Professor Yasser Metwally, who teaches neurology at the Ain Shams University in Cairo, has a website where he posts his "online newspaper." "The aim behind 'pages' in this web site is to build up a comprehensive textbook of neurology useful to both patients, doctors, and neurologists." You can find his website at:
http://yassermetwally.com
His Monday 12/7/09 edition is on orthostatic hypotension. MSA and DLB are specifically mentioned: "Orthostatic hypotension is nearly universal in MSA, present in about 50% of patients with dementia with Lewy bodies, and in 5-50% of patients with Parkinsonâs." Table 1 gives a list of the lab tests for OH. And there are lists for pharmacological and non-pharmacological treatment of OH. Here's a link to the OH-related page and some excerpts.
Robin
http://yassermetwally.com/blog/?p=375
INTRODUCTION
December 7, 2009 â Orthostasis means upright posture, and hypotension means low blood pressure. Thus, orthostatic hypotension consists of symptoms of dizziness, faintness or lightheadedness which appear only on standing, and which are caused by low blood pressure. Only rarely is spinning vertigo caused by orthostasis.
Symptoms that often accompany orthostatic hypotension include chest pain, trouble holding the urine, impotence, and dry skin from loss of sweating. Fainting (syncope) is covered in another page. ...
Neurogenic orthostatic hypotension ...
#2-Central types:
1-MSA â multiple system atrophy or Shy-Drager, Parkinsonâs, dementia with Lewy bodies. Orthostatic hypotension is nearly universal in MSA, present in about 50% of patients with dementia with Lewy bodies (Akaogi et al, 2009), and in 5-50% of patients with Parkinsonâs. (Thaisetthawatkul et al, 2004; Akaogi et al, 2009). However, since Parkinsonism is by far the most common disorder, there may be as many patients with orthostatic hypotension and Parkinsonâs disease as any of the former. Patients with MSA have intact sympathetic noradrenergic innervation. ...
#3-Output types:...
3-PAF â pure autonomic failure or idiopathic orthostatic hypotension. These patients have loss of cardiac sympathetic neurons, and in particular have loss of sympathetic noradrenergic innervation.
4-Parkinsonâs disease (post-ganglionic sympathetic denervation). These patients also have loss of cardiac sympathetic neurons. ...
The diagnosis of orthostasis is made by finding that the systolic/diastolic blood pressure drops at least 25/10 mm mercury on going from lying to standing. After measuring the supine blood pressure, it is recommended that one should have the subject stand for 2 minutes (if tolerated) before measuring the upright blood pressure (Tarazi and Fouad, 1983).
An alternative and more quantitative method of determining if there is orthostatic hypotension is the tilt table test. This procedure uses equipment to record blood pressure and pulse after a 70 degree tilt using a motorized table.
Recently it has been point out that subjects who are stood for longer periods of time may exhibit progressive decline in blood pressure (Gibbons and Freeman, 2006). Delayed orthostatic hypotension (DOH ?) is defined as a greater than 20 mm Hg fall after 3 minutes or more of tilt-table or active standing. This seems to take a rather long time â many (39%) subjects were positive only after 10 minutes of standing or tilt. A tilt (or stand) of 20 minutes was recommended by these authors for diagnosis.
The pulse (heart rate) should be checked also. The lack of a pulse response increase when the blood pressure drops implies a neurological cause.
An excessive pulse response is termed "POTS" or positional orthostatic tachycardia syndrome. POTS can be associated with considerable disability (Benrud-Larson et al, 2002). Note that pulse can increase due to anxiety and deconditioning as well as autonomic disorders and considerable caution must be used in making this diagnosis..
Once an orthostatic syndrome is determined, additional tests are used to determine why the blood pressure isnât properly regulated.
Table 1. Laboratory tests for orthostatic hypotension
Test: Comment
CBC (blood count): Check for anemia â especially important in persons who are bleeding.
EKG, other heart tests: Check for weakness or irregularity of the heart
CT or MRI scan of head: Exclude other nervous system disorders such as multiple system atrophy (MSA)
Autonomic testing (a battery of tests often including tests of blood pressure control and sweating). Tilt table testing, Valsalva testing, and QSART are often included: Localize lesion in nervous system
Cortisol, 6-8 AM: Levels less than 3 indicate adrenal insufficiency. Levels greater than 18 are normal. Levels in the middle can be sorted out with a dynamic cortisol test (e.g. ACTH stimulation or related test)
Plasma norepinephrine (NE) (supine and standing); Serum dopamine: Low levels indicate post-ganglionic level lesion (vasoconstrictors like midodrine will not work in this case). Patients with orthostatic hypotension associated with Parkinsonism have low plasma levels of NE while supine, and thus should not respond to Mitodrine. Patients with MSA have normal levels. See Goldstein (2003). Patients with dopamine beta-hydroxylase deficiency have very high dopamine levels.
Glucose tolerance test, or glycosylated Hgb: Diabetes
RPR or FTA: Syphilis
Urine porphyrins: Porphyria
Serum electrolytes: Dehydration
Serum creatinine and BUN: Kidney failure when high
Gastric and small bowel motility studies: Detect diabetic gastroparesis and related conditions.
Posturography: Should be normal
Rectal biopsy: If amyloid is suspected
Not every test is needed in every situation. More tests may be recommended based on the results of the previous tests. Tilt table tests are not needed in orthostatic hypotension, as the problem has already been idenfied, but may be indicated in persons with fainting (syncope) or simply an undiagnosed orthostatic syndrome.
Management of Orthostatic Hypotension
Note that neither drug nor non-drug treatment can do as good a job as a well working body. All of the strategies outlined in the next section are intended to alleviate symptoms, but they are unlikely to cure orthostatic hypotension.
Non-Drug Treatment for Orthostatic Hypotension
Generally it is best to start with non-pharmacological treatment, and proceed to drug treatment only when this fails. Note that measures such as voloume expansion with increased salt and fluid, moderate exercise and tilt training are relatively safe but their effectiveness has not been demonstrated by controlled trials (Kapoor, 2003). Nevertheless, we think it is reasonable to give these things a try.
1-Use an automatic blood pressure cuff (about $30 at Walgreens or Radio Shack). Check blood pressure and pulse daily, preferably standing and lying flat, and record it. Also check blood pressure when you have symptoms.
2-If possible, eliminate medications that lower blood pressure (usually blood-pressure or heart medications). Check with your doctor first, however, to be sure that this is safe.
3-Take in extra amounts of salt â about 10 gm/day total. Another way to get extra salt is to use salt containing beverages (e.g. "gatorade"). If you start to have trouble breathing or get excessive swelling at the ankles, you may have to use less than 10 gm. Similarly, be careful not to overdo it and end up with hypertension.
4-Wear Jobst stockings (tight custom made leotard like garment â worn by both men and women). These are often not well tolerated, especially in the summer.
5-Sleep with head of bed elevated about 15-20 degrees (4-6 inches). This maneuver increases blood volume and, after a few days, is helpful. It is also helpful in that it may reduce supine hypertension( sometimes blood pressure is too high lying flat, and too low standing up). Try to be up during the day, not lying in bed. Reconditioning may be helpful for persons who have been on bed rest for long periods of time.
6-Eat frequent small meals (because eating lowers blood pressure). Avoid sudden standing after eating.
7-Avoid straining at stool (because this may lower the blood pressure)
8-Avoid hot showers or excessive heat. Use air conditioners.
9-Get up gradually in the morning. Take 5 minutes to get up and use support. Perform isometric exercises before moving about.
10-Water injestion â -drinking 16 oz of water over 5 minutes can prevent a fainting spell (Lu et al, 2003).. This should not be done very often as it could lead to water intoxication.
11-Orthostatic training. Under the supervision of a physical therapist, gradually increased upright stance. Also use physical countermeasures (see page on tilt training). The literature suggests that this is very effective.
Tilt-training, a series of prescribed upright posture exercises may be helpful in vasovagal faints as well as orthostatic faints. Tilt training also includes some effective physical countermeasures such as leg-crossing with lower body tensing, squating, and arm-tensing (Benditt and Nguyen, 2009)
Drug treatment for Orthostatic Hypotension
Certain medications may be helpful, usually as a combination. Most useful drugs are Florinef (fludrocortisone), erythropoetin and Midodrine.
1-Two strong cups of coffee in the morning
2-Fludrocortisone (Florinef) forces more salt into the bloodstream, 0.1 mg daily starting dose. Blood pressure raises gradually over several days with maximum effect at 1-2 weeks. Alter doses at weekly or biweekly intervals. Hypokalemia (low potassium) occurs in 50%, and hypomagnesemia in 5%. These may need to be corrected with supplements. Florinef should not be used in persons with CHF (congestive heart failure). Florinef does not work in the orthostatic intolerance syndrome of chronic fatigue syndrome (Rowe et al, 2001). Headache is a common side effect.
3-Effexor (an antidepressant which raises blood pressure as a side effect).
4-Inderal and other beta-blockers (small doses are used for positional-orthostatic-tachycardia syndrome (POTS), start inderal at 10 mg/d, increase to 30-60 mg/d over 2-3 weeks. Other useful agents are Nadolol (10 mg qd), Pindolol (2.5-5 mg 2-3 times/day) and atenolol (25). Several controlled trials did not show these agents to be effective in preventing syncope (Kapoor, 2003)
5-Motrin or Indocin (blocks blood-pressure lowering effects of prostaglandins).
6-Midodrine. An alpha-1 adrenergic agonist. Causes increased blood pressure, vasoconstriction, pupil dilation, and "hair standing on end". Other common side effects are paresthesia of the scalp or itching. Usual doses are 2.5 mg at breakfast and lunch or three times daily. Doses are increased quickly until a response occurs or a dose of 30 mg/day is attained (Wright et al, 1998). Midodrine levels peak at about 1-2 hours after administration, and have a half-life of about 3-4 hours. Midodrine does not cross the blood-brain barrier and it is thus not associated with CNS effects. In theory, Midodrine might work for the orthostatic hypotension of MSA (or Shy-Drager), but not that of Parkinsonism. Most patients on Midodrine also take Florinef (see above). Midodrine has been shown to be helpful in controlled trials (Kapoor, 2003).
7-Erythropoietin. This agent is used if there is also anemia and other measures have failed. Doses of 25 to 75 U/kg TIW are used, by injection.
8-Methylphenidate 5-10 mg orally 3 times/day given with meals. An amphetamine â side effects may include agitation, tremor, insomnia, supine hypertension.
9-Ephedrine 12.5-25 mg orally three times/day. Side effects may include tachycardia, tremor and supine hypertension.
10-Fluoxetine 10-20 mg daily. Side effects may include nausea and anorexia. Paroxetine (Paxil) has also been shown to reduce syncope at 2 years.
11-Phenobarbital may improve POTS.
12-Desmopressin. This analog of vasopressin is used as a nasal spray. Low blood sodium is a possible side effect.
Other measures
1-Atrial pacing can be considered when the heart rate is very low. However pacing has been reported not helpful in treatment of recurrent vasovagal syncope (Connolly et al, 2003). Pacemakers may be effective in carotid sinus syndrome (a cause of syncope, not orthostatic hypotension).
2- 3,4 Dl-threo-dihydroxyphenylserine (DOPS), an artificial amino-acid, may be helpful in certain situations (Freeman, 1996) including dopamine beta-hydroxylase deficiency and post-prandial hypotension from various etiologies. L-DOPs has also been used on an investigational basis (Gibbons et al) in persons refractory to other drugs.
Jeanie