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.
Department of Clinical Neurophysiology, Kings College Hospital, Denmark Hill, London SE5 9RS, UK.
M J
MJ
Hennessy
M
M
Koutroumanidis
E
E
Hughes
C D
CD
Binnie
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