Surgical treatment of status epilepticus: A palliative approach

Authors

  • Peter A. Winkler

    Corresponding author
    • Department of Neurosurgery, Christian Doppler Medical Center, Research Laboratory for Microsurgical Neuroanatomy, Paracelsus Medical University of Salzburg, Salzburg, Austria
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Address correspondence to Peter A. Winkler, Professor and Chairman, Department of Neurosurgery, Christian Doppler Medical Center, Research Laboratory for Microsurgical Neuroanatomy, Paracelsus Medical University of Salzburg, Ignaz Harrerstrasse 79, A-5020 Salzburg, Austria. E-mail: p.winkler@salk.at

Summary

Although status epilepticus (SE) does not resemble a domain for neurosurgical indications in single occasions, a microneurosurgical procedure in patients with catastrophic epilepsy and status epilepticus should be considered as an ultimate ratio-choice in these patients. From a personal series of >600 epilepsy surgery procedures in a period from August 1, 1993 until March 13, 2013, 22 patients were identified with catastrophic epilepsy and all of them with at least one episode of status epilepticus. Five of the patients had surgery under ongoing status epilepticus. Twelve patients became seizure-free, two patients had >90% seizure reduction, seven patients >50% seizure reduction, and one patient was unchanged. No surgery-related complications in terms of permanent morbidity were ascertained in the presented series. In the subgroup of the five patients operated in the acute phase of SE one patient became seizure-free (Engel class. I), one showed Engel class II, two Engel class III, and one Engel class IV with no worthwhile improvement. Patients with catastrophic epilepsy including status epilepticus can benefit from resective epilepsy surgery, even with incomplete resection of the epileptogenic lesion.

Status epilepticus (SE), or prolonged seizures, represents a serious medical and neurologic emergency. SE has been defined through the International Classifications of Epileptic Seizures as a seizure lasting for >30 min or intermittent seizures lasting for >30 min from which the patient does not regain consciousness, and when the unconsciousness is caused by the seizure activity (Gastaut, 1983).

This definition applies to any seizure type. The mortality rates in SE were investigated in several studies in the last 20 years and have varied from as low as 8% to as high as 50% (Maytal et al., 1989; DeLorenzo et al., 1996; Knake et al., 2001; Tejeiro & Gomez Sereno, 2003; Vignatelli et al., 2003; Waterhouse & Towne, 2005; Sheth et al., 2006; Ding et al., 2013). Recent advances in the treatment of SE have improved the prognosis. Nevertheless status epilepticus does not resemble a domain for neurosurgical indications; in single occasions a microneurosurgical procedure in patients with catastrophic epilepsy and status epilepticus should be considered as an ultima ratio-choice in these patients.

A palliative approach in epilepsy surgery is presented in this publication.

Methods

From a personal series of >600 epilepsy surgery procedures during a period from August 1, 1993 until March 13, 2013, 22 patients were identified with catastrophic epilepsy and all of them with at least one episode of status epilepticus. Five of the patients had surgery with ongoing status epilepticus. Eight patients received palliative primary incomplete resections of the epileptogenic lesions; 13 patients received unilateral resections of bilateral lesions. In one patient both bilateral lesions were removed. (Table 1).

Table 1. Treatment in patients with status epilepticus (SE) = 22a
  1. a

    Five of them were operated on with ongoing status epilepticus.

8Palliative primary incomplete resections
13Unilateral resections of bilateral lesions
1Bilateral resection

Results

Twelve patients became seizure-free, two patients showed >90% seizure reduction, seven patients had >50% seizure reduction, and one patient was unchanged (Table 2). No surgery-related complications in terms of permanent morbidity were ascertained in the presented series.

Table 2. Results
  1. No surgery-related complications in terms of permanent morbidity were ascertained in the presented series.

12Seizure-free
2>90% seizure reduction
7>50% seizure reduction
1Unchanged

In the group of the five patients operated in acute phase of SE, one patient became seizure free (Engel class. I), one showed Engel class II, two Engel class. III, and one Engel class IV with no worthwhile improvement (Table 3).

Table 3. Patients operated in acute phase of SE
Patients numberOutcome
1Engel class I
1Engel class II
2Engel class III
1Engel class IV

Discussion of the Literature

Different modalities were proposed in the literature over the years as an alternative and as an ultimate approach in patients with catastrophic epilepsy and status epilepticus (Gorman et al., 1992; Rossi et al., 1999; Krsek et al., 2002; Ng et al., 2003; Khoury et al., 2005; Zumsteg et al., 2005; Costello et al., 2006; Ng et al., 2006; Mohamed et al., 2007; Ng et al., 2007; Nahab et al., 2008; Zamponi et al., 2008; Lega et al., 2009; Loddenkemper et al., 2009; Tellez-Zenteno et al., 2009; Chandra et al., 2011; Prasad et al., 2011; Wehner et al., 2011; Chassoux et al., 2012; Weimer et al., 2012). Single case reports were described in the literature applying resections of epileptogenic focus, multilobar resection, tumor resection, and callosotomy (Gorman et al., 1992; Rossi et al., 1999; Krsek et al., 2002; Ng et al., 2003; Khoury et al., 2005; Zumsteg et al., 2005; Costello et al., 2006; Ng et al., 2006; Mohamed et al., 2007; Ng et al., 2007; Nahab et al., 2008; Lega et al., 2009; Loddenkemper et al., 2009; Tellez-Zenteno et al., 2009; Chandra et al., 2011; Wehner et al., 2011; Chassoux et al., 2012; Weimer et al., 2012). In a total and cumulative number of 44 patients, a resection of the epileptogenic foci was achieved (Gorman et al., 1992; Rossi et al., 1999; Ng et al., 2003; Khoury et al., 2005; Zumsteg et al., 2005; Costello et al., 2006; Ng et al., 2006; Mohamed et al., 2007; Ng et al., 2007; Nahab et al., 2008; Lega et al., 2009; Loddenkemper et al., 2009; Tellez-Zenteno et al., 2009; Wehner et al., 2011; Chassoux et al., 2012; Weimer et al., 2012). The multiple subpial transsections (MSTs) were described on two cases with moderate results (Ng et al., 2003; Weimer et al., 2012). The vagus nerve stimulation (VNS) was carried out in seven cases with encouraging results ( Zamponi et al., 2008; Prasad et al., 2011). There are some patient outcome data suggesting that VNS allowed early cessation of SE and discharge from the ICU (Zamponi et al., 2008). Available follow-up demonstrated that the patient experiences significant seizure reduction in the long term (Zamponi et al., 2008). There are no valid data of larger series about deep brain stimulation (DBS) and alternative methods in the treatment of SE. For DBS in summary with the targets and stimulation parameters investigated so far, the effects of electrical brain stimulation on seizure frequency have been moderate at best (Kellinghaus et al., 2003; Franzini et al., 2008, 2012; Valentin et al., 2012) (Table 4). A different subgroup of eight patients resembles the children with electrical status epilepticus in sleep and cognitive impairment (Loddenkemper et al., 2009). Six of eight patients in one series became seizure free after functional hemispherectomy (Loddenkemper et al., 2009). The Landau-Kleffner syndrome (LKS) shows a bitemporal status epilepticus during sleep (BTESES) in all cases (Rossi et al., 1999). This phenomenon was described in a series of 11 patients affected by LKS (Rossi et al., 1999). Four of the patients presented a shift from a BTESES toward an intercalated electrical status epilepticus during sleep accompanied by a global regression of cognitive and behavioral functions in three of four cases (Rossi et al., 1999). It is important for the prognosis to utilize antiepileptic treatment and possibly neurosurgical techniques to eliminate electroencephalography (EEG) paroxysmal abnormalities (Rossi et al., 1999). In the patient with status gelasticus, a modified interhemispheric-transcallosal approach was successfully applied (Winkler et al., 2000a).

Table 4. Surgical treatment of status epilepticus—published cases
Procedure(s)Total number
Resections of epileptogenic focus44 ± 1
Tumor resection1
Multilobar resection1
Callosotomy1
Multiple subpial transsection2
Vagus nerve stimulation7
Deep brain stimulation0
Alternative methods, e.g., trigeminal stimulation1
 ∑ 57 ± 1

In all the patients investigated invasively, a special technique for three-dimensional visualization of the cortical relief, the venous topography, and the different electrodes points was carried out (Winkler et al., 2000b).

Conclusions

Patients with catastrophic epilepsy including status epilepticus can benefit from resective epilepsy surgery, even with incomplete resection of the epileptogenic lesion. In the analyzed group, >50% of the patients enjoyed freedom from seizures. However, surgery resulted in a marked improvement in quality of life, even for patients without complete seizure relief. These preliminary results are encouraging and need further intensive research and investigations.

Disclosures

The author has no relevant conflicts of interest to declare.

The author confirms that he has read the Journal's position on issues involved in ethical publication and affirms that this report is consistent with those guidelines.

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