Neurophysiologic Assessment of ET Patients Treated by Vim DBS

NCT05362448 | Unknown

• 1 other identifier: 274481
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Essential tremor is a chronic and progressive neurological disease characterized by upper limb tremor. This is one of the most frequent movement disorders. Most of the time the disease worsens over the time, affecting patients' work abilities and in the most severe cases activities of daily living such as eating or dressing. For the most disabled patients, Deep brain stimulation (DBS) of the thalamic ventral intermediate median nucleus (Vim), a procedure consisting in an electrode implantation in a structure of the brain involved in tremor genesis, is the gold standard treatment. While this therapy is most of the time highly effective in alleviating the tremor, some subjects may exhibit gait impairment or upper limb coordination troubles years after the surgery, which are thought to be due to the involuntary stimulation of efferent cerebellar fiber tract. Unfortunately, this DBS induced side effect cannot be systematically avoided and may limit the possibilities of settings adaptation required to control the tremor. Surprisingly, while it could be a valuable therapeutic option for these patients suffering from DBS induced balance troubles, little is known about the effect of varying the rate of stimulation on the gait disorders associated with essential tremor and Vim DBS. The aim of or study is consequently to assess the effect of different frequency of stimulation on tremor, gait and balance disorders as well as on eye movements in patients uni or bilaterally stimulated in the Vim for a severe and medically intractable essential tremor. Patients followed at the National Hospital for Neurology and Neurosurgery (University College London Hospital) will be included. To better characterize the different symptoms, the investigators will use ataxia and tremor rating scale together with 3D gait motion analysis, oculography and computerized spiral test analysis. Our findings might lead to a better understanding of Vim-DBS associated gait disorders in essential tremor.

Conditions

Essential Tremor

Keywords

Deep brain Stimulation; Ventral Intermediate nucleus; Gait motion analysis; Balance against force perturbation analysis; Computerized spiral test analysis; Frequency

Outcome Measures

Primary Outcomes (1)

• Center of Pressure Displacement

  Quantitative continuous variable assessed using balance against force perturbation analysis under the three different DBS settings conditions and with the DBS switched off

  1 day

Secondary Outcomes (24)

• Side effect threshold

  1 day

• Therapeutic threshold

  1 day

• Therapeutic window

  1 day

• Total Energy Delivered

  1 day

• Charge density

  1 day

Study Arms (4)

80 Hz

ACTIVE COMPARATOR

Stimulation with a frequency of 80 Hz

Device: Frequency

130 Hz

ACTIVE COMPARATOR

Stimulation with a frequency of 130 Hz

Device: Frequency

180 Hz

ACTIVE COMPARATOR

Stimulation with a frequency of 180 Hz

Device: Frequency

DBS off

SHAM COMPARATOR

Absence of stimulation

Device: Frequency

Interventions

Frequency DEVICE

First, we will calculate for each patient and each frequency the amplitude therapeutic window (difference between therapeutic and side effect threshold). We will determine an optimal amplitude for each frequency that we will apply in the second part of the study.

130 Hz; 180 Hz; 80 Hz; DBS off

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age \> 18 years
• No gender specification
• Patient suffering from severe medically intractable essential tremor and treated by Vim-DBS
• Willing and able to provide written informed consent

You may not qualify if:

• Concurrent and/or recent involvement in other research that is likely to interfere with the intervention within the last 3 months before study enrolment
• Patients presenting with other cause(s) of balance or gait disorders (stroke, concomitant neurological, rheumatological or orthopaedic disease, severe hypopallesthesia, visual impairment, neuromuscular or vestibular disorders)
• Recently implanted patients (\<3 months)
• Patients unable to provide written informed consent (patients presenting with psychiatric or cognitive disorders)

Sponsors & Collaborators

• University College London Hospitals: lead

Study Sites (1)

National Hospital for Neurology and Neurosurgery

London, England, WC1N 3BG, United Kingdom

RECRUITING

MeSH Terms

Conditions

Essential Tremor

Condition Hierarchy (Ancestors)

Movement Disorders; Central Nervous System Diseases; Nervous System Diseases

Central Study Contacts

Patricia Limousin, MD PhD

CONTACT

02034567890; p.limousin@ucl.ac.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Research Fellow

Study Record Dates

• First Submitted: April 11, 2022
• First Posted: May 5, 2022
• Study Start: May 23, 2022
• Primary Completion: November 1, 2022
• Study Completion: November 1, 2022
• Last Updated: May 27, 2022

Record last verified: 2022-05

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)