P1: SBT
0521779407-05 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:49
Autonomic Dysfunction 205■Impotence
■Vomiting, dysphagia, constipation, diarrhea, gastric fullness
■Postural hypotension or paroxysmal hypertension
■Fixed heart rate or paroxysmal, postural or persistent tachycardia
■Impaired thermoregulatory sweating
■Hyperthermia
■Pupillary abnormalities
■Somatic neurologic abnormalities sometimes present, indicating
involvement of CNS or PNStests
■Blood studies: normal
■CT or MRI: may reveal structural cause for symptoms in brain stem
or cervical cord; usually normal in Shy-Drager syndrome or primary
autonomic failure
■Autonomic function studies: abnormal BP and heart rate response
to standing, Valsalva maneuver; abnormal heart rate or cutaneous
vasomotor response to deep inspiration; abnormal thermoregula-
tory sweating; impaired sympathetic skin response
■NCS: may reveal dysfunction of PNSdifferential diagnosis
■Postural hypotension may occur in cardiac, metabolic, toxic or
endocrine disorders; w/ hypovolemia; w/ certain meds (eg, dopa-
minergics, antidepressants, hypnotics, antihypertensives, etc); after
prolonged bed rest
■Dysautonomia resulting from peripheral neuropathy (eg, diabetic or
amyloid neuropathy, Guillain-Barre syndrome) is suggested by the
clinical & electrodiagnostic findings
■Associated signs of parkinsonism or cerebellar deficit suggest Shy-
Drager syndrome or multisystem atrophymanagement
■Asymptomatic
➣No treatment needed
➣Avoid alcohol & likely precipitants
■Symptomatic postural hypotension
➣Treat underlying cause; use following measures as needed
➣Make postural changes gradually
➣Copious fluids: salt supplements
➣Waist-high elastic hosiery
➣Sleep w/ head of bed propped up