Midline theta rhythm revisited.
The midline theta rhythm consists of runs of theta waves occurring in the midline, especially in the central and parietal vertex regions. Few reports regarding this uncommon EEG finding have been published. It has been given various names, e.g. theta discharges in the middle-line, theta spindles, etc. Out of the 4,236 patients who were administered EEG examinations during an investigation period of 9 months, the midline theta rhythm, with a frequency in the range of 4-7 Hz, voltage over 50 microV, duration over 3 seconds, and most prominent in the central and parietal vertex areas, was recorded in 35 (0.83%). The age distribution of these patients peaked in two groups, adults aged 21-40 years and elderly patients aged 61-77 years. The waveform of the theta rhythm observed in adults 40 years old and under was often sinusoidal and regular. In this group, the most common clinical disorder was epilepsy. Often, the appearance of the theta rhythm observed in elderly patients was triangular and irregular, and sometimes sharp. In this group, the common clinical symptoms were headaches and dizziness, characterized by diagnoses of organic brain diseases such as cerebrovascular disorders. This study re-examines the clinical significance of the midline theta rhythm, taking into consideration studies that have been published in the past.
Okada
S
S
Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan.
Urakami
Y
Y
D000328:Adult; D000368:Aged; D001925:Brain Damage, Chronic / Q000503:physiopathology; D002540:Cerebral Cortex / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012189:Retrospective Studies; D013826:Theta Rhythm; D014851:Wakefulness / Q000502:physiology*