Contralateral motor automatisms in neocortical temporal lobe epilepsy

BACKGROUND: The lateralizing value of the motor automatisms is generally doubted in most patients with temporal lobe epilepsy. However, subgroup analysis of the seizures of temporal lobe origin suggests a role for motor automatisms in discriminating seizures of neocortical versus mesial temporal lobe origin. METHODS: Video-EEG of a patient with well-defined neocortical temporal lobe epilepsy was reviewed to assess the localizing value of motor automatisms. RESULTS: We report a patient with left upper extremity motor automatisms and clonic movements of the proximal left lower extremity with altered awareness as the sole manifestations of right temporal neocortical seizures. CONCLUSION: Early onset unilateral motor automatisms without dystonic posturing can localize the seizure origin to the contralateral temporal lobe neocortex.     

Nonmanipulative proximal upper extremity automatisms lateralize contralaterally in temporal lobe epilepsy

Purpose : Upper extremity automatisms are considered to be an ipsilateral seizure lateralizing sign in temporal lobe epilepsy (TLE). Herein we describe different types of contralateral upper extremity automatisms (CUEAs). Methods : One hundred ninety‐three video–(electroencephalography) EEG recordings of 59 patients were reviewed. Other than two patients who refused surgery, all patients underwent standardized temporal lobectomy with favorable postoperative outcome. Fifty‐seven seizures of 21 patients were selected with CUEAs. We evaluated their electroclinical characteristics and their relation to other lateralizing motor symptoms. Results : Two types of CUEAs were observed. Nonmanipulative, proximal upper extremity automatisms were seen unilaterally and contralaterally to the operated side. These automatisms were rhythmic; repetitive; and often occurred with a circulatory component resembling waving, flaunting, circling, or stirring movements. They occurred in 29 seizures (15%) of 11 patients (19%), in most seizures in the first half of the seizure, and never postictally, in various time sequences and combined with dystonic/tonic posturing or limb immobility. Manipulative/distal type of CUEAs occurred in 11 seizures (6%) of 7 patients (12%) on the unexpected contralateral side. These CUEAs were seen in all phases of the seizures, including in the postictal state. Discussion : Nonmanipulative unilateral proximal upper extremity automatism is a reliable lateralizing sign to the contralateral hemisphere in TLE. This sign may be pathophysiologically related to dystonic/tonic posturing. Manipulative distal automatisms have less lateralizing value.     

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.     

Semiology of Temporal Lobe Seizures: Value in Lateralizing the Seizure Focus

Summary: Purpose: To determine the lateralizing value of the clinical manifestations of seizures in patients with temporal lobe epilepsy (TLE), we made a retrospective videotape analysis of complex partial seizures (CPS) in 55 patients who underwent temporal lobectomy and were seizure-free postopera-tively for >2 years. Methods: Blinded to clinical details, we reviewed videotapes from video-EEG telemetry monitoring with attention paid to seizure semiology. Results: Useful lateralizing features included unilateral clonic activity (with the seizure focus contralateral in all patients), unilateral dystonic or tonic posturing (with the seizure focus contralateral in 90 and 86%, respectively), unilateral automatisms (with the seizure focus ipsilateral in 80%), and ictal speech preservation (with the seizure focus contralateral to the language-dominant hemisphere in 80%). Versive head rotation occurring ≤10 s before seizures secondarily generalized consistently predicted a contralateral focus. Seizure manifestations less predictive but suggestive of lateralization included ictal speech arrest and postictal speech status, with predictive values of 67%. Seizure manifestations not providing reliable lateralizing information included eye deviation, type of aura, and versive head movements occurring at times other than immediately before seizures secondarily generalized. Conclusions: In TLE, several clinical seizure manifestations are useful in lateralizing the seizure focus, although some provide no reliable information. Therefore, ictal semiology can assist in the evaluation of patients for seizure surgery, providing additional information in the lateralization of TLE.     

Clinical,semiological, electroencephalographic,and neuropsychological features of “pure” neocortical temporal lobe epilepsy

Aims: We examined the clinical, semiological, scalp EEG, and neuropsychological features of patients with “pure” neocortical temporal lobe epilepsy (NTLE) who were successfully treated by neocortical temporal resection sparing the mesial temporal structures. Methods: This retrospective study included 17 patients with lesional NTLE who satisfied the following criteria: presence of a discrete structural lesion in the lateral temporal lobe on preoperative MRI; lateral temporal resection sparing the mesial temporal structures; follow‐up for at least two years after surgery; and favourable postoperative seizure outcome (Engel Class I). The study included 10 females and seven males, and the age at surgery ranged from 15 to 48 years (mean: 30.7 years). Auras, video‐recorded seizure semiology, interictal and ictal EEG, and pre‐ and post‐operative neuropsychological data were reviewed. Twenty patients with mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis, who had a favourable postoperative seizure outcome (Engel Class I), were selected as a control group. Results: Age at seizure onset was significantly greater in patients with NTLE than in controls. A history of febrile convulsion was significantly less frequent in NTLE patients. Epigastric ascending sensation (6% versus 40%; p=0.017), oral automatisms (29% versus 80%; p=0.003), gestural automatisms (47% versus 80%; p=0.047), and dystonic posturing (0% versus 40%; p=0.003) were significantly less frequent in NTLE than controls. Ictal unitemporal rhythmic theta activity was also significantly less frequent in NTLE than controls (35.3% versus 75%; p=0.015). Preoperative IQ score (range: 68 to 114; mean: 88.9) and preoperative memory quotient score (range: 56–122; mean: 98.1) were significantly higher in NTLE (p=0.003 and p=0.048, respectively). Conclusion: There were notable differences in clinical, semiological, EEG, and neuropsychological features between “pure” NTLE and MTLE. These findings may be useful to identify the epileptogenic zone.     

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.     

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.     

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.     

Lateralizing Value and Semiology of Ictal Limb Posturing and Version in Temporal Lobe and Extratemporal Epilepsy

Summary: Purpose : Unilateral dystonic limb posturing in partial seizures has been shown to be an accurate lateralizing sign indicating seizure onset in the contralateral hemisphere. However, its clinical utility may be reduced by confusion with other lateralized ictal motor phenomena. In this study, the ictal phenomena of dystonic limb posturing, tonic limb posturing, unilateral immobile limb, and version were distinguished and examined in patients with temporal and extratemporal seizures.
Methods : Partial seizures in 54 patients, successfully treated by surgery (34 temporal, 20 extratemporal; 14 frontal, 3 parietal, and 3 occipital), were analyzed blindly by 3 reviewers. Interobserver agreement was tested with kappa indexes and positive predictive value (PPV) was determined for each sign.
Results : In patients with temporal lobe epilepsy (TLE), dystonic posturing occurred in 35.3% (kappa 0.78, positive predictive value (PPV) for the sign being contralateral to seizure onset 92%); tonic limb posturing occurred in 17.7% (kappa 0.36, PPV 40%); unilateral immobile limb occurred in 11.8% (kappa 0.23, PPV 100%); and version occurred in 35.3% (kappa 0.77, PPV 100%). In patients with extratemporal epilepsy, dystonic posturing occurred in 20.0% (kappa 0.31, PPV 100%); tonic limb posturing occurred in 15.0% (kappa 0.08, PPV 67%); and version occurred in 40.0% (kappa 0.54, PPV 100%). The higher kappa indexes were significant for dystonic posturing (p < 0.001) and tonic limb posturing (p = 0.032) in TLE. Dystonic posturing (p = 0.034), tonic posturing (p = 0.07), and version (p = 0.0038) occurred earlier in extratemporal seizures than in temporal seizures.
Conclusions : Of the limb ictal motor phenomena, only dystonic posturing was accurate and had good interobserver agreement.     

Significance of lateralization of upper limb automatisms in temporal lobe epilepsy: A quantitative movement analysis

Purpose: To evaluate the significance of lateralization of ictal upper limb automatisms in patients with temporal lobe epilepsy (TLE). Methods: Ictal upper limb automatisms of 28 patients with temporal lobe epilepsy were quantified. Duration of automatisms in relation to total seizure duration, movement speed, extent, length, and predominant frequencies of the movements were analyzed for both upper extremities separately and compared to the lateralization of the epileptogenic temporal lobe. Results: Predominantly ipsilateral upper limb automatisms were more common (n = 19) than predominantly contralateral automatisms (n = 9). The duration of ictal ipsilateral upper limb automatisms was significantly longer than the duration of contralateral automatisms (ipsilateral automatisms: 29 of 86 s total seizure duration; contralateral automatisms: 19 of 110 s total seizure duration; p = 0.048). Patients with ipsilateral upper limb automatisms had more often exclusively unitemporal interictal epileptiform discharges (IEDs) (84.2%) than patients with contralateral automatisms (11.1%; p < 0.001). The positive predictive value (PPV) of the combination of these parameters is 84.2%. Excellent surgical seizure outcome was better in patients with ipsilateral upper limb automatisms (77.8%) compared to those with contralateral automatisms (20%) (p = 0.09). The quantitative analysis of movement extent, average speed, maximum speed, and repetition rate of ipsilateral and contralateral upper limb automatisms did not show any statistically significant difference in this patient sample. Conclusion: The lateralization of upper limb automatisms in TLE has a good lateralizing value if the lateralization of IEDs were also taken into consideration.     

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.     

Interictal regional delta slowing is an EEG marker of epileptic network in temporal lobe epilepsy

Purpose: Several studies have suggested that interictal regional delta slowing (IRDS) carries a lateralizing and localizing value similar to interictal spikes and is associated with favorable surgical outcomes in patients with temporal lobe epilepsy (TLE). However, whether IRDS reflects structural dysfunction or underlying epileptic activity remains controversial. The objective of this study is to determine the cortical electroencephalography (EEG) correlates of scalp‐recorded IRDS, in so doing, to further understand its clinical and biologic significances. Methods: We examined the cortical EEG substrates of IRDS with electrocorticography (ECoG‐IRDS) and delineated the spatiotemporal relationship between ECoG‐IRDS and both interictal and ictal discharges by recording simultaneously scalp and intracranial EEG in 18 presurgical candidates with TLE. Key Findings: Our results demonstrated that ECoG‐IRDS is typically a mixture of delta/theta slowing and spike‐wave potentials. ECoG‐IRDS was predominantly recorded from basal and anterolateral temporal cortex, occasionally in mesial, posterior temporal, and extratemporal regions. Abundant IRDS was most commonly observed in patients with neocortical temporal lobe epilepsy (NTLE), whereas infrequent to moderate IRDS was usually observed in patients with mesial temporal lobe epilepsy (MTLE). The anatomic distribution of ECoG‐IRDS was highly correlated with the irritative and seizure‐onset zones in 10 patients with NTLE. However, it was poorly correlated with the irritative and seizure‐onset zones in the 8 patients with MTLE. Significance: These findings demonstrate that IRDS is an EEG marker of epileptic network in patients with TLE. Although IRDS and interictal/ictal discharges likely arise from the same neocortical generator in patients with NTLE, IRDS in patients with MTLE may reflect a network disease that involves temporal neocortex.     

The neurobiological substrates of behavioral manifestations during temporal lobe seizures: A neuroethological and ictal SPECT correlation study

Ictal behavior coupled with SPECT findings during 28 seizures in patients with temporal lobe epilepsy (TLE) with unilateral hippocampal sclerosis (13 left; 15 right) was displayed as flowcharts from right-sided (RTLE) plus left-sided (LTLE) seizures. Ictal SPECT was classified blind to neuroethology. Behaviors were categorized as ipsilateral to the epileptogenic zone (IL), contralateral to the epileptogenic zone (CL), or bilateral. SPECT intensity and region were categorized as IL or CL to the epileptogenic zone. All patients developed automatisms and had hyperperfusion in their temporal lobes. Patients’ verbal responses to questions had statistical interactions in RTLE but not in LTLE sum. Most CL dystonic posturing was correlated to IL basal ganglia hyperperfusion. Basal ganglia activation occurred in seizures without dystonic posturing and CL manual automatisms, and lack of IL dystonic posturing and the presence of CL cerebellar hemispheric hyperperfusion were also observed. Coupling of neuroethology and SPECT findings reliably evaluates ictal behavior and functionality of associated brain areas.     

Clinical features of neocoritcal temporal lobe epilepsy

Few Studies have examined the clinical features of neocortical temporal lobe epilepsy (NTLE) in carefully selected patients. We reviewed records from 21 patients wtih NTLE, defined by intracranial electroencephal9ogram (EEG), who have been seizure free for 1 year or more following temporal lobectomy. The mean age of onset at the time of first seizure was 14 years (range, 1–41 years). Febrile seizures were reported in only 2 patients (9.5%). In contrast to prior mesial temporal lobe epilepsy (MTLE) studies, seizure-free intervals between the initial cerebral insult or first seizure and habitual seizures were uncommon. Possible or known risk factors for epilepsy were reported in 13 of 21 patients (62%). Fifteen (71%) patients reproted auras, with experiential phenomena being the most common type. Magnetic resonance imaging was normal or nospecific in 15 patients, revealed mild hippocampal atrophy in 2, tumors in 2, and resonance imaging was normal or nospecifc in 15 patients, revealed mild hippocampal atrophy in 2, tumors in 2, and heterotopic gray matter and hippocampal atrophy in 1, and cortical dysgensis in 1. Neuropsychological testing showed deficits consistent with the seizure focus in 13 patients (62%), and Wada test showed ipsilateral memory deficits in 10 (48%). The most common behavioral manifestatin was a motionless stare at ictal onset (48%). In contrast to prior studies of MTLE, only 1 NTLE patient had frequent independent, contralateral temporal lobe epileptiform spikes on scalp EEG.     

Association of Ipsilateral Head Turning and Dystonia in Temporal Lobe Seizures

Summary: We evaluated head turning in 239 complex partial seizures (CPS) with or without generalization in 32 patients with unilateral temporal lobe epilepsy (TLE). Head turns occurred in 187 seizures of 31 patients, more than once in 71 seizures. The first head turn was ipsilatera1 to the focus in 162 seizures (87%), with a mean latency of 22 s, as compared with 83 s for contralateral first head turns. Concomitant dystonic posturing of the arm occurred with 71% of all ipsilateral head turns and with 16% of all contralateral head turns. The mean difference in absolute latency between the first head turn and concomitant dystonic posturing was 6 s. Examination of all instances of concomitant head turning and dystonic posturing (160) showed them to be contralateral to each other in 154 (96%). Furthermore, the dystonia was contralateral and head turning was ipsilateral to the focus in 149 (93%). Forty-one seizures secondarily generalized, with transitional tonic head deviation contralateral to the focus in 35. Early head turning suggests an ipsilateral temporal seizure focus, particularly when associated with contralateral dystonic posturing. Similar mechanisms may account for both. Tonic head deviation preceding secondary generalization probably has a different mechanism.     

Non-invasive examinations successfully select patients with medial temporal lobe epilepsy for anterior temporal lobectomy]

We retrospectively analyzed 8 patients with intractable medial temporal lobe epilepsy (MTLE) who underwent the anterior temporal lobectomy with hippocampectomy (ATL) without invasive examinations such as chronic subdural electrode recording. Five patients had a history of febrile convulsion. While all 8 patients had oral automatism, automatism of ipsilateral limbs with dystonic posture of contralateral limbs was demonstrated in 2 patients. Bilateral temporal paroxysmal activities on interictal EEG was observed in 4 patients and all patients had clear ictal onset zone on unilateral anterior temporal region. MRI demonstrated unilateral hippocampal sclerosis in 5 cases. Interictal FDG-PET depicted hypometabolism of the unilateral temporal lobe in all cases, however, ECD-SPECT failed to reveal the hypoperfusion of the unilateral temporal lobe in a case. Postoperatively, 7 cases became seizure free, and one had rare seizure. Non-invasive examinations, especially ictal EEG and concordant FDG-PET findings, in patients with oral automatism in seizure semiology, successfully select patients with MTLE for ATL.     

An evaluation of lateralizing signs in patients with temporal lobe epilepsy

Resective epilepsy surgery has been accepted as an effective treatment for patients with medically intractable temporal lobe epilepsy (TLE) to control the seizures and to limit cognitive dysfunction. Complete resection of the epileptic zone, and therefore the success of the surgery, depends on the identification of the seizure focus. Reliable lateralizing semiologic signs, together with other presurgical assessments, are of great importance for an accurate identification of the seizure focus. In this respect, this study evaluated the frequency of semiologic signs in medically intractable temporal lobe epilepsy (TLE) together with the lateralizing values and variations according to the age and gender groups. Two hundred seventy-three seizures of 55 patients of the Adult Epilepsy Monitoring Unit of Gazi University Faculty of Medicine with the diagnosis of medically intractable TLE, whose epileptic foci were detected through noninvasive presurgical procedures and seizures were controlled successfully after anterior temporal lobectomy (ATL), were analyzed retrospectively. Seizure semiologies of the patients were evaluated in terms of lateralizing values, and it was inquired whether age/gender causes any variation. Versive head rotation, unilateral dystonic limb posturing, asymmetric tonic limb posturing, and the combination of unilateral hand automatisms and dystonic posturing were determined as the semiologic signs with the highest lateralizing values (90–100%). While hand automatisms were observed frequently in the group with early seizure-onset age (onset age ≤ 2), asymmetric tonic limb posturing was detected as more frequent in the group with later seizure-onset age (onset age > 2; p < .005). In addition to this, semiologic signs were noted to be different between male and female groups; psychic and autonomic auras and ictal emotional signs were associated with women (p < .005).     

Metabolic profiles and correlation with surgical outcomes in mesial versus neocortical temporal lobe epilepsy

Aims

Differentiating mesial temporal lobe epilepsy (MTLE) and neocortical temporal lobe epilepsy (NTLE) remains challenging. Our study characterized the metabolic profiles between MTLE and NTLE and their correlation with surgical prognosis using ¹⁸F-FDG-PET.

Methods

A total of 137 patients with intractable temporal lobe epilepsy (TLE) and 40 age-matched healthy controls were recruited. Patients were divided into the MTLE group (N = 91) and the NTLE group (N = 46). ¹⁸F-FDG-PET was used to measure the metabolism of regional cerebra, which was analyzed using statistical parametric mapping. The volume of abnormal metabolism in cerebral regions and their relationship with surgical prognosis were calculated for each surgical patient.

Results

The cerebral hypometabolism of MTLE was limited to the ipsilateral temporal and insular lobes (p < 0.001, uncorrected). The NTLE patients showed hypometabolism in the ipsilateral temporal, frontal, and parietal lobes (p < 0.001, uncorrected). The MTLE patients showed extensive hypermetabolism in cerebral regions (p < 0.001, uncorrected). Hypermetabolism in NTLE was limited to the contralateral temporal lobe and cerebellum, ipsilateral frontal lobe, occipital lobe, and bilateral thalamus (p < 0.001, uncorrected). Among patients who underwent resection of epileptic lesions, 51 (67.1%) patients in the MTLE group and 10 (43.5%) in the NTLE group achieved Engel class IA outcome (p = 0.041). The volumes of metabolic increase for the frontal lobe or thalamus in the MTLE group were larger in non-Engel class IA patients than Engel class IA patients (p < 0.05).

Conclusions

The spatial metabolic profile discriminated NTLE from MTLE. Hypermetabolism of the thalamus and frontal lobe in MTLE may facilitate preoperative counseling and surgical planning.     

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.