Topical Review Article: Transient Neonatal Myasthenia Gravis

Abstract

Transient neonatal myasthenia gravis is a postsynaptic neuromuscular transmission defect occurring in 21% of infants born to women with active (and, less commonly, in remission) acquired myasthenia gravis. Although passive-transfer acetylcholine receptor (AChR) antibodies are found in the majority of these newborns, their pathogenic role is questionable because only some infants are symptomatic. Pathogenesis in infants without AChR antibodies is unknown. There is still no biologic marker for prenatal identification of this subpopulation of newborns, although HLA typing may be a promising tool. Sucking, swallowing, and respiratory difficulties are the most common presenting signs in the first day of life. Final diagnosis is done when administration of acetylcholinesterase agents transiently corrects the neuromuscular transmission defect. Serum AChR antibody titers follow the same pattern as their mothers. Supportive management and anticholinesterase agents prior to feedings are necessary in about 80% of patients. In the majority of infants the condition resolves spontaneously.

Clinical evaluation and management of myasthenia gravis

“…An acquired transient weakness termed "neonatal myasthenia," attributed to antibodies crossing the placenta from mother to fetus, occurs in about 12% of infants born to mothers with autoimmune MG. 7,110 A myasthenic child born to a mother without autoimmune MG may have one of a rapidly growing list of rare congenital myasthenic syndromes that have now been separated into genetic defects of presynaptic, synaptic, or postsynaptic neuromuscular transmission ( Table 1). Some of the conditions have characteristic clinical presentations.…”

Transiente neonatale Myasthenia gravis

“…Die transiente neonatale MG tritt mit einer Häufigkeit von 1:20.000 bis 1:40.000 auf und betrifft 12-54% der Neugeborenen von Müttern mit MG [26,29,30,32]. Die perinatale Letalität liegt bei bis zu 10%, wofür respiratorische Komplikationen ausschlaggebend sind [30].…”

“…Umgekehrt scheint das MyasthenieRisiko für Neugeborene von Müttern, die zum Zeitpunkt der Geburt in Remission sind, geringer zu sein [12,17,21,26,29,35,36]. Unklar ist bisher aber, warum nicht jedes Neugeborene einer Myasthenie-Patientin erkrankt bzw.…”

Muskelsykdommer med debut i barnealder

“…Ved neonatal myasthenia gravis er antistoffer mot acetylkolinreseptorer overført fra moren i svangerskapet. Av barn til affiserte mødre vil 10 -20 % straks etter fødselen vise symptomer på muskelsvakhet (17). Disse symptomene er forbigående, men intensivbehandling kan vaere nødvendig initialt.…”