# Autonomic dysfunction after stroke | Symptoms, Causes, Tests and Treatment | OSANG > Approximately 60-80% of stroke patients are accompanied by various forms of autonomic dysfunction, which independently affects the prognosis and mortality of stroke [1]… - Official page: https://osns.co.kr/en/encyclopedia/post-stroke-autonomic-dysfunction - Organization: OSANG Neurosurgery ## Page content Autonomic Medicine ## Autonomic dysfunction after stroke Post-Stroke Autonomic Dysfunction · G90.8 Post-stroke autonomic dysfunction is a condition in which abnormalities occur in autonomic nerve functions such as cardiovascular, sweating, digestion, and urinary function due to damage to the central autonomic nervous network caused by a stroke. ## At a glance Approximately 60-80% of stroke patients are accompanied by various forms of autonomic dysfunction, which independently affects the prognosis and mortality of stroke. The main cause is damage to the central autonomic nervous system, including the insula, medial frontal lobe, and amygdala. Reduced heart rate variability (HRV) is a risk factor for cardiac arrhythmia and sudden death after stroke, and orthostatic hypotension is a major obstacle to the rehabilitation process. - 01Definition and Overview - 02Brain-Heart Axis - 03cardiovascular autonomic disorder - 04Non-cardiovascular autonomic disorders - 05diagnosis - 06Treatment and Management ## Definition and Overview Post-stroke autonomic dysfunction is a condition in which extensive abnormalities in autonomic function occur due to direct invasion of the central autonomic network (CAN) due to cerebrovascular damage or indirect neurohumoral changes. Approximately 60-80% of stroke patients are accompanied by at least one type of autonomic dysfunction, which independently affects mortality, cardiovascular complications, and functional outcome in the acute phase of stroke. ## Brain-Heart Axis ### Central autonomic network The insular cortex, anterior cingulate cortex, amygdala, hypothalamus, and brainstem autonomic nuclei (nucleus medullaris sulcus nucleus, etc.) constitute the central autonomic network. This network comprehensively regulates cardiovascular, respiratory, digestive, sweating, and pupillary reactions. ### Left and right lateralization of the insula In a study by Oppenheimer et al., it was found that stimulation of the right insula caused a sympathetic response (increased heart rate, increased blood pressure), and stimulation of the left insula caused a parasympathetic response (decreased heart rate). Therefore, right insular stroke may result in increased sympathetic activity and increased risk of arrhythmia, and left insular stroke may result in changes in parasympathetic activity. ### Catecholamine hypersecretion In acute stroke, especially extensive infarction of the cerebral hemisphere or cerebral hemorrhage, blood catecholamines (epinephrine, norepinephrine) rapidly increase due to hyperactivation of the hypothalamic-sympathetic-adrenomedullary axis. This causes myocardial damage (neurogenic stunned myocardium), arrhythmia, and acute heart failure. ## cardiovascular autonomic disorder ### cardiac arrhythmia Electrocardiogram abnormalities are observed in approximately 25% of acute stroke patients. QT prolongation, ST changes, T wave inversion, atrial fibrillation, and ventricular tachycardia are reported, and are particularly frequent in insular lobe involvement. ### Heart rate variability (HRV) changes After stroke, HRV significantly decreases, reflecting a decline in autonomic control of the heart. In a meta-analysis, HRV decline was identified as an independent predictor of mortality after stroke. - Decreased SDNN: Decreased overall autonomic modulation ability. - RMSSD, reduced HF: decreased parasympathetic function. - Increased LF/HF ratio: sympathetic dominance ### Orthostatic hypotension Poststroke orthostatic hypotension is observed in approximately 35-50% of patients in the acute phase, and is caused by a combination of deconditioning caused by long-term bed rest and autonomic dysreflexia. Orthostatic hypotension is a major barrier to early rehabilitation and increases the risk of falls. ### Increased blood pressure variability After stroke, a non-dipping pattern in which 24-hour blood pressure variability increases and nocturnal blood pressure drop (dipping) disappears is common. Increased blood pressure variability is a risk factor for stroke recurrence and cardiovascular events. ## Non-cardiovascular autonomic disorders ### abnormal sweating Unilateral hemihyperhidrosis or anhidrosis on the ipsilateral or contralateral side of the stroke lesion may occur. More common in hypothalamic or brainstem injuries. ### Digestive autonomic disorder Gastroparesis and constipation due to decreased intestinal motility are common after stroke. It is an important factor in managing nutritional status along with dysphagia. ### bladder dysfunction Bladder dysfunction after stroke is reported in approximately 40-60% of cases, with urge incontinence being the most common. It is caused by damage to the urinary center of the pons or loss of inhibitory function in the cerebral cortex. ### Temperature regulation disorder Central fever may occur when the hypothalamus is damaged, and fever after a stroke is a factor that worsens brain damage and requires active fever relief. ## diagnosis ### Cardiovascular autonomic assessment - Continuous electrocardiogram monitoring (telemetry): acute arrhythmia surveillance - 24-hour ambulatory blood pressure measurement (ABPM): assessment of blood pressure variability and nocturnal dipping - HRV analysis: quantitative assessment of autonomic control ability - Orthostatic blood pressure test: Screening for orthostatic hypotension ### Comprehensive autonomic nervous system examination From the subacute phase to the recovery period, a battery of autonomic tests including Valsalva maneuver, cardiorespiratory heart rate variability, standing tilt test, and QSART are performed to evaluate the extent and severity of functional impairment. ## Treatment and Management ### Acute Cardiovascular Care - Continuous electrocardiogram monitoring (recommended at least 72 hours) - Beware of drugs that cause QT prolongation - Management of blood pressure volatility (preventing sudden drops in blood pressure) ### Orthostatic hypotension management - Progressive head-up tilt training - Wear elastic stockings and belly band - Intake of sufficient water (2-2.5 L/day) and salt (6-10 g/day) - Medications: midodrine, fludrocortisone — as needed ### Consideration of autonomic nerves in the rehabilitation process Rehabilitation exercise programs should be designed considering the state of autonomic function. In patients with orthostatic hypotension, strategies such as gradually increasing the tilt angle and contracting lower limb muscles before standing are applied. Regular aerobic exercise has been reported to improve HRV and contribute to restoring autonomic balance. ### long term tracking Since autonomic dysfunction after stroke is a risk factor for recurrence of cardiovascular events, regular HRV monitoring and blood pressure management are necessary in the long term. Track the recovery of autonomic function and adjust the treatment plan. ## Frequently asked questions ### Q01Why can heart problems occur after a stroke? The brain and heart are closely connected through the central autonomic network. In particular, when the insula is damaged, the sympathetic-parasympathetic balance that regulates the heart is broken, which can lead to arrhythmia, myocardial damage (takotsubo cardiomyopathy), and QT prolongation. Cardiac complications are reported in approximately 25% of acute stroke patients. ### Q02Can dizziness after a stroke be due to autonomic problems? It is possible. Orthostatic hypotension after a stroke is relatively common, and dizziness may occur due to a drop in blood pressure when standing, especially after long-term bed rest. It is important in rehabilitation planning to distinguish between vestibular damage caused by the stroke itself and orthostatic dizziness caused by autonomic dysfunction. ### Q03Why is HRV testing important for stroke patients? Reduced HRV is an independent predictor of cardiac arrhythmias, sudden death, and poor functional outcome after stroke. In a meta-analysis, the risk of death was approximately 2 to 3 times higher in stroke patients with decreased HRV. HRV monitoring is useful for early screening of high-risk patients and tracking autonomic recovery during rehabilitation. ### Q04Can autonomic dysfunction recover after a stroke? Partial recovery is possible. Acute autonomic dysfunction tends to improve over several weeks to months with cerebral edema disappearing. However, in cases of extensive insular damage or brainstem infarction, permanent autonomic deficits may remain. Early rehabilitation and autonomic function training are helpful for recovery. ### Q05How do you manage autonomic dysfunction in stroke patients? For orthostatic hypotension, progressive standing training, elastic stockings, and water and salt supplementation are the primary treatments. ECG monitoring is continued in patients at high risk for cardiac arrhythmia. Bladder dysfunction, digestive motility disorders, etc. are treated with symptomatic treatment and rehabilitation in parallel. ## Related articles - Irritable Bowel Syndrome - sympathetic nervous system - Aging and autonomic nervous system - Pupillary Dysfunction This article provides general medical information and does not replace an individual diagnosis or treatment plan. 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