The encephalogram as a risk predictive test for work at height

Regulating standard 35 (NR-35) defines work at height as "any activity performed two meters above from ground level and involving risk of falls" and recommends the performance of medical examination to detect "conditions that might cause sudden loss of consciousness and falls from heights". As a result many occupational physicians began to recommend routine electroencephalogram (EEG) to assess employees working at height. However, the validity of EEG for asymptomatic workers is uncertain.

To analyze occupational accidents related to work at height occurring from January 1, 2000 to December 31, 2014, at a university hospital, and to correlate them with the results of EEGs performed along that period.

Cross-sectional study involving review of EEG test,s clinical-occupational records and Work Accident Reports (WAR) of all employees working at height from January 1, 2000 to December 31, 2014. Terms in the WAR descriptions were established to investigate the relationship of accidents with "sudden loss of consciousness and falls from heights", such as "fall from a height", "sudden ill feeling", "loss of consciousness", "vertigo", "dizziness" and "syncope". EEG results were classified in three categories: normal, non-epileptic abnormalities and epileptic patterns. WAR descriptions were correlated with EEG results.

From 2,464 WARs issued along the investigated period, 2,228 were excluded because they did not correspond to work at height. From the remaining 236 WARs, 61 were excluded because EEG was not performed, therefore, 175 cases were included for analysis. Among the EEG tests assessed, 171 were normal, 4 exhibited non-epileptic abnormalities and none an epileptic pattern. Among all the analyzed cases, 13 descriptions included terms such as "fall from height", "loss of consciousness", "sudden ill feeling", "vertigo", "dizziness" and "syncope"; all the corresponding cases had normal EEG.

EEG was not a good predictor of risk for accidents related with work at height in the analyzed sample. EEG should not be performed for assessment of asymptomatic workers, but only in cases with clinical suspicion of neurological abnormalities.