Epilepsy is a chronic brain condition that causes recurring seizures, which occur when part(s) of the brain receives a burst of abnormal electrical signals that temporarily interrupts normal electrical brain function. Seizures can involve either a part of the body (partial) or the entire body (generalized). Seizures range from fleeting lapses of attention or muscle jerks to severe and prolonged convulsions, exhibiting a spectrum of frequency from less than one per year to several per day.
During epilepsy, the intricate network of cells in the brain, responsible for transmitting and receiving messages from various parts of the body, experiences a disturbance in its usual electrical activity. Typically, communication between brain cells occurs through a seamless transmission of electrical impulses. However, in epilepsy, this pattern is disrupted, leading to sudden bursts of electrical energy akin to an erratic lightning storm, occurring between cells in specific brain regions. As a consequence of this electrical disruption, individuals may encounter alterations in awareness, including loss of consciousness, as well as changes in sensations, emotions, and muscle movements.
It’s crucial to note that a single seizure does not necessarily indicate epilepsy, as up to 10% of individuals worldwide may experience one seizure in their lifetime. Epilepsy is defined by the occurrence of two or more unprovoked seizures. This brain condition, also known as a seizure disorder, manifests in diverse types, with identifiable causes in some cases while remaining unknown in others.
Types
Epilepsy can manifest with generalized or focal seizures, each impacting the brain differently and necessitating distinct identification and treatment approaches.
Generalized seizures affect both sides of the brain which can be seen as abnormal electrical discharges on the EEG. These seizures may manifest as motor seizures, involving physical movement, or non-motor seizures, which do not entail visible movements. A common sign for all types of generalized seizures is that the patient is unconscious, the abnormal movements are symmetrical and autonomic signs (like breathing and circulatory problems) are present.
- A tonic-clonic seizure, also known as a grand mal seizure, is a type of generalized epileptic seizure characterized by distinct phases:
Tonic Phase: During this phase, the person experiences sudden muscle stiffness (tonic contraction). They may fall if standing or lose control of their posture. Breathing may temporarily stop, leading to bluish skin (cyanosis).
Clonic Phase: Following the tonic phase, rhythmic jerking movements occur. These movements affect both sides of the body symmetrically. The person may bite their tongue, leading to oral bleeding.
Postictal State: After the seizure, the person enters a recovery phase. They may feel confused, tired, and disoriented. Memory loss related to the seizure event can occur.
- Tonic: Muscles in the body become stiff.
- Atonic: Muscles in the body relax.
- Myoclonic: Short massive jerking in parts of the body.
- Clonic: Periods of shaking or jerking parts on the body.
- Absence seizures, also known as petit mal seizures, are brief episodes of altered consciousness. During an absence seizure, the person experiences a sudden stop in activity without falling. They may exhibit the following behaviors: Staring blankly into space, lip smacking, eyelid fluttering, chewing motions, finger rubbing, small movements of both hands. Absence seizures are more frequent in children and are sometimes mistaken for daydreaming or inattention.
Focal seizures. Conversely, focal seizures originate from a specific area of the brain and only affect that region.
- Focal Aware Seizures (Formerly Simple Partial Seizures): During these seizures, the person remains aware of their surroundings. Symptoms may include déjà vu, jerking movements, or sensory experiences like taste or smell.
- Focal Impaired Awareness Seizures (Formerly Complex Partial Seizures): Awareness is affected to some extent. Symptoms can vary and may involve altered emotions, thinking, or sensations.
Diagnosis
Diagnosing epilepsy entails a comprehensive evaluation by a medical professional, incorporating symptoms, physical examinations, and diagnostic tests such as electroencephalography (EEG), computed tomography (CT or CAT scan), or magnetic resonance imaging (MRI). Accurate diagnosis is crucial, delineating both the type of epilepsy and the specific seizures associated with it, as various classifications of seizures correspond to distinct forms of the disorder.
Diagnostic tests for epilepsy encompass EEG to measure brain electrical activity (sometimes video EEG) and brain scans, particularly MRI, to detect anomalies like tumors, infections, or vascular irregularities.
However, diagnosing epilepsy can be challenging, as similar symptoms may arise from other conditions like fainting, migraines, or panic attacks. Typically, confirmation of epilepsy necessitates the occurrence of more than one seizure, facilitating differentiation from other disorders. Detailed accounts of seizure experiences, encompassing timing, activities preceding the event, and sensations felt before, during, and after the seizure, aid specialists in diagnosis.
Formally, epilepsy is diagnosed if two or more seizures occur without a known medical cause, excluding conditions such as alcohol withdrawal or low blood sugar. The diagnostic process involves thorough medical history-taking, physical examinations, and possibly blood work to rule out alternative etiologies. Moreover, evaluating symptoms experienced during seizures, including muscle movements, changes in consciousness, bowel or bladder control, breathing patterns, skin color, and communication impairments, assists in confirming the diagnosis of epilepsy.
Treatment epilepsy encompasses various approaches tailored to individual needs.
- Antiepileptic Medications (AEDs): Medication constitutes the primary therapy, with anticonvulsant drugs aiming to control seizures and manage the disorder effectively while minimizing side effects. Examples: Carbamazepine, phenytoin, valproic acid, lamotrigine, levetiracetam.
- Lifestyle Modifications:
- Sleep: Maintain regular sleep patterns.
- Avoid Triggers: Identify and avoid factors that trigger seizures (e.g., alcohol, stress).
- Regular Meals: Balanced meals and hydration.
- Safety Measures: Prevent injury during seizures.
- Diet therapy: For individuals with specific forms of epilepsy, diet therapy may offer therapeutic benefits, with the ketogenic or modified Atkins diet demonstrating efficacy in reducing seizures, primarily among children with refractory epilepsy. However, despite these treatment modalities, approximately 30% of patients remain medically resistant, necessitating specialized care at epilepsy centers.
- Surgery: Surgery emerges as a viable option for patients with medically resistant epilepsy, particularly those with partial epilepsy originating from a single brain region. Pre-surgical evaluation determines the suitability of surgery and potential risks, involving both non-invasive and invasive tests to assess seizure control and neurological outcomes post-surgery.
Efforts to enhance epilepsy care at the primary healthcare level through training programs for healthcare providers have shown promise in reducing the treatment gap. Ultimately, surgery presents a valuable therapeutic avenue for patients unresponsive to conventional drug treatments, highlighting the importance of comprehensive epilepsy management strategies.
References:
Cleveland clinic: Epilepsy: https://my.clevelandclinic.org/health/diseases/17636-epilepsy
Mayo: Epilepsy: https://www.mayoclinic.org/diseases-conditions/epilepsy/symptoms-causes/syc-20350093
World Health Organisation: Epilepsy: https://www.who.int/news-room/fact-sheets/detail/epilepsy
AANS: Epilepsy: https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Epilepsy NHS: https://www.nhs.uk/conditions/epilepsy/
Johns Hopkins Medicine: medical management of epilepsy: https://www.hopkinsmedicine.org/health/conditions-and-diseases/epilepsy/medical-manage ment-of-epilepsy
MedicalNewsToday: what to know about 4 types of epilepsy: https://www.medicalnewstoday.com/articles/types-of-epilepsy
WebMD: Types of seizures: https://www.webmd.com/epilepsy/types-of-seizures-their-symptoms
Centres for disease control and prevention: Types of seizures: https://www.cdc.gov/epilepsy/about/types-of-seizures.htm
Verified by Dr. Petya Stefanova
