Causes and types of hippocampal sclerosis

Hippocampal sclerosis is one of the forms of epilepsy, the cause of which is the pathology of the parts of the limbic system of the brain. The main generator of epileptic activity is gliosis in combination with atrophy of the cortical plate of the underlying white matter. To diagnose the disease, neurologists at the Yusupov Hospital use modern methods of instrumental research, perform laboratory tests and minimally invasive diagnostic procedures.

Sclerosis of the hippocampus is accompanied by loss of neurons and scarring of the deepest part of the temporal lobe. Often caused by severe brain injury. It is left handed and right handed. Brain damage due to trauma, neoplasm, infection, lack of oxygen, or uncontrolled spontaneous seizures leads to the formation of scar tissue in the hippocampus. It begins to atrophy, neurons die and form scar tissue.

Causes and types of hippocampal sclerosis

Based on structural changes, two main types of temporal lobe epilepsy are distinguished:

with the presence of a volumetric process (tumor, congenital pathology, aneurysm of a blood vessel, hemorrhage) affecting the limbic system;

without the presence of clearly verified volumetric changes in the area of the medial temporal lobe.

The reasons

The following causes of hippocampal sclerosis are known:

hereditary predisposition;

hypoxia of brain tissue;

brain injury;

infections.

Today, the following theories of the development of hippocampal sclerosis are considered the main ones:

the influence of febrile convulsions leading to regional metabolic disorders and edema of the temporal lobe cortex . Neuronal death occurs, local gliosis and atrophy develop, as a result of which the volume of the hippocampus decreases, reactive expansion of the sulcus and the lower horn of the lateral ventricle.

acute circulatory disorders in the basin of the terminal and lateral branches of the posterior cerebral artery cause basal ischemia of the temporal lobe, secondary diapedetic sweating , neuronal death, gliosis , and atrophy.

violation of the development of the temporal lobe during embryogenesis.

Symptoms

Sclerosis of the hippocampus usually leads to focal epilepsy. Epileptic seizures appear in groups or individually. They are complex, starting with strange indescribable sensations, hallucinations or illusions, followed by a numb gaze, food and rotational automatisms. They last about two minutes. With progression, generalized tonic-clonic seizures may occur.

Attacks with sclerosis of the hippocampus may be accompanied by various symptoms:

behavior change;

memory loss;

headaches;

increased anxiety;

sleep problems;

panic attacks.

Patients develop impaired cognitive abilities (memory, thinking, ability to concentrate). Seizures that disrupt brain activity can lead to sudden loss of consciousness, as well as autonomic cardiac dysfunction. Patients with left-sided hippocampal sclerosis have more severe parasympathetic dysfunction compared to patients with right-sided mesial sclerosis.

Epilepsy attacks are accompanied by auditory or vestibular hallucinations, belching or autonomic manifestations, paresthesias, and unilateral facial twitching. Patients note the difficulty of learning, memory impairment. They are conflicted, emotionally labile, have an increased sense of duty.