AMNESIA - impaired memory; can act as an isolated disorder (amnestic syndrome) or be combined with aphasia, apraxia, agnosia. Often, other neuropsychiatric disorders (attention, speech, thinking disorders) or affective disorders (for example, anxiety or depression) are hidden behind a complaint of memory impairment. Memory impairment especially often occurs with bilateral lesion of the limbic system, primarily the hippocampus, diencephalic region and medial-basal regions of the frontal cortex. At the same time, memorization of a new material mainly suffers. As a result, the patient does not remember the events that occurred after the onset of the disease ( anterograde amnesia ). The intellect, attention, and speech functions of such patients are preserved; therefore, during the first conversation, they often give the impression of completely healthy people. However, if the conversation with the patient had to be interrupted for at least a few minutes, then, returning to it, you may find that the patient does not remember a word of what he was just talking to. The memory for events that occurred before the onset of the disease ( retrograde amnesia ) suffers to a lesser degree, while more distant events are usually better remembered than those that occurred relatively recently. Sometimes patients with retrograde amnesia fill the resulting memory lapses with false memories (confabulations). Information concerning self-identification is particularly resistant to amnestic processes (for example, patients even with very rough amnesia remember their name). Severe retrograde amnesia with the inability to remember your name or the most significant events of your life is usually a sign of psychogenic amnesia observed in hysteria or other mental illnesses.
The cause of acute amnesia can be a traumatic brain injury , stroke , herpetic encephalitis , metabolic encephalopathy, intoxication. The hippocampus is extremely sensitive to hypoxia and ischemia, and can suffer from circulatory arrest, suffocation, or carbon monoxide poisoning. Gradually increasing amnesia is a manifestation of degenerative brain disease, tumors , mental illness, etc. Transient memory disorders may be caused by epilepsy, cerebral circulation disorders, migraine attacks.
Transient global amnesia is found in women of middle and old age. The episode of such amnesia usually lasts for several hours and is characterized by a sudden complete loss of the ability to memorize new information and moderate retrograde amnesia mainly to relatively recent events. Patients are disoriented in space and time and look confused. They persistently try to find out from those around where they are, how they ended up here, but, being unable to remember the answers, they constantly ask the same questions. After several hours, the memory is restored, only the episode itself is amnesized. Unlike epilepsy and transient disorders of cerebral circulation, transient global amnesia in the vast majority of cases remains a single episode.
Subacute development of isolated predominantly anterograde amnesia is possible against the background of chronic alcoholism or eating disorders (Korsakov amnestic syndrome) and is associated with a deficiency of vitamin B ,. Gradually developing amnesia can be a sign of Alzheimer's disease, dyscirculatory encephalopathy, or a brain tumor. Often there is an age-related decline in memory, which reflects the processes of “normal aging of the brain,” has a benign character and does not cause social maladjustment of the patient (benign senile forgetfulness).
Treatment . In case of non-progressive diseases, neuropsychological rehabilitation methods are effective. Drug treatment includes drugs aimed at the underlying disease, drugs that enhance cholinergic transmission in the brain - piracetam at 2-4 g / day, gliatilin 400-800 mg 3 times a day, pyritinol (encephabol) 300-600 mg / day, cerebrolysin 10 - 20 ml intravenously, Semax.