Electrophysiological tests facilities for:

Electroencephalography (EEG)

The electrical activity of brain is recorded by this test. The record is analysed for abnormalities in brain rhythm.

EEG is done in the following conditions:

  • Epilepsy to confirm the diagnosis.
  • In spells of unconsciousness/ fainting - EEG is useful in differentiating these disorders from epilepsy.
  • Encephalitis (viral inflammation of brain e.g viral infections)
  • Dementia
  • Stroke
  • Brain tumour

The EEG is useful for diagnosis to decide about medication, in monitoring the response to treatment and in long term follow up to evaluate the course of the disease.

Details of Procedure:

  • The test is painless.
  • The patient lies on the bed quietly.
  • Electrodes (small metal discs) are placed on the head.
  • During the test the patient may be asked to open and close the eyes on a few occasions, may be asked to breathe rapidly for few minutes. The patient is encouraged to relax with eyes closed and encouraged to sleep.
  • The time required for preparation and actual recording may take approximately 40-60 minutes.
  • There are no side effects.

Instructions :

  • Do not apply oil on the head.
  • Take a light meal, avoid fasting.
  • Take routine drugs.
  • Small children and uncooperative patients may be given sedative medicine.This is an outpatient procedure.
  • There is no need for admission to the hospital.

Report Information:

The report will provide information about the presence or absence of abnormalities (es/o epilepsy) and the state of the patient if there is an altered sensorium. The report is finalized by the Senior Doctor and provided within 24 hours or immediately if urgent.


Video EEG

What is VEEG?

Video EEG is a non-invasive diagnostic tool that records the electrical activity of your brain as well as your physical behavior.

What is the aim of VEEG?

VEEG aims to observe what is happening during a seizure or an event along with brain activity recorded via EEG simultaneously.

Duration can vary from 1 to 7 hours or > 24 hours, depending on the indication for the test; doctors can suggest VEEG when the nature of the event is not clear, or want to determine the origin of the seizure.

Why is it done?

Video EEG is helpful to find out what is happening in your brain & also record your physical activity at the same time.

VEEG is also helpful if you have any of the following neurological conditions such as-



Role and Benefit of VIDEO-EEG

  • Seizure disorder- to determine the type and the onset of the seizure especially before planning epilepsy surgery.
  • Fainting or blackout episodes.
  • Determine the type of event –Epileptic or non-epileptic.
  • To differentiate the seizure types.

How is VEEG Performed?

Preparation:

Before performing the Video-EEG test, a technician will give you a few instructions as follows –

You must wash your hair and dry it properly before coming for the test.

Don’t apply any hair oil after hair wash.

You can take your routine medications.

Fasting is not required, you can take your breakfast or lunch.

You can carry your comfortable clothes, sheets & pillow, etc.

The procedure of the test:

The technician measures your head and marks where to place electrodes.

Areas marked are cleaned with the Nuprep gel.

Electrodes are attached to the scalp with 10 – 20 paste.

Technicians can apply cotton to hold it in place, the head & electrodes are covered by gauze dressing.

The room is kept clean, dark, and quiet, at your comfortable temperature and in dim light.

There can also be a small music system to help you relax.

A technician should check the audio, the video is on & camera is on focus.

Complete instructions are given to you so that you can relax and then the recording will be started.

If technicians see any event during recording, they should write the timing of the event and give a few commands to the patient like-

  • Tell your name
  • Raise your right hand
  • Remember few words
  • Pen
  • Water
  • Apple

EMG

The EMG test is used to evaluate the status of the muscles, nerves, roots and anterior horn cells. A number of neurological disorders present with weakness or atrophy (thinning) of muscles.

Some common disorders are:

  • Muscular dystrophy
  • Myopathy
  • Neuropathy.
  • Carpal tunnel syndrome
  • Nerve injuries
  • Cervical/lumbar radiculopathy
  • Motor neuron diseases

The EMG may be done either alone or in combination with nerve conduction studies (NCS) depending on the neurological disorder.

Common symptoms of muscle involvement:

  • Difficulty in climbing stairs.
  • Difficulty in getting up from sitting/squatting position.
  • Difficulty in performing movements like buttoning, breaking chapatis, mixing food, combing hair.
  • Raising hands above the head.

Details of Procedure:

  • A thin disposable EMG needle is inserted into the muscle to be examined. Depending on the type of disease or more muscles may be required to be tested.
  • You may experience mild pain during the procedure.
  • There is no risk of transmitting the infection since disposable needles are used and they are destroyed after use.
  • You can have your regular food and medication on the day of the test.
  • You should wear loose clothes so that the test can be easily done

Nerve Conduction Studies (NCS)

  • Nerve conduction studies are used to evaluate the function of the nerves.
  • There are mainly two types of nerves - motor and sensory. The nerve conduction studies are specially designed to perform motor nerve conduction and sensory nerve conduction.

Procedure:

  • The test takes 30-40 minutes.
  • Electrodes(sensors) are placed on the skin at different points.
  • The nerves are stimulated with mild electric current.
  • Instructions-Before the Test:

  • Wear loose clothes, which will allow easy examination.
  • Fasting is not required.
  • For uncooperative children, sedation may be required.
  • There is no after-effect following the test.
  • Indication for NCS:

  • Numbness in hands & legs.
  • Pinprick sensation
  • Pain in hands & legs
  • Burning sensation in hands & feet
  • Weakness in arms & legs.
  • Role of Nerve Test for Nerve Injury

    Click to Know More

    Repetitive Nerve Stimulation (RNST)

    Repetitive nerve stimulation tests are a special type of nerve conduction study. Rather than a single electric shock, a brief series of shocks is applied to a motor nerve and responses are recorded from a muscle supplied by that nerve. The study is generally performed before and after brief exercise of the muscle. Serial response amplitudes are recorded. Repetitive nerve stimulation is useful for evaluating myasthenia gravis and other disorders of neuromuscular transmission.

    Role of Repetitive Nerve Stimulation Test

    Visual Evoked Potential (VEP)

    VEP provides information regarding conduction in visual pathway from the retina to brain (occipital cortex).

    VEP is recommended for following diseases:

    Impairment of vision due to:

    • Multiple Sclerosis
    • Optic Neuritis
    • Tumours of the brain (pituitary tumours)
    • Head injuries
    • Drugs which may cause visual impairment
    • In children with mental retardation/ delayed development to assess visual status

    Details of Procedure:

    • The test is performed in dark room.
    • Each eye is tested separately.
    • The patient is asked to focus on a point on the monitor, which shows
    • Checkerboard pattern.
    • Small metals plates (electrodes) are applied to the head, which record the
    • Electrical potential.
    • The procedure usually take approximately 30 minutes.

    Instructions:

    • Hair should be washed, dried, with no oil, gel, spray etc.
    • If the patient is using spectacles or contact lenses than he/she should wear them at the time of examination.
    • For children who are uncooperative sedation may be required.

    Brainstem Auditory Evoked Potential (BAER)

    This test examines the integrity of auditory pathway through the brainstem. The sound enters ear canal and stimulates auditory nerve. The electrical impulse travels from auditory nerve through the brainstem to auditory cortex. During testing, the patient hears the repetitive click sound through the earphone.

    BAER is recommended for following diseases:

    • Hearing problem
    • Dizziness/ Vertigo
    • Multiple Sclerosis
    • Tumours of the Brainstem
    • Head Injuries
    • Delayed development in children
    • Jaundice in children

    Details of Procedure:

    • The procedure is carried in a sound proof room.
    • The stimulus is provided using headphone in one ear followed by second ear.
    • The electrical response is recorded by small metal plates (electrodes).
    • The test is not painful.

    Instructions:

    • Hair should be washed, dried, with no oil, gel, spray etc.
    • For children who are uncooperative sedation may be required.
    • The procedure usually take approximately 30 minutes.

    Somatosensory (SSEP)

    This test examines the sensory system from the peripheral nerve to the sensory cortex of brain. Weak electrical stimuli are applied to the peripheral nerve, for example median or ulnar nerve for upper extremity study and tibial nerve for lower extremity study.

    SSEP is recommended for following diseases:

    • Numbness/ weakness of arm or leg.
    • Diseases of the spinal cord.
    • Multiple Sclerosis.

    Details of Procedure:

    • The electrical stimulation is applied to nerve in the arm or the leg.
    • The response is recorded from the neck and the head by electrodes placed over the surface.
    • Mild pain is experienced when electrical stimulation is applied.

    Instructions:

    • Should wear loose clothes, which will allow easy examination.
    • Fasting not required.
    • For children who are uncooperative sedation may be required.
    • There is no after effect following the test.
    • This is done as an outpatient procedure.