TcMEP’s – Transcranial Motor Evoked Potentials

TcMEP’s are acquired by stimulating over the motor cortex and recording from needle electrodes placed into patient’s muscles. Using TcMEP’s ensures that the signals travelling from the brain down the anterior tracts of the spinal cord allowing the patient to move are successfully communicating with the patient’s muscles

SEPs – Sensory Evoked Potentials

SEPs are acquired by stimulating over the distal peripheral nerves, in the arms and legs and recoding from the sensory cortex. This allows us to assess the posterior spinal cord, and interpret if the patient’s sensory function is preserved

FrEMG – Free-Running EMG

Free-running EMG is recorded from the same needles placed in the patient’s muscles that record EMG. It measures passive nerve root activity and can indicate nerve root irritation.



TrEMG – Triggered EMG (Including Nerve Proximity Testing/Identification/Pedicle Screw Testing)

Unlike free-running EMG, a probe is placed either on or nearby nerve roots to initiate a response from a single root, or groups of nerve roots. This technique identifies nerves in order to avoid damaging the nerve roots during certain surgical stages (i.e. distraction/reduction) or certain procedures (e.g. lateral lumbar fusions, tumour removal)Direct stimulation of the spinal cord itself can be used to identify nervous tissue vs. abnormal tissue




EEG – Electroencephalography

EEG is used during spinal surgery to assess the depth of anaesthesia