Patients aged 14 years or older with an electro-clinical diagnosis of JME were recruited. Healthy controls, including the siblings, were matched with patients with regard to age, sex, and education.
All patients underwent EEG and clinical assessment. Demographic data, age at seizure onset, duration of epilepsy, seizure types, seizure frequency, antiepileptic drug treatment, photosensitivity, psychiatric comorbidity, and previous psychological/psychiatric treatment were documented among other parameters.
The following tests were utilized in the study:
SCID I and SCID II
The Structured Clinical Interviews for DSM-IV Axis I (SCID-I) and Axis II (SCID-II) represent the American Psychiatric Association’s official interview instruments for the assessment of DSM-IV Axis I clinical disorders and Axis II personality disorders, respectively [11, 12].
Facial Expressions of Emotion: Stimuli and Test
Facial Expressions of Emotion: Stimuli and Test (FEEST; [13]) contains validated series of photographs showing six basic emotions (happiness, fear, disgust, anger, sadness, surprise) in addition to neutral expressions.
Empathy Quotient
The Empathy Quotient (EQ; [14]) is a validated self-report questionnaire assessing the capacity to empathize with others, i.e., to recognize the affective state of another individual and to respond with an appropriate emotion.
Moving Triangles
The Moving Triangles test measures the extent to which subjects make mental state attributions to dynamic visual stimuli [15].
Reading the Mind in the Eyes Test
The Reading the Mind in the Eyes Test (“Eyes test”; [16]) measures higher-level facial emotion perception, where the subject has to infer mental and affective states from social cues of the eye region.
Faux Pas Test
The Faux Pas Test estimates the ability to recognize and understand a social faux pas, a statement in which the speaker accidentally offends or insults another person [17].
Functional MRI
Functional data were acquired using EPI T2*-weighted sequences with the following parameters: 3‑mm slice thickness (interslice gap: 1.2 mm), FOV 250 mm, matrix size 64 × 64 (voxel size 1.72 × 1.72 × 3.75 mm), which allowed imaging of the complete temporal lobe, as well as frontal and parietal areas. Analysis of fMRI data was performed with the SPM12 (Statistical Parametric Mapping 12, Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, London, UK). The data were realigned to account for motion, smoothed with a 5-mm Gaussian smoothing kernel, and normalized to a standard template in Montreal Neurological Institute space.
fMRI paradigms
We assessed emotion recognition by a well-characterized “dynamic fearful faces” paradigm. For assessment of social cognition, a theory of mind (ToM) fMRI paradigm was employed.
Statistical analysis
The patients’ coded data (clinical, imaging, psychiatry, neuropsychology) were analyzed with SPSS (IBM, Armonk, New York, USA). The patients’ clinical characteristics were summarized using descriptive statistical methods, such as frequencies, percentage, means, and standard deviations. We performed a subgroup analysis by using descriptive statistics in an explorative way. Categorical data were analyzed by means of Pearson’s chi-squared test (if all expected numbers of counts are at least 1); otherwise Fisher’s exact test was used. Either the Freeman–Halton extension of Fisher’s exact probability test or the chi-squared test with Yates correction was used for tables larger than 2 × 2. In the case of significant differences, pair-wise comparisons were carried out by means of Pearson’s chi-squared test (if all expected numbers of counts are at least 1); otherwise Fisher’s exact test was used. Noncategorical data (e.g., age at seizure onset) were first analyzed by rank-based ANOVA. Two-by-two comparisons were performed by means of either the Mann–Whitney test or t test depending on scale and distribution type. In a comparative analysis of different groups, only those with sample size greater than five were included.
Ethical framework
All study participants and parents of underage subjects were asked to give their written informed consent after a full explanation of the purposes of the study, MRI/fMRI procedures, SCID I and II interviews and neuropsychological testing. The study was approved by the Ethics Committees of the city of Salzburg.