Supine catch sign--a simple clinical test to differentiate between true and false (pseudo) radial nerve palsy

Patients at times present with neurological symptoms and signs for which at times extensive investigation fails to identify any structural or organic pathology within the nervous system. These pseudo neurological syndromes can mimic almost any organic disease of the central and peripheral nervous system. Some such as pseudo seizures also referred to as psychogenic non-epileptic seizures (PNES) are more commonly encountered than others. Pseudo neurological syndromes presenting as mononeuropathies have been documented in the neurological literature. We document here a patient presenting with wrist drop suggestive of radial nerve palsy and illustrate a simple clinical test which can help differentiate between true and false (pseudo) radial nerve palsy.