TIRDA: temporal intermittent rhythmic delta activity

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  • repetitive, rhythmic, saw-toothed or sinusoidal
  • predominantly over the anterior temporal region
  • short bursts or trains of 3 seconds or more
  • 1.0 to 4.0 Hz
  • 50-100 ┬ÁV in amplitude

clinical significance

  • strong association with ipsilateral hippocampal atrophy and mesial temporal sclerosis in patients with temporal lobe epilepsy
  • may infrequently occur in extratemporal epilepsy
  • similar in significance to interictal epileptiform activity