Localizing and lateralizing value of behavioral change in childhood partial seizures

OBJECTIVE: To describe clinical characteristics as well as localizing and lateralizing value of behavioral change (BC) at the onset of childhood seizures. METHODS: Five hundred forty-one videotaped seizures of 109 consecutive patients < or = 12 years with partial epilepsy and postoperatively seizure-free outcome were analyzed. Behavioral change (the first clinical feature of a certain seizure with a sudden change in the child's behavior) was evaluated by two independent investigators. RESULTS: Thirty-three (30%) patients showed BC at least once during their seizures. Behavioral changes appeared in arrestive form in 19 and with affective activities in 18 children; four patients produced both kinds of BCs, separately. Arrest-type BC happened in 16 of 50 children with right- and 3 of 59 patients with left-sided seizure onset zone (p < 0.001). Affective-type BC was observed in 17 of 67 temporal lobe epilepsy patients while it happened in only 1 of 42 children with extratemporal lobe epilepsy (p = 0.001). CONCLUSIONS: Arrest-type BC lateralizes to the right hemisphere, while affective-type BC localizes to the temporal lobe in childhood partial seizures. Type of BCs can add important information to the presurgical evaluation of young children with refractory partial epilepsy.     

Localizing and lateralizing value of epileptic symptoms in temporal lobe epilepsy

The symptoms and signs associated with all stages of a temporal lobe seizure may be helpful in determining both the localization and lateralization of seizure onset. Auras, when present, may be very suggestive of temporal lobe onset and may further localize to a mesiobasal or lateral temporal lobe site of onset. During the ictus, automatisms and motor phenomena may be highly indicative of temporal lobe seizure activity and may even help lateralize the discharge. In the post-ictal period, motor paresis and aphasia are helpful in lateralization. Video E.E.G. data has provided extensive information on the utility of ictal symptomatology in seizure localization. Thus, the seizure semiology provides important adjunctive information in evaluating patients for epilepsy surgery and should be concordant with information obtained from ictal EEG, neuroimaging and neuropsychology.     

Localizing and lateralizing features of auras and seizures

The symptomatology of auras and seizures is a reflection of activation of specific parts of the brain by the ictal discharge, the location and extent of which represent the symptomatogenic zone. The symptomatogenic zone is presumably, though not necessarily, in close proximity to the epileptogenic zone, the area responsible for seizure generation, the complete removal or disconnection of which is necessary for seizure freedom. Knowledge about the symptomatogenic zone in focal epilepsy is acquired through careful video/EEG monitoring and behavioral correlation of seizures and electrical stimulation studies. Ictal symptomatogy provides important lateralizing and/or localizing information in the presurgical assessment of epilepsy surgery candidates. As the initial symptoms of epileptic seizures, many types of auras have highly significant localizing or lateralizing value. Similarly, motor signs during focal and secondary generalized seizures, language manifestations, and autonomic features offer reliable clues to the delineation of the epileptogenic zone. Some focal epilepsies (e.g., neocortical temporal lobe epilepsy, insular lobe epilepsy, temporal-plus epilepsies, and parieto-occipital lobe epilepsy) generate seizure manifestations that mimic temporal lobe epilepsy, potentially contributing to surgical failure. To optimize surgical outcome, careful interpretation of ictal symptomatology in conjunction with other components of the presurgical evaluation is required.     

The localizing and lateralizing value of ictal/postictal coughing in patients with focal epilepsies.

Postictal coughing has so far been reported to indicate a temporal origin of focal epilepsy. A trend towards non-dominant hemisphere lateralization and mesial temporal localization has been suggested. However, postictal coughing has also been reported in a few patients with extratemporal epilepsies. We have retrospectively evaluated the localizing and lateralizing value of ictal/postictal coughing in 197 patients with temporal and extratemporal epilepsy who received presurgical video-EEG long-term recordings from 1999 to 2001. There was no statistical significant difference in percentage of coughing patients in both groups. However, only patients belonging to the temporal group presented with coughing as a regular element of seizure semiology (simple partial and complex partial seizures) whereas in the extratemporal group coughing occurred more sporadically. Within the temporal group a statistically significant tendency to left-sided seizure onset and a statistically not significant preponderance of mesial seizure onset was observed. Additional vegetative signs were observed only in about half of the patients. These results suggest that coughing occurs in both temporal and extratemporal lobe epilepsy and may only be indicative of temporal lobe seizure onset if representing a regular semiologic element. Coughing may be due to two different mechanisms, one dependent and the other independent from additional vegetative symptoms.     

Prognostic value of the consistency of lateralizing ictal features and ictal EEG in patients undergoing temporal lobectomy for refractory complex partial seizures.

PURPOSE: Ictal and postictal clinical manifestations have lateralizing value in the presurgical evaluation of intractable seizures. The consistency and frequency of these signs during seizures and the associated implications for postoperative seizure outcome are unknown. METHODS: The videotaped complex partial seizures of 49 patients with known postoperative outcomes greater than 2 years after temporal lobectomy were blindly reviewed for: (1) unilateral hand posturing (UHP), (2) unilateral hand automatism (UHA), (3) forced and nonforced head turning (HT), and (4) postictal dysphasia (PID). The presence and laterality of each assessable sign were recorded. Data were analyzed as follows: (1) the prevalence of each sign in patients with Engel class 1 and Engel class 2-4, and (2) the postsurgical outcome when the sign was present in more than or less than 50% of the seizures for each patient. We reviewed patients' presurgical work-up, specifically ictal EEG and MRI. RESULTS: The prevalence of UHP, UHA, HT, and PID was similar for Engel class 1 and Engel class 2-4 patients. Engel class 1 outcome when UHP, UHA, HT, and PID were present for greater than 50% of seizures was no different compared to when these signs were present for less than 50% of seizures. Patients who had concordant ictal EEG and MRI abnormalities had the best postsurgical outcome. CONCLUSIONS: The consistency and frequency of ictal manifestations in the presurgical evaluation of complex partial seizures does not predict seizure outcome. The presence of any specific lateralizing sign need not be present in every complex partial seizure for the sign to hold predictive value. Concordant ictal EEG and MRI abnormalities are still the best predictors of outcome.     

癫痫患者先兆症状的临床定位意义

目的 探讨癫痫患者先兆症状的临床定位意义。方法 31例癫痫患者按照有无先兆分为有先兆组(n=19)和无先兆组（n=12）,采用独立样本t检验比较两组之间的发病年龄差异有无统计学意义。采用x2检验比较两组之间患者的头颅MRI的异常率及手术有效率差异有无统计学意义。结果 有先兆组的19例患者,分别为精神症状、自主神经症状、躯体感觉、视觉、听觉、头晕共6种先兆,术后先兆症状均消失,以上6种先兆可分别定位于颞叶、颞叶、对侧顶叶或颞叶、枕叶或颞叶、对侧颞叶、颞顶叶。两组间患者的首次发病年龄差异、头颅MRI的异常率差异均无统计学意义。有先兆组和无先兆组患者的手术有效率（分别为15/19和5/12）差异有统计学意义(x2=4.456,P=0.035)。结论 先兆具有一定的定位意义,可以协助判断致痫灶的起源部位,指导外科手术治疗。     

Ictal "hemiballic-like" movement: lateralizing and localizing value

We aimed at determining the lateralizing and localizing values of "hemiballic-like" ictal movements observed in some partial seizures. Among 20 patients disclosing ictal hyperkinetic features and explored by stereotactic-EEG (SEEG), this sign was observed in four patients. In these cases, hemiballic movement was ipsilateral to the ictal-onset zone and was associated with contralateral ictal dystonia. Noninvasive and subsequent invasive recording revealed seizure origin in the inferior parietal lobule or the parietal operculum in three patients and in the inferior prefrontal cortex in one.     

Semiologic value of ictal autoscopy

PURPOSE: Autoscopy is a pathologic perception of one's body or one's face image within space, either from an internal ("as in a mirror") or from an external ("out-of-body experience") point of view. Among various psychiatric and neurologic disorders, partial epilepsy is the main etiology. However, the significance of this rare ictal symptom remains controversial. We report this phenomenon in three epilepsy patients and discuss its semiologic value and neuropsychological significance. METHODS: Interictal EEG and/or video-EEG monitoring was performed, as well as neuropsychological examination and cerebral magnetic resonance imaging (MRI). RESULTS: The three patients had a lesion involving, or limited to, the right parietal region on cerebral MRI. All three patients experienced autoscopy associated with other ictal signs supporting a right parietal lobe origin of seizures. In one patient, seizure origin was documented with video and surface EEG ictal recordings. CONCLUSIONS: Autoscopy was shown to have an ictal mechanism and was associated with seizures arising from the nondominant parietal region. We hypothesize that ictal autoscopy may result from disruption of the normal integration of body representation.     

The lateralizing and localizing value of adversion in epileptic seizures

We studied 24 patients who had adversion as the first clinical manifestation of seizures. Seizures were recorded with depth electrodes as part of the evaluation for possible surgery for epilepsy. Head rotation did not help to lateralize the epileptic focus clinically, because deviations occurred ipsilaterally to the EEG focus in some patients, and because some patients had head rotation in either direction despite a unifocal epileptogenic abnormality. Furthermore, no cortical localization was consistently linked to either direction or degree of adversion. Adversion has no consistent lateralizing or localizing value.     

Localising and lateralising value of ictal piloerection

BACKGROUND: Piloerection is a rare clinical symptom described during seizures. Previous reports suggested that the temporal lobe is the ictal onset zone in many of these cases. One case series concluded that there is a predominant left hemispheric representation of ictal cold. The aim of this study is to evaluate the localising and lateralising value of pilomotor seizures. METHODS: Medical records of patients who underwent video electroencephalogram (EEG) monitoring at the Cleveland Clinic between 1994 and 2001 were reviewed for the presence of ictal piloerection. The clinical history, physical and neurological examination, video EEG data, neuroimaging data, cortical stimulation results, and postoperative follow ups were reviewed and used to define the epileptogenic zone. Additionally, all previously reported cases of ictal piloerection were reviewed. RESULTS: Fourteen patients with ictal piloerection were identified (0.4%). Twelve out of 14 patients had temporal lobe epilepsy. In seven patients (50%), the ictal onset was located in the left hemisphere. Four out of five patients with unilateral ictal piloerection had ipsilateral temporal lobe epilepsy as compared with the ipsilateral side of pilomotor response. Three patients became seizure free after left temporal lobectomy for at least 12 months of follow up. An ipsilateral left leg pilomotor response with simultaneously recorded after-discharges was elicited in one patient during direct cortical stimulation of the left parahippocampal gyrus. CONCLUSIONS: Ictal piloerection is a rare ictal manifestation that occurs predominantly in patients with temporal lobe epilepsy. Unilateral piloerection is most frequently associated with ipsilateral focal epilepsy. No hemispheric predominance was found in patients with bilateral ictal piloerection.     

SCOPE-mTL: A non-invasive tool for identifying and lateralizing mesial temporal lobe seizures prior to scalp EEG ictal onset

Objective

In mesial temporal lobe (mTL) epilepsy, seizure onset can precede the appearance of a scalp EEG ictal pattern by many seconds. The ability to identify this early, occult mTL seizure activity could improve lateralization and localization of mTL seizures on scalp EEG.

Versive seizures in occipital lobe epilepsy: lateralizing value and pathophysiology

To clarify the value of versive seizures in lateralizing and localizing the epileptogenic zone in patients with occipital lobe epilepsy, we studied 13 occipital lobe epilepsy patients with at least one versive seizure recorded during preoperative noninvasive video-EEG monitoring, who underwent occipital lobe resection, and were followed postoperatively for more than 2 years with Engel's class I outcome. The videotaped versive seizures were analyzed to compare the direction of version and the side of surgical resection in each patient. Moreover, we examined other motor symptoms (partial somatomotor manifestations such as tonic and/or clonic movements of face and/or limbs, automatisms, and eyelid blinking) associated with version. Forty-nine versive seizures were analyzed. The direction of version was always contralateral to the side of resection except in one patient. Among accompanying motor symptoms, partial somatomotor manifestations were observed in only five patients. In conclusion, versive seizure is a reliable lateralizing sign indicating contralateral epileptogenic zone in occipital lobe epilepsy. Since versive seizures were accompanied by partial somatomotor manifestations in less than half of the patients, it is suggested that the mechanism of version in occipital lobe epilepsy is different from that in frontal lobe epilepsy.     

Peri-ictal bed leaving in temporal lobe epilepsy: incidence and lateralizing value

We analyzed peri-ictal bed leaving (PBL) symptoms in 105 patients with temporal lobe epilepsy (TLE). All patients were classified as Engel I at the 2-year follow-up visit. Histopathological examination revealed hippocampal sclerosis (TLE-HS) in 64 patients and other lesions in 38 patients (TLE-other); 3 patients had no lesions. We reviewed 412 seizures. PBL was defined as lateralized leaving of the bed occurring during the seizure or up to 3 minutes after the end of the seizure. PBL was observed in 28 of 105 patients (26.7%), and in 45 of 412 seizures (10.9%). PBL occurred more frequently in patients with TLE-HS than in patients with TLE-other (32.8% vs 17.1%, P=0.058). PBL was ipsilateral to the seizure onset in 71.4% of patients and 71.2% of seizures (P=0.012 and P<0.001). In patients with TLE-HS, PBL was ipsilateral to seizure onset in 76.2% of patients and 81.2% of seizures (P=0.008 and P<0.001). In patients with TLE-other, PBL was ipsilateral to seizure onset in 42.8% of patients and 46.1% of seizures. There were no differences in the incidence and lateralizing value between patients with right-sided and those with left-sided TLE. PBL is a relatively frequent peri-ictal sign in patients with TLE. The side of PBL in patients with TLE-HS lateralizes the seizure onset to the ipsilateral temporal lobe.     

Localizing value of torsional nystagmus in small midbrain lesions

BACKGROUND: The topodiagnostic value and specificity of nystagmus in patients with mesencephalic lesions and its relation to tonic torsional deficits and vertical saccade deficits is controversial and anecdotal. METHODS: The authors examined 11 patients with vascular MRI-identified mesencephalic lesions and clinical evidence of vertical-torsional nystagmus on gaze straight ahead, focusing on the three-dimensional nystagmus components recorded with the three-dimensional search coil technique. RESULTS: Combined lesions of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the interstitial nucleus of Cajal (iC) are much more frequent than riMLF and, in particular, iC lesions alone. Eight patients showed contralesional torsional nystagmus with a conjugate vertical component on gaze straight ahead and had anatomic (MRI) and clinical evidence (slowing of vertical saccades) for riMLF involvement. Tonic ocular torsion and the subjective visual vertical were shifted to the contralesional side (n = 7). Torsional nystagmus to the ipsilesional side was uncommon (n = 3) and found in patients with midbrain lesions involving the iC, all of whom also had decreased time constants of the slow phases of gaze-evoked nystagmus. CONCLUSIONS: Contrary to previous proposals, contralesional torsional nystagmus was the most frequent direction and is probably not compensatory for contralesional tonic ocular torsion. Small amplitude vertical saccades with normal velocities in association with ipsilesional torsional nystagmus may indicate isolated iC lesions. Torsional nystagmus following mesencephalic lesions may last for years and may help to distinguish rostral (riMLF) from caudal (iC) midbrain lesions.     

Emotional facial paresis in temporal lobe epilepsy: its prevalence and lateralizing value.

The selection of patients with medically refractory temporal lobe epilepsy (TLE) for surgery depends on the concordance of data from clinical, imaging and electroencephalographic evaluation. Though clinical examination is often normal, emotional facial paresis has been described in patients with TLE. Utilizing a well-characterized group of mesial TLE (MTLE) patients, who have achieved excellent seizure outcome following anterior temporal lobectomy with amygdalohippocampectomy (ATL), we investigated the prevalence, predictive value and associations of emotional facial paresis. When compared to 8 out of 50 control subjects (16%), 36 out of 50 MTLE patients (72%) exhibited unilateral emotional facial paresis; the difference was highly significant (P<0.0001). The presence of contralateral emotional facial paresis correctly predicted the side of ATL in 86.1% patients. The occurrence of emotional facial paresis was significantly associated with longer duration of epilepsy prior to ATL and left ATL. Our observations confirm that emotional facial parersis contralateral to the side of mesial temporal sclerosis (MTS) is a valuable localizing sign in correctly predicting the epileptogenic temporal lobe. We hypothesize that the presence of an intact right hemisphere and pathological changes more extensive than MTS may be required for emotional facial paresis to readily manifest.