Supplementary Sensorimotor Area Research Articles

Somatosensory Auras in Epilepsy: A Narrative Review of the Literature.

An aura is a subjective experience felt in the initial phase of a seizure. Studying auras is relevant as they can be warning signs for people with epilepsy. The incidence of aura tends to be underestimated due to misdiagnosis or underrecognition by patients unless it progresses to motor features. Also, auras are associated with seizure remission after epilepsy surgery and are an important prognostic factor, guiding the resection site and improving surgical outcomes. Somatosensory auras (SSAs) are characterized by abnormal sensations on one or more body parts that may spread to other parts following a somatotopic pattern. The occurrence of SSAs among individuals with epilepsy can range from 1.42% to 80%. The upper extremities are more commonly affected in SSAs, followed by the lower extremities and the face. The most common type of somatosensory aura is paresthetic, followed by painful and thermal auras. In the primary somatosensory auras, sensations occur more commonly contralaterally, while the secondary somatosensory auras can be ipsilateral or bilateral. Despite the high localizing features of somatosensory areas, cortical stimulation studies have shown overlapping sensations originating in the insula and the supplementary sensorimotor area.

SY6.5. Temporal plus epilepsies

Temporal plus epilepsies are characterized by the epileptogenic foci outside the temporal lobe and a mix of temporal and extratemporal features. They have a wide spectrum of semiological presentation depending on the extent of network. They can arise from frontal, parietal, occipital lobes along with temporal lobe networks. We discuss in this review the semiology of different types. Lateralizing and localizing features are mentioned in the table below the review is not exhaustive and it is recommended to read large descriptive semiology’s in journals. Temporal plus epilepsies will have red flags for temporal lobe in that there will be extratemporal auras or signs. These would suggest wider networks more than temporal. So if a typical temporal lobe seizure has amnesia, arrest, lack of awareness, aphasia, etc. Presence of a visual aura would favor a temporal plus network. CL = Contralateral, IL = ipsilateral, NonLAT = Nonlateralizing, FLE = Frontal lobe epilepsy, PLE = Parietal lobe epilepsy, OLE = Occipital lobe epilepsy, SSMA = Supplementary sensorimotor area, IPSI = Ipsilateral.

Bilateral asymmetric tonic seizure in insulo-opercular epilepsy: an anatomo-electro-clinical study

BackgroundInsulo-opercular seizures are highly heterogeneous in seizure semiology and electrical features. Bilateral asymmetric limb posturing, as a classical pattern of supplementary sensorimotor area (SMA) seizure, also occurs in insulo-opercular epilepsy. This study was aimed to study the anatomo-electro-clinical correlations in bilateral asymmetric tonic seizures (BATS), in order to advance the understanding of insulo-opercular epilepsy.MethodsEight patients with insulo-opercular epilepsy as confirmed by stereoelectroencephalography (SEEG) and manifesting BATS as the major ictal motor sign, in Guangdong Sanjiu Brain Hospital Epilepsy Center from 2014 to 2018, were employed in this study. The BATS of the patients were evaluated, and the semiologic features and concomitant intracerebral EEG changes were quantified. Then the variables were examined with Cluster Analysis, and the semiologic features were correlated with anatomic localization using the Kendall correlation test.ResultsOf the 8 patients, the most frequent initial motor sign was bilateral asymmetric tonic posturing (62.5%). Facial tonic-clonic sign also had a high prevalence in the evolution of seizures (87.5%). The results of Cluster Analysis showed that the semiologic features were subdivided into two main groups, one group comprising exclusively BATS and the other including signs of focal tonic seizure, aura, focal limb tonic-clonic seizure (TCS), facial TCS, hypermotor behavior, eye movement, autonomic changes and generalized TCS. The BATS was strongly associated with the posterior long gyrus (PLG) of insula (t = 0.732) and parietal operculum (t = 1.000); the hypermotor behaviors were associated with the anterior long gyrus (ALG) (t = 0.770); and the autonomic changes were associated with the anterior limiting sulcus (ALS) (t = 0.734) and middle short gyrus (MSG) (t = 0.700).ConclusionsThe seizure semiology of insulo-opercular epilepsy is characterized, in temporal order, by BATS, with or without simultaneous hypermotor behaviors, and frequently ends up with facial tonic-clonic signs, which is different from that of the SMA seizure. The early spread network involving the posterior insular lobe and parietal operculum may contribute to this pattern of manifestation.

Ictal Source Locations and Cortico-Thalamic Connectivity in Childhood Absence Epilepsy: Associations with Treatment Response.

Childhood absence epilepsy (CAE), the most common pediatric epilepsy syndrome, is usually treated with valproic acid (VPA) and lamotrigine (LTG) in China. This study aimed to investigate the ictal source locations and functional connectivity (FC) networks between the cortices and thalamus that are related to treatment response. Magnetoencephalography (MEG) data from 25 patients with CAE were recorded at 300Hz and analyzed in 1-30Hz frequency bands. Neuromagnetic sources were volumetrically scanned with accumulated source imaging. The FC networks between the cortices and thalamus were evaluated at the source level through a connectivity analysis. Treatment outcome was assessed after 36-66months following MEG recording. The children with CAE were divided into LTG responder, LTG non-responder, VPA responder and VPA non-responder groups. The ictal source locations and cortico-thalamic FC networks were compared to the treatment response. The ictal source locations in the post-dorsal medial frontal cortex (post-DMFC, including the medial primary motor cortex and the supplementary sensorimotor area) were observed in all LTG non-responders but in all LTG responders. At 1-7Hz, patients with fronto-thalamo-parietal/occipital (F-T-P/O) networks were older than those with fronto-thalamic (F-T) networks or other cortico-thalamic networks (p = 0.000). The duration of seizures in patients with F-T-P/O networks at 1-7Hz was longer than that in patients with F-T networks or other cortico-thalamic networks (p = 0.001). The ictal post-DMFC source localizations suggest that children with CAE might experience initial LTG monotherapy failure. Moreover, the cortico-thalamo-cortical network is associated with age. Finally, the cortico-thalamo-cortical network consists of anterior and posterior cortices and might contribute to the maintenance of discharges.

A Guide for Cortical Electrical Stimulation Mapping.

Electrical stimulation mapping (ESM) of the brain remains a major procedure for guiding epilepsy and tumor surgeries. This article collates available experiences and data in ESM to develop a guide for conducting the procedure. There are many factors that influence the yield of ESM. The stimulation parameters offered in this article need to be adjusted within safe limits to address the factors. Each ESM procedure should be tailored to the patient's age and baseline mental or psychological capacity. Stimulation-induced seizures and EEG afterdischarges disrupt ESM procedure and render the interpretation of the results difficult. There are specific measures that can lessen the risk of seizures and afterdischarges during ESM. Electrical stimulation mapping procedure requires several tasks on the part of those conducting the procedure, such as operating the stimulator and the EEG recording equipment, administering behavioral or language tests and observing both patient and EEG responses to the stimulation. A team of experienced staff is necessary for individual assumption of each task. Knowledge of the spatial relationship between electrode contacts and underlying normal or abnormal brain structures is essential for interpreting ESM results. When testing for motor or sensory response, be aware of the distinction between responses at the primary motor area and responses at the supplementary sensorimotor area. The anatomy of supplementary sensorimotor area is more variable and functional than it is fixed and structural, although its general confines and somatotopic organization are known. In addition, negative motor responses to stimulation must be recognized to avoid misinterpretation of ESM results, especially in language mapping.

Electroclinical semiology of the bilateral asymmetric tonic seizures observed in patients with supplementary sensorimotor area epilepsy confirmed by pre- and post-operative MRI.

To retrospectively reappraise characteristics of the electro-clinical seizure semiology of the bilateral asymmetric tonic seizure (BATS) in the patients with supplementary sensorimotor area (SSMA) epilepsy. From the retrospective analysis of the pre- and post-operative Magnetic Resonance Imaging (MRI) data involving 386 patients who received epilepsy surgery, 123 BATS were identified meeting the clinical criteria and included in the study. For comparison in four extremities involvement, limbs were paired and comparatively evaluated between the contralateral and ipsilateral sides, proximal and distal segments, and upper and lower limbs. For evaluation of sequential events, each tonic phase of the BATS was chronologically divided into 10 equal epochs. In each epoch, distribution of tonic events in 4 extremities and axes was visually evaluated and comparatively analyzed. Asymmetric tonic posturing was the most constant findings in 6 patients, whose upper limbs contralateral to epileptogenic cortex were kept in abduction in all 123 (100%) seizures and extension in 118 (95.9%) seizures. This type of asymmetry became visible and remained stable in the initial three epochs of the tonic phase in 107 out of 123 (87.0%) seizures. In each epoch, especially the initial one, the contralateral upper limbs were involved more frequently than those ipsilateral to the epileptogenic cortex (p < 0.05). By pairwise comparison, an earlier involvement of the contralateral side to epileptogenic cortex was visually observed in 53 out of 280 (18.9%) limb pairs, in which the ipsilateral limbs were preceded by the contralateral ones 4.6 (0.1-16.0) seconds earlier. Both of the proximal and distal segments were simultaneously involved in 260 out of 298 (87.2%) limb pairs, although the former were 4.3 (0.5-16.0) earlier than the latter in 34 out of 298 (11.4%) limb pairs. This study demonstrated that by studying the restricted epileptogenic lesion limited to pure SSMA, unilateral extension and abduction posturing in upper limb were the most prominent and valuable sign for the lesion lateralization in SSMA neurosurgery decision-making.

Epileptic Angina

PurposeTo investigate the probable ictal origin of unexplained episodic chest pain and if possible to lateralize and localize the epileptic focus.MethodsA 14 year old boy presented with episodic short lasting localized chest pain. His cardiac and other systemic work-up were normal. MRI brain did not reveal any structural pathology. Video telemetry was done for characterization of the paroxysms.ResultsInterictal record showed left fronto-central epileptiform discharges. A left hemispheric, predominantly centroparietal ictal rhythm was identified. The possible localizations of this unusual semiology are somatosensory areas I and II, supplementary sensorimotor area, posterior insula and cingulate cortex. Patient responded remarkably to antiseizure drugs.ConclusionPain is a rare manifestation of epilepsy observed in less than 1% of patients. When present, it is usually accompanied by other focal features. This rare occurrence of epileptic seizures masquerading as angina is a novel observation.

Seizures with tonic posturing: Semiologic difference between supplementary sensorimotor area (SSMA) origin and extra-SSMA origin.

In seizures with tonic posturing, differentiation of seizures originating in SSMA from seizures originating in cortices other than SSMA and spreading to SSMA has not been previously attempted. Twenty-two patients were studied with intractable focal epilepsy with tonic limb posturing as the most prominent semiology, who underwent resective surgery and obtained favorable postoperative seizure outcomes. These 22 patients were divided into an SSMA group (N = 12) and an extra-SSMA group (N = 10), according to the location of resection. Resection area in the extra-SSMA group was located in the dorsolateral frontal or prefrontal area in four patients, the frontal operculum (insula) in two, the parietal cortex in three, and the temporoparietal cortex in one patient. Video-recorded seizures were carefully reviewed. Tonic posturing characteristics and the presence or absence of accompanying symptoms were compared between groups. Incidence of preservation of consciousness was significantly higher in the SSMA group (p < 0.001). Patients in the SSMA group demonstrated a propensity for having unilateral or bilateral asymmetrical tonic limb posturing. In contrast, patients in the extra-SSMA group had a statistically significantly higher incidence of bilateral symmetrical tonic limb posturing (p < 0.05). These findings may be helpful in identifying seizure origin.

Seizure-free after surgery in a patient with non-lesional startle epilepsy: A case report

We present the case of a patient with startle epilepsy provoked by auditory, somatosensory and visual stimuli during video-electrocorticography (ECoG) recording. Ictal ECoG of all types of seizures triggered by the three kinds of stimuli showed that seizure onset originated from the left supplementary sensorimotor area (SSMA). The patient has been seizure‐free after the cortex around the left SSMA only had been resected. Therefore, we speculate that left SSMA is the epileptogenic zone of startle epilepsy in this patient and perhaps the primary cortex to modulate the startle reflex in healthy persons.

Mesial Frontal Lobe Epilepsy

Mesial frontal lobe epilepsies can be divided into epilepsies arising from the anterior cingulate gyrus and those of the supplementary sensorimotor area. They provide diagnostic challenges because they often lack lateralizing or localizing features on clinical semiology and interictal and ictal scalp electroencephalographic (EEG) recordings. A number of unique semiologic features have been described over the last decade in patients with mesial frontal lobe epilepsy (FLE). There are few reports of applying advanced neurophysiologic techniques such as electrical source imaging, magnetoencephalography, EEG/functional magnetic resonance imaging, or analysis of high-frequency oscillations in patients with mesial FLE. Despite these diagnostic challenges, it seems that patients with mesial FLE benefit from epilepsy surgery to the same extent or even better than patients with FLE do, as a whole.

Accumbens functional connectivity during reward mediates sensation-seeking and alcohol use in high-risk youth

Background: Differences in fronto-striatal connectivity in problem substance users have suggested reduced influence of cognitive regions on reward-salience regions. Youth with a family history of alcoholism (FH+) have disrupted ventral striatal processing compared with controls with no familial risk (FH−). As sensation-seeking represents an additional vulnerability factor, we hypothesized that functional connectivity during reward anticipation would differ by family history, and would mediate the relationship between sensation-seeking and drinking in high-risk subjects. Methods: Seventy 18–22 year olds (49 FH+/21 FH−) performed a monetary incentive delay task during functional magnetic resonance imaging. Group connectivity differences for incentive (reward/loss) vs. neutral conditions were evaluated with psychophysiological interaction (PPI) analysis, seeded in nucleus accumbens (NAcc). Indirect effects of sensation-seeking on drinking volume through accumbens connectivity were tested. Results: NAcc connectivity with paracentral lobule/precuneus and sensorimotor areas was decreased for FH− vs. increased for FH+ during incentive anticipation. In FH+, task-related functional coupling between left NAcc and supplementary sensorimotor area (SSMA) and right precuneus correlated positively with sensation-seeking and drinking volume and mediated their relationship. In FH−, left NAcc–SSMA connectivity correlated negatively with sensation-seeking but was not related to drinking. Conclusions: These results suggest preexisting differences in accumbens reward-related functional connectivity in high-risk subjects. NAcc coupling with SSMA, involved in attention and motor networks, and precuneus, a default mode structure, appear to mediate sensation-seeking's effect on drinking in those most at-risk. Differences in accumbens connectivity with attention/motor/default networks, rather than control systems, may influence the reward system's role in vulnerability for substance abuse.

Startle epilepsy: clinical characteristics, EEG pattern and surgical treatment

Objective To study the clinical,scalp and intracranial electroencephalogram (EEG) characteristics of startle epilepsy,and its outcome of surgical treatment.Methods The clinical data of 9 patients with startle epilepsy who were treated in our hospital were reviewed retrospectively.Their scalp and intracranial EEG,and MRI were investigated.Results All of the patients were diagnosed as startle epilepsy,and most of seizures were provoked by sudden unexpected stimuli.MRI showed extensive lesions in 8 cases,scalp EEG showed mulifocality or focal epilepsic discharge in all.Intracranial electrodes monitoring were performed in 2 patients to locate the epileptogenic zone.Five patients were treated surgically,3 of them were operated with hemispherectomy,and 2 with focal cortex resection.During 6 -30 months follow up,the seizure outcome were Engel Ⅰ grade in 4,and Engel Ⅲ grade in 1.Conclusions Most of the patients with startle epilepsy has brain lesions involving the perisensorimotor or supplementary sensorimotor area,and were refractory.Resective surgery may get satisfactory outcome. Key words: Startle epilepsy ; Surgical procedures,operative ; Sensorimotor area ;

Frontal Lobe Seizures

Frontal lobe epilepsy is the second most common localization-related or focal epilepsy. Frontal lobe seizures are challenging to diagnose as the clinical manifestations are diverse due to the complexity and variability of the patterns of epileptic discharges, and the scalp electroencephalograph (EEG) can often be normal or misleading. This review focuses on the clinical and EEG features of seizures arising from the frontal lobe. The clinical manifestations in patients with frontal lobe epilepsy are varied. Frontal lobe seizures can be divided into perirolandic, supplementary sensorimotor area, dorsolateral, orbitofrontal, anterior frontopolar, opercular, and cingulate types. Seizures originating from the perirolandic and supplementary sensorimotor areas are clinically distinct, characterized by motor activity or asymmetric tonic posturing with preserved awareness. Seizures arising from dorsolateral, orbitofrontal, frontopolar, and cingulate areas are not as well characterized and have more variable clinical manifestations. Scalp EEG recording is sometimes helpful in localization but is usually normal or misleading in frontal lobe epilepsy. The treatment is similar to other localization-related or focal epilepsies. Medications are the first line of therapy, and surgery is considered for patients who fail to respond to medications. The surgical outcome in frontal lobe resections is less favorable than in anterior temporal lobectomies due to the challenge in locating the epileptogenic zone and the presence of functional areas (eloquent cortex) that can limit the resection. Frontal lobe seizures are characterized by diverse behavioral manifestations. Only a few well-described frontal lobe syndromes exist. The variety of clinical manifestations reflects both the varying sites of seizure origin and propagation routes that seizures may take. Although this review provides a framework for the understanding of these seizures, one should remain cautious in diagnosing seizure localization based on clinical or EEG description. Only a few patients have well-described syndromes and can be diagnosed with confidence. For most patients, new diagnostic methods and genetic testing may help improve our ability to diagnose and treat the conditions discussed in this study.

Brain activation patterns of versive, hypermotor, and bilateral asymmetric tonic seizures

Patients who have seizure onset from different brain regions can produce seizures that appear clinically indistinguishable from one another. These clinically stereotypic manifestations reflect epileptic activation of specific networks. Several studies have shown that ictal perfusion single photon emission computed tomography (SPECT) can reveal propagated ictal activity. We hypothesize that the pattern of hyperperfusion may reflect neuronal networks that generated specific ictal symptomatology. All patients were identified who were injected with (99m)Tc-hexamethyl-propylene-amine-oxime (HMPAO) during versive seizures (n = 5), bilateral asymmetric tonic seizures (BATS; n = 5), and hypermotor seizures (n = 7) in the presurgical epilepsy evaluation between 2001 and 2005. The SPECT ictal–interictal difference image pairs of each subgroup were compared with image pairs of 14 controls using statistical parametric mapping (SPM 2) to identify regions of significant hyperperfusion. Hyperperfused regions with corrected cluster-level significance p < 0.05 were considered significant. We have identified a distinct ictal perfusion pattern in each subgroup. In versive seizure subgroup, prominent hyperperfusion was present in the frontal eye field opposite to the direction of head version. In addition, there was associated caudate and crossed cerebellar hyperperfusion. The BATS subgroup showed pronounced hyperperfusion supplementary sensorimotor area ipsilateral to the epileptogenic region, bilateral basal ganglia, and contralateral cerebellar hemisphere. The hypermotor seizure subgroup demonstrated two clusters of significant hyperperfusion: one involving bilateral frontomesial regions, cingulate gyri, and caudate nuclei, and another involving ipsilateral anteromesial temporal structures, frontoorbital region, insula, and basal ganglia. We have identified distinct hyperperfusion patterns for specific ictal symptomatology. Our findings provide further insight into understanding the anatomic basis of seizure semiology.

Cortical silent period following TMS in a patient with supplementary sensorimotor area seizures

The cortical silent period (CSP) following transcranial magnetic stimulation (TMS) was evaluated in a patient with a dysembrioplastic neuroepithelial tumor (DNET) in the lateral portion of the right superior frontal gyrus (SFG) who suffered from supplementary sensorimotor area (SSMA) seizures. CSP duration was shortened on the affected side. Ipsilateral alterations of motor cortex excitability with TMS in epileptogenic DNET located outside the PMA argue in favour of cortico-cortical connections to primary motor cortex from SSMA. This functional connectivity should be taken into consideration to better understand the pathophysiology of ictal motor manifestations.

Successful epilepsy surgery with a resection contralateral to a suspected epileptogenic lesion

We report on a case of frontal lobe epilepsy in an eight-year-old girl. Seizure semiology and EEG indicated an epileptogenic zone localized in the mesial frontal structures, without clear-cut lateralization. MRI showed a lesion in the right cingulate gyrus, initially regarded as a hamartoma. Ictal SPECT did not have a localization value. MR spectroscopy revealed two metabolic abnormalities: one in the area of the MRI lesion and a second contra-laterally. Invasive monitoring using subdural electrodes covering the convexity and mesial part of the right frontal lobe including mesial strips with bilateral contacts was used. The invasive monitoring failed to localize ictal onset in the right hemisphere; however, electric stimulation induced seizures from electrodes facing the left supplementary sensorimotor area ("through" the falx cerebri). We re-implanted the electrodes over the left frontal lobe and the second invasive monitoring clearly localized the ictal onset zone in the left supplementary sensorimotor area, which was subsequently resected. Histopathology found MRI-negative focal cortical dysplasia. The contralateral lesion was reassessed as nonspecific enlargement of perivascular spaces. The patient has been seizure-free for more than two years.[Published with video sequences].

Monday July 3, 2006 15:00-17:00 Hall 5B Discussion Group Session From functional brain anatomy to clinical seizure semiology

Abstract 1 C. Baumgartner ( 1 Department of Neurology, Medical University of Vienna, Austria ) Motor manifestations during epileptic seizures include focal clonic motor seizures, seizures with asymmetrical tonic posturing and seizures with hypermotor automatisms. Focal clonic motor seizures are generated by epileptic activity in the primary motor cortex and consist of unilateral, jerky, usually rhythmic movements, frequently also tonic components like tonic postural signs and tonic face contractions can be observed. Most frequently they start in the face or hand due to their large representation in primary motor cortex and due to a lower seizure threshold of these cortical regions. Asymmetric tonic seizures or supplementary motor area (SMA) seizures are mediated by epileptic activity in the supplementary sensorimotor area or the premotor cortex, but can also be generated by epileptic activity in other frontal lobe regions. Because frequently somatosensory auras like feelings of pulling, pulsing, heaviness, numbness or tingling which can occur ipsi-, contra- or bilaterally occur the term “supplementary sensorimotor seizures” has been introduced. Asymmetric tonic seizures are characterized by bilateral, asymmetric, tonic or dystonic posturing of the extremities and facial grimacing resulting in tonic posturing. Vocalizations frequently occurring during asymmetrical tonic seizures can be a reactive phenomenon, can be caused by a tonic contraction of the diaphragm and laryngeal muscles and finally can be a consequence of an activation of Broca's area or SMA. While hyperkinetic or ‘hypermotor’ automatisms are not associated with a seizure onset in any specific region within the frontal lobes. They are characterized by prominent and complex, coordinated, purposeless or semipurposefull movements (trembling, waving, rotating, stepping, cycling, rocking, hopping etc.) with an agitated or frenetic appearance. Vocalizations often are explosive and pronounced which seems to be unique for frontal lobe seizures with hypermotor automatisms. Seizures with hypermotor automatisms usually are associated with a loss of consciousness and therefore also are referred to as frontal lobe complex partial seizures.

Laughter and the mesial and lateral premotor cortex

We report the induction of laughter and smiling by cortical electrical stimulation of the frontal lobe of two patients: an 18-month-old boy with a left frontal cortical lesion extending to the vertex and the central gyrus, and a 35-year-old woman with a lesion in the right supplementary sensorimotor area (SSMA). The subjects underwent presurgical epilepsy evaluation with subdural grid electrodes to determine surgical candidacy. Stimulation of the prefrontal area reproducibly induced laughter. The adult patient reported absence of emotional content. Slowing of speech occurred under stimulation of electrodes in the upper and posterior vicinity. In this patient laughter was elicited in the anterior part of the SSMA. In the child, this response was induced by stimulation of the lateral prefrontal cortex near the midline. We conclude that the anterior portion of the SSMA/lateral premotor cortex is involved in generating the motor pattern of laughter.

The predictive localizing value of tonic limb posturing in supplementary sensorimotor seizures.

To determine whether early tonic limb posturing is reliable in lateralizing or localizing of the seizure generator in 14 patients with pharmacoresistent supplementary sensorimotor area (SSMA) seizures. All patients underwent high-quality MRI scans and stereo-EEG recordings. The SSMA seizure semiology predicted focal or regional ictal onset in the SSMA in six (43%) patients: Three had a focal SSMA seizure onset, and three had a regional seizure onset with involvement of one SSMA plus adjacent neocortex. The eight remaining patients had diffuse uni- or bilateral seizure onset. Eight of 14 patients underwent a frontal or central cortical resection, but a good outcome was seen in only 3: 2 with no SSMA resection and 1 with an extensive central removal. SSMA semiology is suggestive of early involvement of this region but is by no means a reliable indicator that the primary SSMA contains the seizure focus.

Tonic Limb Posturing Does Not Aid Seizure-Onset Localization

Clinical semiology of seizure onset has been used to help guide epilepsy surgery. Penfield and colleagues first described the fencing posture as indicative of contralateral involvement of the supplementary sensorimotor area (SSMA; Arch Neurol Psychiatry 1951; 66:289). However, surgical outcomes in patients with frontal lobe epilepsy have been poor (Williamson P et al. Surgically remediable extratemporal syndromes. In: Engel J Jr. Surgical Treatment of the Epilepsies , …