One of the challenges In reconstructive surgery Is to ensure hand sensibili
ty is regained after median nerve repair. We assessed tactile gnosis In 54
patients (mean age 32 [range 4-72] years) after repair of transected median
or ulnar nerves at the wrist level. We found that there Is a well-defined
critical period for sensory relearning after nerve repair. There Is an opti
mum capacity below age 5-10 years followed by a rapid decline, which levels
out after puberty. The curve correlates with previously published data on
critical periods for language acquisition among Immigrants. Recovery of fun
ctional sensibility after nerve repair Is based on a learning process and I
n many ways Is analogous to learning a second language.