Research in Review

• POTS and Ehlers Danlos Syndrome Linked to Chiari 1 Malformation
• Pregnancy and POTS
• Orthostatic instability in a population-based study of chronic fatigue syndrome
• Relation between motion sickness susceptibility and vasovagal syncope susceptibility

POTS and Ehlers Danlos Syndrome Linked to Chiari 1 Malformation

Researchers from the NIH and Chiari Institute have found that some people have Ehlers Danlos syndrome, POTS and Chiari 1 malformation. They presented their findings at the latest Ehlers-Danlos National Foundation conference. Their presentation was videotaped, and it is available on the web at: http://www.thechiariinstitute.com. Click on the Ehlers-Danlos National Foundation link at the bottom of the page to watch the presentation.

Pregnancy and POTS
by Michelle Sawicki

Although there has been little research on pregnancy and POTS, recently two POTS patients in their mid-twenties were monitored throughout their pregnancies (Glatter, Tuteja, Chiamvimonvat, Hamdan & Park, 2005).

Both women developed hyperemesis gravidarum, a severe and intractable form of nausea and vomiting in pregnancy. Hyperemesis gravidarum may result in weight loss, nutritional deficiencies and abnormalities in fluids, electrolyte levels, and acid-base balance. Before intravenous fluid therapy, mortality from hyperemesis gravidarum was not uncommon, but now it is rare with treatment (Edelman & Logan, 2004).

The symptoms of hyperemesis gravidarum were managed with Zofran in both women. One woman continued to take midodrine for POTS symptoms throughout her pregnancy while the other took no medication to treat POTS. Both women experienced an improvement in POTS symptoms until 24 weeks gestation, at which point they both began to suffer severe sinus tachycardia and an increase in fainting.

Both women’s obstetricians recommended early elective delivery due to clinical decompensation (failure of the heart to maintain adequate blood circulation). Both women gave birth by cesarean section at thirty-seven weeks, and both babies were born apparently healthy.

The women were followed-up after delivery, one at six months and the other at twenty-two months. Both reported fewer POTS symptoms after pregnancy than before.

The authors of this study speculate that these women experienced a decrease in POTS symptoms prior to the sixth month of pregnancy due to the typical increase in circulating blood volume by up to 45% during pregnancy.

The authors recommend confining severe POTS patients to at least partial bed rest in the last trimester of pregnancy. They also recommend that pregnant women with POTS be followed closely in a high-risk obstetrical practice and that they consider undergoing early cesarean section, particularly with close monitoring.

References

• Edelman, A. & Logan, J. R. (2004). Pregnancy, Hyperemesis
  Gravidarum. In Sayah, A. J., Talavera, F., Zwanger, M., Halamka,
  J., O’Connor, R. E. (Eds.). emedicine Journal.
  http://www.emedicine.com/EMERG/topic479.htm



• Glatter, K. A., Tuteja, D., Chiamvimonvat, N., Hamdan, M.,
  Park, J. K. (2005). Pregnancy in postural orthostatic tachycardia
  syndrome. Pacing Clin Electrophysiol., 28(6), 591-593. PubMed

Am J Med. 2005 Dec;118(12):1415.

Orthostatic instability in a population-based study of chronic fatigue syndrome.

Jones JF, Nicholson A, Nisenbaum R, Papanicolaou DA, Solomon L, Boneva R, Heim C, Reeves WC.

Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Ga 30333, USA. jaj9@cdc.gov

PURPOSE: Autonomic nervous system dysfunction has been suggested as involved in the pathophysiology of chronic fatigue syndrome. This population-based case control study addressed the potential association between orthostatic instability (one sign of dysautonomia) and chronic fatigue syndrome.

SUBJECTS AND METHODS: Fifty-eight subjects who fulfilled criteria of the 1994 chronic fatigue syndrome research case definition and 55 healthy controls participated in a 2-day inpatient evaluation. Subjects had been identified during a 4-year population-based chronic fatigue syndrome surveillance study in Wichita, Kan. The present study evaluated subjects' current medical and psychiatric status, reviewed past medical/psychiatric history and medication use, used a stand-up test to screen for orthostatic instability, and conducted a head-up tilt table test to diagnose orthostatic instability.

RESULTS: No one manifested orthostatic instability in the stand-up test. The head-up tilt test elicited orthostatic instability in 30% of eligible chronic fatigue syndrome subjects (all with postural orthostatic tachycardia) and 48% of controls (50% with neurally mediated hypotension); intolerance was present in only nonfatigued (n=7) subjects. Neither fatigue nor illness severity were associated with outcome.

CONCLUSIONS: Orthostatic instability was similar in persons with chronic fatigue syndrome and nonfatigued controls subjects recruited from the general Wichita population. Delayed responses to head-up tilt tests were common and may reflect hydration status. These findings suggest reappraisal of primary dysautonomia as a factor in the pathogenesis of chronic fatigue syndrome.

PMID: 16378795

Brain Res Bull. 2006 Jan 15;68(4):217-226. Epub 2005 Nov 2.

Relation between motion sickness susceptibility and vasovagal syncope susceptibility.

Bosser G, Caillet G, Gauchard G, Marcon F, Perrin P.

Service de Cardiologie Pediatrique, Hopital d'Enfants, Centre Hospitalier Universitaire de Nancy, Vandoeuvre-les-Nancy, France; Institut National de la Sante et de la Recherche Medicale (INSERM), [EP]2R, Faculte de Medecine de Nancy, Vandoeuvre-les-Nancy, France; Equilibration et Performance Motrice, UFR STAPS, Universite Henri Poincare-Nancy 1, 30, rue du Jardin Botanique, 54600 Villers-les-Nancy, France.

Motion sickness is common in the population, especially in children, but its physiopathology is only partially understood and the true nature of the particular susceptibility of certain subjects remains completely unknown. Some symptoms of motion sickness, like pallor and cold sweating, are of an autonomic nature and the role of the autonomic nervous system in vasovagal syncope is well known. Our aim was therefore to study the relationship between motion sickness susceptibility and vasovagal syncope susceptibility.

Questionnaires about susceptibility to motion sickness and to vasovagal syncope or presyncope in adulthood and childhood, filled in by 899 students (20.4+/-2.1 years, 405 men), were analyzed. Motion sickness susceptibility in childhood was 31.1% and in adulthood 7.9% (p<0.001). Vasovagal syncope susceptibility in childhood was 36.4% and in adulthood 33.9% (NS).

A relationship between motion sickness susceptibility in adulthood and vasovagal syncope susceptibility in childhood and adulthood (p=0.004 and 0.005, respectively) was found. Despite the limitations of a retrospective study this relationship between motion sickness susceptibility and vasovagal syncope susceptibility may indicate that a common mechanism exists, explaining the particular susceptibility of some subjects to both disorders. This paradigm may prove useful in better understanding the true nature of motion sickness and vasovagal syncope.

PMID: 16377427

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