Functional Link Between Hippocampal and Vestibular Systems: a Pilot Study in Epilepsy Surgery (HIPPOCAMPE)

Functional Link Between Hippocampal and Vestibular Systems: a Pilot Study in Epilepsy Surgery Principal Investigator: Elizabeth VITTE

Vestibular signals deeply influence hippocampal spatial representations and may contribute to the navigational deficits of humans with vestibular dysfunction. The reciprocal influence of hippocampal signals on the vestibular system are more putative. The investigators wish to investigate in this pilot study the consequences on vestibular system of the removal of the hippocampal formation to treat drug resistant temporal lobe epilepsy.

Study Overview

• Status: Completed
• Conditions: Epilepsy
• Intervention / Treatment: Other: vestibular test before and after hippocampal surgery

Detailed Description

Functional link between hippocampal and vestibular systems: a pilot study in epilepsy surgery

Hypothesis:

The human hippocampal formation plays a crucial role in various aspects of memory processing. Work in rodents and some other species emphasized the role of the hippocampus in spatial learning and memory as well. A few human studies also point to a direct relation between hippocampal size, navigation and spatial memory. Patients with acquired chronic bilateral vestibular loss develop a significant selective atrophy of the hippocampus (Brandt et al, 2005) and activation of lateral semicircular canal by caloric stimulation induces activation of hippocampal formation in f-MRI (VITTE et al, 1996). But the investigators still do not know the effects on vestibular responses of the removal of the hippocampal formation to cure temporal lobe epilepsy. If the hippocampal formation directly influences the vestibular response, an asymmetry of the vestibular responses should be recorded postoperatively.

Principal criterion Research for an asymmetry of the vestibular responses (Caloric test, Vestibular Evoked Myogenic potentials: VEMp, Head Impulse Test: HIT, Eye Rotational Test: ERI)

Inclusion criteria

• patients suffering of intractable mesial temporal lobe epilepsy and candidate for surgery,
• without history of any cochlea-vestibular disorder
• older than 18 years,
• French residents,
• with medicare,
• after signed informed consent. Exclusion criteria
• History of cochlea-vestibular disorder
• Pregnancy

Population

• 22 patients suffering of intractable epilepsy and candidate for surgery (10 right side and 10 left side).
• Evaluation before and after surgery

Methodology Vestibular function will be quantified by daily practice vestibular tests

• Research of a spontaneous nystagmus with and without fixation (VIDEONYSTAGMOSCOPY) and segmentary deviations (Fukuda test)
• HIT (testing semicircular canal function at high frequency). Results: Gain in %
• VEMp (testing saccular function). Results: Amplitude in μV and latency in ms
• ERI (testing lateral semicircular function at middle frequency). Results: Nystagmus during and after the rotations in frequency and slow phase velocity (SPV) in °/s
• Caloric test (testing lateral semicircular function at low frequency). Results: Canal paresis in % and SPV in °/S

Results Vestibular function will be quantified with daily practice vestibular tests

• Quantification of the vestibular asymmetry
• Ipsi or contralateral to the side of the surgery?
• Depending on the hemispheric dominance?

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Clichy, France, 92110
    • Hôpital Beaujon

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients suffering of intractable mesial temporal lobe epilepsy and candidate for surgery,
• without history of any cochlea-vestibular disorder
• older than 18 years,
• French residents,
• with medicare,
• after signed informed consent

Exclusion Criteria:

• History of cochlea-vestibular disorder
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: Single

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: hippocampal surgery; Vestibular test before and after hippocampal surgery Principal criterion: Research for an asymmetry of the vestibular responses (Caloric test, Vestibular Evoked Myogenic potentials: VEMp, Head Impulse Test: HIT, Eye Rotational Test: ERI). Investigator performs a blind vestibular test (single blind)

Other: vestibular test before and after hippocampal surgery; Research of a spontaneous nystagmus with and without fixation(VIDEONYSTAGMOSCOPY) and segmentary deviations (Fukuda test); HIT (testing semicircular canal function at high frequency).Results: Gain in %; VEMp (testing saccular function). Results: Amplitude in μV and latency in ms; ERI (testing lateral semicircular function at middle frequency). Results: Nystagmus during and after the rotations in frequency and slow phase velocity (SPV) in °/s; Caloric test (testing lateral semicircular function at low frequency). Results: Canal paresis in % and SPV in °/S

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
caloric test	-Caloric test (testing lateral semicircular function at low frequency). Results: Canal paresis in % and SPV in °/S	6 months after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
vestibular test	Research of a spontaneous nystagmus with and without fixation(videonystagmoscopy) and segmentary deviations (Fukuda test); HIT (testing semicircular canal function at high frequency). Results: Gain in %; VEMp (testing saccular function). Results: Amplitude in μV and latency in ms; ERI (testing lateral semicircular function at middle frequency). Results: Nystagmus during and after the rotations in frequency and slow phase velocity (SPV) in °/s	6 months after surgery

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Investigators: Study Director: Elizabeth Vitte, MD, PhD, Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start: February 1, 2011
• Primary Completion (Actual): November 1, 2016
• Study Completion (Actual): October 1, 2017

Study Registration Dates

• First Submitted: January 27, 2011
• First Submitted That Met QC Criteria: January 27, 2011
• First Posted (Estimate): January 28, 2011

Study Record Updates

• Last Update Posted (Actual): November 7, 2017
• Last Update Submitted That Met QC Criteria: November 3, 2017
• Last Verified: November 1, 2017

More Information

Terms related to this study

• Keywords: hippocampal; vestibular test
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy
• Other Study ID Numbers: P100106; 2010-A01220-39 (Other Identifier: IDRCB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO