Psychiatry and Surgical Treatment

Steffi C. Koch-Stoecker

Kousuke Kanemoto

Introduction

More than half a century after its development, epilepsy surgery has become a routine procedure, especially for resection of mesiotemporal sclerosis. Indications for epilepsy surgery are now well-established, and expected physical benefits following epilepsy surgery can be shown with some certainty. Nevertheless, the implicit hope of patients is that “favourable outcomes in social and psychological domains” will follow seizure relief.⁸² In light of this background, any attempts at prognosis must include more than a prediction of favorable seizure outcome by epileptologic methods. A more comprehensive neuropsychiatric view of epilepsy surgery outcomes is necessary, the importance of which is also underlined by the results of numerous studies from different countries that show a high psychiatric comorbidity in candidates for epilepsy surgery (Table 1). In the last few years, an increasing number of studies support the notion that this comorbidity exists not merely as the parallel existence of two unrelated diseases, but as a common etiology for epilepsies and psychiatric disorders. Examples include the association of fear auras with postoperative mood and anxiety disorders following a temporal lobectomy,⁴⁶ the prediction of seizures in later life by a history of depression,³¹ and the correlation between postoperative psychopathology and the extent of temporal resection.⁴ As a result, the gap between “organic” and “psychiatric” topics has begun to shrink, forcing neurologists and psychiatrists to work together—and producing some encouraging effects, as seen in reports from epilepsy surgery centers.

Table 1 Psychiatric morbidities pre- and postsurgery

Author (Ref.)	Total n	Preoperation	Postoperation	Time of assessment
Temporal
Taylor 1972⁸¹	100	87%	68%	1–10y
Jensen 1979³⁶	74	85%	69%	?
Polkey 1983⁶⁷	40	—	58%	?
Stevens 1990⁸⁰	14	38%	36%	2–3y<
Naylor 1994⁶³	37	35%	38%	?
Manchanda 1996⁵⁷	231	45%	—	—
Ring 1998⁷²	60	20%	57%	3m
Ring 1998⁷²	60	20%	20%	6m
Blumer 1998¹¹	44	57%*	39%	1–3y
Glosser 2000²⁶	44	65%	65%	6m
Anhoury 2000⁴	109	44%	58%	12m
Kanemoto 2001⁴⁰	52	42%	37%	2–12y
Inoue 2001³⁴	226	27%	24%	>2y
Cankurtaran 2005	22	27%	27%	6m
Extratemporal
Naylor 1994⁶³	10	20%	10%	?
Manchanda 1996⁵⁷	43	44.2%	—	—
Blumer 1998¹¹	6	67%	83%	1–3y FLE
FLE, frontal lobe epilepsy. Total n = number of subjects; m/y, months/years. *Described as interictal dysphoric disorder.

The Importance of Psychiatric Evaluation in the Context of Epilepsy Surgery

What do these promising developments mean for patients? The improvement in neuropsychiatric outcome prediction as a statistical piece of data is a helpful, although insufficient, frame in which to understand the complex situation of each individual patient. We know from psychiatric outcome studies²^,³ that mental instability may complicate the process of postoperative recovery. Following seizure cessation, affected patients may still suffer from their psychiatric disorders and may even acquire new ones. These patients face psychiatric disorder–related barriers that prevent them from making use of new opportunities in their seizure-free lives after surgery. Fortunately, individual outcome is not predicted by statistical data alone. We all know patients who transcend negative prognoses, profiting from the support and positive effects of relationships or internal strengths to make their way successfully through life post surgery. The best method for outcome prediction is a synthesis—a clinical psychiatric approach based on a balanced appreciation of the individual context and statistically evaluated group-predictors. The task of a neuropsychiatric assessment, beyond the evaluation of affiliation with special risk groups, is to understand the patient’s motivations and aims within the frame of personal history, match them with realistic possibilities, communicate expected complications, treat actual disorders, and search for individual support strategies. Pre-, peri-, and postoperative psychiatric support during the process of surgery requires that the professional play the complex roles of physician, counselor, and container of hope simultaneously.

The majority of studies on this topic have focused on patients undergoing a temporal lobectomy or amygdalohippocampectomy because of the high proportion of temporal lobe epilepsies (TLEs) among epilepsy surgery candidates, but also of the prominence of psychiatric symptoms in patients with TLE. However, in the small number of reports that have mentioned the prevalence rate of psychiatric morbidities in temporal and extratemporal cases, no apparent difference has been found to exist when mental disorders are summed up as an entity.

This chapter does not cover the specific problems of epilepsy surgery in children, nor does it analyze in-depth psychosocial topics and questions concerning quality of life after surgery.

The Preoperative Phase: Mental Conditions of Surgical Candidates

As shown in Table 1, the reported prevalence of psychiatric morbidities among surgical candidates varies so widely (27%–85%) that no representative figures can be presented. With few exceptions, the mean numbers of psychiatric cases in recent studies exceed 40%, which is lower than the very early data obtained during the 1970s, although still clearly higher than in normal and nonselected epilepsy populations. Recent changes in selection strategies for epilepsy surgery to more strict exclusion criteria for patients with severe psychiatric morbidities, as well as progress in the treatment of epileptic seizures and mental problems, may have decreased the total number of patients. On the other hand, the increasing attention paid to mental disorders in the context of surgery and changes in assessment strategies (such as the use of structured clinical interviews) may account for a more complete perception of the whole situation, at least in recent series that have been reported. However, there are still no generally recognized psychiatric assessment methods for use in surgical centers. Further, the insufficiency of diagnostic systems for use in epilepsy populations has complicated the problem, because it is becoming increasingly clear that some of the most common and disabling psychiatric problems in patients with epilepsy are atypical and cannot be
classified easily within common psychiatric classification systems, such as the International Statistical Classification of Diseases and Health Related Problems (ICD) and the American Diagnostic and Statistical Manual of Mental Disorders (DSM).¹¹^,⁸⁹ Therefore, in the current situation, the variations of psychiatric morbidities among studies are due to the variety of selection methods used, improved treatment strategies, and investigation artifacts.

Although preoperative mental disorders may improve or even remit after surgery in some patients, a substantial portion of psychiatric morbidities emerge for the first time following surgical intervention, most within a few months after operation, with a limited timeframe of less than 1 year. As a net result, the prevalence rate of mental disorders after surgery tends to be close to that before surgery. Under the condition that epilepsy surgery is performed to cure epilepsy and not psychiatric disorders, practitioners should be content with these global outcome effects. However, the implicit expectations of patients, caregivers, and professionals transcend the expectation of mere freedom from seizures.

The Role of Surgical Expectations

Patients are subjected to a number of burdensome procedures during presurgical assessments. Strong motivation or a desire for surgery makes the stressful process more endurable for both patients and the doctors in charge. However, the beneficial effects of the strong desires seen prior to surgery often become a stumbling block after surgery, and might seriously undermine patient and caregiver satisfaction with a medically successful outcome, thus hindering social and psychological readaptation. Notably, Taylor et al.⁸⁴ designated such expectations as “desire beyond seizure freedom.” Furthermore, in a series of insightful investigations, Wilson et al.⁹⁵ revealed that the major components of this desire beyond seizure freedom consist of various expectations of a social and psychological nature (e.g., getting married, increasing self-confidence), and that those who aimed at more “practical” benefits (e.g., driving, employment, travel) tended to be more satisfied with the results of surgery. In a similar study, Wheelock et al.⁹² showed that those with realistic aims and satisfaction with postoperative results had solid family backgrounds and more stable affective situations prior to surgery. These results suggest that desire beyond seizure freedom and implicit agreements between surgeons and patients should be explored, made explicit, and clearly stated and weighted before surgery. All who are involved in surgical procedures for intractable epilepsy should be aware of the simple fact that a surgical procedure, even a successful one, does not automatically make life happier.

Anxiety and Depression

For surgical candidates, the majority of studies agree that, among psychiatric disorders, depression and anxiety prevail, although the reported prevalence rates vary greatly from 27%,¹⁴ to 33%,²⁶ to 77%.² In this regard, it is noteworthy that the rate of preoperative depression may change substantially, depending on the classification criteria and assessment procedures used. The atypical mixed-mood disorder is commonly encountered in patients with longstanding, intractable temporal lobe epilepsy (TLE) and, when the criteria are strictly applied, this disorder does not fit easily into any single standard diagnostic categories based on ICD and DSM. Blumer and Montouris¹⁰ revived Kraepelin’s concept of “epileptische Verstimmung” and designated the pleomorphic, intermittent, rapid cycling presentation of mixed-mood disorder as “interictal dysphoric disorder.” In addition to such a fundamental problem with diagnosis inevitably resulting from the insufficiency of the present standard diagnostic systems for neurobehavioral disorders, differences in assessment tools for affective symptoms as well as the observation period (whole life
prior to the examination or a period at the time of examination) may well produce a profound effect on the results, which makes simple comparisons between studies virtually impossible.

Table 2 Outcome of preoperative psychosis (temporal lobectomy or amygdalohippocampectomy)

Author (Ref.)	Total n	Outcome of psychosis
Author (Ref.)	Total n	Preoperative psychosis	Unchanged/aggravated	Improved/remitted
Simmel 1958⁷⁸	44	11 (25.0%)	11 (100%)
Taylor 1972⁸¹	100	12 (12.0%)	9 (75%)	3 (25%)
Jensen 1979³⁶	74	11 (14.9%)	5 (46%)	6 (54%)
Sherwin 1981⁷⁷	63	7 (11.1%)	7 (100%)
Walker 1984⁹¹	50	5 (10.0%)	5 (100%)
Bruton 1988¹³	248	18 (7.3%)	12 (66.7%)	6 (33.3%)
Stevens 1990⁸⁰	14	3 (21.4%)	2 (66.7%)	1 (33.3%)
Kanemoto 2001⁴⁰	52	12 (23.1%)	8 (66.7%)	4 (33.3%)
Cankurtaran 2005¹⁴	22	0 (0%)
Supplemented and modified from Matsuura’s⁵⁹ review. Patients with postictal psychosis were excluded, if recognized as such from descriptions. Total n = number of subjects.

It remains undetermined whether preoperative diagnoses of anxiety and depressive disorders are predisposed to postoperative anxiety and depressive disorders. Again, it seems plausible that a liability to depression or even a depressed personality structure will not automatically change following surgery for epilepsy, and contradicting data both for²^,⁶⁸ and against⁴^,¹⁴^,⁵⁵ this argument have been provided. About one-third²⁶ to one-half² of all patients with presurgical depression experienced continuing relief from depression after surgery. In another report, virtually no overlapping was found between patients with depression prior to surgery and those after surgical intervention.¹⁴

As mentioned, in their study, Kohler at al.⁴⁶ added a special comment with regard to patients with ictal fear preceding temporal lobectomy. The authors observed that mood and anxiety disorders after a temporal lobectomy were more common in patients who had fear auras preoperatively, compared with patients with other auras or without auras, in particular if they were seizure-free. The role of the amygdala in fear conditioning, kindling, and the concept of forced normalization were suggested as a possible mechanism.

With regard to the laterality effect, some authors have postulated higher rates of depression in patients with left TLE at the time of the presurgical evaluation,¹^,¹¹^,⁹⁰ although more studies have suggested that serious affective dysfunction occurs predominantly in patients with right temporal lobe seizure focus.²²^,²⁴^,²⁶^,⁴⁷^,⁸¹ There are also reports that deny any correlation between focus side and depression in surgical candidates.²^,⁵⁵^,⁵⁷ However, a definitive trend is noted concerning postoperative depression, because right temporal surgery leads to a higher postoperative clinical depression index.²⁶^,⁴⁷^,⁵⁴^,⁶⁸^,⁸¹

Concerning the fate of patients with preoperative depression, the concept of “turning-in” proposed by Hill et al.³² half a century ago is still worth noting. The authors found that some patients who had a reduction in outwardly turned aggressiveness that was apparent prior to surgery showed depressive mood swings that developed postoperatively, which recovered spontaneously in most cases within 18 months after surgery. Thereafter, a number of authors reported results supporting that tendency for aggression and irritability to ameliorate following a temporal lobectomy.¹⁹^,³⁵^,⁶⁷^,⁸¹^,⁹¹

At our center in Bethel, however, we have also observed changes in the opposite direction, as patients who were emotionally withdrawn preoperatively have gained after surgery impulsive energy that turned into irritable, polemic behavior. The case of a man who lost emotional responsiveness to his family members after surgery, presented by Lipson et al.,⁵³ points in a similar direction.

Psychosis

Stable interictal psychotic disorders are notably absent in recent surgical series, because such patients have obviously been screened out during presurgical assessment on the assumption that they are less likely to improve functionally³⁶^,³⁷^,⁷¹^,⁷⁹ or even deteriorate after an anterior temporal lobectomy.²²^,³⁶^,⁵²^,⁵⁴^,⁸¹^,⁸⁶ However, since Fenwick²¹ advocated surgical treatment even for patients with chronic psychoses, using the argument that seizure freedom alone can be worthwhile for patients even if their psychoses persist, this policy of excluding interictal psychosis has slowly started to change.

Recently, two multiple case studies summarized sequels of temporal lobectomy in patients with chronic psychosis. In one of those studies, Reutens et al.⁷¹ described five patients who had been diagnosed with schizoaffective disorder or schizophrenia based on DSM-IV criteria and rendered seizure-free after surgery, with a 2- to 8-year follow-up period. In two of those patients, activities associated with daily living improved visibly. In another two patients, mental as well as social status remained stable, but unchanged. However, in one patient, psychotic symptoms continued and were so crippling that the patient needed repeated admission. Marchetti et al.⁵⁸ reported six patients, five of whom achieved Engel class I seizure outcome and relative improvement in their mental condition. Of those, four patients had a left epileptogenic lesion and two received an initial diagnosis of postictal psychosis, which developed into persistent chronic psychosis later during the course of illness. Although the psychotic symptoms were ameliorated in all four patients with a left-sided lesion, only one of the two with a right-sided lesion improved mentally.

Table 2 lists the ratios of patients with a history of episodic interictal psychosis prior to surgery and the outcome of
pre-existing psychotic symptoms after a temporal lobectomy reported in previous studies. The wide range (0%–25%) of rate of prevalence obtained at different surgical centers may well reflect different exclusion criteria for patients with intermittent (not persistent) psychotic episodes. Except for the Danish series, psychotic symptoms recurred in more than two-thirds of the patients after surgery. In our series, the average duration of postoperative psychotic disorders was far longer (7 months to 7 years; 50% longer than 2 years) than depression (2 to 17 months; 75% shorter than 6 months). It should be noted that a psychotic episode can recur even several years after surgery.⁴⁰^,⁸⁰

In conclusion, treatment of interictal psychosis is not the aim of epilepsy surgery, and only seizure freedom (or improvement of seizure status) can be reasonably expected after surgical intervention. On this basis, patients should be informed that the postoperative development of their psychosis is unpredictable. However, with appropriate psychiatric support, patients can undergo epilepsy surgery and profit from seizure freedom in many respects.

In contrast to interictal psychosis, a number of studies suggest good outcomes for postictal psychotic episodes after a temporal lobectomy, thus rendering them as suitable surgical candidates.¹⁹^,²²^,⁴⁰^,⁷⁴ The direct coupling of this type of psychosis to the occurrence of seizures predicts an excellent improvement under seizure-free postoperative conditions. In this regard, postictal psychosis has been described as a psychiatric indication for epilepsy surgery. However, in the postsurgical phase, those patients are especially liable to develop postoperative depression complicating their readaptation after surgery.⁴⁰ Two studies have reported frequencies of postictal psychoses in candidates for epilepsy surgery, which are rather high at 18%⁸⁷ and 13%.⁴⁰

Other Psychiatric Disorders

In two case reports, rare associations of TLE and obsessive-compulsive disorder (OCD) were ameliorated after a right temporal lobectomy.⁷^,⁴² In contrast, Kulaksizoglu et al.⁵¹ reported a worsening of preoperative obsessive-compulsive personality traits into a full-dressed OCD in two patients following an amygdalohippocampectomy. The authors hinted at the possible contribution of left-sided surgery to the development of OCDs.

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