Causes of Epilepsy
Epilepsy is a neurological disorder caused by abnormal electrical activity in the brain. It is characterized by recurrent and transient seizures. Based on the underlying causes, epilepsy can be classified into two main types: primary epilepsy and secondary epilepsy. Below are the common causes associated with secondary epilepsy.Secondary Epilepsy
1. Cortical Development Disorders
These involve abnormalities in the structure of the cerebral cortex, often linked to developmental issues such as gray matter heterotopia. Such disruptions in brain development can lead to seizures and are a known cause of epilepsy.2. Brain Tumors
Certain types of brain tumors, including gliomas and lymphomas, can trigger epileptic seizures. Additionally, metastatic tumors—particularly those that spread from the lungs to the brain—can also lead to seizure activity.3. Head Trauma
Traumatic brain injuries are a significant cause of secondary epilepsy. In adults, these injuries often result from events such as car accidents, falls from heights, or complications following brain surgery. In infants, seizures may stem from birth-related injuries or falls during early development.4. Central Nervous System Infections
A range of infections affecting the central nervous system can lead to epilepsy. These include conditions like tuberculous meningitis, neurosyphilis, and viral meningitis. In some cases, seizures may also occur in individuals infected with the human immunodeficiency virus (HIV).5. Cerebrovascular Diseases
While not all vascular disorders of the brain lead to epilepsy, certain conditions such as cerebral hemorrhage or cortical infarction—especially when affecting the gray matter or cerebral cortex—can trigger seizures.6. Parasitic Infections
Parasites are a notable cause of epilepsy in certain regions. For instance, in northern areas, pinworm infections are common, while in the lower reaches of the Yangtze River, cerebral paragonimiassis is prevalent. In the middle and lower reaches, schistosomiasis is a primary parasitic cause.7. Genetic Metabolic Disorders
Inherited metabolic conditions, such as mitochondrial encephalopathies, can disrupt normal brain function and lead to seizures. These disorders often affect the brain's energy production and can result in epileptic episodes.8. Neurodegenerative Diseases
In the later stages of conditions like Alzheimer's disease and Parkinson's disease, patients may experience seizures. These occur due to progressive brain damage and neuronal dysfunction associated with such neurodegenerative disorders.Primary Epilepsy
In contrast to secondary epilepsy, primary epilepsy has no identifiable structural or metabolic cause. It is believed to be largely genetic in origin, although the exact mechanisms are not always clear. This type of epilepsy represents a significant portion of all diagnosed cases and often begins in childhood or adolescence.