Use of Electromyograph (EMG) to detect spinal nerve root proximity Vs2
Research type
Research Study
Full title
Use of Electromyograph (EMG) to detect spinal nerve root proximity Vs2
IRAS ID
203415
Contact name
Sumeeta Conry
Contact email
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
To avoid complications while applying a spinal anaesthetic block, the spinal needle should not contact the central nerve. However, no method exists to assess the distance between needle and nerve. This study aims to establish the feasibility of assessing this distance by employing the spinal needle as a stimulating electrode or “stimulator” in the way used during a routine nerve conduction study (NCS).\n\nAn NCS tests a motor nerve by stimulating that nerve using a small electrical current from a stimulator. A current exceeding a threshold activates the nerve, allowing the resulting muscle action to be measured as a compound muscle action potential (CMAP). The activating current depends amongst others on the distance between stimulator and nerve. When using the spinal needle as stimulator, the activating current may therefore indicate the needle-nerve distance. This study aims to determine the relationship between needle-nerve distance and activating current. \n\nBecause the needle-nerve distance cannot be measured directly while applying a spinal block, we will use the CT-data routinely collected during CT-guided spinal nerve root block procedures. This procedure requires a needle delivering a local anaesthetic to be positioned close to the targeted nerve. To achieve this, radiologists take a CT image to assess the position of the needle relative to the nerve. Following this assessment, the radiologist will re-position the needle and take a new CT image. This process is repeated until the needle is close enough to the nerve, typically requiring 3-6 images.\n\nOur study will not change this routine procedure, other than using a stimulating needle to deliver the local anaesthetic. At each needle position, the needle will be stimulated until a CMAP is obtained and the activating current will be recorded. The needle-nerve distance will be measured from the CTs. No extra radiation is therefore delivered during this study.
REC name
North West - Liverpool Central Research Ethics Committee
REC reference
16/NW/0466
Date of REC Opinion
16 Sep 2016
REC opinion
Further Information Favourable Opinion