Clinical Neurophysiology

What is Clinical Neurophysiology…?

It is diagnostic speciality which has evolved from neurology. It is mainly focused on recording and clinically interpreting electrical activity from the brain, spinal cord, peripheral nerves and muscles to diagnose disorders of the central and peripheral nerves systems.

Clinical Neurophysiologist is a specialized consultant neurophysician who performs electro diagnostic tests; interpret results in a correct clinical context providing accurate diagnoses


What are the tests performed…?

Electromyography (EMG), Nerve conduction studies (NCS)

They are diagnostic tests of peripheral nerve system, especially useful in diagnosing diseases in nerve roots, plexuses, peripheral nerves and muscles. These tests also help to localise the lesion site, exclude alternate diagnoses, reveal unsuspected diagnoses, and assess severity, time frame and prognosis of lesions.

Eg: -

  • Radiculopathies

  • Nerve Injuries

  • Entrapment neuropathies – carpal tunnel syndrome

  • Peripheral neuropathies – axonal, demyelinating neuropathies

  • Muscle diseases – myopathies

Electroencephalography (EEG)

It records the electrical activity of the brain using scalp electrodes. It is mainly useful in diagnosing and evaluation seizures. It is also used to diagnose sleep disorders, coma, encephalitis, encephalopathy and neurodegenerative diseases.

Video EEG Telemetry Monitoring

Long term monitoring of EEG with video recording to evaluate undiagnosed seizure like events and screening for epilepsy surgery.

Evoked Potential Studies

There are electrical potentials produced by nervous system in response to specific stimuli.


  • Visual evoked potentials
  • Auditory evoked potentials
  • Somatosensory evoked potentials

They are used for diagnosis of diseases affecting respective sensory pathways.

Botulinum toxin clinic

Evaluation and injection of Botulinum toxin for various movement disorders and spasticity due to stroke, cerebral palsy etc.

Annual Statistics


Number of Patients per year

Special NCS / EMG


Carpal Tunnel Syndrome


Evoked Potential Studies


Botulinum Toxin Therapy

120 to 180

Standard EEG Recording


Prolonged Video EEG Monitoring


EEG Reporting from NHSL & Other Hospitals


How to make a referral

The referral could be made by any consultant through a government hospital. The referral should indicate the patient’s identification details, the clinic or BHT number relevant brief clinical summary, differential diagnosis or clinical question that needs to be answered by the study and the consultant’s signature.

Clinical Neurophysiology Unit, National Hospital of Sri Lanka

The Clinical Neurophysiology Unit of Institute of Neurology, NHSL is the only such unit in the country. It provides comprehensive neurophysiology services to patients with various neurological as well as non-neurological disorders. Main interactions are with neurology, neurosurgery, ophthalmology, otolaryngology, orthopaedic & paediatric units as well as with intensive care units. It serves other hospitals in the country including the hospitals of three armed forces and the police.

The unit commenced in year 2000 when Dr. Sudath Gunasekera was appointed the first Consultant Neurophysiologist, NHSL. There are grade medical officers, nursing and paramedical staff to provide the services.


  1. Nerve conduction tests (NCS), electromyography (EMG) and other related tests.

These tests are provided for patients with disorders in the peripheral nervous system. Special clinics are conducted daily for complicated cases. A separate clinic is conducted for patients with Carpal Tunnel Syndrome since the number of such patients is high. Urgent tests are arranged when necessary, especially for patients with traumatic and non-traumatic acute weakness.

  1. Evoked potential studies

These are available for visual (VEP), auditory (BSER) as well as somatosensory (SSEP) modalities. These are done according to international standards.

BSER threshold tests are done for hearing screening which is particularly useful in children for early detection of hearing impairment. Clinical Neurophysiology unit of NHSL was the first to introduce this test in Sri Lanka under accurate standards and so far provided this service to a large number of patients.

  1. Electroencephalography (EEG)
  1. Standard EEG recording services are provided to patients from NHSL as well as other hospitals which do not have such facilities. All the EEGs are provided with a report by Consultant Neurophysiologist. In addition, EEGs done in other hospitals are also undertaken for reporting by Consultant Neurophysiologist upon requests. Lady Ridgeway Hospital and Mental Hospital in particular receive such services from our unit on a regular basis.

  2. Prolonged video EEG monitoring is also carried out. This is the first ever video EEG monitoring facility with expertise in the procedure and interpretation. The majority of patients who undergo this test are those lined up for epilepsy surgery for which this test is essential.  We played a key role in establishment of epilepsy surgery services in Sri Lanka.

    In additional short term monitoring is provided for diagnostic purposes. Some studies for sleep disorders (Multiple Sleep Latency Test) is also carried out.

  1. Intraoperative Monitoring

This is provided when necessary for epilepsy surgeries and spinal surgeries. The number is limited due to limitations of staff and equipment.

  1.  Botulinum Toxin Therapy Clinic

A specialized clinic for botulinum toxin therapy is conducted every fortnight. This serves to provide botulinum toxin injection for patients with various movement disorders ranging from hemi facial spams and Writer’s cramps to laryngeal spasmodic dysphonia. Some of these patients are given the injection under EMG guidance.

  1. Evaluation of cases of Acute Flaccid Paralysis reported to National Polio Expert Committee.

Neurophysiological evaluation of majority of such cases is done in the neurophysiology unit. Consultant Neurophysiologist also takes part in the committee meeting as a member.

Teaching and Training

We take part in the process of postgraduate medical education by training pre-MD postgraduate students in medicine and paediatrics. We have also taken part in training post MD Senior Registrars in Clinical Neurophysiology, Neurology and Paediatric Neurology.

This unit houses the EEG Technologist Training School of the Ministry of Health. Coordination of their programme including conducting practical hands on training as well as lectures are done by this unit.

Examinations for trainee EEG technologists and efficiency bar examinations for EEG technologists are conducted in this unit under the supervision of Ministry of Health.



Number of Patients per month

Special NCS / EMG


Carpal Tunnel Syndrome


Evoked Potential Studies


Botulinum Toxin Therapy

10 to 15

Standard EEG Recording


Prolonged Video EEG Monitoring


EEG Reporting from NHSL & Other Hospitals


A large number of patients are referred from armed forces and police for various nerve injuries sustained  at the battle front. They are given priority. Presently about 50% of special NCS / EMG tests done are for these patients. These tests cannot be done at those hospitals since necessary equipment or expertise is not available.

The number of patients seen is very large, similar to other clinics in Sri Lanka. This is several times more than that of a clinic in a developed country.

Any other information

Botulinum Toxin injection Tuesday [ Once in 02 Week ] 8.00 a.m Neuro Building E.M.G Room
Special Nerve Conduction Clinic & E.M.G Clinic Monday |Tuesday| Wednesday| Thursday | Friday| Saturday 8.00 a.m. Neuro Building
B.S.E.R.(Brain Stem Auditary Evoke potential Clinic)
S.E.P.(Somato Sensary ) & V.E.P.(Visual Evoke Potential )
Monday| Tuesday | Wednesday| Thursday |Friday 12.30 p.m Neuro Building E.M.G Room
C.T.S (Carpal Tunnel Syndrome )   Monday|Tuesday|Wednesday|Thursday 11.30 a.m Neuro Building E.M.G Room


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