Dysautonomia is a dysfunction of the autonomic nervous system. Because it can manifest itself through very diverse symptoms, but also because it is unrecognized, this pathology is often the subject of diagnostic wandering.

The autonomic nervous system (ANS), also called the visceral nervous system or the vegetative nervous system, controls all the automatic functions of the organism, that is to say all the functions which are carried out without conscious effort: the regulation of the tension blood pressure, heart rate, respiratory rate, body temperature, water and electrolyte balance in the blood, but also digestion, metabolism, production of body fluids (saliva, sweat and tears), urination , defecation or even sexual response.

Dysautonomia designates a neuropathy affecting this autonomic nervous system, and therefore all or part of the aforementioned functions. If the manifestations of this pathology vary, there is almost always a great fatigue and orthostatic hypotension (when the patient stands up, his blood pressure drops sharply).

Dysautonomia can result from:

• nerve damage ;
• natural aging of the autonomic nervous system. This should be taken into account in the elderly, as dysautonomia can worsen the side effects of certain drugs which are commonly prescribed to them;
• a pathology that damages the autonomic nervous system in the long term : diabetes in particular, but also Parkinson’s disease, multiple sclerosis, Guillain-Barré syndrome, botulism, etc. ;
• connective tissue disease : Ehlers-Danlos Syndromes (EDS), in particular, are inherited diseases that affect the matrix between the tissues and support the organs. Strictly speaking, they do not affect the nervous system, but, due to the poor quality of the collagen that underlies the veins, they become distended and have difficulty in bringing blood back to the brain, which causes orthostatic hypotension. For the same reasons, other autonomous functions may be disrupted;
• viral infection : dysautonomic disorders are observed in some patients infected with HIV / AIDS, but also in some people suffering from prolonged symptoms of Covid-19;
• a rare genetic disease : we can cite, for example, familial amyloid neuropathy, a progressive disease that appears in adulthood, with varying severity depending on the age of the patients (the later it occurs, the more amyloidosis deposits on the autonomic nerves and organs. develop rapidly). We can also mention familial dysautonomia, or Riley-Day syndrome, which is found almost only in the Jewish population of Eastern Europe today and which manifests itself from birth by severe anomalies of swallowing and swallowing. digestive motor skills, repeated neurological or respiratory accidents, loss of sensation, cardiovascular instability, kyphoscoliosis and developmental delay.
• of another cause, still unknown : Pure dysautonomia, also called idiopathic orthostatic hypotension or Bradbury-Eggleston syndrome, is a rare neurodegenerative disease that affects the autonomic nervous system. It occurs sporadically in adults, without a clear cause, then evolves over more than twenty years. It is mainly manifested by postural hypotension and / or urinary disorders. Multisystem atrophy (MSA) is another neurodegenerative disorder that sporadically affects adults, but also affects the central nervous system. This pathology resembles a Parkinson’s disease but which is not related to dopamine and presents a more marked impairment of the autonomic system.

Depending on which part of the autonomic nervous system is affected, and the severity of the condition, dysautonomic disorders can be varied. We can find for example:

• orthostatic hypotension : this is the most frequently encountered symptom. Patients feel dizzy or dizzy, even faint, their blood pressure drops excessively when they stand up or stomp. They also experience chronic fatigue and drowsiness;
• an absence of sweating, or on the contrary excessive sweating ;
• erectile dysfunction often appear first in humans;
• urinary disorders, with an overactive or insufficiently active bladder: incontinence or urinary retention;
• cardiovascular instability : tachycardia or bradycardia, attacks of palpitations;
• gastrointestinal disturbances, linked to weaker digestive motricity or, on the contrary, to hyperactivity of the digestive organs: constipation or diarrhea, vomiting linked to a stomach which does not empty completely and with delay, etc. ;
• respiratory problems ;
• dry eyes, without or with few tears, and / or whose pupils fail to dilate or shrink depending on the light;
• loss of sensitivity, especially with regard to pain.

In the same patient, the involvement is rarely complete: only some of the above symptoms are generally reported.

First of all, we try to identify the cause and, when possible, we treat it. Then it is about relieving the symptoms that may be. Thus, heart, urinary or erection problems can sometimes be treated with medication. 

Patients with orthostatic hypotension are advised to elevate the head of their bed about 10 cm and stand up slowly, in a decomposed manner. Wearing a compression or support garment, such as an abdominal belt or compression stockings, can be helpful. In addition, consuming more salt and water helps maintain the volume of blood in the bloodstream, and therefore blood pressure.

Faced with sweating and thermal regulation disorders, it is advisable to avoid hot environments and avoid alcohol. And, faced with digestive problems, an adapted diet can be recommended. When a patient suffers from urinary retention, he must learn to insert a catheter into his bladder through the urethra, to empty it.