Transient loss of consciousness and orthostatic intolerance
J G. van Dijk
Leiden, The Netherlands
Disclosure: Development of test for vigilance for drug trials of sleep disorders (\"Bio Project\")
34 slide(s) – 00:22:05– English –2010-09-28
After viewing this presentation the participant will be able to discuss:
- Major types of TLOC in differential diagnosis
- The need for neurologist to understand reflex syncope
- Major syndromes of orthostatic intolerance
- Differences between orthostatic intolerance and orthostatic hypotension
Transient loss of consciousness (TLOC) is defined as an apparent loss of consciousness with an abrupt onset, a short duration, and a spontaneous and complete recovery. Main groups of causes are syncope, epileptic seizures, functional/psychogenic attacks and less frequent causes. Syncope is defined as TLOC due to cerebral hypoperfusion, and is divided into reflex syncope (synonymous with neurally mediated syncope), syncope due to orthostatic hypotension, and cardiac syncope (arrhythmic or associated with structural cardiac disease). Orthostatic intolerance (OI) concerns symptoms in the standing position in relation to circulatory problems. Complaints vary from fatigue and lightheadedness to syncope.
As various specialties are involved in TLOC care; it is hard to obtain an overview, leading to fragmented care; an inconsistent terminology has contributed to confusion. The current classification of TLOC is the result of multidisciplinary efforts. The approach should be based on knowledge of defining features of all major groups and assessment of risks, highest in those with cardiac syncope.