- Email: [email protected]
34. Guidelines and nomenclature in critical care continuous EEG monitoring
e310
Abstracts / Clinical Neurophysiology 127 (2016) e304–e321
interventions were used, depending on the findings. Six clusters were observed (postulated dysfunctions to be explained). Longterm therapeutic interventions were suggested by the dysfunctional pattern observed in each individual. Treatment response at six months was superior to literature reports on methylphenidate and/or behavioral therapies. In conclusion, neurophysiology can identify different types of dysfunction underlying the spectrum of ADD. Dysfunctional findings, along with psychosocial factors, can guide treatment selection toward a better and faster response. doi:10.1016/j.clinph.2016.05.304
30. QEEG in learning disabled children—Thalia Harmony, Thalia Fernandez (Instituto de Neurobiologia, UNAM Campus Juriquilla, Mexico) Learning disabilities (LD) are one of the most frequent problems that afflict children in elementary school. LD are classified as ‘‘specific” (reading disorder, mathematics disorder, or disorder of written expression) or ‘‘learning disorder not otherwise specified,” which might include problems in all three areas. Children included in this study belonged to the latter group. EEG spectral analysis has shown itself to be useful if adequate norms are used to compare the resting EEG of a child with the norms. The EEG of LD children is characterized by slower activity, principally in the theta range, and less alpha activity than normal children of the same age. Our results in a longitudinal study, showed that there is a very good prognosis for those children that show a marked spurt of EEG maturation, between 9 and 12 years of age: in the presence of more delta and theta activity in comparison with normal children, repeating the study 2 years later, to analyze if the disorder was related to a maturational lag or other type of problem, would be recommended. doi:10.1016/j.clinph.2016.05.305
31. Intraoperative monitoring of motor cranial nerves and cranial nerve nuclei—Jaime R. Lopez (Neurology and Neurosurgery, Stanford University School of Medicine, CA, USA) Intraoperative neurophysiologic monitoring of cranial nerve function is primarily performed in those cranial nerves whose function has a motor component. The rationale, as well as the stimulation and recording techniques employed, is similar to that used in assessing the functional integrity of motor peripheral nerves. The primary difference is in the placement of the recording electrodes and the neural structures that are at risk for injury. In addition, cranial nerve dysfunction is not solely confined to a cranial nerve but can also involve the nucleus of the specific nerve. Thus, a special application of cranial nerve monitoring is the functional assessment and monitoring of cranial nerve nuclei. The goal of this presentation is to review the neurophysiologic techniques, consisting primarily of EMG, used to monitor motor cranial nerves and cranial nerve nuclei, and highlight this with case examples. doi:10.1016/j.clinph.2016.05.306
32. BAEPs and their application in monitoring the auditory pathway—Miguel Angel Collado (Clinical Neurophysiology, Centro Medico ABC, Mexico City, Mexico) We discuss cases with cerebellopontine angle surgery and intraoperative monitoring with auditory evoked potentials. The aim of neuromonitoring is to provide the surgical team with an additional
instrument to assess the functional state of the hearing pathway with objective neurophysiological criteria, during surgery near the eighth cranial nerve. Changes in latency, amplitude or total loss of the responses during a neurovascular decompression of the trigeminal nerve, can be avoided by the surgeon modifying the surgical technique. Monitoring is challenging in chronic lesions with poor basal studies. In cases of acoustic neuroma with preserved, but low voltage potentials, the outcome is good. In other cases, latency increments and transient amplitude attenuation, with normalization at the end of surgery, the postoperative results were good with hearing preservation. The relationship between intraoperative auditory evoked potentials changes and eighth nerve integrity with hearing preservation, are consistent with patient prognosis. doi:10.1016/j.clinph.2016.05.307
33. Special characteristics of cortical motor mapping in children—Martin Segura (Clinical Neurophysiology Unit, Neurology Department, Hospital Nacional de Pediatria ‘‘Dr. Juan P. Garrahan”, Buenos Aires, Argentina) Direct Cortical Stimulation (DCS) for motor mapping and monitoring has special characteristics in children. Several physiological, pathological, and pharmacological factors determine higher cortical motor thresholds (CMT) in this population. It is known that physiological CMT to electrical or magnetic stimulation progressively decrease from the first months of life reaching adult values at about the age of 18 years. Certain pathological conditions such as errors in neuronal migration, dysembryoplastic neuroepithelial tumor, cortical dysplasia, and retro-rolandic low grade glioma may further increase CMT. In addition, some antiepileptic drugs, especially those blocking voltage-dependent Na+ channels also decrease cortical excitability. Despite these difficulties, in our experience DCS was successful in mapping the motor cortex in 34 out of 34 surgeries in 32 children aged 3–17 years old. Under total intravenous anesthesia (propofol plus remifentanil) and employing five-stimulus anodic trains with inter-stimulus intervals of 2–3 ms, DCS intensities needed to evoke limb- or face-muscle responses ranged from 20 to 85 mA. Although these intensities are higher than those reported in adult patients, they remained within safety limits (5.95 uC/ph) and did not exert seizures in any case. Atypical somatotopic representation due to anatomical distortion or cortical reorganization was also found in some patients. doi:10.1016/j.clinph.2016.05.308
34. Guidelines and nomenclature in critical care continuous EEG monitoring—Marc R. Nuwer (University of California Los Angeles, Los Angeles, California, USA) Nomenclature is key to describing clearly the clinical events in a critical care continuous EEG recording. Uniform nomenclature facilitates multicenter studies. It allows clinicians to understand better the meaning of studies performed at another institution. Recent clearer nomenclature proposed definition of many terms, such as for rhythmic or periodic patterns, prevalence, frequency, duration, amplitude, symmetry, and other terms for critical care monitoring (Hirsch, J Clin Neurophys; 2013). A consensus guideline recommends continuous EEG recording (a) to identify nonconvulsive seizures, (b) to assess efficacy of therapy, (c) to identify ischemia in high-risk patients (d), to assess depth of coma or sedation, (e) and for prognosis after cardiac arrest (Herman, J Clin Neurophys; 2015). The consensus guideline also describes personnel qualifications, e. g. for interpreting physicians, technical specification for equipment,
Abstracts / Clinical Neurophysiology 127 (2016) e304–e321
and how recordings should be acquired, reviewed and interpreted. These are meant to provide guidance for quality patient care services. doi:10.1016/j.clinph.2016.05.309
35. Continuous EEG implementation–interpretation—Aatif Husain (Medical Center and Neurodiagnostic Center, VA. Duke University, Durham, NC, USA) Patients admitted to the hospital with acute neurological problems have a high risk of having seizures. Since most of the seizures are nonconvulsive, continuous EEG (cEEG) monitoring is necessary to detect them. Up to 20% of critically ill patients undergoing cEEG monitoring are found to have seizures or status epilepticus. CEEG monitoring is being recognized as a necessary tool in the evaluation of neurologically critically ill patients. In this presentation, the implementation of a cEEG monitoring service will be discussed. Additionally, the proper selection of patients, duration of monitoring and the conditions for which cEEG monitoring is most useful will be discussed. doi:10.1016/j.clinph.2016.05.310
36. CS11.2 deep brain stimulation in Parkinson disease—Jay Shils (Neurophysiological Intraoperative Monitoring, Rush University Medical Center, Chicago, IL, USA) Surgical treatment for movement disorders in the basal ganglia dates back to the 1930’s when Meyers first described campotomy. In the 1940’s Spiegel and Wycis described the first human use of stereotactic surgery for treatment of psychiatric illnesses. From the 1930’s through the 1960’s neurophysiology played a small role in these procedures, but it was the work of Dr. Albe-Fessard in the 1960’s that opened the door for intra-operative micro-electrode recording that has become a critical tool for functional localization during movement disorders surgery and most centers. The neurophysiologists is no longer the reporter of previous events, the information gained, interpreted, and analyzed by the neurophysiologist is used by the surgeon to plan the course of the procedure. In order for the neurophysiologist to perform these actions they need to not only have a detailed knowledge of the anatomy, basic physiology, and equipment, they also need to be familiar. doi:10.1016/j.clinph.2016.05.311
37. Utility of trans-operatory localization of brain targets for neuromodulation in refractory epilepsy—Ana Luisa Velasco (Head of the Epilepsy Clinic, Neurology and Neurosurgery Service, General Hospital of Mexico, Mexico) Electrical neuromodulation to treat refractory seizures has been used as a functional alternative in patients in whom ablative surgery is not an option. When we talk about neuromodulation, several elements come into consideration. One of them is to select the stimulation target. In this matter, we consider there are two approaches: stop seizure propagation or generation. The decision is based on seizure type and etiology (using all diagnostic procedures in our hands to have a correct diagnosis). If we chose to stop propagation, a careful analysis of the neural paths that permit the epileptic activity to spread, has to be performed. Imaging studies and stereotactic technique are primordial to localize the area to be stimulated, but not enough. In these cases, the intraoperative monitoring plays a very
e311
relevant role. When anatomic and physiologic localization parameters are reached, the outcome of the patient improves dramatically. Intraoperative depth stimulation is performed using low frequency to obtain recruiting responses and high frequency to obtain DC shifts. Recording is performed in scalp EEG to localize responses. Deciding to halt seizure generation needs to precise, the epileptic focus intraoperative recording might not be the best strategy, and thus, intraoperative monitoring is limited. doi:10.1016/j.clinph.2016.05.312
38. Mapping eloquent cortical areas with direct electrical stimulation—Paul Shkurovich Bialik (Clinical Neurophysiology, Centro Medico ABC, Mexico City, Mexico) Neurosurgical treatment of lesions in close spatial proximity to eloquent areas of the brain remains a challenge. The knowledge of topographical anatomy is not always enough to determine resection extension of the lesion. To identify the anatomical relation of a lesion to a cortical area, and to define the maximum limits of such resection, several techniques are used to guide the procedure. Using such techniques, resection of lesions previously classified as unresectable became possible, with relative low morbidity. In order to maximize the extent of the resection, the available neurophysiological and non-neurophysiological tools include imaging studies, both structural and functional like intraoperative MRI. Critical functional areas of the brain like cognitive, motor and language function can be mapped preoperatively with functional MRI, diffusion tensor imaging fiber tracking, magnetoencephalography, and navigated transcranial magnetic stimulation, or intraoperatively by direct electrical stimulation of the cortex or subcortical white matter tracts. Cortical Stimulation Mapping using electrical stimulation is considered the gold standard for mapping functional regions of the brain to create a presurgical plan that maximizes the patient’s functional outcome. doi:10.1016/j.clinph.2016.05.313
39. Safety issues in the operating room—Jay Shils (Neurophysiological Intraoperative Monitoring, Rush University Medical Center, Chicago, IL, USA) Safety for the intra-operative monitoring team can be divided into three concerns: (A) the patient; (B) the operating room personnel; (C) the IOM and operating room equipment. Poor electronic isolation can potentially expose the patient to higher than normal currents in either the IOM electrodes touching the patient, or even other electrical conduits touching the patient such as from the cautery system. Simple impedance test only tell you whether or not an electrode is in contact with the patient, not whether or not it is in the correct place. Improper returns can cause erroneous data by picking up large signals that can obscure the real signals. The two biggest issues with the safety of the operating room personnel are the wires that go from the patient to the IOM equipment and the needles that many groups use for recording. A third, less common safety issue is the potential for electrode wires to be knocked about or even disconnected by the surgeon or assistants. All wires, whether going from the amp and stimulation boxes to the IOM machine, or electrode wires should be neatly hidden under the patient or OR table or run in a neat way, trying to follow areas that are hard to walk over. doi:10.1016/j.clinph.2016.05.314
Abstracts / Clinical Neurophysiology 127 (2016) e304–e321
interventions were used, depending on the findings. Six clusters were observed (postulated dysfunctions to be explained). Longterm therapeutic interventions were suggested by the dysfunctional pattern observed in each individual. Treatment response at six months was superior to literature reports on methylphenidate and/or behavioral therapies. In conclusion, neurophysiology can identify different types of dysfunction underlying the spectrum of ADD. Dysfunctional findings, along with psychosocial factors, can guide treatment selection toward a better and faster response. doi:10.1016/j.clinph.2016.05.304
30. QEEG in learning disabled children—Thalia Harmony, Thalia Fernandez (Instituto de Neurobiologia, UNAM Campus Juriquilla, Mexico) Learning disabilities (LD) are one of the most frequent problems that afflict children in elementary school. LD are classified as ‘‘specific” (reading disorder, mathematics disorder, or disorder of written expression) or ‘‘learning disorder not otherwise specified,” which might include problems in all three areas. Children included in this study belonged to the latter group. EEG spectral analysis has shown itself to be useful if adequate norms are used to compare the resting EEG of a child with the norms. The EEG of LD children is characterized by slower activity, principally in the theta range, and less alpha activity than normal children of the same age. Our results in a longitudinal study, showed that there is a very good prognosis for those children that show a marked spurt of EEG maturation, between 9 and 12 years of age: in the presence of more delta and theta activity in comparison with normal children, repeating the study 2 years later, to analyze if the disorder was related to a maturational lag or other type of problem, would be recommended. doi:10.1016/j.clinph.2016.05.305
31. Intraoperative monitoring of motor cranial nerves and cranial nerve nuclei—Jaime R. Lopez (Neurology and Neurosurgery, Stanford University School of Medicine, CA, USA) Intraoperative neurophysiologic monitoring of cranial nerve function is primarily performed in those cranial nerves whose function has a motor component. The rationale, as well as the stimulation and recording techniques employed, is similar to that used in assessing the functional integrity of motor peripheral nerves. The primary difference is in the placement of the recording electrodes and the neural structures that are at risk for injury. In addition, cranial nerve dysfunction is not solely confined to a cranial nerve but can also involve the nucleus of the specific nerve. Thus, a special application of cranial nerve monitoring is the functional assessment and monitoring of cranial nerve nuclei. The goal of this presentation is to review the neurophysiologic techniques, consisting primarily of EMG, used to monitor motor cranial nerves and cranial nerve nuclei, and highlight this with case examples. doi:10.1016/j.clinph.2016.05.306
32. BAEPs and their application in monitoring the auditory pathway—Miguel Angel Collado (Clinical Neurophysiology, Centro Medico ABC, Mexico City, Mexico) We discuss cases with cerebellopontine angle surgery and intraoperative monitoring with auditory evoked potentials. The aim of neuromonitoring is to provide the surgical team with an additional
instrument to assess the functional state of the hearing pathway with objective neurophysiological criteria, during surgery near the eighth cranial nerve. Changes in latency, amplitude or total loss of the responses during a neurovascular decompression of the trigeminal nerve, can be avoided by the surgeon modifying the surgical technique. Monitoring is challenging in chronic lesions with poor basal studies. In cases of acoustic neuroma with preserved, but low voltage potentials, the outcome is good. In other cases, latency increments and transient amplitude attenuation, with normalization at the end of surgery, the postoperative results were good with hearing preservation. The relationship between intraoperative auditory evoked potentials changes and eighth nerve integrity with hearing preservation, are consistent with patient prognosis. doi:10.1016/j.clinph.2016.05.307
33. Special characteristics of cortical motor mapping in children—Martin Segura (Clinical Neurophysiology Unit, Neurology Department, Hospital Nacional de Pediatria ‘‘Dr. Juan P. Garrahan”, Buenos Aires, Argentina) Direct Cortical Stimulation (DCS) for motor mapping and monitoring has special characteristics in children. Several physiological, pathological, and pharmacological factors determine higher cortical motor thresholds (CMT) in this population. It is known that physiological CMT to electrical or magnetic stimulation progressively decrease from the first months of life reaching adult values at about the age of 18 years. Certain pathological conditions such as errors in neuronal migration, dysembryoplastic neuroepithelial tumor, cortical dysplasia, and retro-rolandic low grade glioma may further increase CMT. In addition, some antiepileptic drugs, especially those blocking voltage-dependent Na+ channels also decrease cortical excitability. Despite these difficulties, in our experience DCS was successful in mapping the motor cortex in 34 out of 34 surgeries in 32 children aged 3–17 years old. Under total intravenous anesthesia (propofol plus remifentanil) and employing five-stimulus anodic trains with inter-stimulus intervals of 2–3 ms, DCS intensities needed to evoke limb- or face-muscle responses ranged from 20 to 85 mA. Although these intensities are higher than those reported in adult patients, they remained within safety limits (5.95 uC/ph) and did not exert seizures in any case. Atypical somatotopic representation due to anatomical distortion or cortical reorganization was also found in some patients. doi:10.1016/j.clinph.2016.05.308
34. Guidelines and nomenclature in critical care continuous EEG monitoring—Marc R. Nuwer (University of California Los Angeles, Los Angeles, California, USA) Nomenclature is key to describing clearly the clinical events in a critical care continuous EEG recording. Uniform nomenclature facilitates multicenter studies. It allows clinicians to understand better the meaning of studies performed at another institution. Recent clearer nomenclature proposed definition of many terms, such as for rhythmic or periodic patterns, prevalence, frequency, duration, amplitude, symmetry, and other terms for critical care monitoring (Hirsch, J Clin Neurophys; 2013). A consensus guideline recommends continuous EEG recording (a) to identify nonconvulsive seizures, (b) to assess efficacy of therapy, (c) to identify ischemia in high-risk patients (d), to assess depth of coma or sedation, (e) and for prognosis after cardiac arrest (Herman, J Clin Neurophys; 2015). The consensus guideline also describes personnel qualifications, e. g. for interpreting physicians, technical specification for equipment,
Abstracts / Clinical Neurophysiology 127 (2016) e304–e321
and how recordings should be acquired, reviewed and interpreted. These are meant to provide guidance for quality patient care services. doi:10.1016/j.clinph.2016.05.309
35. Continuous EEG implementation–interpretation—Aatif Husain (Medical Center and Neurodiagnostic Center, VA. Duke University, Durham, NC, USA) Patients admitted to the hospital with acute neurological problems have a high risk of having seizures. Since most of the seizures are nonconvulsive, continuous EEG (cEEG) monitoring is necessary to detect them. Up to 20% of critically ill patients undergoing cEEG monitoring are found to have seizures or status epilepticus. CEEG monitoring is being recognized as a necessary tool in the evaluation of neurologically critically ill patients. In this presentation, the implementation of a cEEG monitoring service will be discussed. Additionally, the proper selection of patients, duration of monitoring and the conditions for which cEEG monitoring is most useful will be discussed. doi:10.1016/j.clinph.2016.05.310
36. CS11.2 deep brain stimulation in Parkinson disease—Jay Shils (Neurophysiological Intraoperative Monitoring, Rush University Medical Center, Chicago, IL, USA) Surgical treatment for movement disorders in the basal ganglia dates back to the 1930’s when Meyers first described campotomy. In the 1940’s Spiegel and Wycis described the first human use of stereotactic surgery for treatment of psychiatric illnesses. From the 1930’s through the 1960’s neurophysiology played a small role in these procedures, but it was the work of Dr. Albe-Fessard in the 1960’s that opened the door for intra-operative micro-electrode recording that has become a critical tool for functional localization during movement disorders surgery and most centers. The neurophysiologists is no longer the reporter of previous events, the information gained, interpreted, and analyzed by the neurophysiologist is used by the surgeon to plan the course of the procedure. In order for the neurophysiologist to perform these actions they need to not only have a detailed knowledge of the anatomy, basic physiology, and equipment, they also need to be familiar. doi:10.1016/j.clinph.2016.05.311
37. Utility of trans-operatory localization of brain targets for neuromodulation in refractory epilepsy—Ana Luisa Velasco (Head of the Epilepsy Clinic, Neurology and Neurosurgery Service, General Hospital of Mexico, Mexico) Electrical neuromodulation to treat refractory seizures has been used as a functional alternative in patients in whom ablative surgery is not an option. When we talk about neuromodulation, several elements come into consideration. One of them is to select the stimulation target. In this matter, we consider there are two approaches: stop seizure propagation or generation. The decision is based on seizure type and etiology (using all diagnostic procedures in our hands to have a correct diagnosis). If we chose to stop propagation, a careful analysis of the neural paths that permit the epileptic activity to spread, has to be performed. Imaging studies and stereotactic technique are primordial to localize the area to be stimulated, but not enough. In these cases, the intraoperative monitoring plays a very
e311
relevant role. When anatomic and physiologic localization parameters are reached, the outcome of the patient improves dramatically. Intraoperative depth stimulation is performed using low frequency to obtain recruiting responses and high frequency to obtain DC shifts. Recording is performed in scalp EEG to localize responses. Deciding to halt seizure generation needs to precise, the epileptic focus intraoperative recording might not be the best strategy, and thus, intraoperative monitoring is limited. doi:10.1016/j.clinph.2016.05.312
38. Mapping eloquent cortical areas with direct electrical stimulation—Paul Shkurovich Bialik (Clinical Neurophysiology, Centro Medico ABC, Mexico City, Mexico) Neurosurgical treatment of lesions in close spatial proximity to eloquent areas of the brain remains a challenge. The knowledge of topographical anatomy is not always enough to determine resection extension of the lesion. To identify the anatomical relation of a lesion to a cortical area, and to define the maximum limits of such resection, several techniques are used to guide the procedure. Using such techniques, resection of lesions previously classified as unresectable became possible, with relative low morbidity. In order to maximize the extent of the resection, the available neurophysiological and non-neurophysiological tools include imaging studies, both structural and functional like intraoperative MRI. Critical functional areas of the brain like cognitive, motor and language function can be mapped preoperatively with functional MRI, diffusion tensor imaging fiber tracking, magnetoencephalography, and navigated transcranial magnetic stimulation, or intraoperatively by direct electrical stimulation of the cortex or subcortical white matter tracts. Cortical Stimulation Mapping using electrical stimulation is considered the gold standard for mapping functional regions of the brain to create a presurgical plan that maximizes the patient’s functional outcome. doi:10.1016/j.clinph.2016.05.313
39. Safety issues in the operating room—Jay Shils (Neurophysiological Intraoperative Monitoring, Rush University Medical Center, Chicago, IL, USA) Safety for the intra-operative monitoring team can be divided into three concerns: (A) the patient; (B) the operating room personnel; (C) the IOM and operating room equipment. Poor electronic isolation can potentially expose the patient to higher than normal currents in either the IOM electrodes touching the patient, or even other electrical conduits touching the patient such as from the cautery system. Simple impedance test only tell you whether or not an electrode is in contact with the patient, not whether or not it is in the correct place. Improper returns can cause erroneous data by picking up large signals that can obscure the real signals. The two biggest issues with the safety of the operating room personnel are the wires that go from the patient to the IOM equipment and the needles that many groups use for recording. A third, less common safety issue is the potential for electrode wires to be knocked about or even disconnected by the surgeon or assistants. All wires, whether going from the amp and stimulation boxes to the IOM machine, or electrode wires should be neatly hidden under the patient or OR table or run in a neat way, trying to follow areas that are hard to walk over. doi:10.1016/j.clinph.2016.05.314