Difference between revisions of "TIRDA (temporal intermittent rhythmic delta activity)"

Revision as of 14:01, 9 June 2017

• Temporal
• Intermittent: In cycles, so not continuous
• Rhythmic: Repetition of a waveform with relatively uniform morphology and duration, without an interval between consecutive waveforms.
• Delta: Delta waves
• Activity

• Short burst of rhythmic delta activity in the temporal region
• Amplitude of 50-100 microV

• The TIRDA can be more specified with the prevalence, duration, frequency, amplitude, stimulus-induced (SI), Evolving OR Fluctuating (both terms refer to changes in either frequency, location or morphology).
• If a more ictal appearance it can be categorized as TIRDA+:^[1]
  • +F: superimposed fast activity.
  • +S: superimposed sharp waves or spikes, or sharply contoured.
  • +FS: superimposed fast activity and sharp waves or spikes, or sharply contoured.

Clinical relevance

• Strong association with temporal lobe epilepsy
• Occurs in 28% of patients with temporal lobe epilepsy ^[2]

Other intermittent rhythmic delta activity: FIRDA (frontal intermittent rhythmic delta activity) OIRDA (occipital intermittent rhythmic delta activity)

TIRDA in a 72 year old female with left temporal epilepsy (average)

Notes

1. ↑ ACNS STANDARDIZED ICU EEG NOMENCLATURE v. 2012
2. ↑ Geyer JD et al. Significance of interictal temporal lobe delta activity for localization of the primary epileptogenic region. Neurology. 1999 Jan 1. 52(1):202-5.