Combining ictal surface-electroencephalography and seizure semiology improves patient lateralization in temporal lobe epilepsy

PURPOSE: The study goal was to assess the concordance of ictal surface-EEG and seizure semiology data in lateralizing intractable temporal lobe epilepsy (TLE) and to examine the benefits of the combined use of these two methods. METHODS: We independently analyzed the ictal recordings and clinical symptoms associated with 262 seizures recorded in 59 TLE patients. Each seizure was lateralized on the basis of (i) its associated ictal surface-EEG pattern according to a predefined lateralization protocol and (ii) its associated ictal and postictal seizure semiology according to strictly defined clinical criteria. Individual patients were also lateralized based on these data. RESULTS: Ictal surface-EEG findings lateralized 62.6% of seizures and 64.4% of patients. Seizure semiology findings lateralized 46.2% of seizures and 78.0% of patients. There was a high degree of concordance between lateralizations based on these two methods, for both individual seizures and individual patients. Combination of the information from the two methods allowed for lateralization in a greater proportion of both seizures (79.8%) and patients (94.9%). Combined EEG-seizure lateralization was concordant with the side of operation in 33 of 34 patients who underwent successful surgery (Engel's surgical outcome class I/II). CONCLUSIONS: In TLE, there is a high agreement between the lateralization of individual seizures and patients, which is based on ictal surface-EEG findings and seizure semiology. Furthermore, combination of these two methods improves the lateralization of individual seizures and patients. Thus, standardized combined EEG-seizure analysis is a valuable noninvasive tool in the presurgical evaluation of TLE.     

Ictal semiology in patients with medial temporal lobe epilepsy: value in lateralizing the seizure focus]

We have evaluated useful lateralizing signs in 28 patients with medial temporal lobe epilepsy who were seizure-free after anterior temporal lobectomy by reviewing videotapes during video-EEG monitoring. The most frequent types of aura were epigastric sensation and psychic symptom in 8, respectively, both of which did not predict lateralization of the focus. Of the motor signs, early head deviation and unilateral upper extremity automatism predicted an ipsilateral focus in 72 and 80%, respectively. On the other hand, late head deviation(< 15 seconds before secondarily generalized seizure) and unilateral upper extremity dystonic posturing predicted a contralateral focus in 80 and 100%, respectively. Twelve of the patients displayed oroalimentary automatism which did not predict focus lateralization. Three patients with ictal speech demonstrated a seizure focus contralateral to their language-dominant hemisphere. In medial temporal lobe epilepsy, several clinical seizure manifestations such as: early and late head deviation, unilateral upper extremity automatism and dystonic posturing were not a little noted and provided additional information as to the side of seizure origin.     

Clinical seizure lateralization in frontal lobe epilepsy

PURPOSE: We systematically analyzed the lateralizing value of clinical seizure semiology in patients with frontal lobe epilepsy (FLE). METHODS: We studied the incidence, positive predictive value (PPV), and the lateralizing significance of various clinical symptoms in 228 seizures (s) of 31 patients (p) with medically refractory FLE (17 with left-sided and 14 with right-sided seizure onset). Seizures recorded during prolonged video-EEG monitoring were assessed by two independent reviewers blinded for the patient's clinical data. Analysis was performed both for patients and seizures. RESULTS: Version [16 p (52%); PPV, 94%; p=0.001; 47 s (21%); PPV, 75%; p=0.001], unilateral clonic movements [16 p (52%); PPV, 81%; p=0.021; 32 s (14%); PPV, 81%; p=0.001], unilateral dystonic posturing [eight p (26%); PPV, 75%; p=0.289; 46 s (20%); PPV, 80%; p=0.001], unilateral tonic posturing [10 p (32%); PPV, 80%; p=0.109; 19 s (7.4%); PPV, 79%; p=0.019], and unilateral grimacing [10 p (32%); PPV, 100%; p=0.002; 19 s (8%); PPV, 100%; p=0.001] were of lateralizing significance, indicating a contralateral seizure onset. Asymmetric ending [five p (16%); PPV, 80%; p=0.375; nine s (4%); PPV, 89%; p=0.039] after secondarily generalized tonic-clonic seizures was significantly associated with an ipsilateral seizure onset. Pure ictal vocalizations occurred significantly more frequently in seizures of right hemispheric onset [13 p (42%); PPV, 62%; p=0.581; 63 s (28%); PPV, 73%; p=0. 001], whereas in individual patients, this symptom showed no lateralizing significance. The remaining clinical symptoms (figure 4 sign, unilateral hand automatisms, early head turning, postictal nose wiping, and unilateral eye blinking) were not of lateralizing significance in our patients. The results of clinical seizure lateralization corresponded with the final lateralization of the seizure-onset zone in 81% of our patients. CONCLUSIONS: Clinical seizure semiology can provide correct information on the lateralization of the seizure-onset zone in >80% of patients with medically refractory frontal lobe epilepsy.     

Postictal Nosewiping Lateralizes and Localizes to the Ipsilateral Temporal Lobe

Summary: Purpose: We observed many patients with temporal lobe epilepsy (TLE) wiping their nose postictally, usually with the hand ipsilateral to their seizure focus. We wished to determine if this had lateralizing or localizing significance. Methods: We retrospectively studied 87 patients: 47 with unilateral TLE defined by successful surgical outcome [30 with medial TLE (MTLE) and 17 with neocortical TLE (neoTLE)]; and 40 with extratemporal epilepsy (ExTLE). Videotapes of 319 complex partial seizures (CPS) without generalization were reviewed by 1 neurologist, blinded to patient identity, who recorded each episode of nosewiping and the hand with which it was performed. Results: With regard to localizing potential, postictal nosewiping (PINW) was significantly more common in patients with unilateral TLE than in those with ExTLE. In the TLE group, PINW within 60 s of electrographic seizure offset occurred in 60% of patients (28 of 47) and 43% of seizures (74 of 171). In the ExTLE group, PINW was noted in 33% of patients (13 of 40; p < O.05 as compared with TLE) and 15% of seizures (22 of 148; p < O.001). Similar results were obtained with PINW within 30 s of seizure offset. Although PINW was more frequent in MTLE than in neoTLE (67% of patients vs. 47%), this finding did not reach significance. With regard to lateralizing potential, in the TLE group, unilateral PINW (performed with a single hand only) within 60 s of seizure offset was observed in 53% of patients (25 of 47) and was performed with the hand ipsilateral to the seizure focus in 92% (23 of 25). Thirteen patients (9 with TLE) wiped their nose more than once with the same hand in a single seizure within 60 s of offset in 18 seizures; this was done with the hand ipsilateral to the seizure focus in all 18 instances (predictive value = 100%). Conclusions: PINW is more common in unilateral TLE, particularly MTLE, than in ExTLE. PINW performed exclusively with one hand occurs in ～50% of patients with TLE and is highly predictive (92%) of seizure onset ipsilateral to the hand used, especially when it occurs repetitively. We hypothesize that ictal activation of the central autonomic nervous system, particularly the amygdala, results in ictal nasal secretions and causes nosewiping as the patient regains awareness postictally. The ipsilateral hand is used due to contralateral neglect or weakness.     

Localizing Value of Seizure Manifestations of Temporal Lobe Epilepsies and the Consequence of Analyzing Their Sequential Appearance

We investigated the localizing and lateralizing value of principal seizure manifestations in temporal lobe epilepsies (signal symptoms, oroalimentary automatisms, somatomotor manifestations, unilateral dystonic posturing, ictal speech, motionless stare) of 223 complex partial seizures in 50 patients. All the patients had invasive long-term monitoring with the combined implantation of intracerebral electrodes in and subdural electrodes on the bilateral temporal lobes. Postoperative freedom from seizures was ascertained for longer than one year. We found that 35 patients had amygdalohippocampal seizures and 15 had lateral temporal seizures. The value of the manifestations was established in relation to the site and side of seizure origin and to the progression of seizure discharges within the unilateral temporal lobe or to the contralateral cerebral hemisphere. Several signs among the manifestations were found to be reliable in predicting the site or side of the temporal lobe seizure focus. We emphasized the importance of investigating sequential changes of seizure manifestations in relation to ictal EEG findings by means of simultaneous recording.     

Somatosensory auras in refractory temporal lobe epilepsy

PURPOSE: To determine the prevalence, manifestations, lateralizing value, and surgical prognostic value of somatosensory auras (SSAs) in patients with refractory temporal lobe epilepsy (TLE). METHODS: Eighty-one consecutive patients undergoing temporal lobectomy for refractory complex-partial seizures were screened for SSAs. The characteristics of the somatosensory phenomena, occurrence of other aura types, seizure semiology, findings of EEG and imaging studies, temporal lobe neuropathology, and postoperative seizure outcome were determined in each patient with SSAs. RESULTS: Nine (11%) of 81 patients with refractory temporal lobe seizures reported distinct SSAs as part of their habitual seizures. The most common manifestation of SSAs was tingling (eight of nine, 89%), but sensory loss (one of nine, 11%) and pain (one of nine, 11%) also were reported. Five patients had unilateral somatosensory symptoms, and four patients had bilateral somatosensory symptoms. Seizure origin was in the contralateral temporal lobe in four (80%) of five patients with unilateral SSAs, including all patients with unilateral SSAs affecting a limb. Partial temporal lobe resection produced complete seizure remission in all nine (100%) patients 1 year after surgery and in seven (78%) of nine patients 2 years after surgery. CONCLUSIONS: SSAs occur more frequently than previously appreciated in patients with refractory temporal lobe seizures and usually manifest as either unilateral or bilateral tingling. In patients with temporal lobe seizures, unilateral SSAs involving a limb suggest a seizure origin in the contralateral temporal lobe. The surgical outcome of TLE patients with SSAs is favorable. Thus the presence of SSAs should not serve as a deterrent to temporal lobe resection in patients with clearly defined TLE.     

Value and limitations of seizure semiology in localizing seizure onset.

Seizure semiology has been the foundation of clinical diagnosis of seizure disorders. This article discusses the value and the limitations of behavioral features of seizure episodes in localizing seizure onset. Studies have shown that some semiologic features of seizures are highly accurate in the hemispheric lateralization and lobar localization of seizures. There is good agreement between blinded reviewers in lateralizing video-recorded seizures in temporal lobe and extratemporal lobe epilepsies. However, seizure semiology alone should not be used to determine the site of seizure onset. Each semiologic feature may falsely localize seizure onset. Seizure semiology in some patients may signify the site of seizure propagation rather than origination. Moreover, seizure semiology may not be as reliable in multifocal epilepsies as it is in unifocal epilepsies. Many semiologic features of seizures of adults are often missing in seizures of children. Seizure semiology should be analyzed and integrated with EEG and neuroimaging data to localize the seizure focus. A sample of the recorded seizures should be shown to the patient's relatives or friends to verify that it is representative of habitual seizures.     

Age-dependent seizure semiology in temporal lobe epilepsy

OBJECTIVE: To examine the effects of age on different aspects of temporal lobe seizure semiology. METHODS: We performed a video analysis of 605 archived seizures from 155 consecutive patients (age 10 months to 49 years) selected by seizure freedom after temporal lobectomy. Eighty patients had hippocampal sclerosis (HS). Beside semiological seizure classification, we assessed age dependency of several axes of seizure semiology: (1) aura, (2) number of different lateralizing signs, occurrence of ictal (3) emotional signs, (4) autonomic symptoms, (5) automatisms, and (6) secondary generalization as well as (7) the ratio of motor seizure components. RESULTS: From the 155 patients, 117 reported aura, 39 had ictal emotional signs, 51 had autonomic symptoms, 130 presented automatisms, while 18 patients showed secondary generalization at least once during their seizures. Altogether 369 (median: 2/patient) different lateralizing signs were recorded. Frequency of HS (p < 0.001), ictal automatisms (p < 0.001), secondary generalization (p = 0.014), number of different lateralizing signs (p < 0.001) increased while the ratio of motor seizure component (p = 0.007) decreased by age. Auras, emotional symptoms, and autonomic signs occurred independently of patients' ages. Hippocampal sclerosis adjusted linear models revealed that the frequency of automatisms and secondarily generalized seizures as well as the number of different lateralizing signs are HS-independent significant variables. CONCLUSION: Our findings support that brain maturation significantly influences the evolution of some important aspects (motor seizures, lateralizing signs) of temporal lobe seizure semiology. Conversely, other aspects (aura, emotional, and autonomic signs) are independent of the maturation process. This is the first report investigating age dependency of epileptic seizure semiology comparing all age groups.     

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.     

Ictal Contralateral Paresis in Complex Partial Seizures

Summary: Certain behaviors that occur during a complex partial seizure (CPS) are useful in lateralizing the side of seizure onset. In 5 (5.3%) of 94 consecutive patients with partial epilepsy, we observed ictal unilateral arm and hand paresis during 27 of 34 CPS. In all these seizures, this behavior occurred contralateral to an epileptogenic temporal lobe, as determined by video-EEG monitoring and surgical outcome. In 5 of the 27 seizures, an observer demonstrated that the paretic arm and hand were flaccid. None of these patients had postictal (Todd's) paralysis. In most of the seizures, the arm ipsilateral to seizure onset had simultaneous purposeful movements or automatisms, sometimes with awkward posturing. Ictal unilateral paresis is distinctly different from ictal dystonia or postictal paralysis and consistently lateralizes seizure onset to the contralateral temporal lobe. Recognition of this particular ictal behavior and comparison to other simultaneous behaviors can aid in the lateralization and possibly localization of the epileptogenic zone.     

Mismatch negativity is abnormal but not lateralizing in temporal lobe epilepsy

We investigated the changes of mismatch negativity (MMN) in patients with temporal lobe epilepsy (TLE) and explored the possible role of MMN in lateralizing their seizure focus. Thirty patients with TLE and thirty healthy controls were included. MMN was elicited in each subject. Patients with TLE were divided into three subgroups: unilateral left TLE; unilateral right TLE, and bilateral TLE. MMN amplitudes and latencies were compared between the patients with TLE and the control group, and also among the three subgroups of TLE, using repeated measures analyses of variance (ANOVA). To assess the lateralizing value of MMN, MMN latencies and amplitudes at the mastoid sites between the ipsilateral and contralateral sides of epileptic focus in patients with unilateral TLE were compared using t-test. Compared with controls, each subgroup of patients with TLE had longer latencies of MMN at both fronto-central and mastoid sites, but the amplitudes of MMN were not significantly different. The amplitudes and latencies of MMN were not significantly different between the ipsilateral and contralateral sides of seizure focus at mastoid sites. The present findings of prolonged latencies of MMN are suggestive of cognitive impairment in TLE. Both the mastoid sites and the fronto-central sites are involved, which likely reflect widespread cortical abnormalities in TLE. However, the changes of MMN during the interictal phase are not useful for lateralizing the seizure focus in patients with TLE.     

Speech manifestations in lateralization of temporal lobe seizures

To evaluate the role of speech manifestations in lateralization of temporal lobe seizures, we reviewed videotapes of 100 complex partial seizures in 35 patients who underwent temporal lobectomy for intractable epilepsy. All patients had prolonged electroencephalographic video monitoring with scalp and subdural electrodes, and their speech dominance was determined with an intracarotid amobarbital test. Speech manifestations were observed in 79 seizures and were classified as vocalization, normal speech, or abnormal speech. Vocalization of sounds without speech quality occurred ictally in 48.5% of patients. Normal speech (identifiable speech) occurred ictally in 34.2% of patients. Abnormal speech (speech arrest, dysphasia, dysarthria, and nonidentifiable speech) occurred in 51.4% of patients, either ictally or postictally. Of all the above speech manifestations, only postictal dysphasia and ictal identifiable speech had significant lateralizing value: 92% of patients with postictal dysphasia had their seizures originating from the dominant temporal lobe (p less than 0.001), and 83% of those with ictal identifiable speech had their seizures from the nondominant side (p = 0.013). This study shows that speech manifestations are common in complex partial seizures of temporal lobe origin and can provide an excellent clinical tool for lateralization of seizure onset.     

Lateralized ictal immobility of the upper limb in patients with temporal lobe epilepsy

The primary aim of this study was to establish the incidence and the lateralizing value of 'lateralized ictal immobility of the upper limb' (LIL) in patients suffering from temporal lobe epilepsy (TLE), and to describe the connection between LIL and other clinical ictal signs. We retrospectively reviewed video records of 87 patients with TLE. We reviewed a total of 276 focal epileptic seizures with or without secondary generalization. We studied the incidence of LIL, its lateralizing value, and its relationship to other ictal clinical signs. Of the 87 patients, 49 had undergone a successful resective surgery at least 1 year prior to the study. LIL is a late sign in the course of partial seizure. It occurred in 25 of our 87 patients (28.7%), and in 47 of 276 seizures (17.1%). In all of the evaluated seizures, LIL occurred contralateral to the side of seizure onset (P < 0.001). LIL was always associated with ipsilateral upper limb automatisms, and in 63.1% of the occurrences, it was immediately followed by ictal dystonia. LIL is a more accurate term to describe what has previously been called 'ictal paresis' in the literature. Due to the inability to execute proper testing during a partial seizure, it is better to use the term LIL when making a visual analysis of a seizure. LIL is a more suitable term to describe the studied ictal sign. It is a relatively frequent sign in patients with TLE. LIL has an excellent lateralizing value for the contralateral hemisphere. It is a negative motor sign, and its genesis is probably associated with the epileptic involvement of the contralateral frontal lobe.     

Ictal head turning in frontal and temporal lobe epilepsy

Purpose: To quantitatively evaluate the difference of ictal head turning movements between patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE). Methods: We investigated 38 seizures of 31 patients with unilateral TLE and 22 seizures of 14 patients with unilateral FLE where head turning occurred in the seizure evolution. The head movements were defined as ipsilateral or contralateral in reference to the lateralization of the patient’s focal epilepsy syndrome. Head movements were quantified by either referencing the head position with manually placed markers or by automatic detection of infrared marked reference points. The time of onset, duration, and angular speed of the head movements were computed, and interindividual and intraindividual analyses were performed. Key Findings: All of the TLE seizures had both contralateral and ipsilateral head turning, whereas all FLE had contralateral head turning; only 6 of 22 seizures were associated with ipsilateral head turning. Ipsilateral head turning always preceded contralateral head turning in both TLE and FLE. The head turning occurred significantly sooner after clinical seizure onset in FLE than in TLE patients (ipsilateral 0.5 vs. 16.0 s, contralateral: 4.5 vs. 21.3 s; p < 0.001). Furthermore, the duration of head turning was shorter in FLE for contralateral head turning (4.1 s) than in TLE (contralateral 6.0 s, p < 0.01); the ipsilateral head turning in the two groups did not differ (3.0 vs. 2.9 s) in duration. The angular speed of head turning did not differ for ipsilateral and for contralateral head turning in FLE and TLE. Significance: Quantitative analysis of head turning demonstrates significant differences between patients with FLE and TLE. These differences likely represent differences in spread of epileptic activity. This information may be useful in the seizure evaluation of patients considered for resective epilepsy surgery.     

Effect of interseizure interval on seizure lateralization in patients with bilateral seizure foci

We investigated whether there is a cluster effect depending on localization of seizure foci in patients with bilateral seizure foci. We evaluated 171 seizure pairs from 193 seizures recorded in 28 patients. Seizure lateralization was determined by the lateralization of ictal discharges; if the ictal EEG pattern was not lateralized, lateralization was determined by clinical seizure semiology. The logarithm of the interseizure interval (ISI) was significantly related to seizure concordance only in patients with extratemporal seizure foci, but not in those with bitemporal foci. In the former group, the mean ISI for concordant seizure pairs was significantly shorter than that for discordant seizures pairs (292 min versus 631 min, p=0.023). Seizure types composing seizure pairs had a significant influence on ISI regardless of the localization of seizure foci. ISIs were shortest in seizure pairs with only partial seizures. However, types of seizure pairs were significantly related to concordance rates of seizure lateralization only in patients with extratemporal foci (p=0.005). In conclusion, our results suggest that the cluster effect on seizure localization exists in patients with extratemporal seizure foci, but not in those with bitemporal foci.     

Identifying potential surgical candidates in patients with evidence of bitemporal epilepsy

PURPOSE: To determine which patients with evidence of medically refractory bitemporal epilepsy are potentially good candidates for surgical therapy. METHODS: We reviewed 42 adults with intractable seizures who were found to have bitemporal ictal onsets, based on scalp video-EEG long-term monitoring (LTM). All underwent invasive LTM before surgery. Surgical outcomes were classified as seizure free, >75% reduction in seizures, or <75% reduction in seizures, >or=1 year after resection. We related the following factors to outcome: (a). >75% preponderance of interictal scalp EEG discharges to one temporal region; (b). magnetic resonance imaging (MRI) findings; (c). lateralizing deficits on verbal or visual reproduction memory testing; and (d). memory failure with injection contralateral to side of surgery on Wada testing. RESULTS: Twenty-six (62%) of 42 patients had unilateral ictal onsets based on intracranial studies. Seizure freedom (occurring in 64% of this group), or >75% seizure reduction (found in 12% of subjects) occurred only when at least one of the following three factors was concordant with the side of surgery: preponderance of interictal scalp EEG discharges, unilateral temporal lesion on MRI, or lateralizing verbal or visual reproduction memory deficits on neuropsychological tests (p = 0.004). Seven subjects with bilateral ictal onsets based on intracranial studies had resections based on preponderance of seizures to one side, or other lateralizing noninvasive abnormality. Five of these (all of whom had >or=80% of seizures originating from one side) had >75% reduction in seizures. CONCLUSIONS: Invasive monitoring to pursue possible surgical therapy for patients with surface EEG evidence of bitemporal epilepsy may be justified only when some lateralizing feature is found in other noninvasive assessments.     

Rhythmic ictal nonclonic hand (RINCH) motions: a distinct contralateral sign in temporal lobe epilepsy

PURPOSE: To describe a new ictal sign in temporal lobe seizures-rhythmic ictal nonclonic hand (RINCH) motions and to determine its lateralizing significance and other ictal manifestations associated with it. METHODS: We identified 15 patients with temporal lobe epilepsy who demonstrated RINCH motions and reviewed video-EEG recordings of all their seizures. We analyzed the epilepsy characteristics and all clinical features of recorded seizures, with particular attention to RINCH motions. RESULTS: RINCH motions were unilateral, rhythmic, nonclonic, nontremor hand motions. RINCH motions were usually followed by posturing, sometimes with some overlap. They involved the hand contralateral to the temporal lobe of seizure onset in 14 of 15 patients. CONCLUSIONS: RINCH motions are a distinct ictal sign that could be considered a specific type of automatism. They appear to be a lateralizing contralateral sign and are associated with dystonic posturing in temporal lobe epilepsy.     

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.     

Lateralizing value of unilateral motor and somatosensory manifestations in frontal lobe seizures

PURPOSE: To evaluate the lateralizing value of unilateral somatosensory aura, unilateral tonic posturing, head version, non-forced head turning, ictal cloni, dystonic posturing, and postictal nose wiping in seizures originating in the frontal lobe. METHODS: We included patients who had consecutively undergone presurgical evaluation with ictal video-EEG monitoring at our institution, had had resective epilepsy surgery involving the frontal lobe, and had remained seizure-free >1 year after operation. Twenty-seven patients aged 1-42 years (mean 18) met the inclusion criteria. Fifteen patients had right-sided, 12 patients had left-sided epileptogenic regions. Seizures recorded during EEG-video monitoring were re-evaluated by two investigators in order to identify lateralization signs in frontal lobe seizures. One of the investigators was blind to patients' clinical data. RESULTS: We analyzed 153 seizures of 27 patients. The most common unilateral phenomenon was the unilateral tonic posturing occurring in 48% of all the patients and in 25% of all seizures. Somatosensory aura and head version appeared exclusively contralateral whereas clonus occurred in 92% and unilateral tonic posturing in 89% of seizures contralateral to the epileptogenic region. Ictal non-forced head turning and postictal nose wiping showed no lateralizing significance. Dystonic posturing did not occur. CONCLUSIONS: Somatosensory aura, head version, ictal cloni, and tonic posturing are reliable lateralizing signs in frontal seizures. These signs may help in identifying the epileptogenic region during presurgical evaluation of patients suffering from frontal lobe epilepsy.