Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance☆☆☆

Abstract 

Objectives: To measure postural changes in cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance. Study design: We studied 28 patients (age, 10 to 22 years) and 20 healthy control subjects (age, 6 to 27 years). Cerebral oxygenated hemoglobin (oxy-Hb) and deoxygenated Hb were noninvasively and continuously measured with near infrared spectroscopy during active standing. Beat-to-beat arterial pressure was monitored by Finapres. Results: Orthostatic intolerance determined by cardiovascular responses to standing was observed in 16 of 28 patients: instantaneous orthostatic hypotension in 8, delayed orthostatic hypotension in 2, and postural orthostatic tachycardia in 6. A rapid recovery of oxy-Hb by near infrared spectroscopy at the onset of active standing was not found in 15 of 16 patients with chronic fatigue and orthostatic intolerance and in 6 of 12 patients with chronic fatigue without orthostatic intolerance but only in 2 of 20 control subjects. Thirteen of 16 patients with orthostatic intolerance showed prolonged reduction in oxy-Hb during standing. Conclusions: Impaired cerebral hemodynamics in patients with chronic fatigue syndrome and postural orthostatic tachycardia suggest a link between impaired cerebral oxygenation and chronic fatigue. However, this cannot explain the symptoms in patients meeting the criteria of chronic fatigue without orthostatic intolerance. (J Pediatr 2002;140:412-7)

Abbreviations:  CBF , Cerebral blood flow, CFS , Chronic fatigue syndrome, deoxy-Hb , Cerebral deoxygenated Hb, INOH , Instantaneous orthostatic hypotension, NIRS , Near infrared spectroscopy, oxy-Hb , Cerebral oxygenated hemoglobin, POTS , Postural tachycardia syndrome