title: Electrophysiological findings in patients with low density lipoprotein receptor related protein 4 positive myasthenia gravis.
abstract: The aim was to determine the electrophysiological profile of our cohort of low density lipoprotein receptor related protein 4 (LRP4) positive myasthenia gravis (MG) patients.
  
  
  
  A repetitive nerve stimulation (RNS) test and jitter analysis using a concentric needle electrode were performed in 17 LRP4 positive MG patients. The results were compared to 31 muscle-specific tyrosine kinase (MuSK) positive and 28 acetylcholine receptor (AChR) positive MG patients.
  
  
  
  The RNS test was negative in almost all patients belonging to the LRP4/seronegative and LRP4/MuSK groups. It was positive most frequently in the AChR MG patients, especially those without anti-LRP4 antibodies. The presence of anti-LRP4 antibodies was connected to lower decrement values, whilst the independent presence of anti-AChR or anti-MuSK antibodies was connected to higher decrement values. Lowest jitter was recorded in patients with LRP4/seronegative MG. The highest percentage of pathological jitter analysis test results was present in MuSK and AChR MG patients. The isolate presence of anti-LRP4 antibodies did not influence the mean consecutive difference values, whilst mean consecutive difference values were higher in the presence of anti-AChR or anti-MuSK antibodies.
  
  
  
  Low density lipoprotein receptor related protein 4 positive patients make a distinct MG subgroup with rarely detected pathological electrophysiological test results. The lack of influence of anti-LRP4 antibodies on the different electrophysiological parameters brings into question the pathogenic role of anti-LRP4 antibodies in MG.
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia. ananikolic74@yahoo.com.|Medical Faculty, Belgrade University, Belgrade, Serbia. ananikolic74@yahoo.com.
authors.forename: A V
authors.initials: AV
authors.lastname: Nikolic
authors.affiliation: Institute for Medical Statistics, Medical Faculty, Belgrade University, Belgrade, Serbia.
authors.forename: S D
authors.initials: SD
authors.lastname: Bojic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia.|Medical Faculty, Belgrade University, Belgrade, Serbia.
authors.forename: V M
authors.initials: VM
authors.lastname: Rakocevic Stojanovic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia.|Medical Faculty, Belgrade University, Belgrade, Serbia.
authors.forename: I Z
authors.initials: IZ
authors.lastname: Basta
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia.|Medical Faculty, Belgrade University, Belgrade, Serbia.
authors.forename: D V
authors.initials: DV
authors.lastname: Lavrnic
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D026502:LDL-Receptor Related Proteins / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000276:immunology* / Q000503:physiopathology*; D009460:Neurologic Examination; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology
chemical_list: D001323:Autoantibodies; D026502:LDL-Receptor Related Proteins; C551781:LRP4 protein, human; D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases
keywords: electrophysiology; jitter; low density lipoprotein-receptor-related protein 4; myasthenia gravis; neurophysiology; repetitive nerve stimulation