Epilepsy is a neurological disorder characterized by recurring seizures caused by abnormal electrical activity in the brain. The causes of epilepsy are varied and depend on many factors. The main ones include:
1. Genetic factors
In some people, epilepsy is associated with a hereditary predisposition. Certain gene mutations can increase the likelihood of developing the disease, especially if they are related to the function of nerve cells or their interactions.
Idiopathic epilepsy (without an obvious structural or metabolic cause) is often genetic.
2. Brain injury
Head injuries: Previous traumatic brain injury, especially with loss of consciousness or damage to brain tissue, can lead to epilepsy.
Strokes: Impaired blood flow to the brain can cause tissue damage and provoke seizures.
Tumors: The presence of tumors in the brain sometimes leads to epileptic seizures.
3. Infectious diseases
Meningitis, encephalitis, neurocysticercosis, and other infections that affect the brain can lead to the development of epilepsy.
Some infections in early childhood or the prenatal period (e.g., toxoplasmosis, rubella) also increase the risk.
4. Brain development disorders
Abnormalities in brain development in the prenatal period, such as cortical dysplasia, can cause epilepsy.
Early brain damage caused by hypoxia, toxins, or infections also contribute to an increased risk.
5.Metabolic and toxic causes
Metabolic disorders such as hypoglycemia, hypocalcemia, hypomagnesemia can cause seizures.
Chronic alcohol consumption, poisoning with toxic substances or drugs (e.g. cocaine, amphetamines) can provoke seizures.
6. Age-related changes
In children, epilepsy can be associated with genetic and metabolic factors, as well as with birth injuries.
In older people, epilepsy is more often caused by strokes, tumors, or age-related changes in the brain.
7. Triggering factors for seizures
In people prone to epilepsy, seizures can be caused by:
Lack of sleep.
Stress.
Photostimulation (bright or flashing lights).
Consumption of alcohol or drugs.
Sudden changes in temperature or metabolism (e.g. fever).
Mechanism of an epileptic seizure
An epileptic seizure occurs due to a disturbance in the electrical activity of neurons in the brain. Normally, neurons communicate through electrical impulses that are controlled by a balance of excitatory and inhibitory signals. In epilepsy, this balance is disrupted, leading to “overload” of neurons and synchronous electrical activity that causes a seizure.
Stem cells have great potential for the treatment of epilepsy due to their ability to repair damaged tissue, including nerve cells, and regulate abnormal activity in the brain.
The main mechanisms by which stem cells may help treat epilepsy include:
1. Regeneration of nerve cells
Replacement of lost neurons: Epilepsy is often associated with damage or death of neurons in certain areas of the brain, such as the hippocampus. Stem cells can differentiate into neurons, replacing the lost cells.
Restoration of neuronal networks: New neurons can integrate into existing neural circuits, restoring normal electrical activity and reducing the likelihood of epileptic seizures.
2. Modulation of inflammation
Chronic inflammation in the brain is associated with increased excitability of neurons, which contributes to epileptic activity. Stem cells (especially mesenchymal cells) have anti-inflammatory properties and can reduce inflammation in damaged areas of the brain, stabilizing nerve tissue.
3. Support of existing neurons
Stem cells secrete neurotrophic factors (e.g. BDNF, GDNF) that promote the survival and normal functioning of existing neurons. This may help restore the balance of excitatory and inhibitory signals in the brain that is disrupted in epilepsy.
4.Correction of abnormal electrical activity
The abnormal electrical activity that underlies epilepsy can be reduced by introducing stem cells that can restore normal function to inhibitory neurons (such as gamma-aminobutyric acid – GABA neurons), which reduce brain excitability.
5. Potential for drug delivery
Stem cells can be used as “biological factories” to deliver substances that prevent or reduce seizures, such as anti-seizure proteins or genes.
Types of stem cells used in epilepsy research
Embryonic stem cells (ESCs):
Have a high capacity to differentiate into a variety of cell types, including neurons.
Induced pluripotent stem cells (iPSCs):
Can be converted into neurons or glial cells to replace damaged tissue.
Mesenchymal stem cells (MSCs):
Easily harvested from bone marrow or fat tissue.
Possess powerful anti-inflammatory and regenerative properties.
Neural stem cells (NSC):
Naturally present in the brain and can be used to restore damaged areas.
Advantages of using stem cells therapy in epilepsy treatment:
Possibility of complete restoration of damaged tissue.
Long-term effect due to cell replacement and restoration of brain functions.
The process of replacing neuronal cells using stem cells includes several stages, starting with the selection of the appropriate cell type and ending with their integration into the neural networks of the brain.This process is complex and requires precise coordination between cell therapy, neurophysiology and immunology.
Steps of neuronal cell replacement
1. Selection and preparation of stem cells
Cell type:
Neural stem cells (NSC): isolated from the brain or created from other stem cells.
Embryonic stem cells (ESCs) or mesenchymal stem cells (MSCs) may also be used, depending on the goal of the therapy.
Differentiation: Stem cells undergo a process of differentiation to become the specific types of neurons or glial cells that are needed for replacement. For example, GABA neurons are used for inhibitory neurons, and glutamatergic neurons are used for excitatory neurons.
2. Cell migration
Once injected, stem cells begin to migrate to areas where they can replace damaged or lost neurons.
The cells respond to chemical signals released by damaged tissue, such as chemoattractants and neurotrophins.
3. Differentiation and maturation
Once the target is reached, stem cells continue to differentiate into specialized neurons.
This process includes:
Formation of dendrites and axons.
Maturation of synapses to transmit signals.
4. Integration into neural networks
Newly formed neurons must integrate into the existing neural networks of the brain. This is a key step, because without proper integration, the new cells may not function or even cause an imbalance in brain activity.
To integrate, cells:
Establish synaptic connections with neighboring neurons.
Begin to participate in signal transmission, compensating for lost functions.
5. Cell support and survival
To survive and function normally, new cells need adequate support:
Neurotrophic factors such as BDNF (brain-derived neurotrophic factor) stimulate the growth and survival of new neurons.
Glial cells (astrocytes and oligodendrocytes) provide nutrition, protection and restoration of the myelin sheath of axons.
Benefits of neuronal replacement
- Restoration of functions lost as a result of epilepsy (e.g. control of excitatory and inhibitory signals).
- Long-term effect due to replacement of lost cells.
- Potential restoration of brain structures damaged as a result of seizures.