Head-up tilting is a useful provocative test for psychogenic non-epilepticseizures

Differentiating psychogenic non-epileptic attack disorder (NEAD) from true epilepsy is difficult. This often results in a misdiagnosis and unnecessary and ineffective treatment. Prolonged EEG/video recording is the most sensi tive tool for differentiating NEAD from epilepsy, but is costly and therefo re limited in availability. Provocative tests, particularly the use of sali ne injection, can reduce the length of monitoring but give rise to ethical dilemmas. This study assesses the value of head-up tilt testing as a provoc ative test for NEAD. Twenty-one patients (17 female, mean age 34.6 +/- 11.5 years) with recurren t seizure-like episodes and a clinical diagnosis of NEAD were studied. Pati ents were tilted to 80 degrees on an electric tilt table with footplate sup port for up to 45 minutes during continuous EGG, EEG and blood pressure mon itoring. Seventeen patients (81%) experienced typical symptoms (non-epilept iform limb shaking in 15 patients, absence in one patient, myoclonic jerkin g in one patient) during head-up tilt without significant EEG abnormalities or haemodynamic changes. The mean time to onset of seizure-like activity w as 13.2 +/- 11 minutes (range 0-31 minutes). No patients suffered injury or any other significant side-effect. Provocative testing using suggestion an d head-up tilt is a sensitive tool for diagnosing NEAD and represents a saf e, simple and inexpensive outpatient technique for investigating patients w ith suspected NEAD. (C) 1999 BEA Trading Ltd.