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Objective extraction of concealed information by Visual Evoked Potentials (VEPs) and Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA)
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Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
motor nuclei in neighboring myotomes. The aim of the study was to determine if CSP testing may serve as a useful aid in evaluation of brachial plexus injury involving root avulsion. Methods: In 19 patients with traumatic brachial plexus injury (15 males, age 18–62 years) we performed clinical examination, imaging studies (CT myelogram) and neurophysiologic testing. Needle EMG was obtained from muscles supplied by C5-T1 myotomes. CSP was recorded after painful stimuli were delivered to thumb (C6 dermatome), middle (C7) and little (C8) fingers while subjects maintained voluntary contraction of intrinsic hand muscles. Results: Electrodiagnostic and imaging studies confirmed severe brachial plexopathy in most of patients. In 6 subjects with sensory disturbances, one of the CSP was absent. In the remaining 13 patients, a well defined CSPs were present. Conclusion: In brachial plexopathy with presumed avulsion, the CSP can provide quick physiologic confirmation of preserved or impaired conduction through damaged trunks and roots. In the cases of multiple sensory disturbances, the CSP is impaired or absent.
Supported by PRVOUK P34, IGA-NT 13693, 12282. doi:10.1016/j.clinph.2015.11.111
Parallel Sesion 17 Platform sessions
Sural sensory nerve conduction studies in demyelinating polyneuropathies—A.V. Strobel a, A. Fuglsang-Frederiksen a, a b M. Otto , A. Murtuzova , H. Tankisi a (a Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark, b Department of Neurology, Glostrup University Hospital, Copenhagen, Denmark)
Objective: To examine the pathophysiological state of sensory nerve conduction studies in different types of demyelinating polyneuropathies. Methods: A total 16 Acute Inflammatory Demyelinating Polyneuropathy (AIDP), 12 Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and 7 Hereditary Motor Sensory Neuropathy (HMSN) Type 1 patients were included prospectively. In all patients, bilateral sural nerves were examined with near nerve technique. The pathophysiological states of the sensory nerves were described as normal, demyelinating, axonal or neuropathic using ESTEEM criteria (Tankisi et al., 2005). Result: In 16 AIDP patients, sural nerve was normal in 8, demyelinating in 2 and axonal in 6 while, in 12 CIDP patients sural nerve was normal in 4, demyelinating in 2, axonal in 5 and neuropathic in 1. In AIDP and CIDP patients with demyelinating sensory nerves, an atypical disease course with poor response to therapy was observed. In all 7 HMSN Type 1 patients, sural nerves were demyelinating. Conclusion: In inflammatory demyelinating polyneuropathies sural nerve is mostly axonal, however demyelinating sensory sural nerves may indicate subtypes. Sensory nerves are always demyelinating in HSMN Type 1 which may help in differential diagnosis. Key message: Sensory sural nerve conduction studies may contribute to differential diagnosis of inflammatory and hereditary polyneuropathies.
The most sensitive nerves and parameters in electrodiagnosis of polyneuropathies—A.B. Jacobsen, A. Fuglsang-Frederiksen, B. Johnsen, K. Pugdahl, S. Beniczky, L. Duez, H. Tankisi (Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark) Objective: To examine the most sensitive nerve and parameter in polyneuropathy electrodiagnosis. Methods: A total of 157 consecutive patients diagnosed with polyneuropathy were included. In all patients, bilateral peroneal and tibial motor nerve conduction studies (NCSs) and sural sensory NCSs with surface electrodes and near-nerve technique. (NNT) were done. The sensitivities were compared using chi-square statistics. Results: Sural NCSs with NNT was more sensitive than surface NCSs for conduction velocity (CV) (29% versus 11%) and amplitude (80% versus 28%) (p < 0.01). F-wave latencies were more often abnormal in tibial (61%) than in peroneal (37%) nerve (p < 0.01). CMAP amplitudes tended to be more frequently abnormal in peroneal (46%) than tibial (39%) nerves (p = 0.08). Distal motor latency was equally sensitive in peroneal (28%) and tibial (31%) nerves similarly to CV, 58% and 60% respectively. Conclusion: Sural nerve amplitude with NNT is the most sensitive parameter in polyneuropathy electrodiagnosis. Tibial nerve F-wave latency is the most abnormal parameter when sural nerve is examined with surface electrodes only. Tibial nerve F-wave latency and peroneal and tibial CVs are the most common motor abnormalities. Key message: Sural nerve preferentially with needle electrodes should be examined in addition to motor nerves in polyneuropathy electrodiagnosis. doi:10.1016/j.clinph.2015.11.113
Objective extraction of concealed information by Visual Evoked Potentials (VEPs) and Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA)—N. Hanna, D. Urbach, J. Attias (Communication Disorders, University of Haifa, Haifa, Israel) Objective: To study the application of VEP’s to identify cortical measures differentiating between lie and true concealed information. This was tested in memorized and retrieval paradigm. Methods: VEP’s were recoded from 31 electrodes among 15 subjects in response to modified ‘‘Sternberg paradigm”, which included implemented concealed information both in the three memorized items (Memory set) and the retrieval stimulus (Probe). Subjects were instructed to lie only on specific stimulus and to correctly report to the others serving as the ‘‘true stimulus” that contained control stimulus. Latency, amplitude, and source current density estimation were compared across Lie and control stimuli. Results: Amplitude of P3b was significantly augmented in the lie stimulus of the ‘‘memory set” compared to the controls. Moreover, this was associated in excitation of right prefrontal cortex as reflected by sLORETA. Probe lie stimuli were associated with prolonged P3 latency and prolonged reaction time, as well as increased brain activity in right parietal lobe. Conclusions: For the first time, VEP’s could extract objectively measures to differentiate between lie and true concealed information. These findings may have important application to the brain processes associating with the memory and recall of lie information. Key message: Lie detector by visual ERP’s.
doi:10.1016/j.clinph.2015.11.112 doi:10.1016/j.clinph.2015.11.114
Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
motor nuclei in neighboring myotomes. The aim of the study was to determine if CSP testing may serve as a useful aid in evaluation of brachial plexus injury involving root avulsion. Methods: In 19 patients with traumatic brachial plexus injury (15 males, age 18–62 years) we performed clinical examination, imaging studies (CT myelogram) and neurophysiologic testing. Needle EMG was obtained from muscles supplied by C5-T1 myotomes. CSP was recorded after painful stimuli were delivered to thumb (C6 dermatome), middle (C7) and little (C8) fingers while subjects maintained voluntary contraction of intrinsic hand muscles. Results: Electrodiagnostic and imaging studies confirmed severe brachial plexopathy in most of patients. In 6 subjects with sensory disturbances, one of the CSP was absent. In the remaining 13 patients, a well defined CSPs were present. Conclusion: In brachial plexopathy with presumed avulsion, the CSP can provide quick physiologic confirmation of preserved or impaired conduction through damaged trunks and roots. In the cases of multiple sensory disturbances, the CSP is impaired or absent.
Supported by PRVOUK P34, IGA-NT 13693, 12282. doi:10.1016/j.clinph.2015.11.111
Parallel Sesion 17 Platform sessions
Sural sensory nerve conduction studies in demyelinating polyneuropathies—A.V. Strobel a, A. Fuglsang-Frederiksen a, a b M. Otto , A. Murtuzova , H. Tankisi a (a Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark, b Department of Neurology, Glostrup University Hospital, Copenhagen, Denmark)
Objective: To examine the pathophysiological state of sensory nerve conduction studies in different types of demyelinating polyneuropathies. Methods: A total 16 Acute Inflammatory Demyelinating Polyneuropathy (AIDP), 12 Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and 7 Hereditary Motor Sensory Neuropathy (HMSN) Type 1 patients were included prospectively. In all patients, bilateral sural nerves were examined with near nerve technique. The pathophysiological states of the sensory nerves were described as normal, demyelinating, axonal or neuropathic using ESTEEM criteria (Tankisi et al., 2005). Result: In 16 AIDP patients, sural nerve was normal in 8, demyelinating in 2 and axonal in 6 while, in 12 CIDP patients sural nerve was normal in 4, demyelinating in 2, axonal in 5 and neuropathic in 1. In AIDP and CIDP patients with demyelinating sensory nerves, an atypical disease course with poor response to therapy was observed. In all 7 HMSN Type 1 patients, sural nerves were demyelinating. Conclusion: In inflammatory demyelinating polyneuropathies sural nerve is mostly axonal, however demyelinating sensory sural nerves may indicate subtypes. Sensory nerves are always demyelinating in HSMN Type 1 which may help in differential diagnosis. Key message: Sensory sural nerve conduction studies may contribute to differential diagnosis of inflammatory and hereditary polyneuropathies.
The most sensitive nerves and parameters in electrodiagnosis of polyneuropathies—A.B. Jacobsen, A. Fuglsang-Frederiksen, B. Johnsen, K. Pugdahl, S. Beniczky, L. Duez, H. Tankisi (Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark) Objective: To examine the most sensitive nerve and parameter in polyneuropathy electrodiagnosis. Methods: A total of 157 consecutive patients diagnosed with polyneuropathy were included. In all patients, bilateral peroneal and tibial motor nerve conduction studies (NCSs) and sural sensory NCSs with surface electrodes and near-nerve technique. (NNT) were done. The sensitivities were compared using chi-square statistics. Results: Sural NCSs with NNT was more sensitive than surface NCSs for conduction velocity (CV) (29% versus 11%) and amplitude (80% versus 28%) (p < 0.01). F-wave latencies were more often abnormal in tibial (61%) than in peroneal (37%) nerve (p < 0.01). CMAP amplitudes tended to be more frequently abnormal in peroneal (46%) than tibial (39%) nerves (p = 0.08). Distal motor latency was equally sensitive in peroneal (28%) and tibial (31%) nerves similarly to CV, 58% and 60% respectively. Conclusion: Sural nerve amplitude with NNT is the most sensitive parameter in polyneuropathy electrodiagnosis. Tibial nerve F-wave latency is the most abnormal parameter when sural nerve is examined with surface electrodes only. Tibial nerve F-wave latency and peroneal and tibial CVs are the most common motor abnormalities. Key message: Sural nerve preferentially with needle electrodes should be examined in addition to motor nerves in polyneuropathy electrodiagnosis. doi:10.1016/j.clinph.2015.11.113
Objective extraction of concealed information by Visual Evoked Potentials (VEPs) and Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA)—N. Hanna, D. Urbach, J. Attias (Communication Disorders, University of Haifa, Haifa, Israel) Objective: To study the application of VEP’s to identify cortical measures differentiating between lie and true concealed information. This was tested in memorized and retrieval paradigm. Methods: VEP’s were recoded from 31 electrodes among 15 subjects in response to modified ‘‘Sternberg paradigm”, which included implemented concealed information both in the three memorized items (Memory set) and the retrieval stimulus (Probe). Subjects were instructed to lie only on specific stimulus and to correctly report to the others serving as the ‘‘true stimulus” that contained control stimulus. Latency, amplitude, and source current density estimation were compared across Lie and control stimuli. Results: Amplitude of P3b was significantly augmented in the lie stimulus of the ‘‘memory set” compared to the controls. Moreover, this was associated in excitation of right prefrontal cortex as reflected by sLORETA. Probe lie stimuli were associated with prolonged P3 latency and prolonged reaction time, as well as increased brain activity in right parietal lobe. Conclusions: For the first time, VEP’s could extract objectively measures to differentiate between lie and true concealed information. These findings may have important application to the brain processes associating with the memory and recall of lie information. Key message: Lie detector by visual ERP’s.
doi:10.1016/j.clinph.2015.11.112 doi:10.1016/j.clinph.2015.11.114