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