Self-induced hypoxia has been reported particularlyin adolescents, and it can result in neurological injury. Here,we present a case of electroencephalogram (EEG) abnormalitiesinduced by habitual neck compression differentiated fromepileptic seizures by Tc-99m HMPAO SPECT. A 19-year-oldmale was admitted for evaluation of recurrent generalizedtonic-clonic seizures. No interictal EEG abnormality was detected;however, abnormal slow delta waves were found immediatelyafter habitual right neck compression. To differentiateEEG abnormalities due to a hemodynamic deficit inducedby habitual neck compression from an epileptic seizure,Tc-99m HMPAO SPECT was performed immediately afterright carotid artery compression. Abnormal delta waves weretriggered, and cerebral hypoperfusion in the right internalcarotid artery territory was detected on Tc-99m HMPAOSPECT. The slow delta wave detected on the EEG resultedfrom the cerebral hypoperfusion because of the habitual neckcompression.