Surgical treatment of temporal lobe epilepsy

• temporal lobe epilepsy
• temporal lobectomy
• surgical treatment

The paper published in this issue by Jutila et al (this issue, pp 486–94) adds to the literature regarding surgical treatment of temporal lobe epilepsy.¹ This paper presents results from a national centre for adults in Finland. The strength of this report is that it has long term follow up from a relatively defined population. The benefit of temporal lobectomy in treatment of refractory temporal lobe epilepsy has been accepted for many years and a recent creative controlled trial from a Canadian group clearly established its efficacy over medical therapy.² The efficacy of treatment appears to be maintained over the long term, although there is a significant attrition of cases who are initially seizure free for the first 12 months. However, according to the Finnish experience reported here, such late relapses generally do not represent a return to severe intractable temporal lobe epilepsy.

Can selection of cases be improved and why do not all patients respond?³ These issues have been central to over 100 studies of temporal lobectomy in the last decade (for review see Hennessy et al). Relatively few markers have emerged as definitively helping in choice of patients. The finding of a localised lesion on magnetic resonance imaging and a predominance of focal seizures were positively associated with good outcome by Jutila et al, findings that are supported by earlier reports.⁴ The current study also found earlier age of onset as predictive of good outcome, but this has not emerged as a robust factor in previous studies.⁴ Methodological problems in such post hoc analyses can be critical.⁴ Improvement in our ability to select cases for operation, and perhaps more importantly reject inappropriate cases, will await more detailed studies. However, Jutila et al found that some of their “palliative” cases, by which they meant patients in whom there were less convincing evidence for a unilateral confined epileptogenic zone, did have a significant seizure free rate. The study emphasises the importance of a multidisciplinary team in the complex presurgical evaluation of candidates. Seizure surgery should be performed in centres with multidisciplinary expertise and experience to maximise outcomes.