Tag: orthostatic intolerance

Orthostatic intolerance in adolescent chronic fatigue syndrome

Abstract:

OBJECTIVES: To demonstrate the association between orthostatic intolerance and the chronic fatigue syndrome (CFS) in adolescents and to delineate the form that orthostatic intolerance takes in these children.

STUDY DESIGN: We investigated the heart rate and blood pressure (BP) responses to head-up tilt (HUT) in 26 adolescents aged 11 to 19 years with CFS compared with responses in adolescents referred for the evaluation of simple faint and to responses in 13 normal healthy control children of similar age.

RESULTS: A total of 4/13 of the controls and 18/26 simple faint patients experienced typical faints with an abrupt decrease in BP and heart rate associated with loss of consciousness. One CFS patient had a normal HUT. A total of 25/26 CFS patients experienced severe orthostatic symptoms associated with syncope in 7/25, orthostatic tachycardia with hypotension in 15/25, and orthostatic tachycardia without significant hypotension in 3/25. Acrocyanosis, cool extremities, and edema indicated venous pooling in 18/25. None of the control or simple faint patients experienced comparable acral or tachycardic findings.

CONCLUSIONS: We conclude that chronic fatigue syndrome is highly related to orthostatic intolerance in adolescents. The orthostatic intolerance of CFS often has heart rate and BP responses similar to responses in the syndrome of orthostatic tachycardia suggesting that a partial autonomic defect may contribute to symptomatology in these patients.

 

Source: Stewart JM, Gewitz MH, Weldon A, Arlievsky N, Li K, Munoz J. Orthostatic intolerance in adolescent chronic fatigue syndrome. Pediatrics. 1999 Jan;103(1):116-21. http://www.ncbi.nlm.nih.gov/pubmed/9917448

 

Does the chronic fatigue syndrome involve the autonomic nervous system?

Abstract:

PURPOSE: To investigate the role of the autonomic nervous system in the symptoms of patients with chronic fatigue syndrome (CFS) and delineate the pathogenesis of the orthostatic Intolerance and predisposition to neurally mediated syncope reported in this patient group.

PATIENTS AND METHODS: Twenty-three CFS patients and controls performed a battery of autonomic function tests. The CFS patients completed questionnaires pertaining to autonomic and CFS symptoms, their level of physical activity, and premorbid and coexisting psychiatric disorders. The relationship between autonomic test results, cardiovascular deconditioning, and psychiatric disorders was examined with multivariate statistics and the evidence that autonomic changes seen in CFS might be secondary to a postviral, idiopathic autonomic neuropathy was explored.

RESULTS: The CFS subjects had a significant increase in baseline (P < 0.01) and maximum heart rate (HR) on standing and tilting (both P < 0.0001). Tests of parasympathetic nervous system function (the expiratory inspiratory ratio, P < 0.005; maximum minus minimum HR difference, P < 0.05), were significantly less in the CFS group as were measures of sympathetic nervous system function (systolic blood pressure decrease with tilting, P < 0.01; diastolic blood pressure decrease with tilting, P < 0.05; and the systolic blood pressure decrease during phase II of a Valsalva maneuver, P < 0.05). Twenty-five percent of CFS subjects had a positive tilt table test. The physical activity index was a significant predictor of autonomic test results (resting, sitting, standing, and tilted HR, P < 0.05 to P < 0.009); and the blood pressure decrease in phase II of the Valvalsa maneuver, P < 0.05) whereas premorbid and coexistent psychiatric conditions were not. The onset of autonomic symptoms occurred within 4 weeks of a viral infection in 46% of patients-a temporal pattern that is consistent with a postviral, idiopathic autonomic neuropathy.

CONCLUSION: Patients with CFS show alterations in measures of sympathetic and parasympathetic nervous system function. These results, which provide the physiological basis for the orthostatic intolerance and other symptoms of autonomic function in this patient group, may be explained by cardiovascular deconditioning, a postviral idiopathic autonomic neuropathy, or both.

 

Source: Freeman R, Komaroff AL. Does the chronic fatigue syndrome involve the autonomic nervous system? Am J Med. 1997 Apr;102(4):357-64. http://www.ncbi.nlm.nih.gov/pubmed/9217617

 

Possible relationship between chronic fatigue and postural tachycardia syndromes

Abstract:

Postural tachycardia syndrome refers to the development of symptoms such as light-headedness, visual blurring, palpitations and weakness on assuming an upright posture; these symptoms are relieved by resuming a supine posture. This syndrome is occasionally associated with idiopathic hypovolemia, impaired vasomotor tone, deconditioning and autonomic neuropathy, but has not been reported in association with chronic fatigue syndrome (CFS).

We describe five patients who satisfied the CFS criteria of the Centres for Disease Control and Prevention. Upright tilt-table testing induced significant hypotension and increased heart rate in all five patients, consistent with clinical and autonomic manifestation of postural tachycardia syndrome.

 

Source: De Lorenzo F, Hargreaves J, Kakkar VV. Possible relationship between chronic fatigue and postural tachycardia syndromes. Clin Auton Res. 1996 Oct;6(5):263-4. http://www.ncbi.nlm.nih.gov/pubmed/8899252