Article Text
Abstract
Aims Syncope is transient loss of consciousness (TLOC) caused by transient cerebral hypoperfusion. Neurally mediated syncope (NMS) is the most common cause. The head-up tilt test (HUTT) is the gold standard for diagnosing and categorising NMS, and is used locally in cases of diagnostic uncertainty, e.g. in cases with frequent, or atypical, or treatment resistant TLOC. This clinical audit completes the 1st cycle, started as a student project in 2009.1
Methods A registered retrospective clinical audit of 93 children under 18 years of age who underwent video-EEG-HUTT, in the Clinical Neurophysiology Department January 2009 to September 2014 was done. Audit of process assessed the procedures. Audit of outcome evaluated the results of the tests, documentation of test results, and use of results in the subsequent care of the patient. Requests were vetted by a consultant paediatric neurologist or paediatrician with expertise in cardiology, who attended the HUTT and wrote the report.
Results Beat-to-beat BP and automatic sphygmomanometer monitoring were used in 94%. End-tidal CO2 was recorded in 61%. The HUTTs demonstrated diagnostic abnormalities in BP and or HR in 26%. A further 9% of HUTTs demonstrated reproduction of symptoms but with normal BP and HR changes. The addition of video-EEG, demonstrating a normal background rhythm, including alpha-rhythm (posterior 8–13 cycle per second rhythm) excluded syncope, epileptic seizure, sleep attack, migraine, and raised intracranial pressure, and confirmed the events as functional/medically unexplained TLOC or dissociative states. In 65% no useful physiological information was obtained.
Conclusions Useful information was obtained from over a third of HUTTs. The new additions of video-EEG and beat-to-beat BP ensured that attacks were better understood. Patients with functional/medically unexplained TLOC/dissociative states who had symptoms without abnormal cardiovascular changes were clearly distinguished. A longer HUTT of 60 min at 60 degrees may yield more positive responses as most positives occurred between 25–45 min. Overall a significant improvement on the 1st audit was found.
Acknowledgements We are very grateful to all the clinical neurophysiology staff for helping with these investigations.
Reference
Sanne D et al. J Paeds and Child Health 2011;47:292–98