PMID- 35747537
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230602
IS  - 2163-0402 (Print)
IS  - 2163-0933 (Electronic)
IS  - 2163-0402 (Linking)
VI  - 12
IP  - 3
DP  - 2022 Jun
TI  - Electrodiagnostic Characteristics Suggestive of Muscle-Specific Kinase Myasthenia 
      Gravis.
PG  - 211-217
LID - 10.1212/CPJ.0000000000001166 [doi]
AB  - BACKGROUND AND OBJECTIVES: Muscle-specific kinase (MuSK) antibody-positive 
      myasthenia gravis (MuSK + MG) is a form of MG with bulbar-predominant symptoms 
      often resistant to conventional treatments. Patients with MuSK + MG may have an 
      electrodiagnostic (EDX) profile distinct from other MG. This study compares EDX 
      features of MuSK + MG with acetylcholine receptor (AChR) antibody-positive MG 
      (AChR + MG) to discern whether any unique EDX pattern exists that can aid in 
      clinical diagnosis. METHODS: From January 1, 2010, through December 31, 2020, all 
      patients with MuSK + MG at our institution were identified and randomly matched 
      to an AChR + MG cohort in a 1:2 ratio based on sex, age at onset, and 
      subsequently Myasthenia Gravis Foundation of America (MGFA) clinical severity for 
      a case-control study. Each patient's clinical profile, treatment, and EDX testing 
      were summarized and analyzed. RESULTS: Twenty-two patients with MuSK + MG (18 
      female) and 44 patients with AChR + MG were studied. The average symptom duration 
      at presentation was shorter in the MuSK + MG group (4.7 years) compared with AChR 
      + MG (10.9 years). Myotonic discharges were rare in both groups but more 
      frequently observed in patients with MuSK + MG (10%) identified in 5 muscles in 2 
      patients compared with AChR + MG (2%) noted in only 1 muscle in 1 patient. 
      Patients with MuSK + MG more often had myopathic appearing motor unit potentials 
      (MUPs) (41% vs 30%) compared with AChR + MG. Myopathic appearing MUPs were found 
      in milder cases of MuSK + MG (MGFA class I-IIB) compared with AChR + MG (MGFA 
      Class IIB-V). DISCUSSION: Patients with MuSK + MG may have a recognizable EDX 
      profile from AchR + MG that includes (1) myotonic discharges, (2) greater 
      occurrence of myopathic appearing MUPs in clinically mild disease, and (3) 
      symptoms leading to earlier testing.
CI  - (c) 2022 American Academy of Neurology.
FAU - Skolka, Michael
AU  - Skolka M
AD  - Department of Neurology (MS, CJK, RSL), Mayo Clinic, Rochester, MN; and 
      Department of Neurology (CJL, DIR), Mayo Clinic, Jacksonville, FL.
FAU - Lamb, Christopher J
AU  - Lamb CJ
AD  - Department of Neurology (MS, CJK, RSL), Mayo Clinic, Rochester, MN; and 
      Department of Neurology (CJL, DIR), Mayo Clinic, Jacksonville, FL.
FAU - Rubin, Devon I
AU  - Rubin DI
AD  - Department of Neurology (MS, CJK, RSL), Mayo Clinic, Rochester, MN; and 
      Department of Neurology (CJL, DIR), Mayo Clinic, Jacksonville, FL.
FAU - Klein, Christopher J
AU  - Klein CJ
AD  - Department of Neurology (MS, CJK, RSL), Mayo Clinic, Rochester, MN; and 
      Department of Neurology (CJL, DIR), Mayo Clinic, Jacksonville, FL.
FAU - Laughlin, Ruple S
AU  - Laughlin RS
AUID- ORCID: 0000-0002-1884-5824
AD  - Department of Neurology (MS, CJK, RSL), Mayo Clinic, Rochester, MN; and 
      Department of Neurology (CJL, DIR), Mayo Clinic, Jacksonville, FL.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Neurol Clin Pract
JT  - Neurology. Clinical practice
JID - 101577149
PMC - PMC9208421
EDAT- 2022/06/25 06:00
MHDA- 2022/06/25 06:01
PMCR- 2023/06/01
CRDT- 2022/06/24 02:16
PHST- 2021/09/29 00:00 [received]
PHST- 2022/02/01 00:00 [accepted]
PHST- 2022/06/24 02:16 [entrez]
PHST- 2022/06/25 06:00 [pubmed]
PHST- 2022/06/25 06:01 [medline]
PHST- 2023/06/01 00:00 [pmc-release]
AID - NEURCLINPRACT2021070086 [pii]
AID - 10.1212/CPJ.0000000000001166 [doi]
PST - ppublish
SO  - Neurol Clin Pract. 2022 Jun;12(3):211-217. doi: 10.1212/CPJ.0000000000001166.