Neurological examination: Procedures to follow (clinical tests)

Article reviewed and approved by Dr. Ibtissama Boukas, physician specializing in family medicine

In case of trouble or dysfunction of the nervous system, the doctor performs a neurological examination. You are probably wondering what it is? First of all, it should be noted that this examination should not not be confused with a psychiatric examination, which instead focuses on behavioral abnormalities.

Neurological examination especially evaluate the functioning of the nervous system through various tests and procedures to be followed. We are going to talk about the procedures needed during a neurological exam.

What is a neurological exam?

A neurological examination is a clinical examination that consists of analyzing the state of the nervous system and the performance of the functions assigned to it. It is then a complete exploration of the nervous system. This assessment study all functions controlled and supervised by this system.

Anatomically, the nervous system includes the nervous system central (brain, spinal cord), nervous system ring road (nerves…) and the nervous system vegetative (orthosympathetic, parasympathetic and enteric). Each element of this system plays specific roles.

The brain and spinal cord provide everything related to the state of consciousness. Conversely, the vegetative system ensures the automatic functions, even if the individual is in a coma.

Basically, the nervous system is the main player in consciousness, intelligence, knowledge, memorization, behavior, communication, pain management, regulation of internal and external organs. It also ensures various cycles through the secretion of various hormones. In short, his functions are vital.

Neurological assessment is based on the examination of cognitive functions (knowledge, memories, etc.), sense organs, sensitivity, reflexes and motor skills.

So, neurological examination complete is long. It requires a lot of time. This is why he must be guided by carrying out preliminary diagnoses: anamnesis or interrogations on the history of the disease, the symptoms felt by the patient, the antecedents… The relative examinations will be carried out first and then completed if necessary.

Indications for a neurological examination

Neurological examination is usually performed when the doctor detects diseases, pathologies or traumas involving abnormalities or functional disorders of the nervous system. It is indicated to identify various syndromes such as syndromes:

• central motor (pyramidal, extrapyramidal, abnormal movements);
• peripheral motor syndromes (myogenic, myasthenic, peripheral neurogenic);
• sensory syndromes;
• balance disorders;
• other syndromes (example: meningitis).

Clinical tests during a neurological examination

Neurological clinical examination requires following a specific procedure. First, at the hardware level, we use:

• a reflex hammer;
• absorbent cotton;
• needles ;
• a tuning fork;
• a tongue depressor;
• cold and hot water tubes;
• a flashlight ;
• an ophthalmoscope.

Then, the tests to be performed must follow a very specific order:

• study of higher functions;
• successive study of cranial nerves, walking, muscle strength and tone, reflexes, motor coordination;
• sensitivity study.

Examination of the other systems (cardio-vascular, abdominal, pleuro-pulmonary, osteo-articular), of the lymph node areas, of the thyroid area and of the skin covering, should not be omitted.

Here are some details about these tests:

Examination of the cranial nerves

The examination of the cranial nerves concerns in particular the optic, olfactory, occulo-motor, and spinal nerves.

Gait and standing examination

For this type of physical neurological test, the patient is asked to walk back and forth and stand with their feet together. This makes it possible to observe the axis of the body and the balance capacity of the subject.

Muscle tone examination

For'assess muscle tone, the patient is subjected to exercises which will involve movements of the various joints at rest.

Muscle strength test

The examination of muscle strength uses two types of techniques.

• La Barré maneuver : the patient extends both arms horizontally in anteflexion for a few seconds. Normally, the patient holds on both sides without problem (against the force of gravity).
• La Mingazzini maneuver: it consists in asking the patient lying on his back to lift the 2 lower limbs for a few seconds, hips and knees bent at 90°. Normally, the patient holds the Mingazzini on both sides without any problem (against the force of gravity).

Muscular forces are examined bilaterally, by segment. They are rated on a scale of 0 to 5. Both sides will need to be compared.

Study of reflexes

The study of reflexes generally involves two types of tests.

• Osteotendinous reflex tests: they are carried out at the level of the upper and lower limbs. One can quote for example the examination of the bicipital reflex by the percussion of the tendon of the biceps [at most of the elbow of the patient]. The response should be a flexion of the patient's forearm with a contraction of his biceps.
• The mucocutaneous reflex test to detect responses to skin or mucous membrane touches (eg eyes, anus, etc.).

Assessment of muscle coordination

To test muscle coordination, one can for example ask the patient to put the tip of his index finger on the tip of his nose or his ear, in a rapid manner.

The sensitivity test

The sensitivity test applies to:

• la superficial sensitivity : touch, heat, cold;
• la deep sensitivity : in the face of vibrations for example;
• la developed or combined sensitivity: it is used specifically in cases of cortical damage to assess the patient's ability to discern different stimuli.

Complementary imaging examinations in neurological examination

To complete the exploration of the nervous system and having more precise data, additional examinations are necessary. They mainly include imaging, electro-neuro-myogram and electro-encephalogram or EEG.

medical imaging

Sometimes essential, imaging provides more details to know the diagnosis and establish a specific treatment.

X-ray scanner

Especially carried out in an emergency, the X-ray scanner makes it easy to detect anomalies, even if they are camouflaged. One can take for example the case of a hematoma, in inter-cerebral position, or located between the brain and the cranial box.

MRI (Magnetic Resonance Imaging)

Unlike CT, MRI does not involve the use of radiation. If with an MRI brain, we can clearly do a study of the brain, MRI medullary allows to analyze the abnormalities of the spinal cord. This examination is often indicated for stroke, for example.

Electro-neuro-myogram or ENMG

ENMG, electro-neuro-myogram or electromyogram (EMG) assess the relationship between nerve fibers and muscles.

It consists of studying the conduction velocity of motor fibers and sensory fibers. During the examination, the patient performs various tests that repeatedly stimulate the muscles. At the same time, a device records the electrical activities of the muscle.

We use electrodes placed on the skin or pushed slightly into the muscles. These electrodes are then connected to a device which records the results. The latter are presented in the form of tracings showing the speed of conduction of the electrical impulse in the nerves as well as the speed of its propagation.

This examination provides additional information concerning peripheral nerve disorders (trauma, neuropathy, etc.), spinal motor neuron disorders, muscle diseases (myopathy) and myasthenia (junction disorder between nerves and muscles).

Electroencephalography or EEG

This examination consists of measure the electrical activity of the brain, more precisely neurons.

To do this, electrodes connected to a device are placed on the patient's scalp at very specific points. The device then saves the results as traces.

This method helps a lot in the evaluation and analysis of the various brain waves (delta, theta, beta, alpa).

It makes it possible to highlight the presence of neurological disorders associated with dysfunctions or anomalies of cerebral activity. It provides more information on epileptic syndromes, strokes and encephalitis.

Pathologies suspected during a neurological examination

THEexam neurological generally occurs in the event of:

• neurodegenerative diseases(which result in a degradation of certain nerve cells): Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis or Charcot disease, Huntington's disease, etc.;
• others neurological diseases such as chronic pain, epilepsy, different forms of intellectual deficit, language disorders, autism, meningitis, meningoencephalitis, strokes, etc.

Sources

https://www.cen-neurologie.fr/fr/premier-cycle/examen-neurologique

https://www.vocabulaire-medical.fr/encyclopedie/305-neurologie-premiere-partie-les-examens

https://www.msdmanuals.com/fr/professional/troubles-neurologiques/examen-neurologique

https://www.infosante.be/guides/examen-du-systeme-nerveux-examen-neurologique

https://fr.wikipedia.org/wiki/Examen_clinique_neurologique