- Email: [email protected]
O-24 MRI detection of human motor unit fasciculation in Amyotrophic Lateral Sclerosis
Abstracts / Clinical Neurophysiology 130 (2019) e21–e116
O-23 Cervical muscle weakness correlates with respiratory function in Amyotrophic Lateral Sclerosis—Susana Pinto a,b,*, Marta Gromicho a, Michael Swash a,c, Mamede Carvalho a,d (a Institute of Physiology and Institute of Molecular Medicine, Faculty of Medicine, University of Lisbon., Lisbon, Portugal, b Division of Clinical Neurophysiology, Department of Pharmacology and Clinical Neurosciences, Umeå University, Umeå, Sweden, c Barts and the London School of Medicine, Queen Mary University of London., London, United Kingdom, d Department of Neurosciences and Mental Health, Hospital de Santa Maria-CHLN., Lisbon, Portugal) ⇑
Corresponding author.
Background: In Amyotrophic Lateral Sclerosis (ALS) weak cervical muscles are commonly found. These accessory muscles of respiration are innervated by medially spinal-located motor neurons close to phrenic nerve nuclei. A correlation between cervical strength and prognosis has been described. We investigate the association with respiratory function. Methods: Consecutive ALS patients assessed with flexor/extensor cervical muscle strength, revised functional ALS rating scale (ALSFRS-R), phrenic nerve studies and forced vital capacity (FVC) within 3 months were included. Flexor/extensor strength were assessed respectively in dorsal decubitus/sitting and categorized as normal/abnormal (MRC = 5/MRC < 5). Mean phrenic nerve amplitude (PhrenAmpl) was abnormal if <0.4 mV. Abnormal FVC was considered if <60% predicted. ALSFRS-R’s respiratory subscore (RofALSFRS-R) < 12 defined symptomatic respiratory insufficiency. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and the area under the curve (AUC) of the receiver operating characteristics were calculated. Ethical consent was granted. Results: We included 281 patients (157 men, disease duration 16.216 months; meanFVC 80.424%; MeanPhrenAmpl 0.50.25 m). Weak cervical flexion/extension: 156/59 patients. Abnormal PhrenAmpl: 100 patients; Abnormal FVC: 45; Abnormal RofALSFRS-R: 108. Sensitivity, specificity, PPV, NPP of extensor muscles for PhrenAmpl, FVC and RofALSFRS-R: 31%-35.5%, 84.5%-85.2, 33.3–52.5%, 66.1%-86.1%, respectively. Sensitivity, specificity, PPV, NPP of flexor muscles for PhrenAmpl, FVC and RofALSFRS-R: 66.6%-73.3%, 51.5%-54.1%, 24.4%-46.8%, 70.7%-90.1%, respectively. Combined flexor/extensor sensitivity, specificity, PPV, NPP: 68.5%77.7%, 48.5%-51.4%, 26%-46%, 70%-91.2%, respectively. AUC: 0.58– 0.64. Conclusion: Weak cervical muscles indicate higher probability of respiratory involvement. Weak extensors are a strong predictor (high specificity) of respiratory compromise in ALS, which should be regarded as a significant warning in clinical practice. doi:10.1016/j.clinph.2019.04.339
O-24 MRI detection of human motor unit fasciculation in Amyotrophic Lateral Sclerosis—Roger Whittaker *, Paola Porcari, Luis Braz, Timothy Williams, Ian Schofield, Andrew Blamire (Newcastle University, Newcastle Upon Tyne, United Kingdom) ⇑
Corresponding author.
Methods: The lower limbs of 6 healthy controls and 4 patients with confirmed ALS were scanned using a novel diffusion weighted MRI protocol sensitive to micrometer-scale movement of skeletal muscle. Motor unit activity was assessed at rest and during electrical motor nerve stimulation time-locked to scanner acquisition. Results: Incremental stimulation revealed a reproducible pattern of overlapping signal voids with dimensions and temporal profiles consistent with the contraction of single motor units. Patients with ALS showed a significantly higher rate of spontaneous motor unit fasciculation at rest (mean 99.1/min, range 25.7–161 in patients vs 7.7/min, range 4.3–9.7 in controls, p < 0.05) and a significantly higher percentage muscle cross sectional area in which fasciculation was detected (15.9%, SD 2.8 vs 2.9%, SD 1.6, p < 0.05). Conclusions: This study is the first use of imaging to detect fasciculation in ALS patients. The technique is quick to perform and entirely pain-free. The ability to detect changes in motor unit function which precede motor unit degeneration may allow earlier diagnosis and recruitment to clinical trials. doi:10.1016/j.clinph.2019.04.340
O-25 MUNIX alteration in three consecutive muscles innervated by ulnar nerve in Amiyotrophic Lateral Sclerosis—Taskin Gunes a,b,*, Gorkem Sirin a,b, Baris Isak a,b (a Department of Neurology, Marmara University Hospital, Istanbul, Turkey, b TRIALS Study Group, Istanbul, Turkey) ⇑
Corresponding author.
Background: The motor unit number index (MUNIX) method is used to estimate alterations attributed to changes in number and size (MUSIX) of motor units (MUs) using the compound muscle action potential (CMAP) and surface electromyographic interference pattern (SIP). Material and methods: In sixteen patients with Amyotrophic Lateral Sclerosis (ALS) and 16 controls, compound muscle action potentials (CMAP), MUNIXs and MUSIXs were recorded from flexor carpi ulnaris (FCU), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) muscles. Results: In ALS patients, mean values of MUNIXs recorded form FCU (76.7 ± 24.01 vs 71.5 ± 32.4, P = 0.22), ADM (130.3 ± 1.4 vs. 66.4 ± 2.3, P = 0.008), and FDI (181.8 ± 1.3 vs. 63.6 ± 2.8, P = 0001) muscles were lower and MUSIXs of FCU (59.9 ± 11.6 vs. 54.4 ± 13.4, P = 0.6), ADM (85.6 ± 1.4 vs. 99.1 ± 1.6, P = 0.34), and FDI (72.9 ± 1.2 vs. 99.9 ± 1.6, P = 0.03) were higher than controls. CMAPs deteriorated in proximal (i.e., FCU; 6 ALS vs. 0 controls, P = 0.009) muscle more than distal (i.e., ADM; 5 ALS vs. 0 control, P = 0.02 and FDI; 3 ALS vs. 1 control, P = 0.3) while MUNIXs deteriorated in distal (i.e., FDI; 9 ALS vs. 0 control, P = 0.003) more than proximal (i.e., ADM; 7 ALS vs. 1 control, P = 0.02, and FCU; 1 ALS vs. 0 control, P = 0.5) muscles. Conclusions: Unlike CMAPs, MUNIX was considered to define denervation process overwhelming the impact of re-innervation using SIPs. In addition to utility in long term assessment of ALS patients, MUNIX could be used to estimate quantitative alterations in motor units for diagnostic purpose. doi:10.1016/j.clinph.2019.04.341
Objective: To develop a clinically applicable non-invasive method for detecting motor unit fasciculation in patients with Amyotrophic Lateral Sclerosis (ALS).
e29
O-23 Cervical muscle weakness correlates with respiratory function in Amyotrophic Lateral Sclerosis—Susana Pinto a,b,*, Marta Gromicho a, Michael Swash a,c, Mamede Carvalho a,d (a Institute of Physiology and Institute of Molecular Medicine, Faculty of Medicine, University of Lisbon., Lisbon, Portugal, b Division of Clinical Neurophysiology, Department of Pharmacology and Clinical Neurosciences, Umeå University, Umeå, Sweden, c Barts and the London School of Medicine, Queen Mary University of London., London, United Kingdom, d Department of Neurosciences and Mental Health, Hospital de Santa Maria-CHLN., Lisbon, Portugal) ⇑
Corresponding author.
Background: In Amyotrophic Lateral Sclerosis (ALS) weak cervical muscles are commonly found. These accessory muscles of respiration are innervated by medially spinal-located motor neurons close to phrenic nerve nuclei. A correlation between cervical strength and prognosis has been described. We investigate the association with respiratory function. Methods: Consecutive ALS patients assessed with flexor/extensor cervical muscle strength, revised functional ALS rating scale (ALSFRS-R), phrenic nerve studies and forced vital capacity (FVC) within 3 months were included. Flexor/extensor strength were assessed respectively in dorsal decubitus/sitting and categorized as normal/abnormal (MRC = 5/MRC < 5). Mean phrenic nerve amplitude (PhrenAmpl) was abnormal if <0.4 mV. Abnormal FVC was considered if <60% predicted. ALSFRS-R’s respiratory subscore (RofALSFRS-R) < 12 defined symptomatic respiratory insufficiency. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and the area under the curve (AUC) of the receiver operating characteristics were calculated. Ethical consent was granted. Results: We included 281 patients (157 men, disease duration 16.216 months; meanFVC 80.424%; MeanPhrenAmpl 0.50.25 m). Weak cervical flexion/extension: 156/59 patients. Abnormal PhrenAmpl: 100 patients; Abnormal FVC: 45; Abnormal RofALSFRS-R: 108. Sensitivity, specificity, PPV, NPP of extensor muscles for PhrenAmpl, FVC and RofALSFRS-R: 31%-35.5%, 84.5%-85.2, 33.3–52.5%, 66.1%-86.1%, respectively. Sensitivity, specificity, PPV, NPP of flexor muscles for PhrenAmpl, FVC and RofALSFRS-R: 66.6%-73.3%, 51.5%-54.1%, 24.4%-46.8%, 70.7%-90.1%, respectively. Combined flexor/extensor sensitivity, specificity, PPV, NPP: 68.5%77.7%, 48.5%-51.4%, 26%-46%, 70%-91.2%, respectively. AUC: 0.58– 0.64. Conclusion: Weak cervical muscles indicate higher probability of respiratory involvement. Weak extensors are a strong predictor (high specificity) of respiratory compromise in ALS, which should be regarded as a significant warning in clinical practice. doi:10.1016/j.clinph.2019.04.339
O-24 MRI detection of human motor unit fasciculation in Amyotrophic Lateral Sclerosis—Roger Whittaker *, Paola Porcari, Luis Braz, Timothy Williams, Ian Schofield, Andrew Blamire (Newcastle University, Newcastle Upon Tyne, United Kingdom) ⇑
Corresponding author.
Methods: The lower limbs of 6 healthy controls and 4 patients with confirmed ALS were scanned using a novel diffusion weighted MRI protocol sensitive to micrometer-scale movement of skeletal muscle. Motor unit activity was assessed at rest and during electrical motor nerve stimulation time-locked to scanner acquisition. Results: Incremental stimulation revealed a reproducible pattern of overlapping signal voids with dimensions and temporal profiles consistent with the contraction of single motor units. Patients with ALS showed a significantly higher rate of spontaneous motor unit fasciculation at rest (mean 99.1/min, range 25.7–161 in patients vs 7.7/min, range 4.3–9.7 in controls, p < 0.05) and a significantly higher percentage muscle cross sectional area in which fasciculation was detected (15.9%, SD 2.8 vs 2.9%, SD 1.6, p < 0.05). Conclusions: This study is the first use of imaging to detect fasciculation in ALS patients. The technique is quick to perform and entirely pain-free. The ability to detect changes in motor unit function which precede motor unit degeneration may allow earlier diagnosis and recruitment to clinical trials. doi:10.1016/j.clinph.2019.04.340
O-25 MUNIX alteration in three consecutive muscles innervated by ulnar nerve in Amiyotrophic Lateral Sclerosis—Taskin Gunes a,b,*, Gorkem Sirin a,b, Baris Isak a,b (a Department of Neurology, Marmara University Hospital, Istanbul, Turkey, b TRIALS Study Group, Istanbul, Turkey) ⇑
Corresponding author.
Background: The motor unit number index (MUNIX) method is used to estimate alterations attributed to changes in number and size (MUSIX) of motor units (MUs) using the compound muscle action potential (CMAP) and surface electromyographic interference pattern (SIP). Material and methods: In sixteen patients with Amyotrophic Lateral Sclerosis (ALS) and 16 controls, compound muscle action potentials (CMAP), MUNIXs and MUSIXs were recorded from flexor carpi ulnaris (FCU), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) muscles. Results: In ALS patients, mean values of MUNIXs recorded form FCU (76.7 ± 24.01 vs 71.5 ± 32.4, P = 0.22), ADM (130.3 ± 1.4 vs. 66.4 ± 2.3, P = 0.008), and FDI (181.8 ± 1.3 vs. 63.6 ± 2.8, P = 0001) muscles were lower and MUSIXs of FCU (59.9 ± 11.6 vs. 54.4 ± 13.4, P = 0.6), ADM (85.6 ± 1.4 vs. 99.1 ± 1.6, P = 0.34), and FDI (72.9 ± 1.2 vs. 99.9 ± 1.6, P = 0.03) were higher than controls. CMAPs deteriorated in proximal (i.e., FCU; 6 ALS vs. 0 controls, P = 0.009) muscle more than distal (i.e., ADM; 5 ALS vs. 0 control, P = 0.02 and FDI; 3 ALS vs. 1 control, P = 0.3) while MUNIXs deteriorated in distal (i.e., FDI; 9 ALS vs. 0 control, P = 0.003) more than proximal (i.e., ADM; 7 ALS vs. 1 control, P = 0.02, and FCU; 1 ALS vs. 0 control, P = 0.5) muscles. Conclusions: Unlike CMAPs, MUNIX was considered to define denervation process overwhelming the impact of re-innervation using SIPs. In addition to utility in long term assessment of ALS patients, MUNIX could be used to estimate quantitative alterations in motor units for diagnostic purpose. doi:10.1016/j.clinph.2019.04.341
Objective: To develop a clinically applicable non-invasive method for detecting motor unit fasciculation in patients with Amyotrophic Lateral Sclerosis (ALS).
e29