AMNESIA - memory impairment; can act as an isolated disorder (amnestic syndrome) or be combined with aphasia, apraxia, agnosia. Often, a complaint of memory impairment conceals other neuropsychic disorders (impaired attention, speech, thinking) or affective disorders (for example, anxiety or depression). Memory impairment especially often occurs with bilateral lesions of the limbic system, especially the hippocampus, diencephalic region and the medial-basal parts of the frontal cortex. In this case, the memorization of new material mainly suffers. As a result, the patient does not remember the events that occurred after the onset of the disease ( anterograde amnesia ). Intelligence, attention, speech functions in 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 her, you may find that the patient does not remember a word from what was just spoken to him. The memory of events that occurred before the onset of the disease ( retrograde amnesia ) suffers to a lesser extent, while more distant events are usually better remembered than those that took place relatively recently. Sometimes patients with retrograde amnesia fill the resulting memory lapses with false memories (confabulations). Information regarding self-identification is particularly resistant to amnestic processes (for example, patients with very severe 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 with hysteria or other mental illnesses.
The cause of acute amnesia can be traumatic brain injury , stroke , herpetic encephalitis , metabolic encephalopathy, intoxication. The hippocampus is extremely sensitive to hypoxia and ischemia and can suffer from circulatory arrest, asphyxiation or carbon monoxide poisoning. Gradually increasing amnesia is a manifestation of a degenerative disease of the brain, tumor , mental illness, etc. Transient memory impairment can be caused by epilepsy, cerebrovascular accident, migraine attacks.
Transient global amnesia occurs in middle-aged and older women. The episode of such amnesia usually lasts several hours and is characterized by a sudden complete loss of the ability to remember new information and moderate retrograde amnesia mainly for 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 a few hours, the memory is restored, only the episode itself is amnesized. In contrast to 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’s amnestic syndrome) and is associated with vitamin B deficiency. Gradually developing amnesia may be a sign of Alzheimer's disease, discirculatory encephalopathy, or a brain tumor. Often there is an age-related decrease in memory, which reflects the processes of “normal brain aging”, has a benign character and does not cause social maladaptation of the patient (benign senile forgetfulness).
Treatment . In non-progressive diseases, methods of neuropsychological rehabilitation 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) at 300 - 600 mg / day, cerebrolysin 10 - 20 ml intravenously, semax.