The doctor called olfactory hallucinations a possible symptom of epilepsy.

Olfactory hallucinations are one of the symptoms of epilepsy, but they can also be a sign of other diseases. On August 2, Ekaterina Demyanovskaya, an expert at the Hemotest Laboratory and a neurologist, told Izvestia who has them and how to distinguish them.

Olfactory hallucinations are a special condition in which a person senses odors that do not exist in reality. They often become the first symptom of serious neurological disorders. Approximately 15% of patients with temporal lobe epilepsy initially go to the doctor complaining of sudden strange odors that precede typical epileptic seizures. Also, an episode of olfactory hallucinations can be the equivalent of a seizure. In some cases, a violation of the neurophysiology of the brain manifests itself in unusual clinical forms, including attacks of olfactory hallucinations instead of typical seizures.

"Olfactory hallucinations in epilepsy have characteristic features. They most often appear within the aura, that is, a state when the precursors of an attack begin, and a person may feel unpleasant or unusual odors that have no real source," Demyanovskaya explained.

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According to her, hallucinations occur, as a rule, suddenly, last from a few seconds to two to three minutes and are most often described by patients as unpleasant - the smell of burning, rotten eggs, gasoline or chemicals. An important diagnostic criterion is stereotyping: a person repeatedly feels the same smell before an attack. In most cases, such hallucinations are accompanied by other harbingers — a feeling of deja vu, fear or euphoria, rapid heartbeat.

"They can also be combined with other forms of aura, such as visual or auditory impairments. It is especially worth being wary if such episodes occur in a dream. This almost always indicates the epileptic nature of the phenomenon. Olfactory epileptic seizures are also accompanied by stereotypical hallucinations, but there are no seizures or freezes after them, and if you remove the EEG at the moment, typical paroxysmal activity is detected. This happens more often with temporal lobe epilepsy," the doctor added.

However, epilepsy, the expert explained, is not the only possible cause of olfactory hallucinations. They also occur in migraines as part of a migraine aura, schizophrenia (usually in combination with other types of hallucinations), Parkinson's disease, and brain tumors. In psychiatric diseases, they are often pleasant (floral, perfumery scents) and persist for a long time. There is also parosmia, a distorted perception of real smells. This happens with diseases of the ENT organs, on the background and after a new coronavirus infection.

If olfactory distortions and hallucinations occur, it is important to visit a neurologist without delay, who will be able to make a correct diagnosis and start treatment on time. For example, in epilepsy, modern anticonvulsant drugs in most cases make it possible to achieve stable remission with a long, unapproachable period.

On July 24, it was reported that the main factors contributing to the development of epilepsy in children and adolescents are genetic mutations, congenital abnormalities of the nervous system, intellectual disabilities, as well as the consequences of infections suffered during pregnancy and complications during childbirth.