Haider et al described the progression of changes seen in the electroencephalograph (EEG) of patients with barbiturate, sedative or tricyclic antidepressant overdose. The patterns correlated with the degree of progression from mild stupor to deep coma. The authors are from the Royal Infirmary in Edinburgh.
Features in the EEG:
(1) alpha waves
(2) beta waves
(3) theta waves
(4) delta waves
(5) bursts of activity
(6) isoelectric periods
alpha |
beta |
theta |
delta |
bursts |
isoelectric |
Grade |
pure or dominant |
none or rare |
none or rare |
none |
none |
none |
I |
some |
some |
dominant |
some |
none |
none |
II |
none |
none |
some |
dominant |
none |
none |
III |
none |
none |
none |
some or dominant |
none |
brief |
IV |
none |
none |
none |
none |
alternate |
alternate |
V |
none |
none |
none |
none |
rare or few |
dominant |
VI |
none |
none |
none |
none |
none |
pure |
VII |
where:
• The bursts in Grade V are 3-10 cycles per second.
• The bursts in Grade VI are 3-7 cycles per second and low voltage.
Grade |
Patient Status |
I |
conscious |
II |
drowsy |
III |
stupor/coma but responds to painful stimuli |
IV |
stupor/coma but responds to painful stimuli |
V |
deep coma |
VI |
deep coma |
VII |
deep coma |
Specialty: Toxicology, Emergency Medicine, Critical Care
ICD-10: ,