Transient neonatal myasthenia gravis: a case report and literature review / 中国新生儿科杂志

ABSTRACT

Objective:To summarize the clinical features of transient neonatal myasthenia gravis (TNMG).Methods:We retrospectively collected the clinical data of an neonate diagnosed with TNMG in the department of Neonatology at the Affiliated Hospital of North Sichuan Medical College. Literature was retrieved from databases including CNKI, VIP, Wanfang, the Chinese Medical Journal Full Text database, the Chinese biomedical literature database, PubMed, Embase, Web of Science, The Cochrane library, and Medline. Search terms were "neonatal"、"pregnancy"OR"pregnant"OR"maternal"、"myasthenia"OR "myasthenia gravis"、"transient myasthenia gravis"OR"transitory myasthenia gravis"OR"temporary myasthenia gravis"、"congenital myasthenia gravis"OR"geneogenous myasthenia gravis". Searching period was from establishment of database to May 31st 2023. We summarize the clinical characteristics, treatment, and prognosis of reported cases with TNMG.Results:This patient is a full-term male infant who experienced decreased muscle tone, weak crying, and difficulty breathing 10 min after birth. His mother had a history of myasthenia gravis for 13 years. On the second day of birth, his neostigmine test was positive. So he was diagnosed with TNMG and treated with respiratory support and intravenous human immunoglobulin. His symptoms were relieved at day 10 and resolved by day 20. No abnormalities were observed during follow-up up to 6 months of age. A total of 7 Chinese papers and 13 English papers were retrieved, reporting 39 cases in total including this patient. Mothers of 34 cases (87.2%) were diagnosed with MG before delivery, and the other 5 mothers (12.8%) were diagnosed with MG after delivery. The main clinical manifestations in neonates were reduced muscle tone (29 cases, 74.4%), weak crying (23 cases, 59.0%), dyspnea (20 cases, 51.3%), and feeding difficulties (18 cases, 46.2%). 33 cases (84.6%) developed symptoms within the first day after birth, 6 cases (15.4%) had symptoms between day 2 and day 4. Most patients had a disease course for 2-6 weeks (29 cases, 74.4%). 27 cases (69.2%) underwent neostigmine test, all were positive. 30 cases (76.9%) were treated with cholinesterase inhibitors, 5 cases (12.8%) received IVIG and 1 case (2.6%) received an exchange transfusion. Out of the 39 cases, 33 cases (84.6%) were cured and discharged, 6 cases (15.4%) died. The causes of death were pulmonary infection and respiratory failure. Among the 17 patients with follow-up records, except for 1 case who only followed up to 2 months old and had slightly worse head upright, the rest of the children had normal physical and neurological development.Conclusions:TNMG may occur in infants that were born to MG mothers, most of the patients with TNMG develop symptoms on the first day after birth, a few patients develop symptoms 3-4 d after birth. Neostigmine test, serum MG antibody test should be performed to assist diagnosis. Cholinesterase inhibitors and symptomatic support are the main treatment options. TNMG generally have a good prognosis after treatment.