The incidence of Klumpke palsy is estimated at around 0.12% of all births via cesarean section. The incidence of Klumpke palsy in vaginal deliveries is unknown . The incidence was found to be higher with macrosomic and twin pregnancies.
Other causes of Klumpke palsy include Pancoast tumors and traction injuries in the form of 'hanging from a tree'.
Patients present with a 'claw hand' as there is a loss of flexor function of the wrist and the lumbricals, which usually flex the metacarpophalangeal (MCP) joint and extend the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints and interossei of the hand.
The wrist and the MCP are extended and the DIP and PIP are flexed. Since the median nerve is more severely affected, the first two digits have a greater degree of MCP extension and DIP/PIP flexion compared to the third and fourth digits .
Contralateral Horner syndrome due to the damage to the T1 sympathetic ganglion is a rare presentation.
Treatment and prognosis
Klumpke palsy tends to resolve by the age of 6 months. No reports of long-term neurological damage have been identified to date.
The treatment is most often conservative involving aggressive physiotherapy and occupational therapy of the affected arm.