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Retinal ganglion cell layer correlates with cognitive involvement in Alzheimer’s disease and mild cognitive impairment
Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
Cervical Vestibular-Evoked Myogenic Potential (cVEMP) in adrenomyeloneuropathy patients—M. Veciana a, J. Pedro a, S. Yagüe a, A. Pujol b, C. Casasnovas a, E.S. Papathanasiou c (a Neurophysiology Unit, Neurology Department, Bellvitge Hospital, L‘Hospitalet de Llobregat, Barcelona, Spain, b Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L‘Hospitalet de Llobregat, Barcelona, Spain, c Clinical Neurophysiology Laboratory, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus) Objective: Adrenomyeloneuropathy (ADM) is one of the clinical phenotypes of adrenoleukodystrophy, characterized by distal axonopathy and varyng degrees of cerebral demyelination. cVEMPs, elicited by acoustic stimulation, are abnormal in several otovestibular disorders and brainstem lesions affecting the vestibulo-cervical reflex pathways. cVEMP have not been described so far in these patients. The aim of this study was to investigate cVEMP in ADM patients. Methods: We studied cVEMPs, brainstem auditory evoked potentials (BAEP) and motor evoked potentials (MEP) in 11 ADM patients. cVEMPs normal values were obtained from 10 healthy age-matched subjects. Results: BAEP and MEP were abnormal in all patients. cVEMPs had an increase latency in 10 tested ears, absent in 1, and normal in 11 ears. The mean latency of p13 was 16.06 ms (range: 13.6–21.8 ms). When responses were present in both ears for the same subject, no asymmetry ratio was detected in the corrected reflex amplitude. Conclusions: In contrast to BAEP and MEP that are severely affected in all patients, cVEMPs are only abnormal in 50% of patients. This shows relative sparing of the saccular neural pathway compared to the cochlear pathway and corticospinal tract. Key message: cVEMPs are abnormal in 50% of patients with ADM. doi:10.1016/j.clinph.2015.11.115
Retinal ganglion cell layer correlates with cognitive involvement in Alzheimer’s disease and mild cognitive impairment—S. Huang, L. Ferrari, E. Coppi, F. Vitali, G. Magnani, G. Comi, L. Leocani (Department of Neurology and INSPE-Institute of Experimental Neurology Scientific Institute and University Hospital San Raffaele, Milan, Italy) Introduction: Optical coherence tomography (OCT) allows noninvasive measurement of retinal nerve fiber layer (RNFL) which is a potential marker of neuronal loss for monitoring the natural course and treatment effect of Alzheimer’s disease (AD). According to previous studies, the ganglion cell layer (GCL) might be more sensitive than RNFL in detecting early neuronal degeneration. Here we aim to demonstrate the potential of GCL as an alternative for evaluating neuronal loss in patients with AD. Materials and methods: Eighteen patients (seven with AD and eleven with MCI) were included and peripapillary scans of both eyes were acquired with spectral domain OCT. Correlations between GCL, RNFL, and minimental state examination (MMSE) was performed using Pearson’s correlation. Results: The severity of cognitive decline (raw MMSE) was positively associated with thinning of GCL in both left (r = 0.665, p = 0.003) and right eye (r = 0.569, p = 0.014), while no correlation was found between RNFL and MMSE score.
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Conclusion: Our result suggested that the GCL may offer more functional relevant information than the RNFL, which makes it a potential biomarker for monitor AD progression. doi:10.1016/j.clinph.2015.11.116
Quantitative EEG-reactivity to different stimulation methods in comatose patients—M. Ebbesen, B. Johnsen (Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark) Objective: This study investigates quantitative EEG-reactivity (EEG-R) as a tool for comparison of the efficiency of different clinical stimulation methods. Methods: Standardized pain (right and left arm, one leg and sternal massage), auditory and visual stimulation in 30-second epochs were performed during EEG-monitoring of 31 comatose neurosurgical patients. The logarithm to the ratio between the power in a stimulation epoch and the power in the 30-second epoch of rest immediately before was used as a measure of EEG-R in the delta, theta, alpha and beta frequency bands. Results: As muscle artifacts contributed to the power in the beta band, this was not used for further analyses. All four pain stimulation methods showed an increase in alpha activity compared to the auditory and visual stimulation methods. There were no differences between the four pain stimulation methods, except for increased delta activity during sternal massage compared to stimulation of the left hand. Conclusions: It is possible to use quantitative EEG-R in the assessment of different stimulation methods. Pain stimulation provoked more EEG-R than auditory or visual stimulation. Key message: Quantitative EEG-R was used to show that pain stimulation might be more effective than auditory and visual stimulation in comatose patients. doi:10.1016/j.clinph.2015.11.117
Electrocorticographic(ECoG) monitoring in spontaneous intracerebral hemorrhage(sICH): Metabolic profile of cortical spreading depolarizations(CSD)—M. Fabricius a, A.J. Schiefecker b, C.K. Friberg a, R. Beer b, B. Pfausler b, P. Lackner b, G. Broessner b, F. Sohm b, M. Mulino b, C. Thome b, E. Schmutzhard b, R. Helbok b (a Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark, b Neurology, Medical University of Innsbruck, Innsbruck, Austria) Objective: Metabolic changes accompany CSDs in clinical secondary brain injury. This was investigated for the first time after sICH. Methods: Patients with sICH were enrolled in COSBID (Co-operative Study on Brain Injury Depolarisations). Prolonged depressions of ECoG was used to detect CSDs. Brain tissue oxygen tension (PbtO2), cerebral blood flow (CBF), and cerebral metabolism (microdialysis) were monitored in the region of perihematomal edema (PHE).
Cervical Vestibular-Evoked Myogenic Potential (cVEMP) in adrenomyeloneuropathy patients—M. Veciana a, J. Pedro a, S. Yagüe a, A. Pujol b, C. Casasnovas a, E.S. Papathanasiou c (a Neurophysiology Unit, Neurology Department, Bellvitge Hospital, L‘Hospitalet de Llobregat, Barcelona, Spain, b Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L‘Hospitalet de Llobregat, Barcelona, Spain, c Clinical Neurophysiology Laboratory, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus) Objective: Adrenomyeloneuropathy (ADM) is one of the clinical phenotypes of adrenoleukodystrophy, characterized by distal axonopathy and varyng degrees of cerebral demyelination. cVEMPs, elicited by acoustic stimulation, are abnormal in several otovestibular disorders and brainstem lesions affecting the vestibulo-cervical reflex pathways. cVEMP have not been described so far in these patients. The aim of this study was to investigate cVEMP in ADM patients. Methods: We studied cVEMPs, brainstem auditory evoked potentials (BAEP) and motor evoked potentials (MEP) in 11 ADM patients. cVEMPs normal values were obtained from 10 healthy age-matched subjects. Results: BAEP and MEP were abnormal in all patients. cVEMPs had an increase latency in 10 tested ears, absent in 1, and normal in 11 ears. The mean latency of p13 was 16.06 ms (range: 13.6–21.8 ms). When responses were present in both ears for the same subject, no asymmetry ratio was detected in the corrected reflex amplitude. Conclusions: In contrast to BAEP and MEP that are severely affected in all patients, cVEMPs are only abnormal in 50% of patients. This shows relative sparing of the saccular neural pathway compared to the cochlear pathway and corticospinal tract. Key message: cVEMPs are abnormal in 50% of patients with ADM. doi:10.1016/j.clinph.2015.11.115
Retinal ganglion cell layer correlates with cognitive involvement in Alzheimer’s disease and mild cognitive impairment—S. Huang, L. Ferrari, E. Coppi, F. Vitali, G. Magnani, G. Comi, L. Leocani (Department of Neurology and INSPE-Institute of Experimental Neurology Scientific Institute and University Hospital San Raffaele, Milan, Italy) Introduction: Optical coherence tomography (OCT) allows noninvasive measurement of retinal nerve fiber layer (RNFL) which is a potential marker of neuronal loss for monitoring the natural course and treatment effect of Alzheimer’s disease (AD). According to previous studies, the ganglion cell layer (GCL) might be more sensitive than RNFL in detecting early neuronal degeneration. Here we aim to demonstrate the potential of GCL as an alternative for evaluating neuronal loss in patients with AD. Materials and methods: Eighteen patients (seven with AD and eleven with MCI) were included and peripapillary scans of both eyes were acquired with spectral domain OCT. Correlations between GCL, RNFL, and minimental state examination (MMSE) was performed using Pearson’s correlation. Results: The severity of cognitive decline (raw MMSE) was positively associated with thinning of GCL in both left (r = 0.665, p = 0.003) and right eye (r = 0.569, p = 0.014), while no correlation was found between RNFL and MMSE score.
e37
Conclusion: Our result suggested that the GCL may offer more functional relevant information than the RNFL, which makes it a potential biomarker for monitor AD progression. doi:10.1016/j.clinph.2015.11.116
Quantitative EEG-reactivity to different stimulation methods in comatose patients—M. Ebbesen, B. Johnsen (Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark) Objective: This study investigates quantitative EEG-reactivity (EEG-R) as a tool for comparison of the efficiency of different clinical stimulation methods. Methods: Standardized pain (right and left arm, one leg and sternal massage), auditory and visual stimulation in 30-second epochs were performed during EEG-monitoring of 31 comatose neurosurgical patients. The logarithm to the ratio between the power in a stimulation epoch and the power in the 30-second epoch of rest immediately before was used as a measure of EEG-R in the delta, theta, alpha and beta frequency bands. Results: As muscle artifacts contributed to the power in the beta band, this was not used for further analyses. All four pain stimulation methods showed an increase in alpha activity compared to the auditory and visual stimulation methods. There were no differences between the four pain stimulation methods, except for increased delta activity during sternal massage compared to stimulation of the left hand. Conclusions: It is possible to use quantitative EEG-R in the assessment of different stimulation methods. Pain stimulation provoked more EEG-R than auditory or visual stimulation. Key message: Quantitative EEG-R was used to show that pain stimulation might be more effective than auditory and visual stimulation in comatose patients. doi:10.1016/j.clinph.2015.11.117
Electrocorticographic(ECoG) monitoring in spontaneous intracerebral hemorrhage(sICH): Metabolic profile of cortical spreading depolarizations(CSD)—M. Fabricius a, A.J. Schiefecker b, C.K. Friberg a, R. Beer b, B. Pfausler b, P. Lackner b, G. Broessner b, F. Sohm b, M. Mulino b, C. Thome b, E. Schmutzhard b, R. Helbok b (a Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark, b Neurology, Medical University of Innsbruck, Innsbruck, Austria) Objective: Metabolic changes accompany CSDs in clinical secondary brain injury. This was investigated for the first time after sICH. Methods: Patients with sICH were enrolled in COSBID (Co-operative Study on Brain Injury Depolarisations). Prolonged depressions of ECoG was used to detect CSDs. Brain tissue oxygen tension (PbtO2), cerebral blood flow (CBF), and cerebral metabolism (microdialysis) were monitored in the region of perihematomal edema (PHE).