- Email: [email protected]
S1 Radiculopathy Secondary to PIVD
S40
PO2. Electromyography PO2.1 Paraspinal Electromyography A Clinico-Imageological Correlative Study in L5/S1 Radiculopathy Secondary to PIVD R. Borgohain *, P. Venkatswamy, A.K. Meena Nizam’s Institute of Medical Sciences, India E-mail address: [email protected] Background: False positive findings are seen in a high percentage of imaging studies in prolapsed intervertebral discs (PIVD) necessitating electro-diagnosis as a confirmatory test in the diagnosis of radiculopathy induced low back pain. Methods: Aim was validation of paraspinal EMG (pEMG) in electrophysiological evaluation of radiculopathy. Detailed neurological examination was carried out in patients with L5/S1 radiculopathy due to PIVD. Peripheral electroneuromyographic studies and pEMG according to Haig’s technique (Muscle & Nerve 1993) were done; in the latter an increased score denoted increased abnormal EMG activity, and needle positions were classed as specific, medial and intermediate. Results: Twenty patients with a mean age of 40.2+10.1 years were studied. Spontaneous activity was analysed in lumbar paraspinal muscles. Mean symptom duration was 1.23+1.2 years. Nineteen (95%) had neurological deficits such as loss of tendon jerks, radicular sensory loss and muscle weakness. On MR, mean L5 and S1 spinal canal diameters were 10.15+2.0 mm and 10.1+2.2 mm, while mean lateral recess diameters were 3.55+1.5 and 5.15+1.35 mm, respectively. Mean spontaneous EMG scores (at L5/S1 levels in specific EMG position were 1.45+1.7 and 1.15+1.46 respectively. Statistical analysis using Chi-square test showed a highly significant difference in pEMG activity in S1 specific EMG position between subjects with normal and abnormal lateral recesses at the corresponding segment (p = 0.0012). No other statistically significant association was seen. Conclusions: In this study pEMG had a higher sensitivity for abnormalities than either peripheral EMG or imaging studies. The S1 specific pEMG insertion site correlated only for S1 lateral recess MRI abnormalities. PO2.2 Manual Scanning EMG Study of Variability of Motor Unit Potential Parameters M. Veerendrakumar1 *, N. Gayathri2 , D.K. Subbukrishna3 , L.K. Prashanth1 , D. Nagaraja1 1 Dept. of Neurology, National Institute of Mental Health and Neurosciences, India, 2 Dept. of Neuropathology, National Institute of Mental Health and Neurosciences, India, 3 Dept. of Biostatistics, National Institute of Mental Health and Neurosciences, India E-mail address: [email protected] Background: In quantitative motor unit potential (MUP) analysis, investigators have employed different criteria for sampling MUPs. This leads on to different positions of concentric needle (CN) electrode within the motor unit (MU) territory and hence varying values for MUP parameter(s). The aim of this study is to know of the effect of CN electrode position on MUP parameters. Methods: Manual scanning EMG of Biceps brachii muscle was done using CN electrode and Keypoint.NET EMG system (Band width 2 Hz 10 KHz). At minimal contraction, when the first recruited MUP was visualised on oscilloscope, all of its subsequent firings were recorded continuously for 1 2 minutes. During this time, CN electrode was gradually advanced to maximise MUP amplitude and minimise rise time (<500 ms). At each of the sites where the MUP showed significant change in amplitude or morphology, the electrode was held steady and 20 40 discharges of the MUP were collected. MUP discharges were analysed off-line using Multi-MUP analysis program. 4 7 templates corresponding to different positions of CN electrode within the MU territory were identified. For templates having >4 discharges with clean baseline, duration cursors were positioned and MUP parameters were calculated. Results: 28 MUPs were sampled from two patients with neuromuscular disorders. Each MUP was recorded at 5.6 (0.99) sites. At different sites within the MU, MUP parameters changed, sometimes markedly. The grand 9.3(4.3), amplitude mean coefficients of variation were: duration 43.9(18.2) area 22.5(12.4), phases 23.9(18.7), turns 46.8(20.3), 34.1(207.3). thickness 26.4(11.9), size index
Posters: PO2. Electromyography Conclusions: MUP parameters vary at different recording sites within the MU territory. Among the parameters, duration shows least variability while size index shows maximal variability. For evaluation of neuromuscular disorders, MUP parameters with low variability may be more reliable than parameters with greater variability. PO2.3 Snap, Crackle & Pop a Normal Variant of Increased Insertional Activity May Be Misleading for Electromyographer: Case Series Ghulam Shabbir *, Nadeem Ahmed, Bhojo A. Khealani, Assadullah, Ghulam Qadir Buledhi, Mustafa Khan Dept of Neurophysiology Aga Khan University Hospital Karachi and Liaquat University of Medical Sciences Jamshoro, Pakistan E-mail address: [email protected] Background: Placing a needle recording electrode into healthy muscle tissue & advancing, it in quick but short intervals ‘JABS’ results in brief bursts of electrical potentials. This results in a crisp sound, with a series of negative & positive spikes. These waveforms are referred to as insertional activity the total time of insertional activity persisting after needle cessation has a mean of 48±18 ms. The total time of insertional activity for monopolar needle is less than 230 ms & that of concentric needle less than 300 ms. Increased insertion activity is more than 300 500 ms, indicating denervation, myopathy or a normal variant, which is called as Snap, Crackle & Pop. Very few case reports of Snap, Crackle & Pop are reported. This is usually seen in young male patients, having history of bodybuilding, (muscle making exercises). Methods and Results: Four male patients, having well built were referred for NCS/EMG study with query of some possible neuro-muscular problem. In all four patients we noted diffuse increased insertional activity on needle exam, normal morphology of MUAP with normal recruitment & full interference pattern noted. One patient has had prior NCS/EMG that was concluded as either diffuse neurogenic process or inflammatory myopathy. Our neurophysiologic data suggests that the needle EMG examination showed diffuse increased insertional activity, including genioglossus and frontalis muscles is indicating a normal variant called as Snap, Crackle & Pop. Conclusions: Electromyographer should be aware about the normal variants/artifacts like Snap, Crackle & Pop, rather than concluding falsely as abnormal. Further large studies may be more helpful for the pathogenesis of this entity. PO2.4 The Study of Mean Duration in Anal Sphincter Electromyography: Overview of 335 Cases of Multiple System Atrophy and Related Neurological Diseases Han Wang *, Hua Du, Ben-hong Li, Li-ying Cui, Xiao-fu Tang Dept. of Neurology, Peking Union Medical College Hospital, China E-mail address: [email protected] Background: The value of anal sphincter electromyography (ASEMG) is challenged because the mean duration (MD) of motor unit action potential (MUAP) exceeding 10 ms could also present in other diseases, such as Parkinson’s disease (PD), Parkinson’s syndrome (PDS) and cauda equine lesion (CEL), etc. It has been reported that the MD longer than 13 ms could be more specific in differentiating MSA from PD, but the related studies with large sample size is lacking. Methods: 335 cases with intact data were selected from the ASEMG data bank, including 131 patients with MSA, 44 with PD, 76 with PDS, 36 with CEL, 10 with cerebellar ataxia (CA), 20 with orthostatic hypotension (OH) and 18 patients as normal control. The results of the ASEMG were reviewed retrospectively. Sensitivity and specificity of mean duration in differentiating MSA-probable from PD and other related diseases were evaluated by ROC curves. Results: The mean duration was significantly longer in MSA-probable (15.69±2.66 ms) than in PD (12.40±1.44), PDS (12.60±1.79), CA (12.46±2.25), OH (12.91±1.79), CEL (13.24±2.49) and normal control (11.56±1.59 ) (P < 0.001). The specificity of MD in differentiating MSA-probable from PD, PDS, and CA improved (81.8, 78.4, and 80, respectively) by 13.7 ms than 10 ms (<10%). Conclusions: ASEMG is valuable in differentiating MSA-probable from PD and other neurological diseases. 13.7 ms is more specific as a cut-off value of MD than 10 ms.
PO2. Electromyography PO2.1 Paraspinal Electromyography A Clinico-Imageological Correlative Study in L5/S1 Radiculopathy Secondary to PIVD R. Borgohain *, P. Venkatswamy, A.K. Meena Nizam’s Institute of Medical Sciences, India E-mail address: [email protected] Background: False positive findings are seen in a high percentage of imaging studies in prolapsed intervertebral discs (PIVD) necessitating electro-diagnosis as a confirmatory test in the diagnosis of radiculopathy induced low back pain. Methods: Aim was validation of paraspinal EMG (pEMG) in electrophysiological evaluation of radiculopathy. Detailed neurological examination was carried out in patients with L5/S1 radiculopathy due to PIVD. Peripheral electroneuromyographic studies and pEMG according to Haig’s technique (Muscle & Nerve 1993) were done; in the latter an increased score denoted increased abnormal EMG activity, and needle positions were classed as specific, medial and intermediate. Results: Twenty patients with a mean age of 40.2+10.1 years were studied. Spontaneous activity was analysed in lumbar paraspinal muscles. Mean symptom duration was 1.23+1.2 years. Nineteen (95%) had neurological deficits such as loss of tendon jerks, radicular sensory loss and muscle weakness. On MR, mean L5 and S1 spinal canal diameters were 10.15+2.0 mm and 10.1+2.2 mm, while mean lateral recess diameters were 3.55+1.5 and 5.15+1.35 mm, respectively. Mean spontaneous EMG scores (at L5/S1 levels in specific EMG position were 1.45+1.7 and 1.15+1.46 respectively. Statistical analysis using Chi-square test showed a highly significant difference in pEMG activity in S1 specific EMG position between subjects with normal and abnormal lateral recesses at the corresponding segment (p = 0.0012). No other statistically significant association was seen. Conclusions: In this study pEMG had a higher sensitivity for abnormalities than either peripheral EMG or imaging studies. The S1 specific pEMG insertion site correlated only for S1 lateral recess MRI abnormalities. PO2.2 Manual Scanning EMG Study of Variability of Motor Unit Potential Parameters M. Veerendrakumar1 *, N. Gayathri2 , D.K. Subbukrishna3 , L.K. Prashanth1 , D. Nagaraja1 1 Dept. of Neurology, National Institute of Mental Health and Neurosciences, India, 2 Dept. of Neuropathology, National Institute of Mental Health and Neurosciences, India, 3 Dept. of Biostatistics, National Institute of Mental Health and Neurosciences, India E-mail address: [email protected] Background: In quantitative motor unit potential (MUP) analysis, investigators have employed different criteria for sampling MUPs. This leads on to different positions of concentric needle (CN) electrode within the motor unit (MU) territory and hence varying values for MUP parameter(s). The aim of this study is to know of the effect of CN electrode position on MUP parameters. Methods: Manual scanning EMG of Biceps brachii muscle was done using CN electrode and Keypoint.NET EMG system (Band width 2 Hz 10 KHz). At minimal contraction, when the first recruited MUP was visualised on oscilloscope, all of its subsequent firings were recorded continuously for 1 2 minutes. During this time, CN electrode was gradually advanced to maximise MUP amplitude and minimise rise time (<500 ms). At each of the sites where the MUP showed significant change in amplitude or morphology, the electrode was held steady and 20 40 discharges of the MUP were collected. MUP discharges were analysed off-line using Multi-MUP analysis program. 4 7 templates corresponding to different positions of CN electrode within the MU territory were identified. For templates having >4 discharges with clean baseline, duration cursors were positioned and MUP parameters were calculated. Results: 28 MUPs were sampled from two patients with neuromuscular disorders. Each MUP was recorded at 5.6 (0.99) sites. At different sites within the MU, MUP parameters changed, sometimes markedly. The grand 9.3(4.3), amplitude mean coefficients of variation were: duration 43.9(18.2) area 22.5(12.4), phases 23.9(18.7), turns 46.8(20.3), 34.1(207.3). thickness 26.4(11.9), size index
Posters: PO2. Electromyography Conclusions: MUP parameters vary at different recording sites within the MU territory. Among the parameters, duration shows least variability while size index shows maximal variability. For evaluation of neuromuscular disorders, MUP parameters with low variability may be more reliable than parameters with greater variability. PO2.3 Snap, Crackle & Pop a Normal Variant of Increased Insertional Activity May Be Misleading for Electromyographer: Case Series Ghulam Shabbir *, Nadeem Ahmed, Bhojo A. Khealani, Assadullah, Ghulam Qadir Buledhi, Mustafa Khan Dept of Neurophysiology Aga Khan University Hospital Karachi and Liaquat University of Medical Sciences Jamshoro, Pakistan E-mail address: [email protected] Background: Placing a needle recording electrode into healthy muscle tissue & advancing, it in quick but short intervals ‘JABS’ results in brief bursts of electrical potentials. This results in a crisp sound, with a series of negative & positive spikes. These waveforms are referred to as insertional activity the total time of insertional activity persisting after needle cessation has a mean of 48±18 ms. The total time of insertional activity for monopolar needle is less than 230 ms & that of concentric needle less than 300 ms. Increased insertion activity is more than 300 500 ms, indicating denervation, myopathy or a normal variant, which is called as Snap, Crackle & Pop. Very few case reports of Snap, Crackle & Pop are reported. This is usually seen in young male patients, having history of bodybuilding, (muscle making exercises). Methods and Results: Four male patients, having well built were referred for NCS/EMG study with query of some possible neuro-muscular problem. In all four patients we noted diffuse increased insertional activity on needle exam, normal morphology of MUAP with normal recruitment & full interference pattern noted. One patient has had prior NCS/EMG that was concluded as either diffuse neurogenic process or inflammatory myopathy. Our neurophysiologic data suggests that the needle EMG examination showed diffuse increased insertional activity, including genioglossus and frontalis muscles is indicating a normal variant called as Snap, Crackle & Pop. Conclusions: Electromyographer should be aware about the normal variants/artifacts like Snap, Crackle & Pop, rather than concluding falsely as abnormal. Further large studies may be more helpful for the pathogenesis of this entity. PO2.4 The Study of Mean Duration in Anal Sphincter Electromyography: Overview of 335 Cases of Multiple System Atrophy and Related Neurological Diseases Han Wang *, Hua Du, Ben-hong Li, Li-ying Cui, Xiao-fu Tang Dept. of Neurology, Peking Union Medical College Hospital, China E-mail address: [email protected] Background: The value of anal sphincter electromyography (ASEMG) is challenged because the mean duration (MD) of motor unit action potential (MUAP) exceeding 10 ms could also present in other diseases, such as Parkinson’s disease (PD), Parkinson’s syndrome (PDS) and cauda equine lesion (CEL), etc. It has been reported that the MD longer than 13 ms could be more specific in differentiating MSA from PD, but the related studies with large sample size is lacking. Methods: 335 cases with intact data were selected from the ASEMG data bank, including 131 patients with MSA, 44 with PD, 76 with PDS, 36 with CEL, 10 with cerebellar ataxia (CA), 20 with orthostatic hypotension (OH) and 18 patients as normal control. The results of the ASEMG were reviewed retrospectively. Sensitivity and specificity of mean duration in differentiating MSA-probable from PD and other related diseases were evaluated by ROC curves. Results: The mean duration was significantly longer in MSA-probable (15.69±2.66 ms) than in PD (12.40±1.44), PDS (12.60±1.79), CA (12.46±2.25), OH (12.91±1.79), CEL (13.24±2.49) and normal control (11.56±1.59 ) (P < 0.001). The specificity of MD in differentiating MSA-probable from PD, PDS, and CA improved (81.8, 78.4, and 80, respectively) by 13.7 ms than 10 ms (<10%). Conclusions: ASEMG is valuable in differentiating MSA-probable from PD and other neurological diseases. 13.7 ms is more specific as a cut-off value of MD than 10 ms.