Prediction & Mechanisms of Recovery Following IEDS

NCT06370897 | Not Yet Recruiting DMC

• 1 other identifier: 337421
• Study Type: observational
• Target: 41
• Locations: 0 countries
• Sites: N/A

Brief Summary

Inner Ear Decompression sickness (IEDS) accounts for 20% of all types of decompression sickness (the bends) in divers. The condition commonly affects the peripheral vestibular system (inner ear). IEDS results in acute symptoms of dizzyness (vertigo) and imbalance. Even with the recommended treatment of hyperbaric oxygen therapy some people do not recovery fully. However, even in the presence of a permanent vestibular deficit many people can show a behavioural recovery where symptoms improve over time. Recovery can be aided by vestibular rehabilitation (VR) which is now routine for acute IEDS but was not provided before 2021, and is not widespread across the UK (United Kingdom) or world, meaning people may have a suboptimal recovery. This project will investigate if and how people recover after an acute episode of IEDS and whether people who had IEDS in the past show changes in the central (brain) processing of vestibular function and in symptoms of dizziness, balance and posture. This project has two main parts. Part one is a prospective observational study where people with an acute onset of IEDS are serially monitored while they are receiving hyperbaric treatment and VR over 10-14 days. Part two is a retrospective observational study where who have had IEDS in the past 15 years are re-assessed in a one-off session. The tests in both parts involve clinical tests and specialist eye movement recordings that assess vestibular function. We will also determine the site of any vestibular pathology by using selective stimulation of the vestibular end organ or nerve and assess whether there are any changes in how the structure and function of central vestibular pathways in the brain. In people with chronic IEDS with vestibular symptoms we will offer participants a course of VR over 12 weeks and assess whether this is associated with any improvement in symptoms.

Conditions

Decompression Sickness

Keywords

vestibular, inner ear

Outcome Measures

Primary Outcomes (6)

• Side of peripheral vestibular damage: Prospective cohort

  Side (left or right) of vestibular dysfunction as determine by video head impulse test (v HIT) testing

  T0=baseline within 24 hours of IEDS in the prospective cohort

• Site of peripheral vestibular damage: Prospective cohort

  Site of dysfunction: semi-circular canals affected as determine by v HIT testing. One or a combination of Horizontal, anterior or posterior canals.

  T0=baseline within 24 hours of IEDS in the prospective cohort

• Extent of peripheral vestibular damage: Prospective cohort

  VOR gain (unit less) as measured by v HIT at T0 (Range 0-1 higher values are better outcome)

  T0=baseline within 24 hours of IEDS in the prospective cohort

• Side of peripheral vestibular damage: Retrospective cohort

  Side (left or right) of vestibular dysfunction as determine by video head impulse test (v HIT) testing

  1 time point: 0-10 years post injury

• Site of peripheral vestibular damage:Retrospective cohort

  Site of dysfunction: semi-circular canals affected as determine by v HIT testing.One or a combination of Horizontal, anterior or posterior canals.

  1 time point: 0-10 years post injury

• Extent of peripheral vestibular damage:Retrospective cohort

  VOR gain (unit less) at T0 (Range 0-1 higher values are better outcome)

  1 time point: 0-10 years post injury

Secondary Outcomes (21)

• VOR gain v HIT: Prospective Study

  7-10 days , 3 months and 12 months post injury

• VOR gain: Prospective Study

  7-10 days , 3 months and 12 months post injury

• VOR Time constant:Prospective Study

  7-10 days , 3 months and 12 months post injury

• Patient reported outcome measure: Prospective Study

  7-10 days , 3 months and 12 months post injury

• Clinical measure of walking: Prospective Study

  7-10 days , 3 months and 12 months post injury

Study Arms (2)

Prospective Cohort

Divers admitted with suspected IEDS

Retrospective Cohort

Divers diagnosed with Inner ear decompression sickness (IEDS) at Deep Diving Research Centre within past 10 years

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Population: Divers Exposure: Dive resulting in IEDS symptoms

You may qualify if:

• Divers admitted with suspected IEDS

You may not qualify if:

• Medically unstable
• Unstable orthopaedic deficits
• Retrospective study :
• Divers diagnosed with IEDS at DDRC within past 10 years
• We will include all co-morbidities as these could affect prognosis and recovery following IEDS.
• Healthy control comparator group :
• Normative data will be gathered on an age matched group. There will be at least 10 participants for each decade (\<30yrs ,30-40yrs, 40-50 yrs,50-60yrs,60-70 yr.)
• Adults over 18 years
• Neurological, sensory or orthopaedic conditions that could affect balance.

Sponsors & Collaborators

• University of Plymouth: lead

Related Publications (15)

• Gempp E, Louge P. Inner ear decompression sickness in scuba divers: a review of 115 cases. Eur Arch Otorhinolaryngol. 2013 May;270(6):1831-7. doi: 10.1007/s00405-012-2233-y. Epub 2012 Oct 26.

  PMID: 23100085 BACKGROUND

• Tremolizzo L, Malpieri M, Ferrarese C, Appollonio I. Inner-ear decompression sickness: 'hubble-bubble' without brain trouble? Diving Hyperb Med. 2015 Jun;45(2):135-6.

  PMID: 26165540 BACKGROUND

• Mitchell SJ, Doolette DJ. Pathophysiology of inner ear decompression sickness: potential role of the persistent foramen ovale. Diving Hyperb Med. 2015 Jun;45(2):105-10.

  PMID: 26165533 BACKGROUND

• Landolt JP, Money KE, Topliff ED, Ackles KN, Johnson WH. Induced vestibular dysfunction in squirrel monkeys during rapid decompression. Acta Otolaryngol. 1980;90(1-2):125-9. doi: 10.3109/00016488009131707.

  PMID: 6969520 BACKGROUND

• Landolt JP, Money KE, Topliff ED, Nicholas AD, Laufer J, Johnson WH. Pathophysiology of inner ear dysfunction in the squirrel monkey in rapid decompression. J Appl Physiol Respir Environ Exerc Physiol. 1980 Dec;49(6):1070-82. doi: 10.1152/jappl.1980.49.6.1070.

  PMID: 6969248 BACKGROUND

• Kurata N, Kawashima Y, Ito T, Fujikawa T, Nishio A, Honda K, Kanai Y, Terasaki M, Endo I, Tsutsumi T. Advanced Magnetic Resonance Imaging Sheds Light on the Distinct Pathophysiology of Various Types of Acute Sensorineural Hearing Loss. Otol Neurotol. 2023 Aug 1;44(7):656-663. doi: 10.1097/MAO.0000000000003930. Epub 2023 Jun 29.

  PMID: 37400150 BACKGROUND

• Song CI, Pogson JM, Andresen NS, Ward BK. MRI With Gadolinium as a Measure of Blood-Labyrinth Barrier Integrity in Patients With Inner Ear Symptoms: A Scoping Review. Front Neurol. 2021 May 20;12:662264. doi: 10.3389/fneur.2021.662264. eCollection 2021.

  PMID: 34093410 BACKGROUND

• Vargas-Figueroa VM, Caceres-Chacon M, Labat EJ. Scuba Diving-Induced Inner-Ear Pathology: Imaging Findings of Superior Semicircular Canal and Tegmen Tympani Dehiscence. Am J Case Rep. 2024 Jan 2;25:e941558. doi: 10.12659/AJCR.941558.

  PMID: 38163945 BACKGROUND

• Gempp E, Louge P, de Maistre S, Morvan JB, Vallee N, Blatteau JE. Initial Severity Scoring and Residual Deficit in Scuba Divers with Inner Ear Decompression Sickness. Aerosp Med Hum Perform. 2016 Aug;87(8):735-9. doi: 10.3357/AMHP.4535.2016.

  PMID: 27634609 BACKGROUND

• Curthoys IS, Halmagyi GM. Vestibular compensation: a review of the oculomotor, neural, and clinical consequences of unilateral vestibular loss. J Vestib Res. 1995 Mar-Apr;5(2):67-107.

  PMID: 7743004 BACKGROUND

• McDonnell MN, Hillier SL. Vestibular rehabilitation for unilateral peripheral vestibular dysfunction. Cochrane Database Syst Rev. 2015 Jan 13;1(1):CD005397. doi: 10.1002/14651858.CD005397.pub4.

  PMID: 25581507 BACKGROUND

• Darlington CL, Smith PF. Molecular mechanisms of recovery from vestibular damage in mammals: recent advances. Prog Neurobiol. 2000 Oct;62(3):313-25. doi: 10.1016/s0301-0082(00)00002-2.

  PMID: 10840152 BACKGROUND

• Bense S, Bartenstein P, Lochmann M, Schlindwein P, Brandt T, Dieterich M. Metabolic changes in vestibular and visual cortices in acute vestibular neuritis. Ann Neurol. 2004 Nov;56(5):624-30. doi: 10.1002/ana.20244.

  PMID: 15449325 BACKGROUND

• Hong SK, Kim JH, Kim HJ, Lee HJ. Changes in the gray matter volume during compensation after vestibular neuritis: a longitudinal VBM study. Restor Neurol Neurosci. 2014;32(5):663-73. doi: 10.3233/RNN-140405.

  PMID: 25096973 BACKGROUND

• Helmchen C, Klinkenstein J, Machner B, Rambold H, Mohr C, Sander T. Structural changes in the human brain following vestibular neuritis indicate central vestibular compensation. Ann N Y Acad Sci. 2009 May;1164:104-15. doi: 10.1111/j.1749-6632.2008.03745.x.

  PMID: 19645887 BACKGROUND

MeSH Terms

Conditions

Decompression Sickness

Condition Hierarchy (Ancestors)

Barotrauma; Wounds and Injuries

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Rehabilitation

Study Record Dates

• First Submitted: April 8, 2024
• First Posted: April 17, 2024
• Study Start: June 1, 2024
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): September 1, 2028
• Last Updated: May 13, 2024

Record last verified: 2024-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Data will become available on study completion and after publication of results.
• Access Criteria: Access to data will be via written request from other relevant healthcare professionals and research groups.