Cardiogenic syncope and epilepsy.

SYNCOPE has been defined as 'a failure of the heart's action resulting in loss of consciousness or sometimes in death' (O.E.D.). Since Gower's discussion of vaso-vagal attacks (1907) many forms of reflex syncope have been described and studied, among them cough syncope (Baker, 1949), carotid sinus syncope (Weiss, 1935) and micturition syncope (Coggins, Lillington & Gray, 1964). The sudden and transient interruption of consciousness seen in a syncopal attack is not uncommonly associated with organic heart disease-cardiogenic syncope (Brigden, 1966)-occurring as it may with sudden changes of rhythm, heart block, paroxysmal tachycardia, myocardial infarction, aortic or pulmonary stenosis, ball-valve obstruction of the mitral valve and lesions associated with severe pulmonary hypertension. The physiological mechanisms involved are reviewed in detail by Wayne (1961). That syncope, if prolonged more than 15-20 sec, may be followed by epileptiform convulsions and incontinence is well attested (Spens, 1793; Campbell, Symonds & Williams, 1950) occurring particularly often in the dentist's chair (Symonds, 1950). The differentiation between epilepsy and syncope in certain cases therefore may be difficult, for although implicit in a diagnosis of epilepsy is a consideration of a primary disorder of brain (Williams, 1958), variants of focal epilepsy, possibly with a hypothalamic excitatory point, may produce apparent syncopal attacks with reflex cardiovascular changes (Kinnier Wilson, 1928; Kershman, 1949). The establishment of a not immediately apparent cardiac cause for syncope in four patients who were referred to a neurological clinic with an initial diagnosis of epilepsy was felt to warrant drawing further attention to this diagnostic problem, particularly as three were seen within the space of I month.