EMG involves the insertion of small needles into the muscles. NCS involves administering small electrical impulses to the nerves, on the surface of the skin, and measuring the electrical response of the muscle in question. NCS investigation in LEMS primarily involves evaluation of compound motor action potentials (CMAPs) of effected muscles and sometimes EMG single-fiber examination can be used.CMAPs show small amplitudes but normal latency and conduction velocities. If repeated impulses are administered (2 per second or 2 Hz), it is normal for CMAP amplitudes to become smaller as the acetylcholine in the motor end plate is depleted. In LEMS, this decrease is larger than observed normally. Eventually, stored acetylcholine is made available, and the amplitudes increase again. In LEMS, this remains insufficient to reach a level sufficient for transmission of an impulse from nerve to muscle; all can be attributed to insufficient calcium in the nerve terminal. A similar pattern is witnessed in myasthenia gravis. In LEMS, in response to exercising the muscle, the CMAP amplitude increases greatly (over 200%, often much more). This also occurs on the administration of a rapid burst of electrical stimuli (20 impulses per second for 10 seconds). This is attributed to the influx of calcium in response to these stimuli. On single-fiber examination, features may include increased jitter (seen in other diseases of neuromuscular transmission) and blocking.Blood tests may be performed to exclude other causes of muscle disease (elevated creatine kinase may indicate a myositis, and abnormal thyroid function tests may indicate thyrotoxic myopathy).
Adverse effects
Common side effects of Odevixibat include diarrhea, stomach pain, vomiting, abnormal liquid function tests, and a deficiency in vitamins A,D, E and K.

Contraindications
Odevixibat cannot be given to a child on a liquid diet. Society and culture
Legal status
In May 2021, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommended granting a marketing authorization in the European Union for odevixibat for the treatment of PFIC in people aged six months or older. It was approved for medical use in the European Union in July 2021. References
External links
"Odevixibat". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03566238 for "This Study Will Investigate the Efficacy and Safety of A4250 in Children With PFIC 1 or 2 (PEDFIC 1)" at ClinicalTrials.gov