Brain Matters

http://forum.parkinson.org/forum/viewtopic.php?t=7949

Posted: Tue Aug 18, 2009 7:16 pm   
Post subject: What are the autonomic symptoms of PD?    
Posted by:  Hubert H. Fernandez, MD

When orthostatic hypotension is verified, medications that contribute or exacerbate the condition must first be reduced or eliminated. Sometimes, even patients with a history of hypertension will develop low blood pressure after being diagnosed with Parkinson disease and may need to have their antihypertensive medications reduced, if not completely eliminated. Dopaminergic medications (particularly the dopamine agonists) may also aggravate orthostatic hypotension. Non-pharmacologic strategies which may improve orthostatic symptoms include increasing fluid intake, increasing salt in the diet, caffeine, and using tight, thigh-high support stockings to prevent pooling of blood below the waist. Purchasing a hospital bed, or raising the head of a normal bed, to 10-30 degrees may improve standing blood pressure when performed on a regular basis over several weeks. If needed, pharmacologic agents that raise blood pressure may be used...

TREATMENT OF ORTHOSTATIC HYPOTENSION (Part One)
Roy Freeman, MD
Associate Professor of Neurology
Harvard Medical School
Boston, MA USA

The article is undated; the author told me that it's "very old."  You can also find this article on the Neuropathy Association's website at:
http://www.neuropathymd.org/pdf/35/Treatment%20of%20Orthostatic%20Hypotension.pdf
MSA is mentioned twice on page 2. 

Some interesting points made by the article:

* "Man's evolution from a quadrupedal to a bipedal animal, with the accompanying move from a horizontal to an erect posture, placed considerable demands on the ability of the cardiovascular system to maintain adequate cerebral blood flow."

* "Orthostatic hypotension is the most incapacitating symptom of autonomic failure....  Patients typically present with lightheadedness and presyncopal complaints that occur in response to sudden postural change, meals, exertion, or prolonged standing.  Complaints less easily recognized as hypotensive in origin, such as generalized weakness, fatigue, cognitive slowing, leg buckling, visual blurring, headache, and neck pain also may be present.  The visual complaints most likely represent retinal or occipital lobe ischemia.  Neck pain, which may be the only symptom of orthostatic hypotension, is most likely a consequence of neck muscle ischemia."

* "Most patients can be treated successfully with a combination of fludrocortisone and a sympathomimetic agent.  Caffeine, prostaglandin synthetase inhibitors, and erythropoietin are useful supplementary agents in patients with more refractory symptoms.  Finally, there are rare
patients who will require the addition of the tertiary and experimental agents to treat their symptoms.  There is, however, a small group of patients who remain refractory to all therapeutic endeavors."  (Refractory means resistant to treatment or cure.)

The article discusses the non-pharmacological and the pharmacological treatments for OH.  There's a very good list of the medications in use.

One medication the article does not describe is pyridostigmine.

Another medication not mentioned in the Harvard article is droxidopa, which, as of June '06, was not available in the US yet.

Another item I didn't find in the Harvard article on treating OH is water.  Here's a link to an article on "The effects of water ingestion on orthostatic hypotension in two groups of chronic autonomic failure: multiple system atrophy and pure autonomic failure":
http://jnnp.bmjjournals.com/cgi/content/full/75/12/1737

The article note that "Oral ingestion of water increases seated blood pressure in patients with chronic autonomic failure by mechanisms that remain unclear."  The results of the study on the effects of water ingestion are:  "Standing prior to water ingestion caused a significant fall in blood pressure in all patients.  After water ingestion there was a rise in seated blood pressure.  Seated and standing blood pressure at 15 and 35 minutes after water ingestion was significantly higher than before water, with an improvement in orthostatic symptoms.  The time to first significant rise in seated blood pressure occurred at...13 minutes in MSA."