Clinical Aspects of the “Third Rhythm” of the Temporal Lobe

Abstract

We studied clinical aspects of the "third rhythm," which was first described by Niedermeyer as alpha-like activity of the temporal lobe. By scalp EEG, temporal alpha-like activity was recorded in 15 (0.30%) of 4929 patients over 20 years of age. The temporal alpha-like activity was observed in 5 patients who had clinical and brain imaging findings indicating the presence of a cerebrovascular disorder. The alpha-like rhythm of these patients was left-sided, and wicket spikes appeared in the same region as the alpha-like rhythms in 4 of the 5 patients. In 8 of the 15, the temporal alpha-like rhythm was recorded over the defective bone or replacement bone after intracranial surgery. The alpha-like rhythm of these patients was similar to breach rhythm in the temporal region. The remaining 2 patients had not undergone intracranial surgery nor did they show symptoms of cerebrovascular disorders. The temporal alpha-like rhythms in one of these 2 might be a physiological third rhythm detected by scalp EEG through congenital bone thinning. Our observation supports the existence of intrinsic activity of the temporal lobe (the third rhythm). The third rhythm can be recorded by routine scalp EEG in some clinical conditions, and it is important to recognize this rhythm when one encounters temporal rhythmic activity independent of alpha rhythm of the occipital lobe.

Errors in EEG Interpretation and Misdiagnosis of Epilepsy

“…Instead, by far the most common sources of error are simple fluctuations of background activity in the temporal region. Some may meet criteria for wicket spikes [30,31,32,33,34,35,36], but many are simple fluctuations of background activity, as had been suggested by a small earlier study [26]. These ‘nameless’ fluctuations of normal backgrounds do not fit into well-described EEG waveforms, can be found on most EEGs, and have been described under different names [31,32,33,34,35,36].…”

Solid‐phase synthesis for a lifetime

“…Fast‐theta was detectable over the temporal cortex, suggesting slow‐theta is more specific to the hippocampus. A rhythm between the traditional 4–8 Hz band and the alpha band has been identified over the temporal cortex via analysis of iEEG by previous authors (Niedermeyer, 1990, 1991; Shinomiya et al, 1999). Their data demonstrate that the rhythm is unrelated to epileptic activity.…”

Disappearance of Breach Rhythm Heralding Recurrent Tumor Progression in a Patient With Astrocytoma

“…In the third case, breach rhythm was related to congenital bone thinning. 9 However, since there was an arachnoid cyst, reaching into the same region, meningocortical adhesions at the border of the arachnoid cyst cannot be ruled out. Nevertheless, a skull defect seems to be a necessary condition for the occurrence of a breach rhythm.…”