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32. BAEPs and their application in monitoring the auditory pathway
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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
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,