Asymmetry in the autonomic nervous system with reference to the nasal cycle, migraine, anisocoria and Menière's syndrome.

Studies on the nasal cycle have demonstrated that the autonomic tone to the nose is asymmetrical and oscillates in a regular cycle. Autonomic tone may be regulated from a centre in the hypothalamus and normally there is a balance between he autonomic tone of the right and left halves of the body. However, under stress or with hypothalamic instability this balance may be disrupted and result in the marked autonomic asymmetry seen in migraine or Meniér's syndrome. Research on the nasal cycle in conditions where autonomic asymmetry is apparent could change the entire concept of autonomic control.