What are Diagnostic Tests for Neurological Disorders?
Diagnostic tests for neurological disorders are defined as studies or procedures performed to confirm or rule out a neurological disorder. Before making a treatment plan, your physician needs crucial information for a precise diagnosis, which a diagnostic test provides.
Neurological disorders are defined as diseases or conditions that affect the brain, spinal cord, and nerves spread throughout the human body. Some of the common neurological disorders include headaches, stroke, dementia, Parkinson’s disease, seizures, meningitis, brain and spinal cord injury, brain tumours, and multiple sclerosis.
Diagnostic Tests for Neurological Disorders
Diagnosis and evaluation of conditions affecting the nervous system (brain, spinal cord, and nerves) are always complex and complicated as many of the same symptoms occur in different combinations among other neurological conditions. Many of the conditions also do not have clear tests, markers, or causes, and this can make the diagnosis even more difficult.
To diagnose a neurological disorder, your physician will usually begin with a review of your symptoms and medical history and a thorough physical examination. This is followed by specific tests or procedures to arrive at a precise diagnosis. These tests may include:
- Magnetic resonance imaging (MRI): This diagnostic procedure utilises a combination of powerful magnets, radiofrequency, and a computer interface to furnish clear and detailed images of soft tissue structures and organs in the body, including the nervous system. MRI can reveal anatomical images of the spinal cord or brain, measure the flow of blood, or show accumulation of minerals such as iron in the brain. MRI is utilised to diagnose brain and spinal cord tumours, traumatic brain injury, stroke, multiple sclerosis, and neurodegenerative disorders.
- Computed Tomography Scan (CT/CAT Scan)/CT angiography: This is a diagnostic test that provides more detailed images of the nervous system than a traditional X-ray. CAT scan utilises a combination of computer technology and X-rays to produce cross-sectional images, both vertically and horizontally, of the brain and surrounding structures. Computed tomography angiography (CTA) combines a CT scan with the injection of a contrast medium into the bloodstream to highlight the different tissues in the brain and produce images of tissues and blood vessels. CT scans are specifically useful in individuals who are not able to undergo MRI. CT scans can be used to diagnose brain haemorrhage, vascular and bone abnormalities, brain cysts, and tumours, and hydrocephalus, among other disorders.
- Electroencephalogram (EEG): This test is utilised to record ongoing electrical activity of the brain. An EEG can help to detect a variety of neurological disorders such as dizziness, common headaches, strokes, degenerative brain disease, and seizures. EEG can also be utilised to establish organic sources of psychiatric symptoms and disabilities in children and can help physicians in establishing irreversible brain death.
- Positron emission tomography (PET) scan: This is a nuclear medicine imaging technique that reveals the structure and function of the brain, as well as subtle changes in the activities of the cells that are noted at the onset of certain disorders, such as cancer.
- Arteriogram (angiogram): This is an X-ray of the veins and arteries and provides detailed pictures of the arteries, veins, and other supporting structures of the nervous system to help detect narrowing or blockage of the vessels, aneurysms, malformations, or other issues affecting the blood vessels of the spine and brain.
- Nerve Conduction Studies (NCS): The is a test in which electrodes are inserted into the muscles or placed on the skin overlying the muscle or muscle group to record electrical activity and muscle response. This test is performed to assess disorders of the peripheral nervous system which includes the nerves that lead away from the brain and spinal cord and the smaller nerves that branch off from those nerves. Nerve conduction studies are often used to help diagnose nerve disorders such as pinched nerves and Guillain-Barre syndrome.
- Spinal tap (lumbar puncture)/Cerebrospinal fluid (CSF) analysis: A cerebrospinal fluid examination is helpful in diagnosing a number of neurological diseases such as meningitis, encephalitis, and the presence of haemorrhage. In order to obtain a sample of CSF, your doctor performs a procedure known as a spinal tap, where a needle is inserted in your lower spine, and a sample of CSF is removed and examined in a lab.
- Ultrasound (sonography)/Neurosonography: Ultrasound is a diagnostic procedure that uses high-frequency sound waves to produce images of the internal structures of your body. Neurosonography, also called neuroimaging, is the imaging of the nervous system (brain, spinal cord, and nerves) and works on the same principle as ultrasound. It studies blood flow to different parts of the nervous system, diagnosing conditions such as arterial blockage, haemorrhage, aneurysms, tumours, and other neurological abnormalities.
- Electromyography (EMG): This is a test to measure electrical activity in the muscles. Muscles develop abnormal electrical impulses when there is muscle or nerve damage. An EMG study is used to evaluate the condition of the muscles and the nerves controlling the muscles. During an EMG, wires or fine needles are placed into a muscle to evaluate changes in electrical impulses at rest and during movement. EMG study helps to detect muscle and nerve disorders, motor neuron disorders such as amyotrophic lateral sclerosis, and spinal nerve root compression.
- Visual Evoked Potentials (VEP): This is a diagnostic test to record electrical responses of the brain to sensory, auditory, and visual stimuli. A VEP test involves visualizing a television screen displaying an alternative checkerboard and other visual patterns while electrodes (special wires to test electric activity) are connected to your head. This test is performed for the diagnosis of optic nerve problems including multiple sclerosis.