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Completed

NCT Number: NCT03760406

Optimization of VIM Targeting in Essential Tremor Surgery

Deep brain stimulation (DBS) for essential tremor is based on the intermedius ventralis nucleus of the thalamus (VIM) stimulation. This structure is however very difficult to target, as it remains invisible on imaging. The current procedure based on awake surgery with clinical and electrophysiological testings has several limitations that lead us to develop a probabilistic model to locate precisely the target. This study aims to show that asleep DBS surgery based on this new targeting method leads to at least the same clinical results than the classical procedure.

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Key information

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

CHU de Bordeaux, Bordeaux, France

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About this study

The intermedius ventralis nucleus of the thalamus (VIM), which represents the target for deep brain stimulation (DBS) in essential tremor, still remains invisible on 1,5 tesla MRI (the only magnetic field available for stereotactic surgery). The target coordinates currently used are based on stereotactic atlases or mean coordinates from retrospective series. They are so imprecise that intra-operative clinical testing and micro-electrode recordings are mandatory to locate the exact position of the VIM. This procedure is long lasting, requires that the patient is awake, and increases the risk of intracerebral haemorrhage and nosocomial infections. Furthermore, some patients are not improved despite a DBS lead implanted in the electrophysiologically and clinically defined target. To overcome these limitations, investigators developed a probabilistic model based on data extracted from imaging of patients with particularly good outcomes after DBS surgery. This machine-learning model allows calculating to coordinates of the VIM according to the position of radio-anatomical landmarks with a mean precision of 1,65mm.

The aim of this study is to validate this new targeting method on a prospective cohort of patients. DBS surgery will be performed under general anaesthesia, without intra-operative clinical and electrophysiological testing, with a surgical robot and under CT-scan guidance (O-Arm ©).

Neurostimulation device programming will be performed as usual. Patients' tremor and quality of life will be evaluated pre and post-operatively at 3 months, according to the Fahn-Tolosa-Marin (FTM) scale and with an accelerometry recording (for tremor) and with the mPDQ-39 scale for quality of life. Surgical complications and side effects related to neurostimulation will be gathered all along the follow-up.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Severe essential tremor despite the optimal medical management
  • Age between 18 and 75 years
  • Normal MRI scan
  • Mattis Dementia Rating Scale (MDRS) score ≥ 130
  • Affiliation to the social security
  • Signed informed consent

Exclusion criteria

  • Depression (Beck Depression Inventory scale > 20)
  • Contra-indication to surgery or general anesthesia
  • Cerebral atrophy on MRI scan
  • Pregnant or breastfeeding women

Treatment and study plan

Opti-VIM targeting in DBS surgery

Procedure

DBS surgery will be performed under general anaesthesia, without intra-operative clinical and electrophysiological testing, with a surgical robot and under CT-scan guidance (O-Arm ©). The VIM coordinates will be calculated with the probabilistic model that have been developed.

Primary outcomes

  1. Change of Fahn-Tolosa-Marin (FTM) scale score

    Time frame: Before and 3 month after DBS surgery

    Scale global range : min=0 / max=160 Higher values represent worse tremor

Secondary outcomes

  1. Accelerometry recordings : spectral analysis

    Time frame: Before and 3 month after DBS surgery

    Accelerometry recordings at the pre-inclusion visit and at 3 months after surgery in ON and OFF-stimulation conditions with spectral analysis.

  2. Accelerometry recordings : calculation of the total accelerometry power

    Time frame: Before and 3 month after DBS surgery

    Accelerometry recordings at the pre-inclusion visit and at 3 months after surgery in ON and OFF-stimulation conditions with calculation of the total accelerometry power.

  3. Surgical complications

    Time frame: Up to 3 month after DBS surgery

    Onset of infection, hematoma or seizure

  4. Device complications and dysfunction

    Time frame: Up to 3 month after DBS surgery

    rupture or displacement of electrode, pain at the stimulation box implantation site or along the subcutaneous cable if they require further intervention, infection.

  5. Neurostimulation-related side effects

    Time frame: Up to 3 month after DBS surgery

    Onset of dysarthria and ataxia assessed by the items 1 to 4 of the Scale for Assessment and Rating of Ataxia (SARA), ataxia assessed by a posturometry analysis, paresthesia, muscular contractions

  6. Quality of life: change of modified Parkinson's Disease Questionnaire-39 (mPDQ-39) scale score

    Time frame: Before and 3 month after DBS surgery

    Adaptation of Parkinson's Disease Questionnaire-39 to essential tremor Scale global range : min=0 / max=156 Higher values represent worse Quality of life

  7. Coordinates of active contacts

    Time frame: 3 month after DBS surgery

    Coordinates of active contacts (i.e; the contact with the best effect on tremor without side effects) These coordinates (x, y, z) are obtained by merging the images of the 3-month postoperative scanner with the images of the preoperative MRI.

Sponsors and collaborators

Lead sponsor

University Hospital, Bordeaux

Other

Registry information

Acronym: Opti-VIM

Important dates

Study start
2019
Primary completion
2023
Study completion
2023
First posted
Nov 30, 2018
Registry last updated
Jun 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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