abnormal patterns

Last reviewed 01/2018

Abnormal electroencephalogram wave patterns include:

  • theta 8-12 Hz in parietal and occipital regions
  • delta less than 4 Hz - any slow wave pattern suggests acute problems - any acute insult
  • epilepsy: paroxysmal sharp high-voltage waves, e.g. the spike and wave pattern at rate of 3Hz seen in petit mal
  • brain death is indicated by absence of activity in normothermic patients not exposed to sedative drugs
  • periodic complexes - seen in Creutzfeldt-Jakob disease, subacute sclerosing panencephalitis, herpes simplex encephalitis and hepatic coma.
  • diffuse slowing of rhythms - seen in progressive multi - focal leukoencephalopathy