Evaluation of neurosurgical resection strategies in temporal lobe epilepsy

Seizure freedom at one year after surgery: defined as class I in the Engel Outcome Scale. The Engel Outcome Scale is administered post-operatively and determines the improvement/worsening after surgical intervention as follows:
1. Engel class I: seizure-free
2. Engel class II: almost seizure-free
3. Engel class III: significant seizure reduction
4. Engel class IV: no significant improvement

Patients belonging to Engel class I are termed as seizure free, the remaining patients (Engel II - IV) as non-seizure free patients in the present study.

Secondary analysis:
Seizure freeness in subgroups (based on neuropathological analyses), e.g. patients with mesial temporal sclerosis.

Neuropsychological testing:
Each patient underwent comprehensive neuropsychological testing pre-operatively and 12-months post-operatively. For the comprehensive purpose of this study, various neuropsychological parameters are aggregated, resulting in scores for seven major cognitive domains:
1. Verbal learning and memory: two parallel versions of a pre- and post-operative verbal learning test (Verbaler Lern- und Merkfähigkeitstest [VLMT]). The VLMT (German adaptation of the Rey Auditory Verbal Learning Test) requires five trials of learning and recall of a word list consisting of 15 words, free recall immediately after distraction (learning/recall of a second list in one trial) and a recall after a half-hour delay, which is followed by a recognition trial (list with original words plus distractors).
2. Figural learning and memory was obtained using the DCS-R, a German revised version of the DCS, a design list learning test (Diagnostikum für Zerebralschädigung)
3. Language functions:
3.1. Confrontation naming, Boston Naming Test
3.2. Phonematic and semantic fluency
3.3. Token Test, a subtest of the Aachener Aphasie-Test (a german test battery for aphasia) which is seen to measure verbal comprehension
4. Attention functions:
4.1. D2-Test, a letter cancellation test
4.2. The c.I.T., a short test to measure cerebral insufficiency (Kurztest für cerebrale Insuffizienz)
5. Psychomotor speed, mental tracking and cognitive flexibility:
5.1. Trail Making Test A and B (TMT-A/B)
5.2. Motoric sequences after Lurija
5.3. Purdue Pegboard
5.4. Finger Tapping Test
6. Visual and spatial abilities:
6.1. Subtest LPS-7 of the Leistungsprüfsystem (LPS), a german intelligence battery
6.2. The Mosaic-Test, a subtest of the German version of the Wechsler Adult Intelligence Scale-Revised (HAWIE-R)
6.3. Labyrinth test
7. Behaviour and personality features:
7.1. German version of the Beck Depression Inventory (BDI)
7.2. FPZ (Fragebogen zur Persönlichkeit bei zerebralen Erkrankungen), an unpublished German CNS-disease related personality questionnaire
7.3. Quality of Life Inventory in Epilepsy, 10-item version (QOLI-10)

All neuropsychological results were classified into five categories (0 = noticeably abnormal, 1 = moderately abnormal, 2 = borderline, 3 = without pathological findings, 4 = above average).