Autonomic diseases Notes

NOTES NOTES AUTONOMIC DISEASES GENERALLY, WHAT ARE THEY? PATHOLOGY & CAUSES ▪ Autonomic nervous system (ANS) disorders (dysautonomia) ▪ Normative autonomic function ▫ Balanced impulses of sympathetic, parasympathetic ANS ▫ One/both components fail → symptoms ▪ Etiology ▫ Genetic, environmental factors CAUSES ▪ Primary ▫ Pure autonomic failure, familial dysautonomia, multiple system atrophy, postural orthostatic tachycardia syndrome (POTS) ▪ Secondary (neuropathy) ▫ Alcoholism, diabetes mellitus, trauma, HIV infection, multiple sclerosis, Lyme disease, Parkinson’s disease, porphyria, nerve compression (tumor), drug toxicity (vincristine) SIGNS & SYMPTOMS ▪ Breadth of autonomic function → wide symptomatic variation ▪ Common autonomic disease symptoms ▫ ↑↓ heart/respiration rate ▫ ↑↓ blood pressure ▫ Bowel/bladder/erectile dysfunction ▫ Hypohidrosis/hyperhidrosis ▫ Syncope DIAGNOSIS DIAGNOSTIC IMAGING ▪ See individual diseases LAB RESULTS ▪ Nerve biopsy ▫ Neuropathy detection OTHER DIAGNOSTICS ▪ Autonomic function test battery ▫ Monitor heart rate, autonomic functions for pathological changes ▪ Valsalva maneuver ▫ ↑ intraspinal pressure → neuropathic symptom exacerbation ▪ Quantitative sudomotor axon reflex test (QSART) test ▫ Electrical current → sweat gland stimulation ▪ Tilt table test ▫ Individual lies on table → table tilted upright → detects sudden blood pressure change TREATMENT ▪ Treat underlying cause if possible ▪ Mostly symptomatic treatment OSMOSIS.ORG 473

HORNER'S SYNDROME osms.it/horners-syndrome PATHOLOGY & CAUSES ▪ AKA oculosympathetic paresis ▪ Clinical syndrome ▫ Damaged sympathetic neural pathways to eye, associated structures ▪ Sympathetic innervation to eye ▫ Three neurons comprise pathway ▫ 1st order neurons: in posterolateral hypothalamus, preganglionic fibers ▫ 2nd order neurons: in ciliospinal center (Budge’s center) in intermediolateral segment of spinal column (C8–T2) → preganglionic fibers travel to superior cervical ganglion (SCG) → synapse with 3rd order neurons ▫ 3rd order neurons: in SCG, postganglionic fibers follow different paths upon leaving SCG → flushing, absent sweating not mandatory signs ▪ Manifests ipsilaterally SIGNS & SYMPTOMS ▪ Classic triad: ptosis, anhydrosis, miosis ▪ May present with anhidrosis (if 2nd order neurons affected), flushing (impaired vasoconstriction), apparent enophthalmos (ptosis) MNEMONIC: PAM Signs & symptoms of Horner’s syndrome Ptosis Anhidrosis Miosis CAUSES ▪ Condition manifests following pathway interruption ▪ Congenital/acquired ▫ Congenital: may present with heterochromia iridis as eye pigmentation under sympathetic innervation during development ▪ Classification based on lesion’s level ▫ 1st order neuron lesion: Arnold–Chiari malformation, cerebrovascular insult, basal skull tumor ▫ 2nd order neuron lesion: trauma, cervical rib, Pancoast tumor, neuroblastoma, aorta dissection ▫ 3rd order neuron lesion: herpes zoster, internal carotid artery dissection, cluster headache Figure 62.1 An individual with Horner’s syndrome demonstrating ptosis and miosis of the left eye. DIAGNOSIS DIAGNOSTIC IMAGING X-ray ▪ Detects Pancoast tumor, shoulder trauma MRI ▪ Detects aneurysm, dissection 474 OSMOSIS.ORG

Chapter 62 Autonomic Diseases LAB RESULTS ▪ Vanillylmandelic acid (VMA) level ▫ Detects neuroblastoma OTHER DIAGNOSTICS ▪ Neurological exam ▪ Pharmacological diagnostics ▫ Disorder detection, lesion level determination ▫ Cocaine drops: norepinephrine missing from synaptic cleft → absent mydriasis ▫ Apraclonidine: upregulation of α1 receptors (↑ apraclonidine sensitivity) → mydriasis occurs ▫ Hydroxyamphetamine: 1st or 2nd order neuron lesion → mydriasis occurs (postganglionic fibers undamaged); 3rd order neuron lesion → weaker/absent mydriasis in affected eye TREATMENT ▪ Treat the underlying cause if possible ORTHOSTATIC HYPOTENSION (OH) osms.it/orthostatic-hypotension PATHOLOGY & CAUSES ▪ Sudden, sustained systolic blood pressure (> 20mmHg)/diastolic blood pressure (> 10mmHg) drop within three minutes upon standing/ tilting head upright ≥ 60° ▪ Delayed/lowered lower-body vasoconstriction ▪ Lower-body blood accumulation while seated/supine → lower-body vasoconstriction delayed upon standing → ↓ cardiac output → ↓ cerebral perfusion → dizziness, blurred vision, syncope CAUSES ▪ Neuropathy impairs vasoconstriction ▪ Baroreceptor reflex impairment (α1 blockers inhibit vasoconstriction) ▪ Hypovolemia (absolute/relative); atherosclerosis; diabetes mellitus; Addison’s disease; Parkinson’s disease; anorexia nervosa; alcohol, THC intoxication; medication (MAOI) ▪ Occurs in elderly/postpartum individuals COMPLICATIONS ▪ Postural orthostatic tachycardia syndrome (compensatory mechanism for chronic ↓ cardiac output), syncope, injury (falling) SIGNS & SYMPTOMS ▪ Pale skin, vertigo, blurred vision, nausea, heart palpitations DIAGNOSIS LAB RESULTS ▪ Measure blood pressure ▫ Confirm sudden drop OTHER DIAGNOSTICS ▪ Tilt table test ▫ Provokes OH episode TREATMENT MEDICATION ▪ Corticosteroids ▪ Antihypotensives ▪ Supplemental measures (caffeine) OTHER INTERVENTIONS ▪ Increase blood pressure via increased fluid/ salt intake ▪ Treating underlying cause OSMOSIS.ORG 475