Postural Stability Deficiencies in Asymptomatic Individuals With HIV

February 20, 2018 updated by: Martin Rosario, Texas Woman's University

Somatosensory Deficiencies Affect Postural Stability in Asymptomatic Individuals With HIV

Persons with HIV can present vestibular system impairments, affecting postural stability. There is scarce literature related to the contribution of the visual and somatosensory systems in maintaining postural stability in persons with HIV. The purpose of this study is to describe the sensory systems used to maintain postural stability and how the sources of sensory information contributes to postural stability in asymptomatic persons with HIV. Postural stability was measured in 20 asymptomatic persons with HIV (11 male, 9 female, aged 43 ± 8 years). Static postural stability was evaluated during eight conditions that perturbed the visual, somatosensory and vestibular inputs. A paired-samples t-test was conducted to compare center of pressure (COP), antero-posterior displacement (APD) and right-left displacement (RLD) on stable and unstable surface and to characterize each balance sensory system. There was a significant difference in the COP and APD of eyes open condition compared to the remaining conditions on stable surface. Furthermore, there was a significant difference in the COP, APD and RLD for the eyes open on a foam surface compared to the remaining conditions on an unstable surface. Postural instability can be detected in asymptomatic persons with HIV under challenging conditions, previous to the evident appearance of balance impairments.

Study Overview

Detailed Description

The institutional review boards (IRB) of the University of Puerto Rico Medical Science Campus, reviewed and approved this study before any data collection was initiated. An informed consent was provided to each subject to access their medical records, HIV status, CD4+ cell count and as a requirement to participate in the study.

The subjects were recruited from La Perla de Gran Precio (Community wellness center that specializes in individuals with HIV) localized in San Juan, Puerto Rico. Each subject was evaluated by interview and review of their medical record for the inclusion and exclusion criteria assessment. Different tests were performed as a screening tool to identify additional limitations or impairments in the different sensory systems. To rule out severe neuropathy, the subject had to be able to detect a Semmes- Weinstein Monofilament of 5.07 or less in more than two areas of the foot.12,13 The visual system was screened using Snellen chart and the subject had to obtain at least 20/40 of visual acuity. To rule out severe balance impairments, the Romberg Test and Fukuda's Stepping Test were used. For Romberg Test, subjects had to maintain standing position for 30 seconds and Fukuda's Stepping Test required that the subject did not rotate more than 30° from the initial position or deviate more than 0.5 meters from the center of the circle. Functional strength of lower extremities was screened using a Five Times Sit to Stand test, where the subject had to complete the test in 10 seconds or less. Severe proprioception impairments were assessed using a Proprioceptive Awareness test, where the subject was asked to replicate the initial position performed by the evaluator in the contralateral ankle joint in three trials. After the screening of the inclusion and exclusion criteria, a total of 20 subjects were able to participate in the study.

Each subject was instructed to stand in a static bipedal posture on the MatScan® pressure mat and performed eight balance tasks. Data of center of pressure, antero-posterior sways and medial-lateral sways were collected in each of the conditions. Each task took 30 seconds to be performed. The first four tasks were performed with the mat on the hard surface of the floor. These four tasks are as follows:1) eyes open looking at a fixed point to evaluate all systems (EO); 2) eyes closed (with head fixed approximately 90˚) to eliminate visual input (EC); 3) eyes open looking at a fixed point and actively moving head upward and downward to alter vestibular inputs (EO+HUD). The subject was instructed to maintain a movement frequency of 60bpm and amplitude of approximately 45 degrees in each direction: neck flexion and extension; 4) eyes closed (with head fixed approximately 90˚) to eliminate visual input and the head actively moves upward and downward to alter vestibular inputs (EC+HUD). The subject is instructed to maintain the movement frequency and amplitude as described in task 3.

The subjects were asked to perform four more tasks while standing on a thick piece of balance foam that was placed on top of the MatScan®, creating an unstable surface. The remaining four tasks (tasks 5-8) are as follows: 5) eyes open looking at a fixed point while standing on the balance foam to alter somatosensory inputs (EO+BF); 6) eyes closed with head fixed approximately 90˚ while standing on the balance foam to alter somatosensory inputs and eliminate visual inputs (EC+BF); 7) eyes open looking at a fixed point and actively moving the head upward and downward while standing on the balance foam to alter somatosensory and vestibular inputs (EO+HUD+BF). The subject was instructed to maintain the movement frequency and amplitude as described in task 3; 8) eyes closed with head fixed approximately 90˚ and actively move head upward and downward while standing on the balance foam to eliminate visual inputs and alter somatosensory and vestibular inputs (EC+HUD+BF). The subject is instructed to maintain the movement frequency and amplitude as described in task 3.

Data of postural stability was obtained using the MatScan® pressure mat (TekScan, Boston, MA). The data collected from the pressure mat was analyzed with Tekscan Sway Analysis Module™ (SAM) software (TekScan, Boston, MA) designed for this purpose. Mean and standard deviation were used to describe data. The statistical software used was SPSS-20 to perform a Paired-Samples t-test and compare the center of pressure, antero-posterior and right-left body sways displacement. P values <0.05 were accepted as statistically significant.

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

25 years to 57 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. CD4 levels above 300,
  2. age within the range of 25-57 years
  3. walks without assistive device
  4. tolerates standing position for at least 30 minutes
  5. stable cardiorespiratory system.

Exclusion Criteria:

  1. diagnosis of AIDS (CD4 levels less than 200)
  2. diagnosis of Diabetes, Dementia or Arthritis
  3. severe neuropathy
  4. severe balance impairments
  5. severe visual acuity problems that are not treated
  6. BMI > 40,
  7. decreased functional strength in the lower extremities
  8. severe proprioception impairments
  9. falls during the last 6 months
  10. back or lower extremities lesion or surgery during the last 6 months
  11. the use of medications that causes drowsiness 24 hours previous to intervention
  12. women that are pregnant or think they might be pregnant

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Asymptomatic persons with HIV
Each subject was instructed to stand in a static bipedal posture on the MatScan® pressure mat and performed 8 balance tasks. Data of center of pressure, antero-posterior sways and medial-lateral sways were collected in each of the conditions. Each task took 30 seconds to be performed. The first 4 tasks were performed with the mat on the hard surface of the floor. These 4 tasks are as follows: standing with eyes open, standing with eyes closed, standing with eyes open looking and actively moving head upward and downward, and standing with eyes closed and the head actively moving upward and downward. The subjects were asked to perform four more tasks while standing on a thick piece of balance foam that was placed on top of the MatScan®. The remaining 4 tasks are as follows: standing with eyes open, standing with eyes closed, standing with eyes open looking and actively moving the head upward and downward, and standing with eyes closed with head actively moving upward and downward.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postural Stability
Time Frame: Baseline
Postural stability was operationally defined by the center of pressure displacement measured by the MatScan® pressure mat. These sensors detect the displacement as the body sways anterior, posterior or laterally (right or left).
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Martin G Rosario, Ph.D, Texas Woman's University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 22, 2014

Primary Completion (Actual)

May 22, 2015

Study Completion (Actual)

July 22, 2015

Study Registration Dates

First Submitted

February 11, 2018

First Submitted That Met QC Criteria

February 20, 2018

First Posted (Actual)

February 27, 2018

Study Record Updates

Last Update Posted (Actual)

February 27, 2018

Last Update Submitted That Met QC Criteria

February 20, 2018

Last Verified

February 1, 2018

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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