Oct 3, 2008

ELEMENTS OF NORMAL SLEEP ACTIVITY – VERTEX WAVES




SYNONYMS = V WAVES, VERTEX SHARP TRANSIENTS
Shape
Sharp contoured compounded potentials

Amplitude
Up to 250 µv

Frequency / duration
Less than 2 Hz / Duration less than 200 ms

Distribution
Maximum at vertex (C3, C4) but may have wider distribution

Persistence
They are seen at irregular intervals in stages 1 and 2 of NREM sleep

Synchrony
Bisynchronous, may be unilateral

Miscellaneous

  • V waves and K complexes appear in well developed from for the first time at the age of 5-6 months.
  • They are most likely secondarily to auditory evoked potentials that converge from their cortical projection areas to a region underlying the vertex electrodes.

Reference:
1. Fisch BJ. Spehlmann’s EEG primer, Amsterdam: Elsevier, 3rd edition
2. Niedermeyer E, Lopes da Silva F. Electroencephalography: basic principles, clinical applications and related fields, Baltimore, Maryland: Williams and Wilkins, 4th edition
3. Jasper R. Daube. Clinical Neurophysiology, Philadelphia: F. A. Davis Company
4. Kooi, K. A. et al. Polarity and field configuration of the vertex components of the human auditory evoked response: a reinterpretation. Electroencephalogr. Clin. Neurophysiol. 31:166-169

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