Neurology (clinical assessment)

Generalities

The neurological method of clinical assessment consists of localizing the neurological lesions. It is first necessary to define the region of the nervous system that is likely to be the source of the neurological symptoms presented by a patient. It is of course necessary to know whether the disease affects the central nervous system, the peripheral nervous system or both at the same time. Then, within the central nervous system, is the pathophysiological mechanism (the damage) limited to the cerebral cortex, the basal ganglia (cerebral nuclei), the brainstem, the spinal cord, the cerebellum, the meninges, etc. With regard to the peripheral nervous system, is the neurological damage localized to the peripheral nerve, and in this case does it involve the motor nerve or the sensory nerve, the junction between the nerve and the muscle, the muscle itself or several areas at the same time?

To do this, it is useful to refer to the anamnesis, that is, the information provided by the patient and those around him. Then, of course, the clinical examination is the key moment in the neurological consultation. This must provide a lot of information, provided that it is conducted in such a way as to confirm or rule out the impressions felt at the time of the interview.

The neurology consultation begins very quickly. The overall impression of the patient allows us to get a quick idea of their neurological health. The way the patient expresses themselves and transmits information (language disorders, memory problems, behavioral maladjustment) combined with observation is essential. The signs and symptoms described by patients, whether vertigo, diplopia (objects appear double), nystagmus (a series of jerky movements of the eyeball), paresthesia (a kind of tingling sensation), pain, muscle weakness, incontinence, sensations disturbed in various ways (in a sock, in a glove), reflex disorders, etc., allow us to guide the diagnosis in one way or another and, above all, to get an idea of the origin of lesions (spinal cord, cerebellum, peripheral nerve, medulla oblongata, cortex, etc.).

The patient's description of their symptoms in neurology is relatively subjective. Indeed, if we take the example of vertigo, for example, this may be the translation of a syncope about to occur. It may also be a sensation of instability. Let's take another example, that of visual impressions which are not described in the same way in one patient and another. Thus, blurred vision is sometimes described as a unilateral decrease, that is, affecting only one eye. Visual acuity, or even transient blindness or diplopia, will be described differently in another patient. Of course, there is no mention here of the patient's language, which is most often still likely to complicate things.

Researching personal and family history is, of course, essential, as with any medical consultation. In neurology, perhaps more than elsewhere, there is a long list of genetic disorders. These include Charcot-Marie-Tooth neuropathy, Huntington's disease, neurofibromatosis, neuro-ophthalmic syndrome, and Wilson's disease. This is why it is necessary to conduct a search for relevant family data. The search for medical history should not only concern neurological pathologies but also general medical conditions: high blood pressure, heart disease with in particular valvulopathy, stroke, diabetes, dyslipidemia (hypercholesterolemia for example), coagulopathy, AIDS and other infectious diseases, history of chemotherapy or radiotherapy, collagen disease, history of hemorrhage, vascular malformations, organ transplant, rheumatological disease (periarthritis nodosa) endocrine disorders: thyroid dysregulation, etc. The search for medication use (certain anticholesterolemics leading to the occurrence of myositis), drugs, exposure to certain toxins (pesticides: farmers) is also essential to obtain during the interview. Indeed, if we take the example of aminoglycosides, these are suspected of causing toxicity on the inner ear leading to the occurrence of vertigo among others. Still in the context of medications sometimes taken without medical advice, it is necessary to cite the example of the excessive intake of vitamin A, which is particularly harmful in pregnant women or during certain illnesses such as fibromyalgia, for example.

In neurology, it is sometimes useful to call on people around the patient (family, friends, work colleagues, etc.). Thus, when the patient presents with aphasia (language impairment), the testimony of one or more third parties can corroborate or clarify the patient's description. The same is true for amnesia and anosognosia (a patient's lack of awareness of the condition they are suffering from, even though it is clearly evident). Still in the context of confirming the story by a third party, a loss of consciousness (of syncopal or epileptic origin) most often requires the testimony of a person present at the time of the episode.

It is also necessary to specify as much as possible the exact moment of the appearance of the first symptoms as well as their progression. For example, a rapid onset (sometimes in a few seconds) may mean that it is an event linked to a vascular disturbance or even an epileptic seizure or a migraine for example. When the onset is characterized by symptoms that are localized to one limb and that gradually invade the neighboring tissues and then possibly the other limb or the face, it is legitimate to move towards an epileptic seizure. On the other hand, when the patient presents a more gradual onset with a less clear localization, this allows us to evoke a transient ischemic attack. Paresthesias (a sort of tingling, pins and needles), involuntary movements may be in favor of epilepsy.

Conversely, an infection characterized by a stabilization of symptoms after their onset and progression over several days is in favor of a cerebrovascular disease. Still in the vascular field, an evolution towards a transient remission or a regression of the disorders is more in favor of an ischemic process (reduction of the blood supply to the nervous tissue) than a hemorrhagic one. A different presentation of symptoms such as for example a recurrence or a remission concerning different levels of the central nervous system are more in favor of multiple sclerosis or possibly another process linked to an inflammation of the nervous tissue. Symptoms likely to reflect an infection of the nervous system are of course fever but also a stiff neck as well as an alteration of consciousness. In the presence of a patient presenting symptoms that progress slowly but are not accompanied by remission, one thinks rather of a neurodegenerative pathology, an infection or chronic intoxication or even a neoplasia (cancerous process).

As we can see, contacting a patient who may be suffering from a neurological condition is very instructive. After this crucial phase, it is necessary to proceed with the neurological examination, which is also difficult and complex.