Longterm observation were made of 60 patients with vocal cord paralyses which frequently occurred during the 1970 influenza epidemic. There were 26 cases with left paralysis and 13 cases with right paralysis, while 21 cases had bilateral ones.
The recovery of the vocal cord movement began 1 to 6 months after the onset of the paralysis in 41 cases, and more later in 9 cases. Forty-eight cases had full or nearly complete recovery in 3 to 16 months after the onset of their paralyses. In many cases with bilateral paralysis, the right vocal cord began to recover earlier than the left cord.
Four cases of the bilateral paralysis still had persisting paralysis. Two of them repeated the paralysis. Their both vocal cords were at first fixed in the intermediate position and then completely recovered within 7 to 8 months. After 9 to 10 years, however, the both cords were fixed again in the paramedian position. In other 2 cases, the both vocal cords were fixed in the median position and did not recover for 14 years.
Questionnaire was sent to all 60 patients for a survey of the outcome of symptoms in 1984. We received 42 responses and three patients were dead. The recovery of voice was satisfactory in almost all cases. However, one half of the patients of the bilateral vocal cord paralyses suffered from some sequelae such as stridor, snore, waterchoke and slight dyspnea.
