What is clinical neurophysiology?
Clinical Neurophysiology is an area of medicine that applies electrophysiological measurement techniques to evaluate and contribute diagnostic information to problems of the central and peripheral nervous systems. As a specialty, it is closely aligned with both adult and paediatric Neurology, and with Neurosurgery.
The specialty requires an intimate understanding of neurological diseases and of neuro-anatomy. The Clinical Neurophysiologist needs to understand neurological differential diagnosis. They must understand pathophysiology and have an understanding of how electrophysiology may be used to resolve diagnostic questions in the area.
Clinical Neurophysiologists are doctors who have completed basic specialist training in general internal medicine and higher specialist training in Clinical Neurophysiology. They work in hospital departments, particularly in centres where neurology or neurosurgical units are located.
Central Nervous System Testing
Within the central nervous system, Clinical Neurophysiologists are chiefly concerned with evaluation of adults and children who have or are suspected of having epilepsy.
Electroencephalography (EEG) measures electrical signals from the brain. Interpretation of these signals and knowledge of the range of different epileptic disorders allows Clinical Neurophysiologists to help identify patients with epilepsy and to accurately classify the epilepsy, which informs optimal management.
EEG testing can be done routinely as an in- or as an out-patient. Sometimes patients are admitted to hospital for prolonged EEG studies over days or weeks. Long term video-EEG monitoring is carried out to diagnose particularly challenging seizure disorders and can help to guide surgical management of the epilepsy. Clinical Neurophysiologists are part of the multi-disciplinary team who help to make decisions on surgical management of epilepsy and who help neurosurgeons in performing their operations by interpreting electrophysiological tests in theatre. These tests include EEG acquired directly from the brain surface during operation, known as electrocorticography, as well as somatosensory evoked potentials (SSEPs) which are tiny brain signals that are recorded in response to an electrical stimulus, often given at the hands or feet, and motor evoked potentials (MEPs) that are elicited from muscle by electrical stimulation of the motor cortex.
Invasive EEG testing involves placement of electrode grids on the surface of the brain by a neurosurgeon, or guided depth electrodes which can record from deeper brain structures. These specialist techniques are necessary for a small number of patients with particularly challenging epilepsy.
Other Central Nervous System Disorders which are part of the diagnostic and sometimes therapeutic work of Clinical Neurophysiologists include: movement disorders (especially dystonia but also tremor and jerk disorders), visual problems affecting the retina or optic nerve, and sometimes auditory nerve disorders.
Clinical Neurophysiological investigations also play an important role in monitoring physiological function of the nervous system in the intensive care environment and in the neurosurgical or spinal orthopaedic environments. Testing of peripheral and central nervous system in the operative environment can help to identify potential threats to neural pathways and may prevent injury to brain, spinal cord, or nerve in patients undergoing scoliosis correction or removal of neurosurgical pathologies.
Peripheral Nervous System Testing
Electromyography (EMG) and nerve conduction studies (NCS) are the primary tools that Clinical Neurophysiologists use to diagnose disorders of the peripheral nervous system (nerve roots, nerve plexus, nerve, muscle and neuromuscular junction). These disorders can be congenital or may be acquired in life.
Clinical Neurophysiologists carry out EMG/NCS testing in out-patient and in-patient settings. They assess patients with problems of weakness, sensory disturbance and sometimes pain. An understanding of peripheral neuro-anatomy and neurological differential diagnosis is especially important for helping to distinguish disorders of the peripheral nervous system. These disorders include: peripheral neuropathy, entrapment neuropathies, infiltrative or compressive pathologies of nerve roots, myasthenia gravis, other disorders of neuromuscular transmission, and primary muscle disorders (myopathies).
Other techniques that Clinical Neurophysiologists perform in evaluation of peripheral nerve or muscle disorders include autonomic testing, quantitative sensory testing (QST), quantitative EMG, and sometimes neuromuscular ultrasound.
What is the typical working day for Clinical Neurophysiologist?
Clinical Neurophysiologists divide their time between face-to-face patient contacts in the neurophysiology (EMG/NCS) laboratory (traditional clinics), in-patient EMG/NCS work, and reporting of EEG and other tests. Most of this is on-site within the hospital department. Some reporting can be done remotely, which may be necessary when helping to care for in-patients who are having continuous EEG monitoring in the ICU or in the epilepsy monitoring unit.
Clinical Neurophysiologists who work in centres with neurosurgery or spinal orthopaedics may have a commitment to working in theatre to assist in neuro-intraoperative monitoring.
Clinical Neurophysiologists work in very close collaboration with other groups. The closest collaboration is with clinical measurement scientists (or physiologists), who help to carry out electrophysiological testing. Clinical Neurophysiologists are responsible for how testing is carried out and for the interpretation of all testing that takes place within the department.
Much of the work of Clinical Neurophysiologists involves communication with other Doctors, particularly Neurologists, Neurosurgeons, Paediatricians, Orthopaedic surgeons and Intensive care specialists.
Teaching and research are a large component of the job.
What qualities or personal attributes do you need to be a Clinical Neurophysiologist?
Clinical Neurophysiology appeals to people who enjoy diagnostic challenges and working in a precise and methodical manner to answer clinical questions. The specialty appeals in particular to those who have an appreciation of detail, and a determination to approach clinical problems from a fresh perspective and with determination.
Patience, a kind manner, and good communication skills are essential. An interest and skill around the use of computers, complex data-sets and medical equipment helps a lot.
Experience of having worked in adult or paediatric neurology is a particular asset in Clinical Neurophysiology. People who have had such experience and have enjoyed working with patients who may have neurological disorders should consider Clinical Neurophysiology, particularly if their own interests are more focused on diagnosis or the pathophysiology of disease.
Training in Clinical Neurophysiology is completed in two stages:
- Basic Specialist Training in General Internal Medicine (or an equivalent programme) – Two years
- Higher Specialist Training in Clinical Neurophysiology – Four Years