No increased herniation of the cerebellar tonsils in a group of patients with orthostatic intolerance

Emily M. Garland, James C. Anderson, Bonnie K. Black, Robert M. Kessler, Peter E. Konrad, David Robertson

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Orthostatic intolerance, seen predominantly in young women, is characterized by symptoms of lightheadedness, fatigue and palpitations in the upright posture. With standing, plasma norepinephrine levels rise dramatically and heart rate often increases by more than 30 beats per minute, although blood pressure does not usually fall. A theory recently popularized in the media suggests that some cases of orthostatic intolerance are related to hindbrain compression, with or without a Chiari I malformation. As a preliminary investigation of this hypothesis, head or cervical spine MRI scans from 23 females with orthostatic intolerance were reviewed. The cerebellar tonsils averaged 0.3 ± 1.9 mm below the foramen magnum. These results were compared to measurements from a control group averaging 0.4 ± 2.6 mm above the foramen magnum (P > 0.05). Tonsillar depression of at least 3 mm occurred in 13 % of both the patient group and the control group. Tonsillar herniation was not found to influence supine or upright blood pressure, heart rate or plasma norepinephrine levels in the patients. We conclude that herniation of the cerebellar tonsils is not a common cause of orthostatic intolerance. However, the single measurement of tonsillar depression might underestimate the number of patients with hindbrain compression.

Original languageEnglish (US)
Pages (from-to)472-476
Number of pages5
JournalClinical Autonomic Research
Issue number6
StatePublished - Dec 2002
Externally publishedYes


  • Autonomic nervous system
  • Cerebellar herniation
  • Chiari I malformation
  • Orthostatic intolerance

ASJC Scopus subject areas

  • Endocrine and Autonomic Systems
  • Clinical Neurology


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