Autonomic disturbances in fibromyalgia patients : a clinical, transcranial doppler and laboratory study

Abstract EN

Hypothesis: Fibromyalgia (FM) is associated with stress.

The hypothalamic-pituitary-adrenal axis (HPA), together with the sympathetic axis are responsible for regulation of the stress response.

Neuropeptide Y (NPY) colocalizes with nor- epinephrine and both are stimulated during stress peripherally.

On the other hand, assessment of cerebral blood flow which reflects autonomic factors can be measured with transcranial Doppler (TCD).

Aim of study: To emphasize the presence of neurally mediated orthostatic hypotension in FM and its relation to NPY and cerebral circulation, all of which might reflect the autonomic etiology of the disease.

Materials & Methods: The study included 20 female patients suffering of FM diagnosed according to the American College of Rheumatology (ACR) criteria for classification of FM together with 10 healthy female volunteers matched in age and sex.

Thorough clinical examination, TCD, laboratory investigations including serum NPY during the supine position and after using the tilting table (head upright tilt HUT).

Results: There was a highly significant difference between patients and controls after tilting as regards systolic BP (t=5.6), diastolic (t=3.9), pulse (t=2.6) and TCD examination including mean flow velocity (MFV) (t=8.29) and pulsality index (PI) (t=2.75).

However, NPY was found to show a highly significant difference between patients and controls before (t=4.4) and after tilting (t=5.41).

Again, NPY showed a significant correlation with the clinical picture but not with TCD.

Conclusion: The most sensitive in response to HUT testing was TCD (100%).

Consequently it may be considered the most reliable in the diagnosis of neurally mediated hypotension in FM patients.

On the other hand serum NPY sensitivity was only (70%).

Clinical SBP and DBP are specific (100%) but not sensitive (50%).

This shows that dysregulation of ANS has a definite role in the pathogenesis of FM and can be detected by non-invasive means (TCD) to allow for proper therapeutic approaches.