Although TNMG can be life-threatening if not identified and treated promptly, for the majority of infants it is a transient illness with no lasting effects. Symptoms last for an average of 18 days (5 days to 4 weeks), and full recovery is seen in 90% of patients by 2 months of age. The remaining 10% of patients recover by 4 months. There have been reports of more prolonged illness; however, these are usually associated in the more atypical cases and in infants with arthrogryposis. Permanent facial diparesis has also rarely been reported.