Document Detail

Head-down manoeuvre in patients with a high symptom score for orthostatic intolerance reveals impaired right brain frontal lobe vasoreactivity.
MedLine Citation:
PMID:  15978491     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: Autonomic nerve dysregulation produces a sense of impaired well-being and interferes with work performance in affected individuals. In this study, we characterized the pathophysiology of this condition. METHODS: Six patients with high symptom scores for orthostatic intolerance (OI) along with age- and sex-matched normal volunteers were directed to perform a head-down manoeuvre, and the change in cerebral blood flow (CBF) and cerebral oxygen levels (rSO(2)) in the right and left frontal lobes was measured using near-infrared spectroscopy (NIRS). RESULTS: The head-down manoeuvre induced a much greater increase in right-sided total haemoglobin concentration (THbl) in normal volunteers (0.51+/-0.24) when compared to symptomatic patients (0.0+/-0.04) but had no effect on left-sided THbl (P<0.05) in either group. Five of 6 patients showed a gradual decrease in right-sided THbl when assuming a sitting position, and all patients with this pattern complained of symptoms of multiple autonomic dysfunction. Further, this pattern of changes in right-sided THbl was not observed in normal volunteers. CONCLUSIONS: The gradual decrease of THbl with the sitting position and the lack of increase during the head-down manoeuvre in symptomatic patients suggest that these patients have impaired vasoreactivity in the right frontal lobes. SIGNIFICANCE: This impaired vasoreactivity likely reflects dysfunction of the right hemisphere and the sympathetic nervous system in patients with OI.
Nobusada Shinoura; Ryozi Yamada
Publication Detail:
Type:  Comparative Study; Journal Article     Date:  2005-03-26
Journal Detail:
Title:  Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology     Volume:  116     ISSN:  1388-2457     ISO Abbreviation:  Clin Neurophysiol     Publication Date:  2005 Jun 
Date Detail:
Created Date:  2005-06-27     Completed Date:  2005-08-09     Revised Date:  2008-09-10    
Medline Journal Info:
Nlm Unique ID:  100883319     Medline TA:  Clin Neurophysiol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  1286-90     Citation Subset:  IM    
Department of Neurosurgery, Komagome Metropolitan Hospital, 3-18-22 Hon-Komagome, Bunkyo-ku, Tokyo 113-8677, Japan.
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MeSH Terms
Autonomic Nervous System Diseases / physiopathology*
Case-Control Studies
Cerebrovascular Circulation / physiology*
Frontal Lobe / physiopathology*
Functional Laterality / physiology
Head-Down Tilt / physiology*
Hemoglobins / metabolism
Hypotension, Orthostatic / physiopathology*
Oxygen / blood
Spectroscopy, Near-Infrared / methods
Reg. No./Substance:
0/Hemoglobins; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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