The expression of interictal, preictal, and postictal facial-wiping behavior in temporal lobe epilepsy: a neuro-ethological analysis and interpretation

Ictal semiology of gelastic seizures

Gelastic seizures are rare epileptic manifestations characterized by laughter or a smile. The main etiology is represented by hypothalamic hamartoma, but also focal localization of the epileptogenic zone is described. We reviewed a group of patients with gelastic seizures to describe the semiology and to establish any difference related to diverse epilepsy etiologies. Thirty-five seizures from 16 patients (6 females) were reviewed. The study confirms that hypothalamic hamartoma is the more frequent etiology associated with gelastic seizures. Laughter represented the majority of gelastic ictal signs, while the ictal smile was less frequent. In 87.5% of patients, the manifestation of laughter or smile was the only ictal phenomenon, or the first and the most important clinical sign. Interestingly, it has been observed that patients with a lesion localized in the hypothalamic region had more frequently laughter with emotional involvement and that laughter was the only manifestation of the seizure. On the contrary, patients with lesions localized outside the hypothalamic region had more often seizures with laugh without emotional involvement, resembling a more mechanical action, and associated with other semeiological signs. It, therefore, seems possible to assume that the emotional involvement and the expression of mirth during the seizure, especially in children, are more frequently associated with hypothalamic hamartoma. On the contrary, when the semiology includes less conveyed emotion similar to a mechanical action and other symptoms, an extra hypothalamic localization should be considered.

Occipital and occipital "plus" epilepsies: A study of involved epileptogenic networks through SEEG quantification

Compared with temporal or frontal lobe epilepsies, the occipital lobe epilepsies (OLE) remain poorly characterized. In this study, we aimed at classifying the ictal networks involving OLE and investigated clinical features of the OLE network subtypes. We studied 194 seizures from 29 consecutive patients presenting with OLE and investigated by stereoelectroencephalography (SEEG). Epileptogenicity of occipital and extraoccipital regions was quantified according to the 'epileptogenicity index' (EI) method. We found that 79% of patients showed widespread epileptogenic zone organization, involving parietal or temporal regions in addition to the occipital lobe. Two main groups of epileptogenic zone organization within occipital lobe seizures were identified: a pure occipital group and an occipital "plus" group, the latter including two further subgroups, occipitotemporal and occipitoparietal. In 29% of patients, the epileptogenic zone was found to have a bilateral organization. The most epileptogenic structure was the fusiform gyrus (mean EI: 0.53). Surgery was proposed in 18/29 patients, leading to seizure freedom in 55% (Engel Class I). Results suggest that, in patient candidates for surgery, the majority of cases are characterized by complex organization of the EZ, corresponding to the occipital plus group.

The piriform cortex and human focal epilepsy

It is surprising that the piriform cortex, when compared to the hippocampus, has been given relatively little significance in human epilepsy. Like the hippocampus, it has a phylogenetically preserved three-layered cortex that is vulnerable to excitotoxic injury, has broad connections to both limbic and cortical areas, and is highly epileptogenic – being critical to the kindling process. The well-known phenomenon of early olfactory auras in temporal lobe epilepsy highlights its clinical relevance in human beings. Perhaps because it is anatomically indistinct and difficult to approach surgically, as it clasps the middle cerebral artery, it has, until now, been understandably neglected. In this review, we emphasize how its unique anatomical and functional properties, as primary olfactory cortex, predispose it to involvement in focal epilepsy. From recent convergent findings in human neuroimaging, clinical epileptology, and experimental animal models, we make the case that the piriform cortex is likely to play a facilitating and amplifying role in human focal epileptogenesis, and may influence progression to epileptic intractability.

Looking for complexity in quantitative semiology of frontal and temporal lobe seizures using neuroethology and graph theory

Epileptic syndromes and seizures are the expression of complex brain systems. Because no analysis of complexity has been applied to epileptic seizure semiology, our goal was to apply neuroethology and graph analysis to the study of the complexity of behavioral manifestations of epileptic seizures in human frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE). We analyzed the video recordings of 120 seizures of 18 patients with FLE and 28 seizures of 28 patients with TLE. All patients were seizure-free >1 year after surgery (Engel Class I). All patients' behavioral sequences were analyzed by means of a glossary containing all behaviors and analyzed for neuroethology (Ethomatic software). The same series were used for graph analysis (CYTOSCAPE). Behaviors, displayed as nodes, were connected by edges to other nodes according to their temporal sequence of appearance. Using neuroethology analysis, we confirmed data in the literature such as in FLE: brief/frequent seizures, complex motor behaviors, head and eye version, unilateral/bilateral tonic posturing, speech arrest, vocalization, and rapid postictal recovery and in the case of TLE: presence of epigastric aura, lateralized dystonias, impairment of consciousness/speech during ictal and postictal periods, and development of secondary generalization. Using graph analysis metrics of FLE and TLE confirmed data from flowcharts. However, because of the algorithms we used, they highlighted more powerfully the connectivity and complex associations among behaviors in a quite selective manner, depending on the origin of the seizures. The algorithms we used are commonly employed to track brain connectivity from EEG and MRI sources, which makes our study very promising for future studies of complexity in this field.

The epilepsies: complex challenges needing complex solutions

It is widely accepted that epilepsies are complex syndromes due to their multi-factorial origins and manifestations. Different mathematical and computational descriptions use appropriate methods to address nonlinear relationships, chaotic behaviors and emergent properties. These theoretical approaches can be divided into two major categories: descriptive, such as flowcharts, graphs and other statistical analyses, and explicative, which include both realistic and abstract models. Although these modeling tools have brought great advances, a common framework to guide their design, implementation and evaluation, with the goal of future integration, is still needed. In the current review, we discuss two examples of complexity analysis that can be performed with epilepsy data: behavioral sequences of temporal lobe seizures and alterations in an experimental cellular model. We also highlight the importance of the creation of model repositories for the epileptology field and encourage the development of mathematical descriptions of complex systems, together with more accurate simulation techniques.

Early ictal face wiping in frontal lobe epilepsy

We describe two patients with medication-resistant nonlesional mesial frontal lobe epilepsy and seizures that manifested with early face wiping prior to other motor phenomena. Ictal scalp monitoring either was nonlocalizing or involved the central regions. Intracranial monitoring demonstrated anterior mesial frontal ictal low-voltage gamma activity during the face wiping activity in both patients. Habitual seizures with the same clinical characteristics were induced during extraoperative functional mapping with stimulation of the same region. Ictal activation of mesial frontal regions can elicit early ictal face wiping activity, and this clinical sign may play a role in presurgical evaluation.

Ictal extension (dorsiflexion) of the toes in a patient with temporal lobe epilepsy: a new ictal lateralizing sign

Neurologists have analyzed the clinical behaviors that occur during seizures for many years. Several ictal behaviors have been defined in temporal lobe epilepsy (TLE). Ictal behaviors are especially important in the evaluation of candidates for epilepsy surgery. We propose a new ictal lateralizing sign originating from the nondominant hemisphere: extension (dorsiflexion) of the toes (Babinski's, Chaddock's, and Moniz' signs). Our patient is a 16-year-old woman. Her epileptogenic foci were localized to the right neocortical temporal region after noninvasive presurgical investigations. Cranial MRI revealed a right insular lesion compatible with focal cortical dysplasia or cortical tumor. We observed progressive movement of the left leg and, when the patient touched the lateral aspect of the foot to the bed, dorsiflexion of the great toe (Babinski's sign). In other seizures, the patient started a progressive movement of the left leg, rubbing the external border of the left foot on the bed and provoking dorsiflexion of the great toe (Chaddock's sign). The Brissaud reflex component was also observed when the movement was accompanied by internal rotation of the leg and recruitment of the tensor fascia lata, making dorsiflexion more likely to be a reflex response and not voluntary. We also observed forceful passive plantar flexion at the ankle in association with dorsiflexion of the great toe (Moniz' sign). All of these signs were contralateral to ictal seizure onset and to the cerebral epileptogenic lesion. These signs may occur as a result of ictal activation of a specific brain region in this hemisphere.

Can stroke localisation be used to map out the neural network for yawning behaviour?

What are the neuroanatomical structures involved in repetitive yawning during stroke?

Ictal Emotional Expressions of Children with Partial Epilepsy

OBJECTIVE

To systematically analyze the lateralizing and localizing value of ictal emotional expressions (EEs) in children and compare these results with those of earlier adult studies.

METHODS

Five hundred fourteen seizures of 100 consecutive children < or = 12 years with partial (61/100 temporal lobe) epilepsy and postoperative seizure free outcome were included in the study. Video recordings of seizures were reviewed by two independent investigators blinded to the patients' clinical data.

RESULTS

Thirty-five patients produced EE at least once during their archived seizures, including fear (15), crying (12), smile (9), pain (5), happiness (3), and laughing (in one case). Emotional symptoms were divided into two groups: positive (smile, laughing, and happiness) and negative EEs (fear, crying, and pain). Emotional expressions appeared more frequently during extratemporal (49%) than temporal (26%) lobe seizures (p < 0.05). Positive EEs had an extratemporal dominance (p < 0.05), while frequency of negative EEs did not localize the seizure onset zone. Assessing their lateralizing value, positive EEs were more frequent during right-sided seizures (p < 0.05) while negative EEs did not lateralize the seizure onset zone. Frequency of EEs were independent of patients' ages, age at epilepsy onset or duration of epilepsy.

CONCLUSION

This is the first comprehensive childhood study showing that ictal EEs are frequent in childhood and their localizing and lateralizing properties are different from those of adults.

Lateralizing value of postictal automatisms in temporal lobe epilepsy

PURPOSE

To describe clinical characteristics and lateralizing value of postictal automatisms in patients with temporal lobe epilepsy (TLE).

METHODS

One hundred and ninety-three videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed. Ictal as well as postictal (manual, oral and speech) automatisms were monitored.

RESULTS

Thirty-four (62%) of the 55 patients showed PA at least once during their seizures. Postictal automatism was observed in 70 (36%) attacks as manual (21%), oral (13%) or speech (9%) automatisms. Fifteen seizures contained a combination of two different postictal automatisms. The presence of postictal oral automatisms did not lateralize the seizure onset zone (p=0.834). Speech automatisms (repetitive verbal behavior) occurred more frequently after left-sided seizures (p=0.002). Postictal unilateral manual automatism showed no lateralizing value occurring by the ipsilateral hand in 10 and the contralateral upper limb in 6 seizures (p=0.454).

CONCLUSION

: Postictal automatism is a relatively frequent phenomenon in TLE. Postictal speech automatism lateralizes the seizure onset zone to the left hemisphere. Our observation can help the presurgical evaluation of TLE because verbal perseveration frequently occurs spontaneously, even in seizures without appropriate postictal language testing.

Electrode manipulation automatism during temporal lobe seizures

OBJECTIVE

To describe clinical characteristics and lateralizing value of peri-ictal electrode manipulation automatism (EMA) in patients with temporal lobe epilepsy (TLE) and compare our data with ictal manual automatisms described in the literature.

METHODS

Two-hundred and five videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed and EMA (tugging, scratching or adjusting the electrodes and cables) were monitored.

RESULTS

Twenty-eight (51%) patients showed EMA during 47 (23%) seizures. Ictal start was noted in 22 seizures and in 19/22 cases EMA finished before the end of seizure. Ictal EMAs were always associated with automotor seizure components. During 25 seizures, exclusively postictal EMAs were observed. Electrode manipulation was presented during 24/112 left-sided and 23/93 right-sided seizures (p = 0.742). Peri-ictal EMA was unilateral (completed by one hand) in 24/47 seizures (10 ictal, 14 postictal); it was done by the hand ipsilateral to the seizure onset zone in 17/24 and by contralateral hand in 7/24 cases (p = 0.064). We observed concomitant contralateral dystonic posturing during 3/10 seizures with unilateral ictal EMA. Unilateral hand automatism, temporally independent from the EMA appeared in 30 (64%) of the 47 seizures.

CONCLUSION

Peri-ictal EMA is a frequent phenomenon but shows no lateralizing value in TLE. The mechanism of EMA is in many ways dissimilar from that of earlier described manual automatisms.

Yawning: unsuspected avenue for a better understanding of arousal and interoception

Almost all the vertebrates yawn, testifying the phylogenetic old origins of this behavior. Correlatively speaking, yawning shows an ontogenical precociousness since it occurs as early as 12 weeks after conception and remains relatively unchanged throughout life. Thus, it is contended that these common characteristics and their diencephalic origin allow to model an approach from which emerges a pivotal link between yawning and REM sleep. Yawning and stretching reverse the muscular atonia of the REM-sleep and reopen the collapsed airways. Yawning appears as a powerful muscular stretch, recruiting specific control systems particularly the paraventricular nucleus of the hypothalamus, the locus coeruleus and the reticular activating system from which the vigor of this ancestral vestige, surviving throughout evolution with little variation, may increase arousal. On the other hand, the James-Lange theory proposes that afferent feedback from muscles and viscera provides the brain with a feeling that characterizes the active motivational state and arousal. On this basis and using selected supporting findings from the literature and from data provided by daily life, it is contended that yawning takes part in interoceptiveness by its capacity to increase arousal and self-awareness. Adaptative behaviors depend on interactions among the nervous system and the body by a continuous feedback between them. The body's schema is a main component of the self, and interoceptive process is essential to awareness of the body and arousal. Yawning contributes to bodily consciousness as a behavior affiliating a sensory motor act and his perception from which pleasure is derived. Yawning can be seen as a proprioceptive performance awareness which inwardly provides a pre-reflective sense of one's body and a reappraisal of the body schema. The behavioral consequences of adopting specific regulatory strategies and the neural systems involved act upon attention and cognitive changes.Thus, it is proposed that yawning is a part of interoceptiveness by its capacity to increase arousal and self-awareness.

Neuroethology application for the study of human temporal lobe epilepsy: from basic to applied sciences

The aim of this investigation was to apply neuroethology to the study of human temporal lobe epilepsy (TLE). For this purpose, 42 seizures in 7 patients recorded during video/EEG monitoring (1997-1998) were analyzed by means of a behavioral glossary containing all behaviors. Video recordings were reobserved, and all patients' behaviors were annotated second-by-second. Data were analyzed using Ethomatic software and displayed as flowcharts including frequency, mean duration, and sequential statistic interaction of behavioral items (chi2 > or = 10.827, P<0.001). Flowcharts of (1) a group of seizures from a single patient, (2) the sum of four seizures per patient of two patients with right and five patients with left TLE, and (3) the comparison of left versus right TLE are shown. Well-established data in the literature were confirmed, such as aura (especially epigastric), contralateral lateralization value of dystonia and version, consciousness and language alterations in ictal and postictal periods, mostly with respect to dominant hemisphere involvement, among others. Less well established data such as awakening seizures in TLE patients, lateralization value of facial wiping (ipsilateral to the focus), statistically significant associations between behavioral pairs (dyads), and new behavioral sequences in TLE were also observed. We suggest that neuroethology also has great potential in the study of human epilepsy semiology. This work had an important role in method standardization for human epilepsy, setting the basis for the development of future clinical studies including correlation with other diagnostic methods (EEG, magnetic resonance, and SPECT). The next step will be the comparative study of seizures of patients with left and right TLE, with a greater number of patients, and the development of a digital video library.

Biting behavior, aggression, and seizures

PURPOSE

To describe the semiologic features of aggressive behaviors observed in human epileptic seizures with particular reference to the act of biting a conspecific.

METHODS

We analyzed the biting behavior (BB) and other aggressive gestures occurring in a group of 11 patients retrospectively selected from >1,000 patients subjected to video-EEG/SEEG monitoring for presurgical evaluation of drug-resistant seizures.

RESULTS

Patients displaying BB showed (a) a male sex predominance, (b) heterogeneous etiologies and lesion locations, and (c) seizures involving the frontotemporal regions of both hemispheres. The act of biting was a rapid motor action, lasting approximately 600 ms, occurring in the context of strong emotional arousal, fear, and anger, with various bodily gestures with aggressive connotation. BB was mainly a "reflexive" behavior, in that biting acts were evoked (both during and after seizures) by actions of people in close contact with the patient. The sole intrusion of the examiner's hand in the space near the patient's face was effective in triggering BB. Rarely, self-directed or object-directed biting acts were not triggered by external stimuli. Intracranial data (SEEG) obtained in one subject showed that the amygdala/hippocampal region plus the orbitomedial prefrontal cortex had to be involved by ictal activity to observe BB.

CONCLUSIONS

Anatomic and electrophysiologic data in our patients suggest that a model of dual--temporal and frontal--dysfunction could account for the occurrence of ictal/postictal BB. Behavioral data suggest also that BB and related aggressive gestures can be considered as the emergence of instinctive behaviors with an adaptative significance of defense of the peripersonal space.