Table 2

Essential prognostic features for epilepsy surgery (EPF)

EPFPrognostic value and supporting evidence base
FeaturePopulation(s) or subgroup(s)Range of effect sizes for seizure freedomCommentsMeta-analytical
Publication year (first, last)GRADE score
Clinical features
Severe developmental delay and IQ≤75Children and adults, TLE, structural lesions, tuberous sclerosis, hemispherectomiesRR 0.14–0.66 (0.04, 0.94)Favours absence of severe learning disabilityChelune, Naugle; Fallah, Guyatt; Hu, Zhang1998–2019++
Febrile convulsions (FC)TL and ET in children and adultsOR 2.08 (1.2, 3.7)
RR 1.09(1.01, 1.17)
Favours presence of FCTonini, Beghi; West, Nevitt2004–2019+
Very low
Without acute postoperative seizures (APOS)Children and adults, TLE and ETOR 4.2–5.7 (2.97, 9.8)Favours absence of APOS within 30 days of surgeryGiridharan, Horn2016++
Imaging features
Hippocampal sclerosis (HS)Adults and children with TLEOR 2.13 (1.57, 2.86)
RR 1.17(1.12, 1.23)
Favours presence of Mesial Temporal Sclerosis or HSTonini, Beghi; West, Nevitt2004–2019++
Abnormal or lesional MRIAdults and children with TLE and ET, FCD, frontal lobe, occipital lobe and posterior quadrant epilepsies, hemispherectomiesRR 1.28–1.64 (1.20, 2.08)
OR 1.27–4.6 (1.14, 16.62)
Favours abnormal MRI, see online supplemental table 3) for comments on two borderline meta-analysesTonini, Beghi; Téllez-Zenteno, Ronquillo; Yin, Kang; West, Nevitt; Rowland, Englot; Englot, Wang; Englot, Rolston; Harward, Chen; Widjaja, Jain; Cao, Liu2004–2020++
SPECT: subtraction SPECT co-registered to MRI (SISCOM)TL and ETOR 2.44–3.28 (1.34, 5.67)Favours ictal and inter-ictal SPECT-SISCOM abnormalitiesChen and Guo2016++
Neurophysiological features
Focal Ictal or interictal or invasive EEGAdults, children, repeat resections, MRI-negative TLE, tuberous sclerosis, ETOR 1.55–3.89 (1.24, 9.08)
Positive prognostic value on PLS also.
Favours focal EEG changes, for comments on notable exceptions from 2012 to 201315 35 see online supplemental table 3 Krucoff, Chan; Wang, Zhang; Fallah, Guyatt; Ibrahim, Morgan; Englot, Breshears2013–2017+
Very Low
Multimodal concordance
EEG-MRI concordanceTL and ET children and adults, tuberous sclerosis, hemispherectomiesRR 1.25 (1.15, 1.37)
OR 2.17–4.9 (1.07–13.5)
Prognostic value on PLS
Favours EEG and MRI concordanceTonini, Beghi; West, Nevitt; Fallah, Guyatt; Ibrahim, Morgan; Hu, Zhang2013–2019+++
Surgical technique or anatomic features
Temporal lobe (vs ET) resectionsAdults and children with FCD, repeat surgery, low grade gliomasOR 1.35–2 (0.8, 3.45)Favours surgery for TLERowland, Englot; Chen, Chen; Krucoff, Chan; Widjaja, Jain; Shan, Fan; Lamberink, Otte2012–2020+
Very Low
Complete excision (vs subtotal resection)Adults and children with FCD, FLE, repeat resections, TLE, low grade gliomasOR 2.6–12.5 (1.3, 20)
RR 1.11–1.99 (1.03, 2.84)
Favours complete excisionRowland, Englot; Chen, Chen; Englot, Wang; Krucoff, Chan; West, Nevitt; Widjaja, Jain; Shan, Fan2012–2020+++
Pathological features
Presence of tumoursChildren and adults, TLE and ET, gangliogliomas, DNET, neuroepithelial tumoursRR 1.23 (1.14, 1.32)
OR 1.27–2.78 (1.12, 3.57)
Favours tumours over multiple other lesions. See comments in online supplemental table 3 Tonini, Beghi; West, Nevitt; Lamberink, Otte2004–2020+++
Focal cortical dysplasia (FCD)Adults and children, TLE and ETFCD: RR 0.90 (0.85, 0.95)
FCD type II(b): OR 1.38–1.92 (1.01, 3.57)
Favours the absence of FCD, otherwise favours FCD type IIbRowland, Englot; Chen, Chen; West, Nevitt; Lamberink, Otte2012–2019++
Lesional pathology vs non-lesionalAdults and children, FLE, TLE, ET, repeat resections, occipital lobe and posterior quadrant.RR 1.67 (1.36, 28.6)
OR 1.08–3.2 (1.02, 5.3)
Favours presence of focal pathological lesion except in MRI neg TLE (see online supplemental table 3) comments)Englot, Wang; Englot, Rolston; Krucoff, Chan; Wang, Zhang; Harward, Chen; Englot, Breshears; Widjaja, Jain2012–2017++
  • The essential prognostic features (EPFs).

  • See online supplemental table 3 for more details and full list of references.

  • ET, extratemporal; FCD, focal cortical dysplasia.; FLE, frontal lobe epilepsy; OR/RR, OR and relative risks over 1 indicate better outcomes; PLS, projection to latent space; TL, temporal lobe; TLE, Temporal Lobe Epilepsy.