Neurophysiology is the study of the functions of the nervous system including brain, spinal cord, peripheral nerves and muscles. We use computer-based sophisticated EMG machines to perform the tests in an out-patient setting. Each testing procedure takes about 10-30 min per patient. A consultant neurophysiologists conducts the tests and interprets the findings, and a computerised report is given to the patient. Tests done in this unit are useful in investigating various neuromuscular disorders including carpal tunnel syndrome, cervical myeloradiculopathy, sciatica, visual, auditory and somatosensory disorders. This unit is also involved in many neurophysiology research projects carried out in collaboration with the Department of Physiology, Faculty of Medicine, University of Peradeniya.
Following tests are done daily in the EMG Room located in the Ward 12.
1. Nerve Conduction (NCS) test:
Patients suspected with carpal tunnel syndrome (numbness of hands), diabetic neuropathy (numbness of hands and feet) or any other disorder affecting peripheral nerves can be referred for this test.
2. Electromyography (EMG) test:
This is the only test where tiny needles are inserted in to the muscles during the test procedure. You may experience slight discomfort but it is not a painful procedure. Patients suspected with cervical or lumbar radiculopathy, myopathy, motor neuron disease (MND) or any other disorder affecting plexus, roots, anterior horn cells or muscles can be referred for this test. We use single fibre EMG (SFEMG) test to assess patients suspected with a serious neurological disorder called myasthenia gravis.
3. Visual Evoked Potentials (VEP) test:
Patients with optic neuritis and optic atrophy and children including newborn babies suspected with visual disorders can be referred for this test. Child or the adult is made to look at a television screen and the response is recorded from the scalp.
4. Auditory Evoked Potential (BAEP) test:
Patients with acoustic neuroma and children including newborn babies suspected with hearing disorders can be referred for this test. Main perinatal risk factors which may lead to hearing defects include neonatal meningitis, jaundice, hypoxia, low birth weight, prematurity and neonatal ICU stay. There are different names used to identify these tests, viz. ABR test, ERA test, BSER test. Children are usually sedated before doing this test.
5. Magnetic stimulation test (Magstim):
These tests are done in collaboration with the Department of Physiology, Faculty of Medicine, University of Peradeniya for patients suspected with cervical or thoracic myelopathy, spinal root/cord disorders and other neuromuscular disorders.
6. Other neurophysiological tests:
In addition to the above routine neurophysiological tests, many other special tests are done in our unit. Sympathetic skin response (SSR) test, Pattern reversal electroretinography (PERG) test, Electroculography (EOG) test, cognitive event-related potential (ERP) test are a few of them. Somatosensory evoked potential (SSEP) test is done for patients suspected with meralgia paraesthetica and cervical and thoracic myelopathy.
7. Botulinum Toxin Injection Clinic:
Since 1994, we have been using botulinum toxin for various neurological indications. Some of these are hemifacial spasms, writer’s cramps, neck spasms (torticollis), stroke, cerebral palsy, facial palsy, pain syndromes and other neurological disorders.
Mobile neurophysiology service
For the patients who are unable to be sent to the EMG room, we offer bedside neurophysiological testing using a portable EMG machine. This is particularly useful for patients in the intensive care (ICU) setting. Patients suspected with Guillain-Barre syndrome (GBS), myasthenia gravis (MG), critical illness neuropathy/myopathy and patients following organophosphate poisoning and snake bite envenoming fall into this category.
Reporting of all the above tests are done under the supervision of Prof Vajira Weerasinghe, Professor of Physiology, Faculty of Medicine, University of Peradeniya and Consultant Neurophysiologist (mobile number: 0777841707, email: firstname.lastname@example.org).
Visual and Auditory Evoked potentials are reported by Dr. Tharaka Dassanayake, Senior Lecturer, Department of Physiology, Faculty of Medicine, University of Peradeniya and Consultant Neurophysiologist.
Following are the times of individual clinics:
1 pm on Monday, Wednesday, Thursday, Friday (Prof VW)
General Neurophysiology Clinic: NCS, EMG and all other tests
8 am on Tuesday (Dr. TD)
Evoked Potential Clinic: VEP, BAEP
8 am on the first Thursday of the month (Prof VW)
Botulinum Toxin Clinic
Total number of patients seen in the neurophysiology clinic during the past three years:
2015 (first 6 months) 1350