Clinical trial NCT03760406: Optimization of VIM Targeting in Essential Tremor Surgery
Official title: Optimization of VIM Targeting in Essential Tremor Surgery
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Essential Tremor
Keywords: Essential Tremor
Deep brain stimulation
Ventro-intermediate nucleus of the thalamus
Targeting
Asleep surgery
Lead sponsor: University Hospital, Bordeaux
Sponsor class: OTHER
First posted: 2018-11-30
Enrollment: 22
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Change of Fahn-Tolosa-Marin (FTM) scale score
timeFrame: Before and 3 month after DBS surgery
Secondary outcomes:
measure: Accelerometry recordings : spectral analysis
timeFrame: Before and 3 month after DBS surgery
measure: Accelerometry recordings : calculation of the total accelerometry power
timeFrame: Before and 3 month after DBS surgery
measure: Surgical complications
timeFrame: Up to 3 month after DBS surgery
measure: Device complications and dysfunction
timeFrame: Up to 3 month after DBS surgery
measure: Neurostimulation-related side effects
timeFrame: Up to 3 month after DBS surgery
measure: Quality of life: change of modified Parkinson's Disease Questionnaire-39 (mPDQ-39) scale score
timeFrame: Before and 3 month after DBS surgery
measure: Coordinates of active contacts
timeFrame: 3 month after DBS surgery
Other outcomes:
Locations:
city: Bordeaux
country: France
facility: CHU de Bordeaux
city: Bron
country: France
facility: Hospices Civils de Lyon
Study officials:
affiliation: USMR CHU de Bordeaux
name: Antoine BENARD, MD
role: STUDY_CHAIR
References: