TY - JOUR
T1 - Reliability of Handheld Dynamometry to Measure Focal Muscle Weakness in Neurofibromatosis Types 1 and 2
AU - Akshintala, Srivandana
AU - Khalil, Nashwa
AU - Yohay, Kaleb
AU - Muzikansky, Alona
AU - Allen, Jeffrey
AU - Yaffe, Anna
AU - Gross, Andrea M.
AU - Fisher, Michael J.
AU - Blakeley, Jaishri O.
AU - Oberlander, Beverly
AU - Pudel, Miriam
AU - Engelson, Celia
AU - Obletz, Jaime
AU - Mitchell, Carole
AU - Widemann, Brigitte C.
AU - Stevenson, David A.
AU - Plotkin, Scott R.
N1 - Funding Information:
The authors acknowledge the following collaborators for their participation in the REiNS functional outcomes working group: Ann Blanton (SUNY Cortland), Ashley Cannon (University of Alabama at Birmingham), Elizabeth Schorry (Cincinnati Children's Hospital), Brad Welling (Massachusetts Eye and Ear Infirmary), Christopher Moertel (University of Minnesota), Colleen Marchetti (REiNS patient representative), David Viskochil (University of Utah, coordinating role for working group meetings), Dusica Babovic (Mayo Clinic), Fred Barker (Massachusetts General Hospital), D. Gareth Evans (St. Mary's Hospital, Manchester, coordinating role for working group meetings), Heather Thompson (California State University, Sacramento), James Tonsgard (University of Chicago), Kathy Gardner (University of Pittsburgh), Kent Robertson (Indiana University), Rebecca Mullin (St. Thomas' Hospital), Irene Moss (REiNS patient representative), Rosalie Ferner (Guy's Hospital), and Trent Hummel (Cincinnati Children's Hospital). The authors also acknowledge the support of the Children's Tumor Foundation for the REiNS International Collaboration.
Publisher Copyright:
© 2021 American Academy of Neurology.
PY - 2021/8/17
Y1 - 2021/8/17
N2 - Objective: To determine a suitable outcome measure for assessing muscle strength in neurofibromatosis (NF) type 1 and NF2 clinical trials, we evaluated the intraobserver reliability of handheld dynamometry (HHD) and developed consensus recommendations for its use in NF clinical trials. Methods: Patients ≥5 years of age with weakness in at least 1 muscle group by manual muscle testing (MMT) were eligible. Maximal isometric muscle strength of a weak muscle group and the biceps of the dominant arm was measured by HHD. An average of 3 repetitions per session was used as an observation, and 3 sessions with rest period between each were performed on the same day by a single observer. Intrasession and intersession intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) were calculated to assess reliability and measurement error. Results: Twenty patients with NF1 and 13 with NF2 were enrolled; median age was 12 years (interquartile range [IQR] 9-17 years) and 29 years (IQR 22-38 years), respectively. By MMT, weak muscle strength ranged from 2-/5 to 4+/5. Biceps strength was 5/5 in all patients. Intersession ICCs for the weak muscles were 0.98 and 0.99 in the NF1 and NF2 cohorts, respectively, and for biceps were 0.97 and 0.97, respectively. The median CVs for average session strength were 5.4% (IQR 2.6%-7.3%) and 2.9% (IQR 2.0%-6.2%) for weak muscles and biceps, respectively. Conclusion: HHD performed by a trained examiner with a well-defined protocol is a reliable technique to measure muscle strength in NF1 and NF2. Recommendations for strength testing in NF1 and NF2 trials are provided.
AB - Objective: To determine a suitable outcome measure for assessing muscle strength in neurofibromatosis (NF) type 1 and NF2 clinical trials, we evaluated the intraobserver reliability of handheld dynamometry (HHD) and developed consensus recommendations for its use in NF clinical trials. Methods: Patients ≥5 years of age with weakness in at least 1 muscle group by manual muscle testing (MMT) were eligible. Maximal isometric muscle strength of a weak muscle group and the biceps of the dominant arm was measured by HHD. An average of 3 repetitions per session was used as an observation, and 3 sessions with rest period between each were performed on the same day by a single observer. Intrasession and intersession intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) were calculated to assess reliability and measurement error. Results: Twenty patients with NF1 and 13 with NF2 were enrolled; median age was 12 years (interquartile range [IQR] 9-17 years) and 29 years (IQR 22-38 years), respectively. By MMT, weak muscle strength ranged from 2-/5 to 4+/5. Biceps strength was 5/5 in all patients. Intersession ICCs for the weak muscles were 0.98 and 0.99 in the NF1 and NF2 cohorts, respectively, and for biceps were 0.97 and 0.97, respectively. The median CVs for average session strength were 5.4% (IQR 2.6%-7.3%) and 2.9% (IQR 2.0%-6.2%) for weak muscles and biceps, respectively. Conclusion: HHD performed by a trained examiner with a well-defined protocol is a reliable technique to measure muscle strength in NF1 and NF2. Recommendations for strength testing in NF1 and NF2 trials are provided.
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U2 - 10.1212/WNL.0000000000012439
DO - 10.1212/WNL.0000000000012439
M3 - Article
C2 - 34230196
AN - SCOPUS:85114522903
SN - 0028-3878
VL - 97
SP - S99-S110
JO - Neurology
JF - Neurology
IS - 7
ER -