Neurology | Southern

An EEG is a test to detect abnormalities in the electrical activity of the brain.  Cells in the brain communicate with each other via electrical activity. In an EEG, electrodes are placed on the scalp over multiple areas of the brain to detect and record the patterns of electrical activity.An EEG technician performs the test.  You will be asked to lie on your back on a table or in a reclining chair. The technician will apply between 16 and 25 flat metal discs (electrodes) in different positions on your scalp. The discs are held in place with a sticky paste. Your head is not shaved for this. The electrodes are connected to a recording machine, which converts the electrical signals into a series of wavy lines that are drawn onto a moving piece of graph paper. You will need to lie still with your eyes closed because any movement can alter the results. Although having electrodes pasted onto your skin may feel strange, they only record activity and do not produce any sensation. There are no risks from this test. Your doctor may want you to stop some medications before the test. You should avoid all foods containing caffeine for 8 hours before the test.Sometimes it is necessary to sleep during the test, so you may be asked to reduce your sleep time the night before. (Most departments have a list of things to do to get ready for this test). EEGs are used to help diagnose the presence and type of epilepsy (fits/seizures), to look for causes of confusion and to assess various diseases that affect the brain.They are also used to evaluate sleep disorders and to investigate periods of unconsciousness.  The test will need to be interpreted afterwards so the results will not be available at the time of the test but will be sent to the referring doctor or discussed with you at a subsequent clinic.

NCS are tests of the speed of conduction of impulses through a nerve.  A doctor performs the tests with a technician. The nerve is stimulated, usually with patch-like electrodes placed on the skin. One electrode stimulates the nerve with a very mild electrical impulse and the other electrodes record the resulting electrical activity.  The impulse will feel like a small electric shock. Depending on how strong the stimulus is you will feel it to varying degrees and it may be uncomfortable for you. You should feel no pain once the test is finished.This test is used to diagnose nerve damage or destruction.  Information from the test can tell the doctor what part of the nerve is damaged and give an idea as to the disease causing the damage. There are no risks from this test. The test will need to be interpreted afterwards so the results will not be available at the time of the test but will be sent to the referring doctor.

EMG is a test that assesses disorders of muscles and the nerves controlling them. A doctor performs this test.For an EMG, a needle electrode is inserted through the skin into the muscle. The electrical activity detected by this electrode is displayed on a monitor.  This is usually performed with a nerve conduction study.You may be asked to contract the muscle (for example, by bending your arm) which will give the doctor information about how muscles respond to messages from nerves.  There may be some discomfort with the insertion of the electrodes (similar to an injection into a muscle). Afterwards, the muscle may feel tender or bruised for a few days. There is a very low risk of bleeding or infection at the site of the needle but this is minimal. EMG is most often used when people have symptoms of weakness and examination shows impaired muscle strength. It can help to tell the difference between problems with a muscle versus problems with the nerves supplying the muscle.

Cerebral Spinal Fluid (CSF) is the fluid that surrounds the brain and spinal cord.  It is often helpful when diagnosing certain conditions to examine this fluid for cells and chemicals/proteins.  A lumbar puncture allows the doctor to examine the content and pressure of this fluid.  A doctor performs the test in the following manner:The patient lies on his or her side, with the knees pulled up toward the chest. Sometimes the test is done with the person sitting up, but bent over. After the back is cleaned, the doctor injects a local anaesthetic which makes the skin and surrounding area numb.A spinal needle (which is long but smaller in diameter to that used to take a blood test) is inserted between two of the lumbar vertebrae (bones at the base of the spine). Once the needle is properly positioned, spinal fluid pressure is measured, and fluid is collected. The needle is removed, the area is cleaned, and a bandage is placed over the needle site. You will need to lie flat for 20 minutes to one hour after the test. You may find the position for the lumbar puncture uncomfortable but it is important to stay still. The anesthetic will sting or burn when first injected. There will be a hard pressure sensation when the needle is inserted and there is usually some brief pain. This pain should stop in a few seconds. Overall, discomfort is minimal to moderate. The entire procedure usually takes about 30 minutes. The actual pressure measurements and fluid collection only take a few minutes. Risks of lumbar puncture include: allergic reaction to the anaesthetic, discomfort during the test, headache after the test, bleeding into the spinal canal (very rare) anddamage to the spinal cord particularly if the person moves during the test (very rare as the needle is so small). These will all be discussed with you before the procedure and you will be given the opportunity to ask questions.  You will be asked to sign a consent form. 

Computer Tomography (CT)A CT image is created by using an X-ray beam, which is sent through the body from different angles giving cross-sectional images of the body.This is a common test that gives information about any structural abnormalities of the brain.  Magnetic Resonance Imaging (MRI)This procedure uses a combination of magnetic fields and radio waves (not x-rays) which results in an exact, clear image of body structures.It gives detailed information about problems with the brain or spinal cord.

Epilepsy is a condition where people have seizures or ‘fits’.  Seizures may present in many forms but are due to bursts of electrical activity within the brain.   The problem can be with the electricity of the brain on its own or due to some underlying structural lesion of the brain. Anyone can have a seizure if the stimulus is great enough to exceed a threshold in the brain. Factors such as fever, changes in blood chemistry, anxiety, sleep deprivation or alcohol may influence the onset of a seizure.  Although some disorders and traumas play a role in developing epilepsy most people who have epilepsy have no known reason.   A seizure may present as a convulsion, unusual body movement, a change in awareness or simply a blank stare. The person may be unconscious or completely unaware of what is happening.  What type of symptoms people have depends on what part of the brain is involved. The diagnosis of epilepsy is made on the basis of the history so it is useful when you come to clinic if someone who has witnessed an event can come with you.  Depending on your symptoms and examination findings you may undergo an EEG test and/or an MRI of your brain to aid in the diagnosis and planning of treatment.  Not everyone needs these tests and the doctor will talk with you about what is needed.  Epilepsy is usually treated with medication to prevent seizures.  There will also be implications for driving if you are diagnosed with this condition, as it needs to be well controlled before you can drive.  Your doctor will discuss this with you.For more information visit www.epilepsy.org.nz

Parkinson's disease is a disorder of the brain characterised by shaking (tremor), slowing of movement and difficulty with walking and coordination. The disease is due to progressive deterioration of the cells in the part of the brain that controls muscle movement. The disorder may affect one or both sides of the body, with varying degrees of loss of function. Symptoms include: shaking (not always present), stiffness, loss of balance, shuffling walk, slow movements, difficulty initiating any voluntary movement, muscle aches and pains, reduced ability to show facial expressions, voice or speech changes, difficulty writing (may be small and hard to read), difficulty with any activity that requires small movements. Diagnosis is usually made on the history and with an examination, with no need for further testing unless there is some uncertainty.  There are some diseases that can mimic Parkinson’s disease. There is no known cure for Parkinson's disease. Treatment is aimed at controlling the symptoms. Many of the medications can cause severe side effects, so monitoring and follow-up by doctors is important.For more information about Parkinson’s disease and related conditions as well as support groups in New Zealand visit www.parkinsons.org.nz

Most headaches are not due to significant underlying problems but you may be referred if your GP is worried about the nature of your headaches or you are having difficulty controlling them with standard treatment.   Migraine headaches are repeated or recurrent headaches, often accompanied by other symptoms. They can be triggered by certain factors/events/foods. In some people, a visual disturbance called an aura happens before the headache starts.   Other symptoms that may precede or accompany the headache include loss of appetite, nausea, vomiting, increased sweating, irritability, fatigue, intolerance of light or noise.  The headache may last several hours to days.   Prior to coming to clinic for review of headaches it is useful to keep a diary. Write down: when your headaches occurred, how severe they were, additional symptoms, what you've eaten, sleep patterns, menstrual cycles, any other possible factors.   There is no cure for migraine headaches but treatment is aimed at: preventing migraines from occurring, stopping the migraine once early symptoms develop, and treating the symptoms of migraine (e.g. pain, nausea).

Multiple sclerosis is a progressive disease involving the brain and spinal cord.  It occurs over time in multiple sites in these two areas of the nervous system. The cause is not known but it is thought that a person’s immune system for some reason attacks the sheath that surrounds and protects nerves, causing inflammation, scarring and damage to the underlying nerves. Symptoms suffered depend on where and to what degree the nerves are affected.  They include: reduced or abnormal sensation, weakness, vision changes, clumsiness, sudden loss of bladder control and vertigo. Symptoms might appear in any combination and be mild or severe. They are usually experienced for unpredictable periods of time.These symptoms alone don't necessarily indicate MS and can easily be due to other unrelated conditions. The diagnosis is made based on the history, examination and a number of tests including an MRI and sometimes a lumbar puncture. Blood tests are also looking for other conditions that can mimic the same symptoms. 

There is no cure for MS but several treatments are available aimed at preventing attacks, improving symptoms and slowing progression. For more information visit www.msnz.org.nz
 

This refers to a group of progressive disorders where there is destruction of motor neurones (the nerves that control voluntary muscle activity such as speaking, walking, breathing, and swallowing.)  Symptoms include: gradual weakening, shrinking of muscles and uncontrollable twitching of the muscles.  Sensation, memory and personality are not affected. The diagnosis is made with the history examination findings, nerve conduction studies and electomyography tests.  There are often other tests looking for other diseases to exclude before the diagnosis is confirmed.
There is no cure or treatment for MND. Physical therapy, occupational therapy, and rehabilitation improve posture, prevent joint immobility, and slow muscle weakness and wasting. There are some medicines used to treat particular symptoms. The course of disease varies depending on the type of MND and the age of onset but it is progressive. For more information see https://mnd.org.nz/