YEBEH-04346; No of Pages 5 Epilepsy & Behavior xxx (2015) xxx–xxx
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Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the related safety issues Jiyoung Kim a,b, Dae Soo Jung a,b, Kyoung Jin Hwang c, Ji-Hye Seo d,e, Geon-Youb Na d,e, Seung Bong Hong d,e, Eun Yeon Joo d,e, Dae-Won Seo d,e,⁎ a
Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Republic of Korea BioMedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea c Department of Neurology, Kyunghee University Medical Center, Kyunghee University School of Medicine, Seoul, Republic of Korea d Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea e Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea b
a r t i c l e
i n f o
Article history: Received 19 November 2014 Revised 9 March 2015 Accepted 20 April 2015 Available online xxxx Keywords: Epilepsy monitoring units Exercise Adverse events Patient safety Epilepsy
a b s t r a c t Background and purpose: Long-term videoelectroencephalogram (video-EEG) monitoring is performed to diagnose an epileptic seizure and to investigate the differential diagnosis of paroxysmal events. To provoke an epileptic seizure, an exercise method is performed in some cases during long-term video-EEG recording in the epilepsy monitoring unit (EMU). The purpose of this study was two-fold: to assess the frequency and severity of adverse events associated with the use of an exercise bicycle and to find a way to safely use it in the EMU. Methods: A retrospective survey was performed on all epileptic seizure videos recorded in the EMU from January 2012 to December 2013. Three hundred and fifty patients were included in this study. Results: Eleven patients experienced an epileptic seizure while riding the exercise bicycle in the EMU. One patient's foot got stuck between the cycling pedal and its strap, and one patient fell off the exercise bicycle during the epileptic seizure. However, there were no serious adverse events over two years. Conclusion: Epileptic seizures were not frequent while riding the exercise bicycle, and serious injuries did not occur. But, there is a need to improve the safety in the EMU to control the potentially dangerous factors associated with the use of the exercise bicycle and to continuously monitor the patients with help from the staff. © 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction Long-term videoelectroencephalogram (video-EEG) is one of the most important diagnostic methods for epilepsy. Time locking of the EEG and video monitoring allows the correlation of paroxysmal events with electrical brain activities. This procedure is usually performed in the epilepsy monitoring unit (EMU) when epileptologists diagnose the paroxysmal behavior, epileptic seizures, and sleep
⁎ Corresponding author at: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135710, Republic of Korea. Tel.: +82 2 3410 3599; fax: +82 2 3410 0052. E-mail address: [email protected] (D.-W. Seo).
disorders and localize the seizure foci for epilepsy surgery [1–4]. Epileptologists use some methods to precipitate epileptic seizures and to reduce the duration of monitoring; the most common methods are tapering the antiepileptic drug(s), sleep deprivation, and hyperventilation. Occasionally, the exercise method is also used, if it is either feasible or appropriate to provide a seizure [5-8]. During the stay in the EMU, patients may experience various degrees of harmful events and injuries related to seizures, such as status epilepticus, postictal psychosis, aspiration pneumonia, cardiac arrest, fracture, and death [9–13]. Safety issues are very important for patients and staff in the EMU. However, the safety of the exercise method has rarely been evaluated. In our EMU, we have recommended the exercise method for the past two years for all the assessed patients except for the patients undergoing invasive monitoring. We retrospectively reviewed the epileptic seizures that occurred while patients in the EMU were riding the exercise bicycle. The aim of
http://dx.doi.org/10.1016/j.yebeh.2015.04.049 1525-5050/© 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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J. Kim et al. / Epilepsy & Behavior xxx (2015) xxx–xxx
Fig. 1. A chart demonstrating the number of patients who were evaluated in the EMU and developed an epileptic seizure while riding the exercise bicycle.
Table 1 Demographics and clinical features. Patient number
Gender
Age
Age at onset of epilepsy
Total number of AEDs
Etiology
Epilepsy syndrome
1 2 3 4 5 6 7
F M M M F M M
50 38 35 20 27 54 48
25 28 17 8 6 20 37
5 3 3 1 5 5 3
Cryptogenic DNET Posttraumatic Cryptogenic HS HS Postinfectious
8 9 10 11
F F M F
18 44 21 37
11 31 19 29
2 3 2 1
HS Cryptogenic Cryptogenic Vascular malformation
TLE, NL TLE, Rt FLE, Rt FLE, NL TLE, Lt TLE, Lt Unclear (SZ not lateralized and localized) TLE, Lt TLE, Lt Generalized TLE, Lt
2. Methods 2.1. Patients and clinical data
AED: antiepileptic drug, F: female, M: male, HS: hippocampal sclerosis, DNET: dysembryoplastic neuroepithelial tumor, TLE: temporal lobe epilepsy, FLE: frontal lobe epilepsy, NL: nonlateralized, Rt: right, Lt: left, and SZ: seizure.
this study was two-fold: to evaluate the frequency and severity of adverse events that occurred while performing the exercise method in the EMU and to find a way to safely perform the exercise method such as riding the exercise bicycle in the EMU.
In this study, we retrospectively reviewed video-EEG data of all the patients who were hospitalized in the EMU at the Department of Neurology, Samsung Medical Center, Korea from January 2012 to December 2013. Three hundred and ninety-three consecutive patients underwent video-EEG monitoring in the EMU. Forty-three patients underwent invasive video-EEG monitoring using subdural and/or depth electrodes. They were not asked to ride the exercise bicycle during EEG monitoring, and hence, they were excluded from this study. On admission, three hundred and fifty patients who had undergone noninvasive monitoring were recommended the exercise method from the second day of monitoring irrespective of whether they took an antiepileptic drug or not. The patients were asked to ride the exercise bicycle for at least 1 h a day. We used a reclining exercise bicycle. We reviewed all of their medical records and the recorded epileptic seizure videos and identified the epileptic seizures that occurred while the patients were riding the exercise bicycle. The ‘only aura’ event was also considered as an epileptic seizure. Additionally, the patients' medical records were carefully reviewed to confirm the clinical information and to assess the severity of adverse events in the EMU.
Table 2 Patients who developed epileptic seizures during the exercise method (bicycle). Patient Total number number of seizures recorded
Duration of Day of onset of the Number of seizures Semiology of the seizure while riding the exercise monitoring seizure while riding while riding the bicycle the exercise bicycle exercise bicycle in days
Reason for video-EEG monitoring
1 2 3
19 6 2
6 8 16
2 4 16
1 1 2
Refractory seizure Refractory seizure Refractory seizure
4 5 6 7 8 9 10
39 5 23 (only aura: 10) 9 12 (only aura: 8) 19 5 11 4 9 6 12 1 3
3 2 5 3 8 10 2
1 1 2 (only aura) 1 4 4 1
11
4
12
4
1
CPS CPS CPS progressing to GTC seizure CPS CPS Psychic aura CPS CPS CPS Myoclonic SZ progressing to GTC SZ CPS
Adverse events while riding the exercise bicycle
No adverse event No adverse event Foot got stuck, not serious, ictal SPECT was not performed Unclear epilepsy syndrome No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Unclear epilepsy syndrome Fell off the bicycle, not serious Refractory seizure
No adverse event
CPS: complex partial seizure, GTC: generalized tonic–clonic, SPECT: single-photon emission computed topography, and SZ: seizure.
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
J. Kim et al. / Epilepsy & Behavior xxx (2015) xxx–xxx
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2.2. Epilepsy center and EMU Samsung Medical Center is a tertiary referral center for epilepsy in Seoul; the patients are referred from all over the country. The EMU consists of 5 beds, and it is staffed by an epileptologist, a clinical fellow, a nurse, and technicians with specialized training. The EEG was performed using a 64-channel digital video-EEG system (Nicolet Biomedical, Inc., Madison, WI, USA). The surface electrodes were placed according to the international 10-20 system, and additional electrodes were placed whenever needed. During the daytime, one clinical fellow, one nurse, and two EEG technicians worked in the EMU, and during the nighttime and weekend, one clinical fellow, one nurse, and one EEG technician worked in the EMU. We reduced the patients' sleep time from the second day of monitoring to induce an epileptic seizure. On the first day, the patients slept for adequate time and we assessed their sleep EEG to detect the epileptiform discharges. We also reduced the amount of antiepileptic drugs (AEDs). Tapering or withdrawal of AEDs was performed individually by the epilepsy specialist depending on the frequency, duration, and type of seizure. We also encouraged the patient to perform an exercise such as riding the exercise bicycle in the EMU. 3. Results 3.1. Patient profiles and epileptic seizures while riding the exercise bicycle in the EMU We identified 11 patients (3.1%) who experienced an epileptic seizure while riding the exercise bicycle among the patients (350 patients) who were recommended to ride the exercise bicycle for two years. In total, 3.7% of the patients had an epileptic seizure while riding the exercise bicycle among the patients (296 patients) who rode the exercise bicycle (Fig. 1). The mean age of the patients was 35.6 years (range: 18–54 years), and there were six male patients. The mean age at onset of epilepsy was 21.0 years (range: 6–37 years), and the mean number of antiepileptic drugs was 3.0 (range: 1–5). Eight patients had abnormal findings on brain MRI (Table 1). The mean number of recorded seizures was 11.0 (range: 1–39), the mean duration of stay in the EMU was 10.0 days (range: 3–19 days), and the mean day of onset of the first seizure while riding the exercise bicycle was 5.4 days (range: 2–16 days). In two patients, the seizure (patient numbers 3 and 10) progressed from a complex partial seizure (CPS) to a generalized tonic–clonic (GTC) seizure (Table 2). 3.2. Cases and adverse events associated with the use of an exercise bicycle in the EMU Over two years, some adverse events occurred while riding the exercise bicycle (Fig. 2A). Two patients (patient numbers 3 and 10) developed a GTC seizure. A GTC seizure has the potential to cause a serious adverse event. One patient's foot (patient number 3) got stuck between the cycling pedal and the strap (Fig. 2B). During the GTC seizure, both his feet were extensively hyperextended. After the postictal period of confusion, he complained of acute, severe pain in both his feet, but a simple X-ray of his feet and ankles did not show a fracture and the severe pain was relieved after 3 days. Also, ictal SPECT could not be performed because of his unstable posture while riding the exercise bicycle. One patient (patient number 10) fell off the exercise bicycle during the GTC seizure (Fig. 2C), but he did not experience any serious adverse events including fractures and intracranial lesions. 3.3. Staff response and epileptic seizures while riding the exercise bicycle in the EMU In our EMU, the EEG technicians enter the patient's room during an epileptic seizure. They are well trained in performing their task, and
Fig. 2. (A) Exercise bicycle. (B) The patient's foot got stuck between the pedal and strap of the exercise bicycle during a GTC seizure. It is the potential factor that caused a serious adverse event during exercise in the EMU. (C) The patient falls off the exercise bicycle during a GTC seizure.
their average length of service is 10.4 years (range: 5–22 years). Although the staff did not respond to one seizure, they showed an early response to the epileptic seizure and electrical EEG changes that occurred while riding the exercise bicycle. ‘Staff response time’ was defined as the time interval from the ictal EEG onset or push of the seizure button to entry into the patient's room. Mean ‘staff response time’ was 20.0 s (range: 7–50 s). Seven out of the 11 seizures were addressed on the push of the button. Three out of the 11 seizures were addressed at the time of ictal EEG onset. One out of the 11 seizures was not addressed
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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J. Kim et al. / Epilepsy & Behavior xxx (2015) xxx–xxx
Fig. 3. (A) The central station where a technician and an epilepsy fellow watch the patients' real-time video and EEG. (B) When the technician interviews the patient, the technician sees the real-time EEG and looks at the patients in other monitoring units through monitors.
at the time of ictal EEG changes, and this seizure was a complex partial seizure (Fig. 3). 4. Discussion We speculated that exercise would act as a ‘stress factor’ in the EMU, and then we used the reclining exercise bicycle to provoke an epileptic seizure. However, the relationship between exercise and epileptic seizures is controversial [14]. Some recent literatures suggested that exercise reduces seizure frequency or does not increase seizure frequency [15,16]. By contrast, some studies reported that exercise such as riding the bicycle, playing football, and running induced a seizure [6,17–19]. In certain patients, epileptic seizures are considered to be provoked by exercise. These patients should be instructed to perform exercise during long-term video-EEG monitoring. In our study, we used other methods to provoke an epileptic seizure such as AED tapering and sleep deprivation. Also, the amount of exercise varied among the patients. We could not determine the diagnostic yield
of the exercise method for all epileptic seizures during long-term videoEEG monitoring. Considering this point, it is debatable whether the exercise method should be recommended in all patients with epilepsy. However, if the exercise method is used in patients with exerciseinduced seizures, the following points should be considered. First, the exercise method should be performed after considering the seizure type in the patient. In a patient who develops frequent GTC seizures, the exercise method should be avoided as it can lead to falls and serious fractures. Second, potential risk factors related to the use of the equipment or tools should be controlled. For instance, the cycling pedal strap of the exercise bicycle might cause fracture of the leg during an epileptic seizure. Third, the staff of the EMU should conduct continuous surveillance. Dobesberger et al. suggested that all patients should be under continuous surveillance at all times by a well-trained staff since they did not find any significant difference in adverse events between the daytime and nighttime [20]. Lastly, the EMU should be equipped with a video monitor so that the patients can be monitored easily (Figs. 2A, B).
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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5. Conclusion Currently, long-term video-EEG monitoring is used more frequently, and hence, building a safety culture is important for patients in the EMU. Our retrospective observational study demonstrates that the reclining exercise bicycle can be safely used in the EMU. We hope that this study will contribute to developing a safe exercise method or equipment for patients with epilepsy in the EMU. Conflict of interest statement The authors declare that there are no conflicts of interest related to this study. References [1] Ghougassian DF, d'Souza W, Cook MJ, O'Brien TJ. Evaluating the utility of inpatient video-EEG monitoring. Epilepsia 2004;45:928–32. [2] Arrington DK, Ng YT, Troester MM, Kerrigan JF, Chapman KE. Utility and safety of prolonged video-EEG monitoring in a tertiary pediatric epilepsy monitoring unit. Epilepsy Behav 2013;27:346–50. [3] Smolowitz JL, Hopkins SC, Perrine T, Eck KE, Hirsch LJ, O'Neil Mundinger M. Diagnostic utility of an epilepsy monitoring unit. Am J Med Qual 2007;22:117–22. [4] Yogarajah M, Powell HW, Heaney D, Smith SJ, Duncan JS, Sisodiya SM. Long term monitoring in refractory epilepsy: the Gowers Unit experience. J Neurol Neurosurg Psychiatry 2009;80:305–10. [5] Scott CA, Fish TR, Allen PJ. Design of an intensive epilepsy monitoring unit. Epilepsia 2000;41(Suppl. 5):S3–8. [6] Kamel JT, Badawy RA, Cook MJ. Exercise-induced seizures and lateral asymmetry in patients with temporal lobe epilepsy. Epilepsy Behav Case Rep 2014;2:26–30. [7] Shafer PO, Buelow JM, Noe K, Shinnar R, Dewar S, Levisohn PM, et al. A consensusbased approach to patient safety in epilepsy monitoring units: recommendations for preferred practices. Epilepsy Behav 2012;25:449–56.
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[8] Ogunyemi AO, Gomez MR, Klass DW. Seizures induced by exercise. Neurology 1988; 38:633–4. [9] Pack AM. Sudden unexpected death in the epilepsy monitoring unit. Epilepsy Curr 2014;14:78–80. [10] Pati S, Kumaraswamy VM, Deep A, Chung SS, Plueger M, Kiyota G, et al. Characteristics of falls in the epilepsy monitoring unit: a retrospective study. Epilepsy Behav 2013;29: 1–3. [11] Atkinson M, Hari K, Schaefer K, Shah A. Improving safety outcomes in the epilepsy monitoring unit. Seizure 2012;21:124–7. [12] Atkinson M, Shah A, Hari K, Schaefer K, Bhattacharya P. Safety considerations in the epilepsy monitoring unit for psychogenic nonepileptic seizures. Epilepsy Behav 2012;25:176–80. [13] Shafer PO, Buelow J, Ficker DM, Pugh MJ, Kanner AM, Dean P, et al. Risk of adverse events on epilepsy monitoring units: a survey of epilepsy professionals. Epilepsy Behav 2011;20:502–5. [14] Denio LS, Drake Jr ME, Pakalnis A. The effect of exercise on seizure frequency. J Med 1989;20:171–6. [15] Arida RM, Scorza FA, Gomes da Silva S, Schachter SC, Cavalheiro EA. The potential role of physical exercise in the treatment of epilepsy. Epilepsy Behav 2010;17: 432–5. [16] McAuley JW, Long L, Heise J, Kirby T, Buckworth J, Pitt C, et al. A prospective evaluation of the effects of a 12-week outpatient exercise program on clinical and behavioral outcomes in patients with epilepsy. Epilepsy Behav 2001;2:592–600. [17] Schmitt B, Thun-Hohenstein L, Vontobel H, Boltshauser E. Seizures induced by physical exercise: report of two cases. Neuropediatrics 1994;25:51–3. [18] DeToledo JC, Lowe MR. Treadmill injuries in patients with epilepsy. Epilepsy Behav 2003;4:553–5. [19] Nakken KO, Loyning A, Loyning T, Gloersen G, Larsson PG. Does physical exercise influence the occurrence of epileptiform EEG discharges in children? Epilepsia 1997; 38:279–84. [20] Dobesberger J, Walser G, Unterberger I, Seppi K, Kuchukhidze G, Larch J, et al. VideoEEG monitoring: safety and adverse events in 507 consecutive patients. Epilepsia 2011;52:443–52.
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
Contents lists available at ScienceDirect
Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh
Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the related safety issues Jiyoung Kim a,b, Dae Soo Jung a,b, Kyoung Jin Hwang c, Ji-Hye Seo d,e, Geon-Youb Na d,e, Seung Bong Hong d,e, Eun Yeon Joo d,e, Dae-Won Seo d,e,⁎ a
Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Republic of Korea BioMedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea c Department of Neurology, Kyunghee University Medical Center, Kyunghee University School of Medicine, Seoul, Republic of Korea d Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea e Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea b
a r t i c l e
i n f o
Article history: Received 19 November 2014 Revised 9 March 2015 Accepted 20 April 2015 Available online xxxx Keywords: Epilepsy monitoring units Exercise Adverse events Patient safety Epilepsy
a b s t r a c t Background and purpose: Long-term videoelectroencephalogram (video-EEG) monitoring is performed to diagnose an epileptic seizure and to investigate the differential diagnosis of paroxysmal events. To provoke an epileptic seizure, an exercise method is performed in some cases during long-term video-EEG recording in the epilepsy monitoring unit (EMU). The purpose of this study was two-fold: to assess the frequency and severity of adverse events associated with the use of an exercise bicycle and to find a way to safely use it in the EMU. Methods: A retrospective survey was performed on all epileptic seizure videos recorded in the EMU from January 2012 to December 2013. Three hundred and fifty patients were included in this study. Results: Eleven patients experienced an epileptic seizure while riding the exercise bicycle in the EMU. One patient's foot got stuck between the cycling pedal and its strap, and one patient fell off the exercise bicycle during the epileptic seizure. However, there were no serious adverse events over two years. Conclusion: Epileptic seizures were not frequent while riding the exercise bicycle, and serious injuries did not occur. But, there is a need to improve the safety in the EMU to control the potentially dangerous factors associated with the use of the exercise bicycle and to continuously monitor the patients with help from the staff. © 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction Long-term videoelectroencephalogram (video-EEG) is one of the most important diagnostic methods for epilepsy. Time locking of the EEG and video monitoring allows the correlation of paroxysmal events with electrical brain activities. This procedure is usually performed in the epilepsy monitoring unit (EMU) when epileptologists diagnose the paroxysmal behavior, epileptic seizures, and sleep
⁎ Corresponding author at: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135710, Republic of Korea. Tel.: +82 2 3410 3599; fax: +82 2 3410 0052. E-mail address: [email protected] (D.-W. Seo).
disorders and localize the seizure foci for epilepsy surgery [1–4]. Epileptologists use some methods to precipitate epileptic seizures and to reduce the duration of monitoring; the most common methods are tapering the antiepileptic drug(s), sleep deprivation, and hyperventilation. Occasionally, the exercise method is also used, if it is either feasible or appropriate to provide a seizure [5-8]. During the stay in the EMU, patients may experience various degrees of harmful events and injuries related to seizures, such as status epilepticus, postictal psychosis, aspiration pneumonia, cardiac arrest, fracture, and death [9–13]. Safety issues are very important for patients and staff in the EMU. However, the safety of the exercise method has rarely been evaluated. In our EMU, we have recommended the exercise method for the past two years for all the assessed patients except for the patients undergoing invasive monitoring. We retrospectively reviewed the epileptic seizures that occurred while patients in the EMU were riding the exercise bicycle. The aim of
http://dx.doi.org/10.1016/j.yebeh.2015.04.049 1525-5050/© 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
2
J. Kim et al. / Epilepsy & Behavior xxx (2015) xxx–xxx
Fig. 1. A chart demonstrating the number of patients who were evaluated in the EMU and developed an epileptic seizure while riding the exercise bicycle.
Table 1 Demographics and clinical features. Patient number
Gender
Age
Age at onset of epilepsy
Total number of AEDs
Etiology
Epilepsy syndrome
1 2 3 4 5 6 7
F M M M F M M
50 38 35 20 27 54 48
25 28 17 8 6 20 37
5 3 3 1 5 5 3
Cryptogenic DNET Posttraumatic Cryptogenic HS HS Postinfectious
8 9 10 11
F F M F
18 44 21 37
11 31 19 29
2 3 2 1
HS Cryptogenic Cryptogenic Vascular malformation
TLE, NL TLE, Rt FLE, Rt FLE, NL TLE, Lt TLE, Lt Unclear (SZ not lateralized and localized) TLE, Lt TLE, Lt Generalized TLE, Lt
2. Methods 2.1. Patients and clinical data
AED: antiepileptic drug, F: female, M: male, HS: hippocampal sclerosis, DNET: dysembryoplastic neuroepithelial tumor, TLE: temporal lobe epilepsy, FLE: frontal lobe epilepsy, NL: nonlateralized, Rt: right, Lt: left, and SZ: seizure.
this study was two-fold: to evaluate the frequency and severity of adverse events that occurred while performing the exercise method in the EMU and to find a way to safely perform the exercise method such as riding the exercise bicycle in the EMU.
In this study, we retrospectively reviewed video-EEG data of all the patients who were hospitalized in the EMU at the Department of Neurology, Samsung Medical Center, Korea from January 2012 to December 2013. Three hundred and ninety-three consecutive patients underwent video-EEG monitoring in the EMU. Forty-three patients underwent invasive video-EEG monitoring using subdural and/or depth electrodes. They were not asked to ride the exercise bicycle during EEG monitoring, and hence, they were excluded from this study. On admission, three hundred and fifty patients who had undergone noninvasive monitoring were recommended the exercise method from the second day of monitoring irrespective of whether they took an antiepileptic drug or not. The patients were asked to ride the exercise bicycle for at least 1 h a day. We used a reclining exercise bicycle. We reviewed all of their medical records and the recorded epileptic seizure videos and identified the epileptic seizures that occurred while the patients were riding the exercise bicycle. The ‘only aura’ event was also considered as an epileptic seizure. Additionally, the patients' medical records were carefully reviewed to confirm the clinical information and to assess the severity of adverse events in the EMU.
Table 2 Patients who developed epileptic seizures during the exercise method (bicycle). Patient Total number number of seizures recorded
Duration of Day of onset of the Number of seizures Semiology of the seizure while riding the exercise monitoring seizure while riding while riding the bicycle the exercise bicycle exercise bicycle in days
Reason for video-EEG monitoring
1 2 3
19 6 2
6 8 16
2 4 16
1 1 2
Refractory seizure Refractory seizure Refractory seizure
4 5 6 7 8 9 10
39 5 23 (only aura: 10) 9 12 (only aura: 8) 19 5 11 4 9 6 12 1 3
3 2 5 3 8 10 2
1 1 2 (only aura) 1 4 4 1
11
4
12
4
1
CPS CPS CPS progressing to GTC seizure CPS CPS Psychic aura CPS CPS CPS Myoclonic SZ progressing to GTC SZ CPS
Adverse events while riding the exercise bicycle
No adverse event No adverse event Foot got stuck, not serious, ictal SPECT was not performed Unclear epilepsy syndrome No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Refractory seizure No adverse event Unclear epilepsy syndrome Fell off the bicycle, not serious Refractory seizure
No adverse event
CPS: complex partial seizure, GTC: generalized tonic–clonic, SPECT: single-photon emission computed topography, and SZ: seizure.
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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2.2. Epilepsy center and EMU Samsung Medical Center is a tertiary referral center for epilepsy in Seoul; the patients are referred from all over the country. The EMU consists of 5 beds, and it is staffed by an epileptologist, a clinical fellow, a nurse, and technicians with specialized training. The EEG was performed using a 64-channel digital video-EEG system (Nicolet Biomedical, Inc., Madison, WI, USA). The surface electrodes were placed according to the international 10-20 system, and additional electrodes were placed whenever needed. During the daytime, one clinical fellow, one nurse, and two EEG technicians worked in the EMU, and during the nighttime and weekend, one clinical fellow, one nurse, and one EEG technician worked in the EMU. We reduced the patients' sleep time from the second day of monitoring to induce an epileptic seizure. On the first day, the patients slept for adequate time and we assessed their sleep EEG to detect the epileptiform discharges. We also reduced the amount of antiepileptic drugs (AEDs). Tapering or withdrawal of AEDs was performed individually by the epilepsy specialist depending on the frequency, duration, and type of seizure. We also encouraged the patient to perform an exercise such as riding the exercise bicycle in the EMU. 3. Results 3.1. Patient profiles and epileptic seizures while riding the exercise bicycle in the EMU We identified 11 patients (3.1%) who experienced an epileptic seizure while riding the exercise bicycle among the patients (350 patients) who were recommended to ride the exercise bicycle for two years. In total, 3.7% of the patients had an epileptic seizure while riding the exercise bicycle among the patients (296 patients) who rode the exercise bicycle (Fig. 1). The mean age of the patients was 35.6 years (range: 18–54 years), and there were six male patients. The mean age at onset of epilepsy was 21.0 years (range: 6–37 years), and the mean number of antiepileptic drugs was 3.0 (range: 1–5). Eight patients had abnormal findings on brain MRI (Table 1). The mean number of recorded seizures was 11.0 (range: 1–39), the mean duration of stay in the EMU was 10.0 days (range: 3–19 days), and the mean day of onset of the first seizure while riding the exercise bicycle was 5.4 days (range: 2–16 days). In two patients, the seizure (patient numbers 3 and 10) progressed from a complex partial seizure (CPS) to a generalized tonic–clonic (GTC) seizure (Table 2). 3.2. Cases and adverse events associated with the use of an exercise bicycle in the EMU Over two years, some adverse events occurred while riding the exercise bicycle (Fig. 2A). Two patients (patient numbers 3 and 10) developed a GTC seizure. A GTC seizure has the potential to cause a serious adverse event. One patient's foot (patient number 3) got stuck between the cycling pedal and the strap (Fig. 2B). During the GTC seizure, both his feet were extensively hyperextended. After the postictal period of confusion, he complained of acute, severe pain in both his feet, but a simple X-ray of his feet and ankles did not show a fracture and the severe pain was relieved after 3 days. Also, ictal SPECT could not be performed because of his unstable posture while riding the exercise bicycle. One patient (patient number 10) fell off the exercise bicycle during the GTC seizure (Fig. 2C), but he did not experience any serious adverse events including fractures and intracranial lesions. 3.3. Staff response and epileptic seizures while riding the exercise bicycle in the EMU In our EMU, the EEG technicians enter the patient's room during an epileptic seizure. They are well trained in performing their task, and
Fig. 2. (A) Exercise bicycle. (B) The patient's foot got stuck between the pedal and strap of the exercise bicycle during a GTC seizure. It is the potential factor that caused a serious adverse event during exercise in the EMU. (C) The patient falls off the exercise bicycle during a GTC seizure.
their average length of service is 10.4 years (range: 5–22 years). Although the staff did not respond to one seizure, they showed an early response to the epileptic seizure and electrical EEG changes that occurred while riding the exercise bicycle. ‘Staff response time’ was defined as the time interval from the ictal EEG onset or push of the seizure button to entry into the patient's room. Mean ‘staff response time’ was 20.0 s (range: 7–50 s). Seven out of the 11 seizures were addressed on the push of the button. Three out of the 11 seizures were addressed at the time of ictal EEG onset. One out of the 11 seizures was not addressed
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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J. Kim et al. / Epilepsy & Behavior xxx (2015) xxx–xxx
Fig. 3. (A) The central station where a technician and an epilepsy fellow watch the patients' real-time video and EEG. (B) When the technician interviews the patient, the technician sees the real-time EEG and looks at the patients in other monitoring units through monitors.
at the time of ictal EEG changes, and this seizure was a complex partial seizure (Fig. 3). 4. Discussion We speculated that exercise would act as a ‘stress factor’ in the EMU, and then we used the reclining exercise bicycle to provoke an epileptic seizure. However, the relationship between exercise and epileptic seizures is controversial [14]. Some recent literatures suggested that exercise reduces seizure frequency or does not increase seizure frequency [15,16]. By contrast, some studies reported that exercise such as riding the bicycle, playing football, and running induced a seizure [6,17–19]. In certain patients, epileptic seizures are considered to be provoked by exercise. These patients should be instructed to perform exercise during long-term video-EEG monitoring. In our study, we used other methods to provoke an epileptic seizure such as AED tapering and sleep deprivation. Also, the amount of exercise varied among the patients. We could not determine the diagnostic yield
of the exercise method for all epileptic seizures during long-term videoEEG monitoring. Considering this point, it is debatable whether the exercise method should be recommended in all patients with epilepsy. However, if the exercise method is used in patients with exerciseinduced seizures, the following points should be considered. First, the exercise method should be performed after considering the seizure type in the patient. In a patient who develops frequent GTC seizures, the exercise method should be avoided as it can lead to falls and serious fractures. Second, potential risk factors related to the use of the equipment or tools should be controlled. For instance, the cycling pedal strap of the exercise bicycle might cause fracture of the leg during an epileptic seizure. Third, the staff of the EMU should conduct continuous surveillance. Dobesberger et al. suggested that all patients should be under continuous surveillance at all times by a well-trained staff since they did not find any significant difference in adverse events between the daytime and nighttime [20]. Lastly, the EMU should be equipped with a video monitor so that the patients can be monitored easily (Figs. 2A, B).
Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
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5. Conclusion Currently, long-term video-EEG monitoring is used more frequently, and hence, building a safety culture is important for patients in the EMU. Our retrospective observational study demonstrates that the reclining exercise bicycle can be safely used in the EMU. We hope that this study will contribute to developing a safe exercise method or equipment for patients with epilepsy in the EMU. Conflict of interest statement The authors declare that there are no conflicts of interest related to this study. References [1] Ghougassian DF, d'Souza W, Cook MJ, O'Brien TJ. Evaluating the utility of inpatient video-EEG monitoring. Epilepsia 2004;45:928–32. [2] Arrington DK, Ng YT, Troester MM, Kerrigan JF, Chapman KE. Utility and safety of prolonged video-EEG monitoring in a tertiary pediatric epilepsy monitoring unit. Epilepsy Behav 2013;27:346–50. [3] Smolowitz JL, Hopkins SC, Perrine T, Eck KE, Hirsch LJ, O'Neil Mundinger M. Diagnostic utility of an epilepsy monitoring unit. Am J Med Qual 2007;22:117–22. [4] Yogarajah M, Powell HW, Heaney D, Smith SJ, Duncan JS, Sisodiya SM. Long term monitoring in refractory epilepsy: the Gowers Unit experience. J Neurol Neurosurg Psychiatry 2009;80:305–10. [5] Scott CA, Fish TR, Allen PJ. Design of an intensive epilepsy monitoring unit. Epilepsia 2000;41(Suppl. 5):S3–8. [6] Kamel JT, Badawy RA, Cook MJ. Exercise-induced seizures and lateral asymmetry in patients with temporal lobe epilepsy. Epilepsy Behav Case Rep 2014;2:26–30. [7] Shafer PO, Buelow JM, Noe K, Shinnar R, Dewar S, Levisohn PM, et al. A consensusbased approach to patient safety in epilepsy monitoring units: recommendations for preferred practices. Epilepsy Behav 2012;25:449–56.
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Please cite this article as: Kim J, et al, Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the ..., Epilepsy Behav (2015), http://dx.doi.org/10.1016/j.yebeh.2015.04.049
