Assessment of autonomic dysreflexia in patients with spinal cord injury.

Abstract

Objectives and methods-To assess the impairment of supraspinal control over spinal sympathetic centres and the occurrence of autonomic dysreflexia in patients with spinal cord injury. Autonomic dysreflexia is caused by the disconnection of spinal sympathetic centres from supraspinal control and is characterised by paroxysmal hypertensive episodes caused by non-specific stimuli below the level of the lesion. Therefore, patients with spinal cord injury were examined clinically and by different techniques to assess the occurrence of autonomic dysreflexia and to relate disturbances of the sympathetic nervous system to episodes of autonomic dysreflexia. Results-None of the paraplegic patients, but 59% (13/22) of tetraplegic patients (91% of the complete, 27% of the incomplete patients) presented signs of autonomic dysreflexia during urodynamic examination. Only 62% of the tetraplegic patients complained about symptoms of autonomic dysreflexia. Pathological sympathetic skin responses (SSRs) of the hands were related to signs of autonomic dysreflexia in 93% of cases. No patient with preserved SSR potentials of the hands and feet showed signs of autonomic dysreflexia, either clinically or during urodynamic examination. Ambulatory blood pressure measurements (ABPMs) indicated a loss of circadian blood pressure rhythm (sympathetic control) but preserved heart rate rhythm (parasympathetic regulation) only in patients with complete tetraplegia. Pathological ABPM recordings were seen in 70% of patients with symptoms of autonomic dysreflexia. Conclusions-The urodynamic examination was more sensitive in indicating signs of autonomic dysreflexia in patients with spinal cord injury, whereas SSR allowed the assessment of the degree of disconnection of the sympathetic spinal centres from supraspinal control. Using ABPM recordings the occurrence of episodes of autonomic dysreflexia over 24 hours and the effectiveness of therapeutical treatment can be assessed.

Blood pressure and age associated with silent autonomic dysreflexia during urodynamic examinations in patients with spinal cord injury

“…This percentage of silent AD is higher than three previous studies that reported 35, 38 and 43% respectively. 6,8,9 This discrepancy may be due to the different criteria of AD in these studies. Two of them used definite levels of SBP/DBP values as 160/100 and 150/100 mmHg, respectively, whereas one used an SBP increment percentage of 30% of baseline value.…”

“…3,[6][7][8][9] Some of these have also found that the proportion of patients presenting with silent AD ranges from 35 to 43%. 6,8,9 However, only one, the study by Linsenmeyer et al, 6 investigated the differential variables between symptomatic and silent AD. They found that no factor was significant, including BP values, levels of neurologic injury, length of injury, voiding pressures and bladder capacity.…”

Malignant autonomic dysreflexia in spinal cord injured men

“…15 There is clinical evidence that severity of AD correlates with completeness of spinal injury as assessed by ASIA score: only 27% of incomplete quadriplegics present signs of AD in comparison with 91% of complete quadriplegics. 20 One report noted that while patients with motor-complete SCI (ASIA A or ASIA B) had a higher percentage of AD during their initial hospitalization than did patients with motor-incomplete SCI, the latter group were also at risk for developing AD between 1 and 6 months after injury. 21 Assessment of spinal autonomic circuits Two individuals in this report had complete motor SCI (ASIA A and B) and one individual had incomplete motor SCI (ASIA C).…”

Leg sympathetic response to noxious skin stimuli is similar in high and low level human spinal cord injury

“…For example, one of the relatively common clinical manifestations of abnormal autonomic reflexes in high level injuries is autonomic dysreflexia (AD). AD is characterized by paroxysmal hypertensive episodes induced by non-specific stimuli below the level of the lesion (Curt et al, 1997) and symptoms can be triggered in 45-90% of individuals with quadriplegia or high paraplegia (Yarkony, 1994;Teasell et al, 2000). The most common stimuli for inducing AD involve pain and sensory signals from the bowel and bladder (McKinley et al, 1999), and AD is often associated with the occurrence of pressure sores (Johnson et al, 1998) and chronic pain (Widerstrom-Noga et al, 2004).…”