Anosognosia is a self-recognition disorder that for example prevents a person with Alzheimer’s disease from recognizing their disease. To be distinguished from the denial of the disease, this disorder is the consequence of a brain injury.

Healthcare professionals diagnose anosognosia when a patient does not recognize their disease. This disorder of self-recognition can be observed in particular in patients with Alzheimer’s disease, a neurodegenerative disease, or hemiplegia, a particular form of paralysis that affects either the left side or the right side of the body. .

The anosognosia can suggest a denial of the disease. However, these two phenomena must be distinguished. Characterized by a denial of reality, denial is a process of psychological defense. Anosognosia refers to a neuropsychological disorder caused by brain injury.

In neurology, anosognosia is sometimes considered one of the signs of frontal syndrome. This syndrome corresponds to a set of symptoms resulting from an injury or dysfunction of the frontal lobe. In frontal syndrome, anosognosia can be associated with other neurological disorders including certain behavioral and cognitive disorders.

Anosognosia is the consequence of a lesion in the brain. Although the exact location of the lesion has not yet been fully identified, it seems that anosognosia is the consequence of a lesion in the right hemisphere of the brain.

Based on current scientific data, the lesion causing anosognosia could have several possible causes. In particular, it could be the consequence of:

• cerebrovascular accident (stroke), also called stroke, a blood flow disorder in the brain which can lead to the death of nerve cells;
• Alzheimer’s disease, a brain disorder called neurodegenerative because it causes a progressive disappearance of neurons and is manifested by a decline in cognitive functions;
• Korsakoff syndrome, or Korsakoff’s dementia, a neurological disorder which is usually caused by a deficiency of vitamin B1 (thiamine);
• head trauma, a shock to the skull which can be responsible for brain damage.

The consequences and course of anosognosia depend on many factors including the extent and origin of the brain injury. Depending on the case, it is possible to distinguish:

• mild anosognosia, for which the patient discusses his illness only after specific questions on the subject;
• moderate anosognosia, for which the patient recognizes his disease only after visualizing the results of a medical examination;
• severe anosognosia, for which the patient is unaware of his disease, even after a thorough questionnaire and the performance of a medical examination.

The management of anosognosia aims to

• treat the origin of the brain injury;
• limit the risk of complications;
• accompany the patient.

If the choice of treatment depends on the diagnosis, it is usually accompanied by rehabilitation to help the patient become aware of his disease. This awareness facilitates the management of the disease by health professionals.