The 7 types of neurological tests

The nervous system in a set of organs and structures, formed by nervous tissue, which are responsible for collecting and processing the signals to later control and organize the rest of the organs, and thus achieve a correct interaction of the person with their half.

The science in charge of studying all this complex structure is neurology. Which tries to evaluate, diagnose and treat all kinds of disorders of the nervous system. A series of neurological tests have been developed for evaluation and diagnosis tasks. that allow medical personnel to observe the operation of said system.

• Related article: "The 15 most common neurological disorders"

What are neurological tests?

Neurological tests or exams are performed in order to examine whether the patient's nervous system is functioning properly. These tests can be more or less exhaustive depending on what the physician is trying to assess, in addition to the age or condition of the patient.

The importance of these tests lies in their usefulness in early detection of possible alterations

, and thus eliminate or reduce, as far as possible, possible complications that may appear in the long term.

The first tests performed by the clinician are physical tests, in which through the use of hammers, tuning forks, flashlights, etc. the nervous system is tested.

The aspects that are evaluated during this type of neurological examination are:

• Mental state (consciousness)
• Reflexes
• motor skills
• sensory abilities
• Balance
• nerve function
• Coordination

However, in the event that there is suspicion of a possible alteration in any of these aspects, the medical professional has at his disposal a large number of specific and very revealing clinical tests when diagnosing any type of neurological problem.

Types of neurological tests

There are more than a dozen tests to evaluate the state of the nervous system, any of them will be more or less useful depending on what the clinician wants to look for.

Some of them are explained here.

1. cerebral angiography

Cerebral angiography, also known as arteriography, is a procedure to locate possible vascular singularities in the brain.. These irregularities range from possible cerebral aneurysms, blood vessel obstructions or strokes, to cerebral inflammations or malformations in the veins of the brain.

To detect any of these abnormalities, the physician injects a radiopaque substance into one of the cerebral arteries, thus making any vascular problem visible in the X-rays in the brain.

2. Electroencephalogram (EEG)

If what the physician needs is to monitor brain activity, the electroencephalogram can be your reference test. During this test a series of electrodes are placed on the patient's head, these small electrodes carry the electrical activity in the brain to a device that reads the activity and converts it into a trace of the record electric.

In addition, the patient can be subjected to different tests in which he is presented with a series of stimuli such as lights, noises or even medications. In this way the EEG can detect changes in brain wave patterns.

If the medical professional sees it necessary to further narrow down the search or make it more exhaustive, he or she may placing these electrodes directly into the patient's brain through a surgical incision in the skull of this.

The electroencephalogram is very interesting when diagnosing diseases or disorders such as

• Brain tumors
• psychiatric disorders
• metabolic disorders
• injuries
• Inflammation of the brain or spinal cord
• Seizure disorders

3. Lumbar puncture

Lumbar punctures are performed with the aim of obtaining samples of cerebrospinal fluid.. This liquid is analyzed to verify the existence of bleeding or cerebral hemorrhages, as well as to measure intracranial pressure. The purpose is to diagnose a possible brain or spinal infection such as those that occur in some neurological diseases such as multiple sclerosis or meningitis.

Commonly, the procedure to follow in this test begins by laying the patient on one side of him, asking him to place his knees next to his chest. Next, the doctor locates the position between the vertebrae in the middle of which the puncture is to be performed. After administering a local anesthetic, the doctor inserts a special needle and withdraws a small sample of fluid.

4. Computed Tomography (CT)

This test is part of the so-called brain ultrasound, among which are also magnetic resonance imaging and positron emission tomography. The advantage of all of them is that they are painless and non-invasive processes.

Thanks to computed tomography, fast and clear images of organs such as the brain, as well as tissues and bones are obtained.

Neurological CT can help make differential diagnoses in neurological disorders with several similar properties. In addition, it is especially effective in detecting, among others:

• Epilepsy
• Encephalitis
• Intracranial clots or bleeding
• brain damage from injury
• Brain tumors and cysts

The test lasts about 20 minutes, during which the patient must lie down inside the CT chamber. For this test, the person must remain very still while the X-rays scan their body from different angles.

The final result is several cross-sectional images of the internal structure, in this case of the internal structure of the brain. Occasionally, a contrast fluid may be introduced into the bloodstream to facilitate differentiation of the different brain tissues.

5. Magnetic resonance imaging (MRI)

Radio waves are used to obtain images obtained by magnetic resonance that are generated in a device and a large magnetic field that reveal the details of organs, tissues, nerves and bones.

As in CT, the patient must lie still and is inserted into a hollow tube surrounded by a large magnet.

During the test a large magnetic field is created around the patient and through a series of reactions a resonance signal is produced from various angles of the patient's body. A specialized computer processes this resonance by converting it into a three-dimensional image or a cross-sectional two-dimensional image.

Likewise, there is also functional magnetic resonance, in which images of the blood flow of different areas of the brain are obtained thanks to the magnetic properties of blood.

6. Positron emission tomography (PET)

In positron emission tomography, the clinician can obtain images, in two or three dimensions, of brain activity. This image is achieved through the measurement of radioactive isotopes injected into the patient's bloodstream.

These chemical-bound radioactive isotopes flowing into the brain are tracked as the brain performs different tasks. Meanwhile, gamma ray sensors scan the patient and a computer processes all the information, displaying it on a screen. Different compounds can be injected so that more than one brain function can be examined at the same time.

PET scans are especially useful when it comes to:

• Detect tumors and infected tissues
• Determine brain changes after substance use or injury
• Evaluate patients with memory disorders
• Assessment of seizure disorders
• Measure cell metabolism
• show blood flow

7. Evoked potentials

In the evoked potentials test, possible sensory nerve problems can be evaluated, as well as corroborate certain neurological conditions such as brain tumors, spinal cord injuries or multiple sclerosis.

These evoked potentials or responses calibrate the electrical signals that visual, auditory, or tactile stimuli send to the brain.

Through the use of electrode needles, nerve damage is evaluated. One pair of these electrodes measures the electrophysiological response to stimuli on the patient's scalp, and the other pair is placed on the area of ​​the body to be examined. The clinician then notes the time it takes for the generated impulse to reach the brain.

Other tests frequently used for the evaluation and diagnosis of neuronal disorders are:

• Biopsy
• single photon emission tomography
• Doppler ultrasound
• myelography
• electromyography