Is there a risk of seizures in “preventive” awake surgery for incidental diffuse low-grade gliomas?

Abstract

A WHO Grade II glioma (diffuse low-grade glioma [LGG]) is a continuously growing lesion that migrates along white matter pathways and that will inescapably evolve toward a higher grade of malignancy. 39This tumor is usually revealed by inaugural seizures in young adults with no or only mild neurological deficits. 11Despite the lack of prospective randomized trials, a large amount of data reported in the modern literature strongly supports the impact of early and maximal resection on the natural history of the disease, by delaying malignant transformation and thus by significantly increasing survival. 1,15,20,21,30,46,49 Recently the French Glioma Network published the largest surgical series of LGG ever reported, in which multivariate analysis was used to show that extent abbreviatioNs AED = antiepileptic drug; EOR = extent of resection; ILGG = incidental low-grade glioma; KPS = Karnofsky Performance Scale. submitted June 22, 2014. accepted September 10, 2014. iNclude wheN citiNg Published online February 27, 2015; DOI: 10.3171/2014.9.JNS141396. disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.Is there a risk of seizures in "preventive" awake surgery for incidental diffuse low-grade gliomas? obJect Although a large amount of data supports resection for symptomatic diffuse low-grade glioma (LGG), the therapeutic strategy regarding incidental LGG (ILGG) is still a matter of debate. Indeed, early "preventive" surgery has recently been proposed in asymptomatic patients with LGG, after showing that the extent of resection was larger than in symptomatic patients with LGG. However, the quality of life should be preserved by avoiding both neurological deficit and epilepsy. The aim of this study was to determine the risk of seizures related to such a prophylactic surgical treatment in ILGG. methods The authors report a prospective series of 21 patients with ILGG who underwent awake surgery with a minimum follow-up of 20 months following resection. Data regarding clinicoradiological features, surgical procedures, and outcomes were collected and analyzed. In particular, the eventual occurrence and type of seizures in the intra- and postoperative periods were studied, as follows: early (< 3 months) and long-term (until last follow-up) periods. results There were no intraoperative seizures in this series. During the early postoperative period, the authors observed only a single episode of partial seizures in a patient with no antiepileptic drug (AED) prophylaxis-all other patients were given antiepileptic treatment following resection. The AEDs were discontinued in all cases, with a mean delay of 8 months after surgery (range 3-24 months). No patient had permanent neurological deficits. All 21 patients returned to an active familial, social, and professional life (working full time in all cases). Total or even "supratotal" resection (the latter meaning that a margin around the tumor visible on FLAIR-weighted MRI was removed) ...

Low Rate of Intraoperative Seizures During Awake Craniotomy in a Prospective Cohort with 374 Supratentorial Brain Lesions: Electrocorticography Is Not Mandatory

“…A C C E P T E D ACCEPTED MANUSCRIPT 4 at the same institution. Information concerning the following parameters was obtained for all patients: sex, age, Karnofsky Performance Scale (KPS) score, eventual epilepsy history (preoperative seizures, administration of antiepileptic drugs, intractable seizures under multiple antiepileptic drugs), tumor's characteristics (side, pathology), possible previous surgery or biopsy, intraoperative findings (intensity of stimulation, eventual IOS or AC failure), postsurgical course with eventual onset of seizures within the 3 months following resection, and neurological outcomes as well as KPS at 3 months.…”

“…All patients received systematic postoperative prophylaxis with antiepileptic drugs for at least 3 months, including patients with no preoperative seizures (usually levetiracetam 1g per day) (4).…”

The assessment of language functions in awake craniotomies

“…Although patient P20 exhibited right hemiparesis involving mostly the lower extremity, the deficit was not severe (grade 4 on Medical Research Council Scale). Compared to the results reported in literature, and presented in Introduction 14 , there is no statistically significant difference between new early deficits of Group PIP (M = 62.5%) with other patients that underwent awake craniotomy [391,392,393,395,396,400,[403][404][405][406][407][408][409][410] (M = 41.9, SD = 32.169; p = 0.422) or brain surgery under general anaesthesia [391,392,393,395,400] (M = 35.9, SD = 37.842; p = 0.380). Table 5.8 demonstrates the qualitative perspective of the postoperative neurological deficits with a focus on speech and language.…”

Acute progression of untreated incidental WHO Grade II glioma to glioblastoma in an asymptomatic patient

“…16 Indeed, in a recent prospective series of 21 iLGG patients who underwent surgery with a mean follow-up of 49 months following resection, all patients are still alive and enjoy a normal life, with no immediate postoperative seizures in any case but one. 2 These data strongly reinforce the proposal of a screening policy for LGG, to evolve toward a "preventive treatment." 11,15 conclusions With this original case, we highlight the fact that an iLGG can undergo acute and direct transformation into glioblastoma, even in a patient who remains asymptomatic.…”