Autonomic dysreflexia during urodynamics

Spinal Cord. 1998 Nov;36(11):756-60. doi: 10.1038/


Autonomic dysreflexia (AD) is an acute syndrome characterised by inappropriate and massive autonomic response that occurs in patients with spinal cord injury above the T6 level.

Aims: to evaluate the incidence of AD during cystometry and the relationships with clinical and urodynamic features.

Patients and methods: Forty-eight spinal cord injury patients were studied by neurological and urological examination and urodynamic evaluation with concurrent recording of blood pressure, heart rate and symptoms and signs of AD. Patients were considered to have AD if blood pressure reached values higher than 150/100 mmHg.

Results: All the patients showed a significant increase of both systolic and diastolic blood pressure, although only 20 showed pressure values higher than 150/100 mmHg (in seven of them without AD symptoms). AD was more frequent in cervical patients (P = 0.034), but did not correlate with any other clinical features: sex ratio, age, disease duration, completeness of lesion, incidence of detrusor hyperreflexia/areflexia and detrusor-sphincter dyssynergia, voiding modalities, usage of anticholinergic drugs. In three patients blood pressure increase began when uninhibited contraction started, in 11 it was coincident with uninhibited contraction peak and in the other six it appeared at maximum bladder capacity.

Conclusions: (1) during urodynamic evaluation all the patients with lesion level above T6 showed signs of sympathetic stimulation, although only some showed dangerous blood pressure values; (2) the relationship between urodynamic data and dysreflexia crisis shows that both the presence of detrusor uninhibited contractions and bladder distension are able to stimulate the crisis; (3) treatment with anticholinergic drugs is not sufficient to prevent autonomic dysreflexia starting from the bladder, unless it induces detrusor areflexia. These patients are at risk of developing autonomic dysreflexia following bladder distension.

MeSH terms

  • Adolescent
  • Adult
  • Autonomic Nervous System Diseases / epidemiology
  • Autonomic Nervous System Diseases / etiology*
  • Autonomic Nervous System Diseases / physiopathology*
  • Blood Pressure / physiology
  • Cholinergic Antagonists / therapeutic use
  • Female
  • Heart Rate / physiology
  • Humans
  • Incidence
  • Male
  • Neck
  • Neurologic Examination
  • Pulse
  • Reflex, Abnormal / physiology*
  • Spinal Cord Injuries / complications*
  • Spinal Cord Injuries / drug therapy
  • Thorax
  • Urinary Catheterization / methods
  • Urodynamics / physiology*


  • Cholinergic Antagonists