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Objectives We investigated peripheric smell regions of olfactory bulb (OB) volume and olfactory sulcus (OS) depth in temporal and frontal lobe epilepsy patients by cranial magnetic resonance imaging (MRI). Methods In this retrospective study, cranial MRI images of 150 adult patients were included. Group 1 was consisted of 50 adult patients with temporal lobe epilepsy (TLE). Group 2 was consisted of 50 adult patients with frontal lobe epilepsy (FLE). The control group (Group 3) was consisted of 50 healthy subjects without epilepsy. OB volume and OS depth were measured in all groups. Results OB volumes of the temporal and frontal epilepsy groups were significantly lower than those of the control group (padjusted 0.05). In the temporal and frontal epilepsy groups, there were positive correlations between OB volumes; OS depths; left OB volume and bilateral OS depths p 0.05). Conclusion We concluded that temporal and frontal epilepsy maybe related to decrease in OB volume and may cause olfactory impairment. Olfactory deficit maybe related to central epileptic focus. Therefore, early diagnosis and appropriate treatment of epilepsy are important to prevent olfactory impairment.

International audience; The aim of this study was to better understand the significance of interictal changes in water molecule diffusivity defined by diffusion-weighted imaging (DWI) in frontal lobe epilepsy (FLE), as well as to test the accuracy of interictal DWI in the definition of the epileptogenic zone (EZ).DWI was carried out in 14 patients with refractory FLE (9 negative-MRI) as well as in 25 controls. Statistical mapping analysis (SPM2) of diffusivity maps was used to detect, for each subject, significant diffusivity alterations. We then studied the relationships between diffusion and depth recorded electrical abnormalities. Clinical correlates of the extent of diffusivity changes were also tested. We found areas of significantly increased diffusivity (SID) in 13 patients. Eight had SID in the EZ, 9 within the irritative zone (IZ) and 12 outside, mainly in connected areas. We found a correlation between the extent of SID and the duration of epilepsy (p corrected = 0.026, R = 0.621). In addition, SID was significantly less widespread in negative-MRI patients (p = 0.028). However, we found no significant differences concerning either seizure frequency (p = 0.302), seizure generalization (p = 0.841), history of status (p = 0.396), or surgical outcome (p = 0.606). We suggest that SID in normal appearing areas is not a specific signature of epileptogenicity in FLE, and is more likely to reflect multifactorial and potentially evolving neuro-glial injuries.

Frontal lobe epilepsies may present difficulties in focus localization in the pre-operative work-up for epilepsy surgery. This is specially true in patients with normal MRIs. We report on a 16 years-old girl that started with seizures by the age of 8 years. They were brief nocturnal episodes with automatisms such as bicycling and boxing. Seizure frequency ranged from 4-10 per night. Scalp EEG showed few right frontal convexity spiking and intense secondary bilateral syncrhony (SBS). High resolution MRI directed to the frontal lobes was normal. Ictal SPECT suggested a right fronto-lateral focus. Ictal video-EEG showed no focal onset. She was submitted to invasive recordings after subdural plates implantation. Electrodes covered all the frontal convexity and mesial surface bilaterally. Ictal recordings disclosed stereotyped seizures starting from the right mesial frontal. Using a high-resolution tool to measure intra and interhemispheric latencies, the timing and direction of seizure spread from the right fronto-mesial region were studied. Motor strip mapping was performed by means of electrical stimulation. She was submitted to a right frontal lobe resection, 1.5 cm ahead of the motor strip and has been seizure free since surgery (8 months). Pathological examination found a 4 mm area of cortical dysplasia. Invasive studies are needed to allow adequate localization in patients with non-localizatory non-invasive work-up and may lead to excellent results in relation to seizures after surgery.

We quantitatively evaluated the localizing and lateralizing characteristics of ictal upper limb automatisms (ULAs) in patients with temporal lobe epilepsy (TLE; n=38) and frontal lobe epilepsy (FLE; n=20). Movement speed, extent, length, and duration of ULAs were quantitatively analyzed with motion capturing techniques. Upper limb automatisms had a larger extent (p

Frontal lobe epilepsy, the great new epileptological challenge, presents enormous difficulties that still preclude a more profound understanding at the present time. The major subdivision of the frontal lobe into a prefrontal and premotor portion is the first step toward a better and yet limited comprehension of the frontal lobe epilepsies. Prefrontal implies higher mental functions (e.g., ictal forced thinking); rapid generalization to full grand mal evolves quite often from prefrontal foci. The frontal accentuation of classical generalized 3/sec spike-wave absences adds to the conceptual difficulties of the frontal lobe epilepsies. The unique type of disturbed consciousness in classical absences is presumed to be based upon ictal "suspension of the working memory." Limbic components (via orbitofrontal and cingulate mechanisms) also play an important role. Correlations between ictal semiologies and regional frontal lobe functions are still quite controversial.

Frontal lobe epilepsies are much more complex to investigate than those epilepsies of temporal lobe origin. Rapid diffusion of ictal discharge, typical of frontal lobe epilepsy, often renders a clear definition of the epileptogenic zone impossible unless invasive recordings are performed.1 Even with the use of such invasive techniques, the results of frontal lobe cortectomy are not always satisfactory2 and this is certainly so when compared with the results of temporal lobe cortectomies.

Concepts, classification, and approach frontal lobe seizures localization of electrographic discharges in frontal lobe seizures and epilepsies cognitive neurophysiology and neuropsychology of frontal lobe seizures and epilepsies diagnosis, brain imaging, and neuropathology of frontal lobe epilepsies basic mechanisms of frontal lobe epilepsies medical and surgical treatment of frontal lobe seizures and epilepsies.

The utility of the “International Classification of Epilepsies, Epileptic Syndromes, and Related Seizure Disorders,” proposed by ILAE in 1989, was investigated in a neuropsychiatric clinic with a patient population numbering 300. Two hundred and three patients (67.7%) had localization-related epilepsies (LRE), including one idiopathic case. Sixty-six patients (22%) had generalized epilepsies, 50 idiopathic, 2 Lennox-Gastaut syndrome, and 14 symptomatic. Thirty-one patients (10.3%) with generalized tonic-clonic seizures occurring only during sleep had the epilepsies undetermined whether they are focal or generalized. In the symptomatic LRE cases, 34 cases could not be classified, and 7 of the cases with frontal lobe epilepsies were difficult to subtype. Eleven of the symptomatic LRE cases had some independent seizures, multiple foci in surface EEGs and were intractable. These cases may be defined as “multifocal epilepsies.”

The investigation of frontal lobe epilepsies for the determination of surgical treatment gives rise to particular difficulties. Even depth electrode studies of spontaneous seizures, complemented by electrical stimulation, sometimes do not succeed in lateralizing the epileptogenic focus. In the stereotactic EEG (SEEG) laboratory of Hopital Notre-Dame (Saint-Hilaire et al., 1976; Bouvier et al., 1976) we have studied 17 patients with frontal lobe epilepsy. In ten patients we could demonstrate from spontaneous seizures which frontal lobe was involved first by the epileptogenic discharge. In four patients the spontaneous seizures started simultaneously in both frontal lobes. Only electrical stimulation, by reproducing the spontaneous seizure, could lateralize and localize the epileptic focus to one frontal lobe. Finally, in the three remaining patients neither the spontaneous seizures nor electrical stimulation could direct us to one particular frontal lobe. We concluded tentatively that these seizures were either bifrontal at the onset or unifrontal epilepsies with very rapid diffusion to the contralateral frontal lobe.

The aim of a Stereo-EEG investigation is to verify and prove that the hypothesis, done on the basis of the preliminary investigations (clinical, EEG, neuroradiological), are correct. This task is particularly hard in frontal lobe epilepsies, because of anatomical and physiopathological reasons. Among 277 consecutive patients, 86 were explored for a probable frontal epilepsy. The stereotactically introduced electrodes, 1) simultaneously record the electrical activity on both, mesial and lateral cortical areas, and, 2) in 3/4 of cases also investigate extra-frontal, mainly temporal, areas.