Angelo Labate (Italy)
AOU Mater Domini - Magna Graecia University Department of Medical and Surgical SciencesAuthor Of 5 Presentations
USEFULNESS OF 24-HOUR AMBULATORY EEG MONITORING IN THE DIAGNOSIS OF TYPICAL ABSENCES
- Alessia Giugno (Italy)
Abstract
Background and Aims:
Voluntary hyperventilation (VH) is believed to elicit successfully typical absences (TAs), especially in patients with genetic generalized epilepsies (GGE) and absences, including childhood and juvenile absence epilepsy (CAE and JAE) respectively. Failure in recording TAs may lead to diagnostic and therapeutic difficulties. This study evaluated the diagnostic yield of 24-hour ambulatory EEG monitoring (EEG/DIN), compared with VH, in patients with suspected or definite TAs/GGE and possible influence of clinical factors on HV efficacy.
Methods:
108 consecutive individuals (53 women, mean age 12.6±5.4 years), clinically suspected of TAs, underwent EEG recording with VH for 4-5 min of maximal effort from the subject, with monitoring of respiratory excursions by EEG technologist. If standard EEG was uninformative, they were investigated with EEG/DIN.
Results:
Three distinct groups were defined on the basis of HV and EEG/DIN findings: -ì. In 61/108 (56%) subjects (41/61 with CAE, 20/61 with JAE, 43/61 on antiepileptic drugs [AEDs]), HV triggered TAs. -ii. In 36/108 (34%) individuals (17/36 with CAE, 19/36 with JAE; and 26/36 on AEDs), HV was unsuccessful, but EEG/DIN showed TAs or electrophysiological hallmarks of them. -iii. The remaining 11/108 patients had normal EEG with HV and EEG/DIN; the diagnosis of TAs/GGE was ruled out in 9/11 of them. Thereafter, AED was discontinued in 2/4 individuals on therapy.
Conclusions:
This study illustrated a higher diagnostic yield of EEG/DIN than HV in individuals with TAs/GGE. HV was less effective in JAE, regardless of AED therapy. Thus, EEG/DIN greatly helps establish the diagnosis and monitor TAs, especially in JAE.
A MULTIMODAL NEUROIMAGING APPROACH TO NON LESIONAL FRONTAL LOBE EPILEPSY
- Pio Zoleo (Italy)
Abstract
Background and Aims:
Frontal Lobe Epilepsy (FLE) is a common form of epilepsy usually caused by structural lesions on frontal areas. Some FLE patients are defined “non-lesional” (nlFLE) because of the absence of clearly identifiable abnormalities on qualitative brain MRI. Our aim was to investigate nlFLE patients to identify possible microstructural abnormalities, through advanced neuroimaging techniques.
Methods:
We enrolled 127 nlFLE patients and 127 age and sex-matched HC. Diagnosis of nfFLE was based on typical ictal semeiology and interictal frontal EEG discharges; all the study participants underwent 3T brain MRI. Voxel-based morphometry (VBM), cortical-thickness (CT), Diffusion-tensor imaging (DTI) and Tract-based spatial statistics (TBSS) were the whole-brain multimodal MRI analyzes performed. We also focused on the corpus callosum (CC), evaluating thickness, fractional anisotropy (FA) and mean diffusivity (MD) from 50 regions of interest along the callosal midsagittal profile.
Results:
VBM analysis revealed regional atrophy in rolandic operculum in nlFLE patients compared to HC (p-value<0.05, TFCE-corrected). TBSS analysis showed significantly increased callosal FA and MD (p-value<0.05, TFCE-corrected) in nlFLE patients compared with controls, especially in sections I (rostrum, genu and rostral body) and III (posterior midbody) of the CC.
Conclusions:
Our study demonstrates that subtle MRI functional and morphological anomalies exist in FLE patients who did not show qualitative brain alterations, and that corpus callosum is one of the most involved cerebral structures. Our results possibly suggest a contribution from white matter alterations to the network abnormalities sustaining frontal lobe seizures, further questioning the traditional concept of epilepsy as a “cortical–only disease”.
RANDOM-FOREST CLASSIFICATION OF PSYCHOGENIC NON-EPILEPTIC SEIZURES AND TEMPORAL LOBE EPILEPSY.
- Maria Eugenia Caligiuri (Italy)
Abstract
Background and Aims:
Psychogenic nonepileptic seizures (PNES) represent a multifactorial psychopathology, which makes diagnosis particularly challenging: PNES can be misdiagnosed as pharmaco-resistant temporal lobe epilepsy (TLE), and approximately 80% of subjects actually undergo anti-epileptic drug (AED) at the time of correct diagnosis. In this study, we used machine learning (ML) to differentiate PNES and TLE patients.
Methods:
Thirty-six PNES subjects and 43 demographically-matched TLE patients underwent neuropsychiatric/neuroimaging assessment. A 10,000-trees random forest (RF) algorithm, considered more robust to overfitting compared to other ML algorithms, was trained on T1-weighted MRI, i.e., on the entire set of morphological metrics obtained through FreeSurfer (cortical thickness, surface, volume, curvature, gyrification index). All features with a mean decrease in Gini index ≥ 0.30 were selected to construct a new classifier with the lowest out-of-bag error (OOB; accuracy = 100 - OOB).
Results:
Figure 1 shows the most important features discriminating PNES from TLE, ranked according to mean Gini Index decrease. This discriminant network included regions across all lobes of the brain, from parietal-occipital regions to frontal regions, as well as the anterior portion of the corpus callosum. Based on these selected features, the RF algorithm was able to distinguish PNES from TLE with an average accuracy of 77.2%.
Conclusions:
This work provides evidence that ML techniques could aid the differential diagnosis of PNES. Involvement of cingulate and orbitofrontal cortices, a frequent finding when comparing PNES to controls, also represented a distinctive feature from TLE patients. This finding supports the hypothesis that PNES subjects experience disrupted processing of emotional information, which might ultimately lead to the insurgence of seizure-like episodes.
MILD CASE OF UNVERRICHT-LUNDBORG DISEASE PRESENTING AS JUVENILE MYOCLONIC EPILEPSY
- Alessia Giugno (Italy)
Abstract
Background and Aims:
Juvenile myoclonic epilepsy (JME) and Unverricht-Lundborg disease (ULD) are distinct entities, but they share several clinical features. In ULD, the most common mutation is a dodecamer repeat of cystatin B (CSTB) gene on chromosome 21q22.31-2. We reported a JME phenotype in an Italian family with ULD.
Methods:
A 30-year-old man presented one generalized tonic-clonic seizure (GTC), myoclonic jerks on awakening at 13 years of age. He is seizure-free under valproate, carrying a clinical diagnosis of JME. His 37-year-old sister developed action myoclonus, GTCs, photosensitivity, ataxia, at age of 12 years, exhibiting a phenotype of ULD. She is treated by clonazepam, valproate, levetiracetam and perampanel. There was no cognitive impairment. The parents were consanguineous. An extensive clinical, laboratory and genetic investigation with screening for mutations in CSTB gene was performed in the two patients and their parents.
Results:
EEG-polygraphic recording revealed generalized spike and waves (GSWs), photo-paroxysmal-response (PPR), with no myoclonus, in proband; GSWs, PPR, involuntary, stimulus and action activated myoclonic jerks in his sister. Both patients exhibited giant SSEPs and C-reflex bilaterally, normal brain 3T MRI and a similar (60 to 68) homozygous dodecamer expansions in CSTB gene. Their parents showed unremarkable clinical and EEG evaluations.
Conclusions:
The exceptionality of a high functioning ULD patient of age 30 emphasizes the mild end of phenotypic spectrum of CSTB mutations, the phenotypic heterogeneity of ULD and of similar size of CSTB dodecamer expansions. The screening of the CSTB gene should be considered in patients with JME and evidence of recessive transmission.
IMPAIRED EMBODIED COGNITION IN PATIENTS WITH MESIAL TEMPORAL LOBE EPILEPSY AND HIPPOCAMPAL SCLEROSIS
- Ilaria Sammarra (Italy)
Abstract
Background and Aims:
Sensorimotor systems, involved in experiences, are recruited in attributing meaning to words, configuring the so-called embodied cognition. We aim to assess whether the processing of graspable objects and their nouns is impaired in patients with mesial temporal lobe epilepsy (MTLE).
Methods:
Fifteen controls and 14 matched MTLE patients, of which 5 had hippocampal sclerosis (HS), performed 3T-MRI and neuropsychological examination. Forty Italian nouns and 40 digital color photos concerning natural objects as well as 40 pseudoword and 40 distorted images were used as stimuli. Twenty nouns and 20 photos were referred to natural graspable objects, while the remaining to non-graspable ones. Subjects had to respond exclusively whether the stimulus concerned a real object. The mean value of reaction times (RTs) and error numbers were calculated for each Object Graspability and Stimulus Type combination.
Results:
In the controls, the slower RTs were recorded for stimuli related to graspable objects (nouns: 597±109ms; photos: 616±98ms) compared to non-graspable ones (nouns: 574±108ms; photos: 557±111ms). MRI-negative MTLE group had RTs like controls for nouns (graspable: 504±79ms; non-graspable: 476±72ms) and photos (graspable: 569±93ms; non-graspable: 491±68ms). Instead, HS-MTLE patients showed faster RTs for nouns referred to graspable objects (470±53ms) compared to those non-graspable (500±54ms) and photos’ stimuli (graspable: 546±46ms; non-graspable: 510±99ms). The mean error number was greater in the HS-MTLE group (8.6±10.3) compared to MRI-negative MTLE one (2.4±1.6).
Conclusions:
HS-MTLE patients did not show the slower RTs related to graspable objects expressed by nouns with less accurate responses, indicating a dysfunction in embodied cognition mediated by frontoparietal sensorimotor systems.