dysphoric disorder. Their manifestation among patients with mesial temporal lobe epilepsy is counterbalanced by the fact that these individuals tend to be highly ethical and religious. The paroxysmal affects that may emerge with vehemence during episodes of interictal dysphoric disorder play a role in all people, differing in prominence among individuals. For a comprehensive view of the psychiatric aspects of epilepsy, the important premodern findings are reviewed together with recent ones.     

Complex partial seizures presenting as a psychiatric illness

A 36-year-old woman was treated for a wide variety of psychiatric illnesses over a span of two decades before a diagnosis of complex partial seizures was made. Her history included poor impulse control, rage attacks, multiple suicide attempts, rapid mood swings, depression, and psychotic episodes. Bulimia, panic attacks, severe obsessive-compulsive symptoms, and multiple somatic complaints were also present. In retrospect, these symptoms could be attributed to complex partial seizures with cognitive and affective symptomatology, automatisms, and psychosensory symptoms, and were controlled by anticonvulsant medications. Therefore, so-called "purely" psychiatric disorders should not be diagnosed before a diagnosis of limbic epilepsy (however, this might be labeled, e.g., complex partial seizure, psychomotor seizure, psychical seizure, or temporal lobe epilepsy) has been considered.     

Psicosis epiléptica periictal,una causa de psicosis reversible

Introduction

Epileptic psychoses are categorised as peri-ictal and interictal according to their relationship with the occurrence of seizures. There is a close temporal relationship between peri-ictal psychosis and seizures, and psychosis may present before (preictal), during (ictal) or after seizures (postictal). Epileptic psychoses usually have acute initial and final phases, with a short symptom duration and complete remission with a risk of recurrence. There is no temporal relationship between interictal or chronic psychosis and epileptic seizures. Another type of epileptic psychosis is related to the response to epilepsy treatment: epileptic psychosis caused by the phenomenon of forced normalisation (alternative psychosis), which includes epileptic psychosis secondary to epilepsy surgery. Although combination treatment with antiepileptic and neuroleptic drugs is now widely used to manage this condition, there are no standard treatment guidelines for epileptic psychosis.

Clinical cases

We present 5 cases of peri-ictal epileptic psychosis in which we observed an excellent response to treatment with levetiracetam. Good control was achieved over both seizures and psychotic episodes. Levetiracetam was used in association with neuroleptic drugs with no adverse effects, and our patients did not require high doses of the latter.

Conclusions

Categorising psychotic states associated with epilepsy according to their temporal relationship with seizures is clinically and prognostically useful because it provides important information regarding disease treatment and progression. The treatment of peri-ictal or acute mental disorders is based on epileptic seizure control, while the treatment of interictal or chronic disorders has more in common with managing disorders which are purely psychiatric in origin. In addition to improving the patient's quality of life and reducing disability, achieving strict control over seizures may also prevent the development of interictal psychosis. For this reason, we believe that establishing a treatment protocol for such cases is necessary.     

Nonconvulsive status epilepticus precipitated by carbamazepine presenting as dissociative and affective disorders in adolescents

Nonconvulsive status epilepticus can be confused with psychiatric disorders. Inappropriate drug treatment can represent a precipitating factor. We describe two patients with idiopathic generalized epilepsy in whom nonconvulsive status epilepticus, aggravated by carbamazepine, was misdiagnosed as psychiatric disorder. A 14-year-old girl experienced a tonic-clonic seizure at age 12 years preceded by monthly episodes of confusion with awkward behavior since age 9 years. She was treated with carbamazepine, and the episodes of confusion became more frequent, leading to a diagnosis of dissociative disorder. An electroencephalogram during one of these episodes revealed nonconvulsive status epilepticus. Substitution of carbamazepine with valproic acid controlled the episodes of status epilepticus. A 23-year-old woman presented at age 16 years with a tonic-clonic seizure. Since early adolescence, she had had episodes of depressive mood, worsening of school performances, and facial tics. Carbamazepine treatment caused worsening of the depressive episodes and facial tics. An electroencephalogram during a typical episode revealed nonconvulsive status epilepticus. Carbamazepine substitution with valproate led to seizure freedom and behavioral improvement. Nonconvulsive status epilepticus should be suspected and searched for in patients with epileptic seizures and ictal or fluctuating behavioral disorders.     

Psychosis of Epilepsy: A Neurologist's Perspective

Psychosis of epilepsy (POE) comprises a group of disorders that are closely associated with epileptic seizures. These include interictal POE, postictal psychosis, and alternative psychosis (also known as "forced normalization"). Neurologists have, in general, played a limited role in the evaluation and management of patients with POE. Yet, as reviewed in this paper, a good understanding of electrophysiologic, neuroradiologic, and neuropathologic variables associated with POE can yield valuable data in the evaluation of the seizure disorder of these patients. The purpose of this review article is to highlight the clinical, neuroradiologic, neurophysiologic, and neuropathologic aspects of POE that can assist in the evaluation and management of the associated seizure disorder and to identify the circumstances in which a timely therapeutic intervention by neurologists can avert or minimize the occurrence of a psychotic episode. Specifically, the clinical characteristics of interictal POE and ictal, postictal, and alternative psychotic episodes are highlighted together with their potential pathogenic mechanisms and the associated treatment issues. Finally, discussions of psychotic disorders following epilepsy surgery and the pharmacotherapy of psychotic disorders in patients with epilepsy are presented.     

Are psychotic symptoms related to vagus nerve stimulation in epilepsy patients?

Four patients with refractory epilepsy presented with psychotic symptoms following treatment with vagus nerve stimulation (VNS) to control seizures. Besides its anti-epileptic effect VNS has been shown to have an effect on various cognitive and behavioural functions. VNS is known to increase alertness and reduce sedation, which is independent from seizure control. VNS has also been shown to positively affect cognition and to exert strong antidepressant effects. Co-morbidity in epilepsy often comprises psychiatric illnesses. Increased psychiatric symptoms have mainly been described in association with successful outcome following epilepsy surgery as a result of 'forced normalisation'. Different hypotheses on the underlying aetiology of VNS-induced psychotic symptoms other than the previously described 'forced normalisation' are discussed.     

Vagus Nerve Stimulation in 16 Children with Refractory Epilepsy

Summary: Purpose : Vagus nerve stimulation (VNS) has been reported to produce >90% reduction in the number of seizures in children with intractable epilepsy. These encouraging results need confirmation.
Methods : Sixteen children, 10 boys and 6 girls aged 4-19 years, were treated with VNS (Cyberonics, Webster, TX, U.S.A.) for 12-24 months. Seizure frequency, seizure severity, changes in quality of life (QOL: visual analogue scale), and side effects were recorded. Eight children had partial and 8 had generalized seizures; 4 of the latter had Lennox-Gastaut syndrome (LGS).
Results : During the tenth to twelfth month of VNS, 6 of 16 children experienced ≥50% reduction in seizure frequency. One girl became seizure-free. Seizure severity showed an average decrease in the score from 15 to 11. After 10 months of treatment, QOL was estimated to have improved ≥50% in 6 of 16 children. Reduction in seizure frequency, decreased seizure severity, and reported improvement in QOL did not entirely coincide. Six children experienced hoarseness, 1 had neck pain, 2 had hypersalivation, 2 experienced tiredness, 2 had aspiration episodes during liquid intake, and 6 had electrical transmission problems; in 4 the problem has been surgically corrected. Five stimulators were turned off due to lack of efficacy.
Conclusions : Six of 16 children with refractory epilepsy treated with VNS improved, with a reduction not only in seizure frequency but also in seizure severity and in QOL.     

Self-Reported Mood Changes following 6 Months of Vagus Nerve Stimulation in Epilepsy Patients

Vagus nerve stimulation (VNS) for treatment of drug-resistant epileptic seizures has been reported to have additional positive mood effects as obtained by psychiatric ratings. To avoid rater bias effects, this study used self-report questionnaires and examined changes in self-reported mood and health-related quality of life following 6 months of VNS treatment. From 40 adult patients treated with VNS since the beginning of the study, 28 patients (mean age: 35.4 years) with unchanged medication were included. Repeated-measures MANOVA revealed a significant general mood improvement. Post hoc univariate tests obtained improvements of tenseness and dysphoria but not of depression, level of activity, or health-related quality of life. Mood and seizure outcome were correlated. VNS may improve unspecific states of indisposition and dysphoria. Absolute seizure reduction contributes to this antidysphoric effect. Since baseline depression scores were low, findings do not contradict but complement earlier reports of an antidepressive effect of VNS.     

Vagus Nerve Stimulation for Treatment of Partial Seizures: 1. A Controlled Study of Effect on Seizures

Summary: Vagus nerve stimulation (VNS) was shown to reduce seizure frequency in refractory epilepsy patients in two pilot studies. Based on these results, a multicenter, prospectively randomized, parallel, double-blind study of patients with refractory partial seizures was initiated. After a 12–week baseline period, identical vagus nerve stimulators were implanted and patients randomized to either a high or low 14–week VNS treatment paradigm. The primary objective was to demonstrate that high VNS (therapeutic parameters) was more effective in reducing partial seizure frequency than was low VNS (less or noneffective parameters). Patients continued receiving antiepileptic drugs (AEDs) with plasma concentrations held constant throughout the study. We report results of the first 67 patients to exit the 14-week acute phase. After 14 weeks of VNS, 31 patients receiving high VNS experienced a mean seizure frequency percentage reduction of 30.9%, which was statistically significant as compared with the mean seizure frequency percentage reduction of 11.3% in 36 patients receiving low VNS (p = 0.029, t test; p = 0.036, Wilcoxon rank-sum test). In addition to the significant intra group p-values, mean seizure frequency percentage change reached statistical significance for high VNS (p < 0.001) but not low VNS (p = 0.072) as compared with baseline. Twelve of 31 (38.7%) patients receiving high VNS achieved at least 50% reduction in seizure frequency whereas 7 of 36 (19.4%) patients receiving low VNS experienced at least 50% reduction after 14 weeks. The implant procedure and VNS therapy were well tolerated. Our study confirmed the effectiveness of VNS as treatment for epilepsy patients with refractorypartial seizures.     

Seizures as the presenting symptom of brain tumours in children.

Seizures were the presenting clinical symptom in 10 (12%) of 81 consecutive children with a primary brain tumour treated in a tertiary paediatric oncology unit over 5 years. Nine patients experienced partial seizures, and in seven a waking electroencephalogram showed focal or lateralising abnormalities. Astrocytoma was the most common tumour histology. The delay in tumour diagnosis from the onset of seizures ranged from 2 weeks to 2 years with a mean of 6 months. Complete resection of the tumour was the only treatment in three patients and four underwent resection followed by radiotherapy and/or chemotherapy. Two patients died. Three patients became seizure free receiving no antiepileptic medication and the remaining five showed a 50-80% reduction in seizures between 2 and almost 5 years following treatment.     

Vagus nerve stimulation: clinical experience in a large patient series.

During the last decade, intermittent electrical stimulation of the left cervical vagus nerve was established as a new add-on treatment of drug-resistant seizures. Particularly in Europe, the acceptance of vagus nerve stimulation (VNS) was tentative in the beginning because of unknown mechanisms of action. We report the outcome in a sample of 95 adult patients with drug-resistant seizures who have received implants since 1998. The last available follow-up data are included. Unavoidable medication changes (e.g., intoxication) were accepted to examine VNS under usual clinical conditions. Median percentage of reduction in seizure frequency as compared to baseline was 30%. The seizure responder rate (> or =50% reduction) was 45%. Four patients experienced total release from seizures. Adverse effects were mild in general. Seizure outcome was positively correlated with VNS duration. No potential clinical factor (e.g., syndrome, cause, or lesion) could be identified as an indicator of favorable outcome. Patients with on stimulation-on periods of 30 seconds (standard cycle) had a better outcome than patients with stimulation-on periods of 7 seconds (rapid cycle). During an embedded, randomized, controlled trial, no evidence was found for a differential outcome of initial standard cycle versus initial rapid cycle stimulation conditions. Taking into account the good cost-benefit ratio as well as positive effects on well-being, VNS has to be considered an appropriate strategy for the add-on treatment of drug-resistant seizures, particularly in cases not suitable for epilepsy surgery.     

Recognition of the Various Expressions of Anxiety, Psychosis, and Aggression in Epilepsy

Summary:  Anxiety, psychosis, and aggressive behavior are among the frequent comorbid psychiatric disorders identified in patients with epilepsy. Often the clinical manifestations of these disorders vary according to their temporal relation relative to seizure occurrence. Thus, postictal symptoms of anxiety or psychosis differ in severity, duration, and response to treatment with interictal symptomatology. Psychiatric symptomatology in epilepsy can appear concurrently with the seizure disorder and improve or remit on the abolition of epileptic activity. We refer to these as paraictal psychiatric phenomena. Such is the case of aggressive disturbances associated with gelastic seizures caused by hypothalamic hamartomas. In this article, three case studies are presented to illustrate the importance of distinguishing psychiatric symptoms of anxiety, psychosis, and aggression, with respect to their temporal relation with seizure occurrence.     

Association of fear auras with mood and anxiety disorders after temporal lobectomy

PURPOSE: Epilepsy has been associated with increased occurrence of behavioral disorders. Auras reflect abnormal stimulation of brain areas in close proximity to regions from which clinical seizures originate. The purpose of our study was to investigate whether fear auras are associated with a higher rate of mood and anxiety disorders before and 1 year after temporal lobectomy. METHODS: Twenty-two patients with fear auras were compared with matched groups with other auras and no auras. Neurologic and neuropsychological evaluations before, 1-2 months after, and 1 year after temporal lobectomy were reviewed for mood and anxiety disorders and psychotropic medication treatment. A logistic regression model examined effects of patient group and psychiatric status on postoperative psychiatric status. RESULTS: The majority of patients in the three groups experienced mood and anxiety disorders before surgery. Mood and anxiety disorders declined in the control, but not in the fear aura group after surgery. Presence of auras at 1 year after surgery was not related to psychiatric outcome. Postoperative mood and anxiety disorders were more common in patients with persistence of seizures and in those in the fear group who were seizure free. The minority of patients in all groups underwent psychotropic treatment before surgery, but the majority with fear auras underwent treatment after surgery. CONCLUSIONS: Postoperative mood and anxiety disorders were more common in fear aura patients after temporal lobectomy, in particular, if seizure free. Possible mechanisms include the role of the amygdala in fear conditioning, the concepts of forced normalization, and kindling.     

Interictal dysphoric disorder and periictal dysphoric symptoms in patients with epilepsy

Purpose: The issue of phenomenology of mood disorders in epilepsy still remains controversial. It has been suggested that a subgroup of patients may develop an affective syndrome also known as interictal dysphoric disorder (IDD). However, the number of behavioral changes that may occur around the ictus needs to be taken into account for an accurate distinction between “true” psychiatric phenomenology and periictal phenomena. This study aimed at identifying clinical correlates of the IDD, with special attention to the relationship between symptoms and seizures. Methods: A sample of 142 consecutive adult outpatients with epilepsy were assessed using the Interictal Dysphoric Disorder Inventory (IDDI), a 38‐item, self‐report questionnaire specifically developed to evaluate presence and severity of IDD symptoms as well as their habitual association with seizures (coded as before, after, during, or when seizure‐free) and their duration. Results: IDD was diagnosed in 31 subjects but symptoms showed a clear‐cut relationship with epileptic seizures in 54.8% of cases, leading to an operative distinction between true IDD and periictal dysphoric symptoms (PDS). There was no significant difference among patients with IDD, PDS, or those without psychopathology. In the IDD group, symptoms were chronic and unremitting in one‐third of cases, with labile affective symptoms being correlated with age at onset of seizures (rho = ?0.612, p = 0.020) and duration of the epilepsy (rho = 0.833, p < 0.001). Discussion: An operative distinction between IDD and PDS bears the opportunity to identify different clinical endophenotypes that may have different prognoses and require different treatment strategies.     

Comparison of corpus callosotomy and vagus nerve stimulation in children with Lennox-Gastaut syndrome

PURPOSE: To compare the efficacy of corpus callosotomy and vagus nerve stimulation (VNS) for long-term adjunctive therapy in children with Lennox-Gastaut syndrome (LGS). METHOD: Fourteen patients underwent a total corpus callosotomy and 10 patients received VNS implantation. The patients were monitored for more than 12 months after treatment, and seizure rates and complications were retrospectively evaluated. RESULTS: Seizure types among the 24 patients included atonic or tonic seizures with head-drops in 17 patients, generalized tonic seizures in two patients, atypical absence seizures in one patient, generalized tonic-clonic seizures in one patient, and myoclonic seizures in three patients. Of the 14 patients who underwent a corpus callosotomy, nine (64.3%) had a greater than 50% reduction in seizure frequency and five (35.7%) had a greater than 75% reduction. Of the 10 patients who underwent VNS implantation, seven (70.0%) had a greater than 50% reduction in seizure frequency and two (20.0%) had a greater than 75% reduction. There was no significant difference between the two procedures in terms of final efficacy. Complications of corpus callosotomy included aphasia in one patient, ataxia in another, and paresis in a third. Among patients receiving VNS, one patient experienced dyspnea while sleeping and one patient suffered from drooling. These complications were transient and tolerable, and were controlled by simple adjustments of VNS treatment parameters. CONCLUSION: The efficacy and safety of corpus callosotomy and VNS were comparable in children with LGS.     

An analysis of quality of life (QOL) in patients with epilepsy and comorbid psychogenic nonepileptic seizures (PNES) after vagus nerve stimulation (VNS)

PurposePatients with epilepsy (PWE) may suffer from comorbid psychogenic nonepileptic seizures (PNES). The efficacy of vagus nerve stimulation (VNS) in the treatment of epilepsy and depression is established, however the impact on PNES is unknown. Since many patients with PNES have comorbid depression, we explored the impact on quality of life (QOL) that VNS has on PWE and PNES.MethodsThe video electroencephalogram (vEEG) of all patients who underwent VNS at our institution was reviewed. Patients diagnosed with both psychogenic seizures and epileptic seizures on their vEEG were included in this study. These patients were contacted, and given a QOLIE-31 survey to assess their quality of life after VNS. Patients also completed a separate survey created by our group to categorize the quartile of their improvement. Pre-operative psychiatric disease was retrospectively reviewed.ResultsFrom a period of 2001 to 2016, 518 patients underwent placement of VNS for drug resistant epilepsy (DRE) at our institution. In total, 16 patients were diagnosed with both epilepsy and PNES. 11/16 patients responded to our questionnaire and survey. 9 out of 11 patients felt that their epileptic seizures had improved after VNS, while 7 of the 11 patients felt that their psychogenic episodes had improved. 2(28.6%), 1 (14.3%), and 4 (57.1%) of participants said their PNES improved by 25–50%, 50–75%, and 75–100%, respectively. 3(27.3%), 3 (27.3%), 1 (9.1%), and 4 (36.4%) of the participants said their epileptic seizures improved by 0–25%, 25–50%, 50–75%, and 75–100%, respectively. The average overall score for quality of life for the study participants was found to be 51 (± 8) out of 100.ConclusionPatients with epilepsy and comorbid PNES may benefit from VNS. It is unclear whether the benefit is conferred strictly from decreased epileptic seizure burden. The possible effect on PNES may be related to the known effect of VNS on depression. Further studies are necessary to elucidate the role of VNS in the treatment of PNES and possibly other psychiatric disease.