Alteration of the pressure setting of a Codman-Hakim programmable valve by a television

Abstract

A 7-year-old girl presented in semicomatose condition. She had received a ventriculoperitoneal shunt using a Codman-Hakim programmable valve. Head computed tomography demonstrated hydrocephalus and head radiography showed that the pressure setting of the shunt valve had changed to 60 mmH(2)O from 40 mmH(2)O. The pressure setting was returned to 40 mmH(2)O, and she was discharged because her clinical symptoms and hydrocephalus improved. One month later, she lost consciousness again and was transported to our hospital. Hydrocephalus and shunt valve pressure of 50 mmH(2)O were noted, and the pressure setting was returned to 40 mmH(2)O again. She was discharged without complications. We suspected that the valve pressure was caused by close contact with a television, because the patient tended to touch a television with her head during play. The valve pressure did not change after the television was placed on a high stand out of reach. We should recognize that there are many sources of weak magnetic fields that may influence a programmable valve in everyday life.