PRES secondary to autonomic dysreflexia: A case series and review of the literature

Cerebrovascular Reactivity Following Spinal Cord Injury

Background

Spinal cord injuries (SCI) often result in cardiovascular issues, increasing the risk of stroke and cognitive deficits.

Objectives

This study assessed cerebrovascular reactivity (CVR) using functional magnetic resonance imaging (fMRI) during a hypercapnic challenge in SCI participants compared to noninjured controls.

Methods

Fourteen participants were analyzed (n = 8 with SCI [unless otherwise noted], median age = 44 years; n = 6 controls, median age = 33 years). CVR was calculated through fMRI signal changes.

Results

The results showed a longer CVR component (tau) in the grey matter of SCI participants (n = 7) compared to controls (median difference = 3.0 s; p < .05). Time since injury (TSI) correlated negatively with steady-state CVR in the grey matter and brainstem of SCI participants (RS = -0.81, p = .014; RS = -0.84, p = .009, respectively). Lower steady-state CVR in the brainstem of the SCI group (n = 7) correlated with lower diastolic blood pressure (RS = 0.76, p = .046). Higher frequency of hypotensive episodes (n = 7) was linked to lower CVR outcomes in the grey matter (RS = -0.86, p = .014) and brainstem (RS = -0.89, p = .007).

Conclusion

Preliminary findings suggest a difference in the dynamic CVR component, tau, between the SCI and noninjured control groups, potentially explaining the higher cerebrovascular health burden in SCI individuals. Exploratory associations indicate that longer TSI, lower diastolic blood pressure, and more hypotensive episodes may lead to poorer CVR outcomes. However, further research is necessary to establish causality and support these observations.

Headaches Attributed to Disorders of Homeostasis

Headaches attributed to disorders of homeostasis include those different headache types associated with metabolic and systemic diseases. These are headache disorders occurring in temporal relation to a disorder of homeostasis including hypoxia, high altitude, airplane travel, diving, sleep apnea, dialysis, autonomic dysreflexia, hypothyroidism, fasting, cardiac cephalalgia, hypertension and other hypertensive disorders like pheochromocytoma, hypertensive crisis, and encephalopathy, as well as preeclampsia or eclampsia. The proposed mechanism behind the causation of these headache subtypes including diagnostic criteria, evaluation, treatment, and overall management will be discussed.

A Hierarchical Machine Learning Solution for the Non-Invasive Diagnostic of Autonomic Dysreflexia

More than half of patients with high spinal cord injury (SCI) suffer from episodes of autonomic dysreflexia (AD), a condition that can lead to lethal situations, such as cerebral haemorrhage, if not treated correctly. Clinicians assess AD using clinical variables obtained from the patient’s history and physiological variables obtained invasively and non-invasively. This work aims to design a machine learning-based system to assist in the initial diagnosis of AD. For this purpose, 29 patients with SCI participated in a test at Cruces University Hospital in which data were collected using both invasive and non-invasive methods. The system proposed in this article is based on a two-level hierarchical classification to diagnose AD and only uses 35 features extracted from the non-invasive stages of the experiment (clinical and physiological features). The system achieved a 93.10% accuracy with a zero false negative rate for the class of having the disease, an essential condition for treating patients according to medical criteria.

Seizures: A Rare Presentation of Autonomic Dysreflexia in a Young Adult with Complete Spinal Cord Injury

BACKGROUND

Autonomic dysreflexia (AD) is a common complication for individuals with cervical or upper-mid thoracic spinal cord injury (SCI). It is a life-threatening emergency; however, it is rarely encountered by many emergency physicians, thus, ongoing awareness of the topic is necessary.

CASE REPORT

An 18-year-old man with cervical spinal cord injury presented to the Emergency Department with headache, nausea, elevated blood pressure, and seizures. He was treated with antiepileptics and transferred to the pediatric intensive care unit (PICU). The PICU care team recognized AD as the cause of the seizure, secondary to a clogged suprapubic catheter causing overdistension of his bladder. Once replaced, over 1 liter of urine drained from his bladder and his autonomic symptoms resolved. He became hypotensive and required fluid resuscitation, but no further seizures occurred. Why Should an Emergency Physician Be Aware of This? Although rare, AD can result in seizures, intracerebral hemorrhage, or even death if not recognized or treated appropriately. Emergency physicians should recognize headaches, facial flushing, and sweating as early symptoms of AD, along with acute elevation in blood pressure (noting that baseline blood pressure may be lower in individuals with SCI). Management involves evaluating and treating noxious stimuli below the level of neurologic injury. Symptom management alone, without resolution of the underlying issue, can add to morbidity and mortality.

Quantitative analysis of dysautonomia in patients with autonomic dysreflexia

Autonomic dysreflexia (AD) is a life-threatening condition for individuals with cervical or high-thoracic spinal cord injury (SCI). The profile of autonomic dysfunction in AD using validated clinical autonomic tests has not been described so far, although it could be useful to identify SCI patients at greater risk of developing AD non-invasively. With this objective, 37 SCI patients (27% female) were recruited, and hemodynamic and cardiac parameters were continuously monitored to determine the presence of AD, defined as an increase of systolic blood pressure of 20 mmHg or higher after bladder filling with saline. Then, standard autonomic function testing was performed, including Deep Breathing, Valsalva Manoeuvre and Tilt Table Test. Finally, baroreflex sensitivity (BRS), and spectral analysis of heart rate and blood pressure variability were measured at rest. Catecholamines and vasopressin levels were also measured at supine and upright positions. The severity of SCI was assessed through clinical and radiological examinations. AD was observed in 73.3% of SCI patients, being 63.6% of them asymptomatic during the dysreflexive episode. AD patients displayed a drop in sympathetic outflow, as determined by decreased noradrenalin plasma levels, reduced sympathovagal balance and increased BRS. In line with decreased sympathetic activity, the incidence of neurogenic orthostatic hypotension was higher in AD patients. Our results provide novel evidence regarding the autonomic dysfunction in SCI patients with AD compared to non-AD patients, posing non-invasively measured autonomic parameters as a powerful clinical tool to predict AD in SCI patients.

Diverse cognitive impairment after spinal cord injury is associated with orthostatic hypotension symptom burden

This study: 1) compared cognitive functioning between individuals with chronic (>1 year) spinal cord injury (SCI) and non-injured controls and, 2) assessed associations between symptoms of autonomic dysreflexia and orthostatic hypotension with cognitive functioning in SCI participants with a history of unstable blood pressure (BP). Thirty-two individuals with SCI (C4-L2, American Spinal Injury Association Impairment Scale A-D) and thirty age, sex-matched non-injured controls participated in this study. Participants completed a motor-free neuropsychological test battery assessing 1) memory, 2) attention/concentration/psychomotor speed and, 3) executive function. Nineteen participants with SCI who had injuries ≥T6 and a history of unstable BP also completed the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire. Cognitive function was significantly lower in people with SCI across measures of memory and executive function compared to non-injured controls. Significant, moderate-to-large associations were observed between cumulative (frequency x severity) orthostatic hypotension and total BP instability symptoms scores, with measures of attention/concentration/psychomotor speed and executive function. These data demonstrate a 10 - 65% reduced performance across specific realms of cognitive functioning in individuals with SCI relative to non-injured controls. Furthermore, cumulative subjective scores for symptoms of unstable BP were associated with diverse cognitive deficits. These findings, in individuals without co-occurring traumatic brain injury, imply cardiovascular dysregulation plays a role in cognitive deficits observed in this population.