Seizure 2020, Vol 77, Editor’s Choice: Cognitive outcome of pediatric epilepsy surgery across ages and different types of surgeries: A monocentric 1-year follow-up study in 306 patients of school age
It may seem badly out of step with current lived experience and sentiment to produce a Special Issue on paediatric epilepsy surgery while we are facing a crisis, which may well become the greatest acute global challenge since the Second World War. While city streets have emptied, societies are struggling with increasingly stringent “social distancing” and “self isolation” measures, and hospitals are struggling to deal with the stream of acutely ill patients flooding through their doors: why publish articles about highly complex interventions suitable for less than 5% of all individuals with epilepsy – and only available to those who live in rich countries? – And why at this time?
I will try to address these questions, but first I would like to apologise in advance in case my answers seem ridiculously inappropriate by the time they are read. Much like the car manufacturers that have been encouraged to switch to producing ventilators, my colleagues and I have spent much of last week transforming a multidisciplinary tertiary clinical neuroscience service providing a broad range of medical, surgical, immunological, dietary, rehabilitative and psychotherapeutic in- and outpatient treatments into a support service for acute respiratory, intensity and high dependency care. All non-urgent elective neurosurgery (including epilepsy surgery) has been stopped. Most operating theatres and surgical recovery areas are being converted to intensive care units. Many outpatient appointments are being cancelled or delayed and all face-to-face outpatient contacts have been replaced with telephone or video-phone interactions. However, the emergency staffing rotas we discussed only yesterday are already out of date. And the scenarios we imagined as we made our plans last week already seem strangely naive. Now we anticipate that we will need at least twice as many neurologists to support acute medical services and to enable home treatment of neurological emergencies than was deemed necessary only 24 hours earlier. I am therefore acutely aware that anything I write today, as more people and healthcare professionals around the world become direct or indirect victims of Covid-19.
With these provisos out of the way, let me try to answer the questions posed above: Life will continue after the Covid-19 pandemic. While many of us will come to think of our lives as split into two distinct parts – before and after the pandemic – the modern world will not end. People will continue to suffer from long-term conditions such as epilepsy. We will still want to provide effective treatments and reduce the burden of the disease. – And in the case of paediatric epilepsy surgery, we can actually go much further than this. This particular treatment remains our only chance of providing a cure of epilepsy. Even more clearly than adult epilepsy surgery, this treatment does not only have the potential to help patients in the short term, but it can make a profound difference to our patients’ whole life trajectories. Even if shortages of funding, material or staffing should force restrictions upon overstretched health care services after the pandemic: for this reason the resumption of paediatric epilepsy surgery should be given priority over other elective neurosurgical procedures.
My editor’s choice from the current Special Issue of Seizure – guest edited by Jun Park – is an original research paper by Christoph Helmstaedter et al. entitled “Cognitive outcome of pediatric epilepsy surgery across ages and different types of surgeries: A monocentric 1-year follow-up study in 306 patients of school age” (1). This paper reminds us that epilepsy is not simply a disease characterized by recurrent seizures. In most cases, epilepsy is also associated with some degree of cognitive compromise. As demonstrated in the Study of Standard and New Antiepileptic Drugs (SANAD), even at the point of diagnosis (i.e. before commencement of treatment with potential cognitive side effects, and not explained by the number of seizures, type of epilepsy or mood) patients with epilepsy perform worse than healthy volunteers on a range of cognitive measures, particularly of memory and psychomotor speed: In that study, 53.5% patients but only 20.7% of controls scored >2 standard deviations below the control mean in at least one testing domain (2). These cognitive deficits are even more important in children than in adults because they can affect subsequent cognitive development (3). In view of the much better ability of the young brain to recover after epilepsy surgery successful operative interventions in children and adolescents often improve cognitive performance substantially whereas aequivalent improvements are unexpected in older patients even when seizures stop postoperatively (4).
In my Editor’s Choice paper, the large paediatric and adolescent epilepsy surgery series described by Helmstaedter et al. (1), 85% of patients were found to have preoperative impairments in at least one domain (i.e. they performed >2 standard deviations below the level of healthy controls), and 71% had behavioral problems. Postoperatively, the status of 21-50% of the patients changed from impaired in at least one domain to unimpaired across all domains. At the individual patient level significant gains in test performance were observed in 16-42% of patients in different domains. The proportion of patients who had become seizure-free through surgery was 81%. At last follow up, patients in the surgically treated group were more likely than the others to have decreased their antiseizure medicine load.
Postoperative seizure freedom, a younger age at evaluation, a later age at epilepsy onset, a lower antiepileptic drug load, and less baseline damage predicted better cognitive and behavioral outcomes after epilepsy surgery in children and adolescents. In keeping with the finding of previous studies that neuropsychological deficits tended to be less focal / domain specific in children than adults (3); localization and lateralization had little or no impact on neuropsychological outcomes. Likewise, gender and type of pathology were not found to predict postoperative neuropsychological outcome (1).
This study shows how much good we are able to do with the advanced neurosurgical techniques described in the current Special Issue of Seizure on paediatric epilepsy surgery. The final reason for publishing this Special Issue while we are all grappling with the Covid-19 pandemic one way or another is to remind us that a better time will come – a time when we will be able to dust ourselves down and refocus on providing surgical treatments which can completely transform the lives of individuals with epilepsy.
1) Helmstaedter C, Beeres K, Elger C, Kuczaty S, Schramm J, Hoppe C. Cognitive outcome of pediatric epilepsy surgery across ages and different types of surgeries: A monocentric 1-year follow-up study in 306 patients of school age. Seizure 2020; 77: 86-92.
2) Taylor J, Kolamunnage-Dona R, Marson AG, Smith PE, Aldenkamp AP, Baker GA, et al. Patients with epilepsy: cognitively compromised before the start of antiepileptic drug treatment? Epilepsia 2010;51,48-56.
3) Holmes GL, Effect of Seizures on the Developing Brain and Cognition. Semin Pediatr Neurol 2016; 23: 120–126.
4) Helmstaedter C, Reuber M, Elger CE. Interaction of cognitive aging and memory deficits related to epilepsy surgery. Ann Neurol 2002;52,89-94.