Congenital myasthenic syndromes and transient myasthenia gravis.

Hypotonia in the neonatal period and early infancy is a common clinical finding. It can be caused by various heterogeneous disorders of different origin which might lead to diagnostic difficulties. Disorders of the neuromuscular junction, such as congenital myasthenic syndromes and neonatal transient myasthenia gravis are among the aetiologies. We report on a case of congenital myasthenia caused by mutation in the long cytoplasmic loop of the epsilon subunit of the acetylcholine receptor and a neonate of a myasthenic mother diagnosed with transient myasthenia gravis.

[Course and treatment of myasthenia gravis during pregnancy]. / Verlauf und Behandlung der Myasthenia gravis in der Schwangerschaft.

Pregnancy and family planning issues are frequent concerns in the medical care of patients with myasthenia gravis since disease onset often coincides with the life period which is decisive in this respect. Although pregnancy, delivery and breastfeeding represent special circumstances in these patients, they are not associated with higher risks of complications compared to normal pregnancy, delivery and postpartum period. Frequently asked questions regard the course of pregnancy as well as the impact of the disease and particularly medical treatment on pregnancy and the foetus or neonate. Great significance is attached to the mode of delivery since it is still widely accepted that patients with myasthenia gravis have to deliver per elective caesarean section. This paper gives an overview and provides a basis for the medical care and individual counselling of patients with myasthenia gravis who want to start a family or are already pregnant.

Marked hypotonia in an infant of a mother with Devic disease.

A full-term female neonate was born with severe hypotonia and weakness. Her mother had been treated for neuromyelitis optica (Devic disease) for 6 years. Her previous son, born 10 years earlier and before she developed the disease, also had marked hypotonia that gradually improved over several weeks. A suspicion of neonatal myasthenia gravis arose, as a search of the literature revealed the occasional detection of anti-acetylcholine receptor antibodies in patients with Devic disease. A neostigmine test was mildly positive in the baby, but anti-acetylcholine receptor antibodies were elevated. Aquaporin 4 antibodies typical of neuromyelitis optica were not detected in the infant. Because of clinical deterioration, intravenous immunoglobulin was administered with substantial improvement. Anti-acetylcholine antibodies were markedly elevated in the mother's serum, although she showed no clinical signs of myasthenia gravis. It is very likely that her previous baby also had unrecognized transient myasthenia gravis.

Transient neonatal myasthenia gravis in a baby born to a mother with new-onset anti-MuSK-mediated myasthenia gravis.

We describe a 30-year-old pregnant woman with undiagnosed weakness who delivered a severely weak neonate. Subsequent workup of the mother revealed myasthenia gravis with muscle-specific kinase antibodies. The infant responded to intravenous immunoglobulin and symptoms normalized. He was presumed to have an anti-muscle-specific kinase-mediated transient neonatal myasthenia gravis.

[Myasthenia gravis and pregnancy: clinical course and management of delivery and the postpartum phase]. / Myasthénie auto-immune et grossesse: évolution clinique, accouchement et post-partum.

OBJECTIVES: To study influences of pregnancy on the time-course of myasthenia gravis (MG) and of MG on pregnancy, delivery, postpartum and newborn. METHODS: We retrospectively collected data from 100 women affected with MG, hospitalized between 1994 and 2003 in departments of Neurology of Lille University Hospital. RESULTS: Eighteen patients had a total of 36 pregnancies, occurring 7.2 years on average after MG onset. MG exacerbation occurred in 7 patients (26 percent) during pregnancy and in 4 (14.8 percent) during postpartum. One patient died of acute respiratory failure during postpartum. Delay between the onset of MG and pregnancy was the only variable significantly associated with MG exacerbation: 5.8 years when exacerbation and 9.5 years when no exacerbation (p=0.03). Seven miscarriages, two therapeutic abortions and no death at birth were reported. Levels of anti-acetylcholine receptor antibodies were abnormal in 3 of 27 newborns (11 percent), but only one (3.7 percent) developed seronegative transient neonatal myasthenia gravis. DISCUSSION: During pregnancy, the clinical course of MG is variable but exacerbations were associated with a shorter delay between MG diagnosis and pregnancy. The risk of transient neonatal myasthenia gravis is relatively small but exists even when the parturient has stable MG without elevated levels of anti-acetylcholine receptor antibodies. CONCLUSION: Our study confirms pregnancy is more difficult to manage at the beginning of MG. Given the unpredictable course of MG during pregnancy, we recommend women affected with MG to begin a pregnancy when the disease is stable.

Seronegative neonatal myasthenia gravis in one of the twins.

Neonatal myasthenia gravis has been described as a transient condition affecting only a small percent of neonates. We report a twin gestation in a seronegative mother with myasthenia gravis, in which only one twin was affected.