Psychomotor EEG variant of Gibbs: an association with underlying structural pathology.
OBJECTIVE
To describe the association between a unilateral mid-temporal rhythmic theta discharge ("psychomotor variant of Gibbs") with neuroimaging-demonstrated underlying mass lesion.


METHODS
Standard routine awake and scalp electroencephalography, continuous video-EEG monitoring and magnetic resonance brain imaging were employed in the diagnostic work-up of a 9-year-old boy with a severe behavioural disturbance and episodic outbursts of aggression.


RESULTS
EEG showed a unilateral mid-temporal rhythmic discharge which was continuous in drowsiness and which remained confined to the right hemisphere. MRI showed a lesion in the temporal horn of the right lateral ventricle displacing superiorly the white matter stem of the right temporal lobe.


CONCLUSIONS
A rhythmic mid-temporal theta discharge, commonly regarded as a benign EEG variant, may, in some patients, reflect underlying structural pathology. Neuroimaging should be considered particularly when this EEG pattern remains confined to one hemisphere.
Hennessy
M J
MJ
Department of Clinical Neurophysiology, Kings College Hospital, Denmark Hill, London SE5 9RS, UK.
Koutroumanidis
M
M
Hughes
E
E
Binnie
C D
CD
D001927:Brain Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008991:Monitoring, Physiologic; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology*; D013826:Theta Rhythm / Q000379:methods*; D014741:Video Recording