Clinical Neurophysiology: EEG–Video Monitoring
2005; Wiley; Volume: 46; Issue: s8 Linguagem: Inglês
10.1111/j.1528-1167.2005.460801_4.x
ISSN1528-1167
Tópico(s)EEG and Brain-Computer Interfaces
Resumo1 Elaine C. Wirrell, and 2 Christina Cheung ( 1 Pediatrics and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada ; and 2 Faculty of Medicine, Queens University, Kingston, ON, Canada ) Rationale: Adolescent perception of physical and social impact of chronic illness was assessed to determine a) is there greater prejudice toward epilepsy than other chronic disease, b) do adolescents with chronic disease have less prejudice towards similarly affected peers with all, or just their specific chronic disease. Methods: Cohort study. Setting : Outpatient clinics of a tertiary care pediatric hospital. Participants : Cognitively normal teens aged 13–18 without chronic disease (n = 41) and with epilepsy (n = 32), asthma (n = 38), diabetes (n = 21) and migraine (n = 17). Main Outcome Measures: Perceived physical and social impact of 8 chronic diseases (epilepsy, asthma, diabetes, Down's syndrome, arthritis, migraine, leukemia, HIV infection). Results: Epilepsy was perceived to have more adverse physical impact than all chronic illnesses except Down's syndrome. The perception was that it more frequently caused mental handicap, injured the afflicted individual and bystanders and led to death. Epilepsy was also perceived to have more negative social impact particularly on behavior, honesty, popularity, adeptness at sports and fun. Significantly more adolescents' expressed reluctance to befriend peers with epilepsy both from their own and their perceived parental perspectives. Having a chronic disease did not generally alter adolescents' perceptions of peers with chronic disease. However cases with epilepsy ranked this disease to have less social impact than teens with other chronic diseases. Conclusions: Adolescents consider epilepsy to have a greater physical and social impact than most chronic diseases. Educational efforts should focus on the “normality” of most persons with epilepsy, and emphasize the low risk of injury when proper first aide is followed. 1 Tonicarlo R. Velasco, 1 Veriano Alexandre Jr., 1 Marino M. Bianchin, 1 Roger Walz, 1 Charles L. Dalmagro, 1 Regina M.F. Fernandes, 1 Juliana S. Lage, and 1 Americo C. Sakamoto ( 1 Neurology, CIREP, Ribeirao Preto, Sao Paulo, Brazil ) Rationale: Fourteen and six positive spiking is an electroencephalographic phenomenon first described by Gibbs and Gibbs in 1951 as bursts of arch‐shaped surface positive waves at 14 & 6 Hz seen during drowsiness in the posterior temporal leads. It was originally associated with headache, head trauma, epilepsy, behavioral disorders, vomiting and dizziness. However, it can be accepted as a pattern appearing in normal children and adolescents. Here we describe a series of patients with unilateral temporal lobe epilepsy (MTLE) which revealed 14 and 6 Hz positive spikes during video‐EEG. We analyze the relative frequency and lateralization value of this EEG pattern. Methods: Video‐EEG analysis. Electrodes were placed over the scalp according to the international 10–20 system, added to temporal electrodes positioned according to the 10–10 system and sphenoidal electrodes. 14 and 6 Hz positive spikes definition. The EEG was visually assessed by a board‐certified electroencephalographer (TRV) for the presence of 14 & 6 Hz positive spikes, defined as arch shaped waves at 13–17 and/or 5–7 Hz seen generally over the posterior temporal region. The sharp peaks of its component need to be positive in respect to other regions. Side of epileptogenic temporal lobe (TL). The side of epileptogenic TL was defined by high resolution MRI, ictal SPECT, and neuropsychological examination, and ictal video‐EEG. The ictal onset zone (IOZ) was assessed on ictal video‐EEG by two investigators, and when the results were discordant, they were reviewed together to achieve agreement about the localization and lateralization of seizure onset. When the IOZ could not be localized noninvasively, intracranial EEG recordings were performed. Results: From 359 patients examined, 22 had 14 & 6 Hz positive spikes (6,12%). The localization of EEG pattern was in the lateral posterior temporal leads, with maximum amplitude in the T5‐T6 and P7‐P8 electrodes. In the temporal lobe the mesio‐basal region discloses the minimum amplitude (sphenoidal electrodes). In one patient with foramen ovale electrode, we observed high amplitude 14 and 6 Hz positive spikes, probably related to intracranial positioning of electrodes than due to mesio‐basal origin. In 21 patients, 14 and 6 Hz positive spikes were lateralized contralateral to the side of MTLE (p < 0.01). Conclusions: Our findings indicate that 14 & 6 Hz positive spikes are uncommon. The high frequency of lateralized pattern in patients with unilateral MTLE and the fact that occurred consistently in the TL contralateral to the side of hipocampal sclerosis is in agreement with the theory that 14 & 6 Hz positive spikes can be a normal EEG pattern and suggest that the origin of 14 & 6 Hz positive spikes locate in temporal lobe. Although uncommon, the EEG pattern is a reliable method for lateralization of epileptogenic temporal lobe. (Supported by Fapesp, CAPES and CnPq.) 1 Amir M. Arain, and 1 Bassel W. Abou‐Khalil ( 1 Neurology, Vanderbilt University Medical Center, Nashville, TN ) Rationale: Hyperventilation (HV) is used routinely to provoke absence seizures, but is less effective for precipitation of partial seizures. Hyperventilation may also be effective in precipitating nonepileptic seizures. This study was undertaken to determine the effectiveness of hyperventilation in consecutive patients undergoing prolonged video EEG monitoring. Methods: We prospectively used hyperventilation in consecutive patients admitted to our epilepsy monitoring unit for long‐term video‐EEG monitoring. Patients underwent 3 min of hyperventilation on a daily basis (1–6 days). We excluded children younger than 12 and mentally retarded individuals. Results: We evaluated 56 consecutive patients. Their ages ranged from 12 to 85 years. 36 (66%) had localization‐related epilepsy, 19 (34%) had nonepileptic spells, and one had both partial onset seizures and nonepileptic seizures. Events were activated in 5 patients with epilepsy (2 auras, 2 complex partial seizures and 1 secondarily generalized tonic clonic seizure), and in 9 patients with nonepileptic seizures (all were nonepileptic events). The patient with both epileptic and nonepileptic seizures had a nonepileptic spell activated. Spontaneous and activated epileptic seizures did not differ in their clinical characteristics. Conclusions: Voluntary HV is effective in inducing seizures as well as nonepileptic spells during monitoring. The effectiveness of HV in localization‐related epilepsy was higher than expected, possibly due to increased seizure tendency from medication withdrawal. This study suggests that daily HV may be effective in shortening the duration of video‐EEG monitoring, both in patients with epilepsy and those with nonepileptic seizures. 1 Adriana C. Bermeo, 1 Dileep R. Nair, 1 Prakash Kotagal, 1 Mark Bej, 1 Imad Najm, and 1 Hans O. Lüders ( 1 Neurology, Cleveland Clinic Foundation, Cleveland, OH ) Rationale: We studied the changes related to cardiac rhythm in patients with generalized tonic‐clonic seizures (GTCS) as it relates to episodes of apnea and during the motor and premotor phase of the seizure. Methods: Patients in the epilepsy monitoring unit were recruited if they experienced a GTCS. We assessed the heart rate as well as the oxygen saturation in 24 GTCS experienced in 18 patients (2 bitemporal, 2 right temporal, 5 left temporal, 3 focal epilepsy not otherwise localizable, and 2 left hemisphere, 2 left frontal, and 2 primary generalized epilepsy). One of the 24 seizures was excluded because in this seizure we were unable to define the onset of the motor component. In three seizures the baseline heart rate was already in the tachycardic range (defined as >90 beats/min). A significant heart rate escalation (tachycardic response TR) was defined as an escalation of heart rate response during a seizure that was higher than the baseline variability of the patient's interictal heart rate by a third (TR> (interictal HR +1/3 interictal HR)). The slope of the tachycardic response was classified as a fast slope if the maximum heart rate value during the premotor component was achieved in less than 90 seconds and as slow slope if the time to get from baseline to peak was greater than this time. The time of peak hypoxemia was also determined for each seizure. A heart rate deceleration was defined as a drop in heart rate of more than 20bpm within the first minute after the peak hypoxemia (sat O2< 80%). Results: Of the 23 seizures analyzed, 18 (78%) showed a TR in the premotor phase. In this phase the maximum heart rate ranged from 62 to 155 beats/min. Sixteen out of 20 (80%) seizures achieved TR in the premotor phase. A fast slope TR was noted in 10 seizures, which include 5 seizures originating from the right temporal lobe, one seizure originating from the left temporal lobe and four extratemporal seizures. A slow slope response was seen in 7 seizures arising from left temporal lobe and three extratemporal seizures. A heart rate deceleration associated with hypoxemia was seen in 18 out of 24 seizures (75%). There was also a statistically higher variability in the heart rate in the postictal phase as compared to the preictal phase in 20 out of 24 seizures (83%). Conclusions: A TR in the premotor phase of GTCS occured frequently. We were able to demonstrate a difference in the morphology of the TR slope as it relates to the lateralization of the seizure focus in temporal lobe epilepsy. Rapid heart rate decelerations following the ictal tachycardia seem associated with the peak hypoxemia. There was a greater heart rate variability in the postical period as compared with the preictal period in GTCS. These findings may be related to central lateralization of autonomic control and might be speculated to contribute to the mechanisms involved in SUDEP. 2 Elizabeth A. Boles, 1 Melissa F. Brown, 1 Teresa J. Long‐Henson, and 2 Cormac A. O'Donovan ( 1 Diagnostic Neurology, Wake Forest University Baptist Medical Center, Winston‐Salem, NC ; and 2 Department of Neurology, Wake Forest University Baptist Medical Center, Winston‐Salem, NC ) Rationale: Bradycardia and asystole occurring during seizures are thought to be possible risk factors for SUDEP in patients with epilepsy. Pacemaker implantation has been carried out in most patients because of concerns of potential cardiac morbidity and mortality. Literature review of patients reported to have ictal asystole and pacemakers implanted show them to have a long history of seizures and better control of seizures following diagnosis and change in treatment resulting in lack of pacemaker activation. We report a patient with ictal asystole on VEEG who failed prior montherapy that was subsequently treated with Levetiracetam (LEV) and did not undergo pacemaker implantation. Methods: The case is a 27 year old female with a 4 year history of spells consisting of an aura of deja vu and fear followed by loss of consciousness for less than 30 seconds. She was also described as becoming limp with tongue biting and incontinence but no tonic clonic activity. Due to lack of response to Topiramate and need to characterize spells, she underwent VEEG monitoring. Results: VEEG recording of 2 events were done. The two events were preceded by tachycardia which was up to 200 beats per minute(bpm) followed by asystole for 20 seconds in one and tachycardia of 120 bpms followed by bradycardia of 30 seconds in the other. (VEEG will be shown at meeting).There was brief right temporal theta seziure activity seen preceding the second event. SPECT injection was normal. The patient was placed on LEV and underwent a Reveal Loop recorder implantation for continuous EKG recording. The patient has been seizure free for 6 months with no cardiac arrhythmias detected. Conclusions: Ictal asystole has not been associated with increased mortality from epilepsy. The occurrence of asystole during seizures in patients with longstanding epilepsy and reports that seizures may respond to antiepileptic medication supports this concept. Patterns of heart rate change leading to ictal asystole appear unique and will be discussed. Further studies looking at larger numbers of patients with comprehensive cardiac evaluation are needed to further understand the concept of SUDEP rather than single aspects such as bradyarrhythmias. This case suggests that ictal asystole may not necessitate pacemaker implantation. 1 Luis Otavio S. Caboclo, 1 Henrique Carrete Jr., 1 Ricardo S. Centeno, 1 Elza Marcia T. Yacubian, and 1,2 Americo C. Sakamoto ( 1 Neurology and Neurosurgery, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil ; and 2 Neurology, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil ) Rationale: Patients with temporal lobe epilepsy (TLE) and unilateral severe hippocampal sclerosis (HS) may have contralateral temporal scalp ictal onset. This has recently been called “burned‐out hippocampus,” which is believed to be a rare entity (1). In this study we report four patients with unilateral hippocampal sclerosis and contralateral ictal onset registered by scalp‐sphenoidal electrodes. We discuss the importance of such cases in pre‐surgical evaluation of patients with TLE, as well as possible strategies used for evaluation of these particular cases. Methods: We reviewed charts from all patients with TLE submitted to pre‐surgical evaluation, which included high resolution MRI and prolonged video‐EEG monitoring, during a two‐year period (2003–2004). We searched for patients who only had seizures that were clearly contralateral in location to the atrophic hippocampus. Results: Four patients fulfilled the criteria above. All four had unilateral HS with severely atrophic hippocampus, confirmed by volumetric measures. Two of these patients went through semi‐invasive video‐EEG monitoring with foramen ovale (FO) electrodes, which revealed seizures originating from the atrophic hippocampus, hence confirming false lateralization in the scalp EEG. These patients were submitted to surgical treatment – anterior temporal lobectomy – and had favorable prognosis after surgery. The other two patients are still going through pre‐surgical evaluation. Conclusions: Burned‐out hippocampus syndrome may not be as rare as it was previously believed. Further studies will be necessary before one can affirm that patients with unilateral HS and scalp ictal EEG showing contralateral ictal onset may be operated without confirmation of the epileptogenic zone by invasive monitoring. In these patients, semi‐invasive monitoring with FO electrodes might be an interesting alternative. REFERENCE 1. Mintzer S , Cendes F , Soss J , Andermann F , Engel J Jr. , Dubeau F , Olivier A , Fried I . . Epilepsia 2004 ; 45 : 792 – 802 . (Supported by FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior)/CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico).) 1 David R. Chabolla ( 1 Neurology, Mayo Clinic Jacksonville, Jacksonville, FL ) Rationale: To determine if whispering or feeble motor displays in response to commands during the initial post‐ictal recovery of responsiveness can help to differentiate epileptic from psychogenic seizures. Methods: Video‐EEG recordings from 100 consecutive adult admissions to the EMU during 2003 and 2004 were reviewed. The medical history and clinical follow‐up after EMU dismissal were also reviewed. Cases were divided into three diagnostic categories: 1) epileptic seizures (ES), 2) physiological events (phyE) that included movement disorders, parasomnias, and syncope, 3) psychogenic nonepileptic seizure (pNES) that included the somatoform, dissociative, and anxiety disorders with panic attacks. Cases without a recorded spell or with only brief subjective symptoms without loss of responsiveness were excluded from the analysis. Specific attention was paid to the behaviors occurring during the first 1 to 2 minutes of verbal and motor responsiveness in the post‐ictal recovery phase. Whispery verbal responses were identified by low volume, soft speech using breath instead of phonation. A feeble motor response to command involved movement of the correct limb in a manner lacking force, strength, or effectiveness and typically not completing the task. Results: Twenty five (25%) had pNES, 43 (43%) had ES, 9 (9%) had phyE, and 23 (23%) had no recorded symptoms or only brief subjective symptoms without loss of responsiveness. PNES cases consisted of 21 (84%) somatoform or dissociative disorder (all females) and 4 (16%) anxiety disorder with panic attacks (1 female). No cases of malingering or facticious disorder were diagnosed. The 25 pNES patients experienced approximately 240 events (range 1–22/patient). The initial 1 to 2 minutes of verbal or motor response in the post‐ictal recovery phase were associated with whispering or feeble motor responses to command in 16 (21%) of all cases and 76% of pNES cases due to a somatoform or dissociative disorder. These signs were not seen in any of the panic disorder, phyE, or ES cases. In 132 (73%) of the seizures in patients with a somatoform or dissociative disorder, both seizures with motor manifestations as well as those with loss of responsiveness without motor manifestations, one or both of these signs were observed. The 5 pNES patients who did not display a whispery voice or feeble movements, and did not have a panic disorder, showed previously reported signs of indifference, telegraphic speech, or regression to child‐like speech patterns post‐ictally. Conclusions: Psychogenic seizures due to somatoform or dissociative disorders are commonly associated with the presence of a whispery voice or feeble motor responses to commands during the initiation of post‐ictal recovery of responsiveness. These signs were not commonly seen after epileptic seizures. A prospective study of a larger population would be helpful to determine the predictive value of these signs. 1 William S. Corrie, and 1 Venkata V. Jakkampudi ( 1 Department of Neurology, Virginia Commonwealth University, Richmond, VA ) Rationale: Individuals contemplating admission to an epilepsy monitoring unit wish an estimate of the time they should plan to stay and the likelihood that the stay will lead to a diagnosis. We sought to provide data that will aid in answering these questions. Methods: We reviewed all patients 18 years or older who were referred for diagnosis of seizures and seizure‐like behavior in the last five years. From admission history and descriptions of witnesses, we defined a particular seizure pattern or behavior pattern as the event we were asked to assess. We call this the “target event.” Most patients had all anticonvulsant medications discontinued beginning with the morning dose on the day of admission. Some did not take medications with long half‐lives for a longer period before admission. Sometimes, we are asked to identify the nature of a new pattern that occurs with patients on medications, and these patients continue their home medications. On occasion, we found that the “target event” was non‐epileptic, on other occasions it was epileptic. Some patients had additional “non‐target” events. We considered an admission as “not successful” when we did not record the event that represented the current chief complaint and/or the event that the patient's physician needed clarified. Results: We found 180 men and 352 women who were monitored as described above. We observed “target events” in 316 of them. Duration of monitoring was variable. Thus, we report the patients having their first “target event” in a day as a percentage of patients who entered that day without having one in an earlier session. We found that 27.8% had a “target event” on the first day, 13% within the first six hours. The second day, 25.7% had their first event; the third day, 18.6%; the fourth day, 17.1% and 10.0%on the fifth day. Although we recorded only twenty patients yet to have an event on the sixth day, two of them had their first target event on that day. Conclusions: A single day of monitoring will only lead to a diagnosis in about one quarter of admitted adult patients. Three days of monitoring will provide at least one diagnostic event in about one half of the patients. If we recorded no “target events” after four days of monitoring, we have a chance of recording such data in only 10% of these remaining patients. This suggests that four days of monitoring may be a point of diminishing returns. 1,2 Maria Luiza C. Dal‐Cól, 2 Vera Cristina Terra‐Bustamante, 2 Tonicarlo R. Velasco, 1 José Antônio C. De Oliveira, 1,2 Poliana Bertti, 2 Américo C. Sakamoto, and 1 Norberto Garcia‐Cairasco ( 1 Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo, Brazil ; and 2 Neurology, Psychiatry and Psychology, Ribeirão Preto School of Medicine, University of São Paulo ‐ FMRP/USP, Ribeirão Preto, São Paulo, Brazil ) Rationale: The aim of this work was to differentiate behavioral pattern of human right (RTLE) and left (LTLE) temporal lobe seizures with a neuroethological method used and validated in our laboratory for animal models of epilepsy. Methods: We analyzed 14 seizures of 7 patients in each group. Patients were monitorized at CIREP/FMRP/USP between 1997 and 2002. Videos were observed and all patients' behaviors annotated second/second. Data were analyzed using Ethomatic software and displayed as flowcharts including frequency, duration and sequential dyads statistic interaction. (X 2 ≥10.827; >p < 0.001). Results: Pre‐ictal period of both goups were similar, with patients awakened or sleeping. In this case, awakening was the starting point of a seizure. Behaviors as ictal speech; mouth, throat and abdominal clonia; positive verbal command for speech (VC+S) and normal speech (FANO); deglutition automatism; beak and left upper limb paresis; face and eye right hand wiping occurred only in RTLE group. Left hand automatism; eye deviation to the right; right hand tonic posture and relaxing and right upper limb immobility occurred only in LTLE group. Behaviors that happened mostly in the RTLE group: positive verbal command for action (VC+A; 69,2%); left hand dystonia (81,81%); global movements (71,43%). Mostly in the LTLE group: negative verbal command (VC‐; 79,41%), right hand dystonia (76,92%), hip raising (70,97%), left cephalic deviation (69,23%) and left leg automatisms (76,19%). Interaction analysis showed strong interaction (interactions shown, p < 0,001) between global tonic contraction, tremor and global clonic contraction in the LTLE group and more variable clonic and tonic postures in the RTLE, with prominence to left hemibody tonic postures or clonic movements. In the LTLE group we can verify right hand dystonia, and in the RTLE group, an interesting progression from left hand dystonia to left leg dystonia. In the post ictal period, patients from RTLE group present great interaction between CIREP equip questions (INRE) and VC+A, besides VC+S and FANO. In the LTLE group, interactions are mostly between INRE and VC‐. Other interesting feature of the RTLE group is eye, mouth, nose and face wiping with the right hand. Conclusions: We confirmed various behaviors with lateralizatory value described in the literature. Also, recording of all beha
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