Temporal intermittent rhythmic delta activity in electroencephalograms

Marlene M. Normand, Zbigniew K. Wszolek, Donald W. Klass

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Temporal intermittent rhythmic delta activity (TIRDA) has been reported to be highly specific for diagnosing complex partial epilepsy. Of 12,198 electroencephalographic (EEG) recordings performed at the Mayo Clinic between May 1, 1990 and May 1, 1991, 33 records from 27 patients (18 women and nine men; mean age, 41.5 years; range, 13-82 years) showed TIRDA. Clinical seizures were diagnosed in all patients, and complex partial epilepsy was well documented in 23. In a control group of 100 patients without TIRDA and matched for age and sex, generalized seizures were diagnosed in 25 and partial seizures in 15. Differences between TIRDA and control groups were highly statistically significant. Focal temporal sharp waves or spikes occurred in 23 patients with EEG recordings that contained TIRDA; three of these patients also exhibited generalized atypical spike-and-wave discharges. Four patients had TIRDA but no other epileptiform activity, although earlier EEGs of three of these patients contained spikes or sharp waves. These findings confirm earlier work, and we conclude that TIRDA represents an important epileptogenic abnormality.

Original languageEnglish (US)
Pages (from-to)280-284
Number of pages5
JournalJournal of Clinical Neurophysiology
Issue number3
StatePublished - May 1995


  • Complex partial
  • Delta activity
  • Electroencephalography
  • Epilepsy
  • Epileptiform activity
  • Temporal intermittent rhythmic delta activity

ASJC Scopus subject areas

  • Physiology
  • Neurology
  • Clinical Neurology
  • Physiology (medical)


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