Non-pharmacologic management of orthostatic hypotension

Synucleinopathies

The α-synucleinopathies include pure autonomic failure, multiple system atrophy, dementia with Lewy bodies, and Parkinson disease. The past two decades have witnessed significant advances in the diagnostic strategies and symptomatic treatment of motor and nonmotor symptoms of the synucleinopathies. This chapter provides an in-depth review of the pathophysiology, pathology, genetic, epidemiology, and clinical and laboratory autonomic features that distinguish the different synucleinopathies with an emphasis on autonomic failure as a common feature. The treatment of the different synucleinopathies is discussed along with the proposal for multidisciplinary, individualized care models that optimally address the various symptoms. There is an urgent need for clinical scientific studies addressing patients at risk of developing synucleinopathies and the investigation of disease mechanisms, biomarkers, potential disease-modifying therapies, and further advancement of symptomatic treatments for motor and nonmotor symptoms.

Changes in the cardiac autonomic control system during rehabilitation in children after severe traumatic brain injury

BACKGROUND

One of the sequalae of severe traumatic brain injury (TBI) in children is impaired function of the cardiac autonomic control system (CACS) at rest. The CACS response to conventional autonomic tests is little known.

OBJECTIVE

To examine the CACS response to conventional autonomic tests in children after severe TBI during the rehabilitation period and to compare with typically developing (TD) children.

METHODS

This study combined a case-control and follow-up design. The severe TBI group (cases) consisted of 33 children aged 9-18 years, 14-142 days after severe TBI who were followed for 8 weeks during rehabilitation. The control group consisted of 19 TD children matched for age and sex. Heart rate (HR) and heart rate variability (HRV) were evaluated with the Polar RS800CX device at rest (sitting), during a handgrip test and during a paced breathing test.

RESULTS

At the first assessment, we found lower HRV values at rest and a lower HRV response during the paced breathing and handgrip tests in the TBI group than the TD group (p<0.01). After 8 weeks, HRV values did not change at rest in the TBI group, but the response to the autonomic tests improved significantly, with increased HRV values in response to the paced breathing test (p<0.01) and the handgrip test (p = 0.01).

CONCLUSIONS

After severe TBI, children exhibited an impaired CACS response to autonomic tests, with parasympathetic suppression and sympathetic arousal. After 8 weeks of rehabilitation, CACS function recovered partially and the response to the autonomic tests improved with no change in CACS function at rest.

The Cardiac Autonomic Response Recovery to the Modified Tilt Test in Children Post Moderate-Severe Traumatic Brain Injury

OBJECTIVE

To assess the recovery of the cardiac autonomic control system (CACS) response to the modified tilt-test during rehabilitation, in children post moderate-severe TBI at the subacute phase post-injury.

METHOD

Thirty-seven children aged 6-18 years, 14-162 days post moderate-severe TBI, participated in the study. The assessment included CACS values evaluation (heart rate (HR), heart rate variability (HRV) and blood pressure) during the modified tilt-test: five minutes lying supine and five minutes passive standing. Re-assessment was performed after eight weeks of rehabilitation.

RESULTS

In both assessments, only four children reported symptoms associated with orthostatic intolerance during the modified tilt-test. No change was found over time in the HR and HRV values at rest. In response to the modified tilt-test, the systolic blood pressure showed change over time, with a significant interaction effect (p=0.04); while in the first assessment the SBP values showed a hypertension trend in the second assessment the SBP values showed a hypotension trend.

CONCLUSIONS

Children post moderate-severe TBI at the sub-acute phase post-injury, have a better systolic blood pressure response during the modified tilt-test after eight weeks of individually tailored rehabilitation program, despite no change in the CACS values at rest.

CLINICAL TRIAL GOV. NUMBER

NCT03215082.

Assessment of Abdominal Constrictor's Forces for Informing Computational Models of Orthostatic Hypotension

Orthostatic hypotension is defined as a sudden drop in blood pressure upon standing from a sitting or supine position. The prevalence of this condition increases exponentially with age. Nonpharmacological treatments are always the first step in the management of this condition, such as the use of an abdominal constriction belt to optimize the blood volume in the abdomen. A multitude of clinical trials have shown the efficacy of elastic abdominal compression as well as compression using an inflatable bladder; however, there are currently few accessible consumer products that can provide abdominal compression by using an inflatable bladder that ensures the correct amount of pressure is being exerted on the subject. This study serves to quantitatively analyze forces exerted in inflatable abdominal binders, a novel treatment that fits the criterion for a first-line intervention for orthostatic hypotension. Quantitative values aim to indicate both the anatomic regions of the body subjected to the highest pressure by abdominal binding. Quantitative values will also create a model that can correlate the amount of compression on the subject with varying levels of pressure in the inflatable bladder. Inflatable binders of varying levels of inflation are used and localized pressure values are recorded at 5 different vertical points along the abdomen in the midsternal line and midclavicular line, at the locations of the splanchnic veins. These findings indicate both the differences in the compressive force applied through elastic and inflatable binding, as well the regions on the abdomen subject to the highest force load during compression by an abdominal binder. A medical manikin called the iStan Manikin was used to collect data. The pressure values on a manikin were sensed by the JUZO pressure monitor, a special device created for the purpose of measuring the force under compressive garments. The pressure inside the inflatable bladder was extrapolated from a pressure gauge and the pressure was recorded at different degrees of inflation of the belt (mmHG) along two different areas of the abdomen, the midsternal line and the midclavicular line, to discern differences in force exerted on the patient (mmHG). Computational studies on the data from the JUZO pressure monitor as well as the data from the pressure gauge on the inflatable bladder allow us to create a model that can correlate the amount of pressure in the inflatable bladder to the amount of pressure exerted on the belt, thus making sure that the patient is not being harmed by the compressive force. The results of our study indicate that there is no significant difference between the pressures exerted on the midsternal and midclavicular lines of the body by the abdominal binder and that no significant difference exists between the external pressure measured by the inflatable belt and the pressure sensed on the human body by the JUZO sensor; however, we were able to extrapolate an equation that can tell the user the amount of pressure that is actually being exerted on them based on the pressure in the inflatable bladder as recorded by the gauge.

A practical approach to peripheral autonomic neuropathies

PURPOSE OF THE REVIEW

The review focuses on the practical evaluation and management of patients with autonomic neuropathies.

RECENT FINDINGS

Autonomic neuropathies are complex disorders and result in diverse clinical manifestations that affect the cardiovascular, gastrointestinal, urogenital, and sudomotor systems. The autonomic medical history is key when seeing a patient with suspected autonomic neuropathy. The history guides the clinical evaluation, laboratory testing, and autonomic testing in patients with autonomic neuropathies. The treatment of autonomic neuropathies is based on the combination of disease-modifying therapies, symptomatic pharmacologic therapies, and nonpharmacological management. Response to treatment can be assessed with quantitative autonomic biomarkers.

SUMMARY

Treatment of autonomic neuropathies should be individualized, guided by disease state, medications' mechanism of action and adverse event profile as well as cost. Genetic discoveries and pathologic understanding lead to the development of disease-modifying therapies as seen in familial amyloid polyneuropathy.