Diseases of the Autonomic and Peripheral Nervous Systems

Autonomic and peripheral nervous system disorders present distinct perioperative challenges requiring specialized anesthetic management strategies. The autonomic nervous system regulates involuntary bodily functions through sympathetic and parasympathetic divisions, and dysfunction in these pathways creates hemodynamic instability and abnormal pharmacological responses. Multiple system atrophy causes progressive degeneration affecting autonomic control, producing orthostatic hypotension and requiring cautious vasopressor selection due to upregulated alpha-adrenergic receptors that amplify drug effects. Postural orthostatic tachycardia syndrome predominantly affects young women and presents with position-dependent hypotension and compensatory tachycardia managed through preoperative fluid optimization. Paragangliomas and other neuroendocrine tumors secrete catecholamines, necessitating invasive hemodynamic monitoring and immediately available rapid-acting antihypertensive agents to prevent intraoperative hypertensive crises. Carotid sinus hypersensitivity causes exaggerated baroreceptor reflexes leading to profound bradycardia or syncope. Paroxysmal sympathetic hyperactivity manifests as sympathetic storms after traumatic brain injury, requiring aggressive management with opioids and adrenergic antagonists. Peripheral neuropathies carry significant perioperative implications, particularly regarding neuromuscular blocking agent selection and positioning injury prevention. Guillain-Barré syndrome, an acute autoimmune demyelinating disease causing ascending paralysis, absolutely contraindicates succinylcholine due to severe hyperkalemia risk from denervated muscle. Charcot-Marie-Tooth disease, the most common inherited peripheral neuropathy, theoretically poses similar but less severe hyperkalemia concerns. Complex regional pain syndrome creates disproportionate pain responses requiring careful perioperative pain optimization and protective handling. Entrapment neuropathies including carpal tunnel and meralgia paresthetica demand attention to positioning and regional anesthetic techniques. Systemic conditions including diabetes mellitus, vitamin B12 deficiency, and malignancy cause secondary neuropathies affecting anesthetic decisions. Perioperative nerve injuries result from multifactorial causes beyond positioning alone, with preexisting patient factors such as obesity and metabolic derangement contributing substantially to injury risk. Ulnar neuropathy remains the most common postoperative neuropathy, typically presenting within 48 hours. Successful perioperative management requires vigilant hemodynamic monitoring, careful drug selection accounting for receptor upregulation in denervating conditions, judicious muscle relaxant choices, and multimodal neuropathic pain management strategies.