Seizure: Symptoms, Types, Causes and Treatment

Seizures are sudden, uncontrolled electrical disturbances in the brain that can affect behavior, movements, feelings, or levels of consciousness. They can be alarming both for the person experiencing them and for bystanders, making it important to understand how seizures manifest, the different types that exist, what causes them, and how they are treated. This article brings together the latest research and clinical insights to provide a clear, comprehensive guide to seizures.

Symptoms of Seizure

Seizure symptoms can vary widely, from dramatic convulsions to subtle changes in sensation or consciousness. Recognizing these symptoms is key for timely intervention and effective management.

Symptom	Description	Notable Features	Source
Motor	Jerking, stiffening, twitching of body parts	Can be focal or whole-body	3 5 8
Sensory	Unusual smells, tastes, sounds, visual changes	May occur as aura	3 5
Autonomic	Nausea, vomiting, sweating, heart rate changes	Sometimes sole manifestation	1 2
Cognitive/Emotional	Confusion, déjà vu, fear, language changes	May indicate seizure focus	3 5 8
Awareness	Loss or impairment of consciousness	Common in generalized/focal	3 5 8
After-effects	Confusion, fatigue, tongue bite, amnesia	Post-ictal state	3

Table 1: Key Symptoms

Understanding Seizure Symptoms

Seizure symptoms depend on which areas of the brain are involved. They can be divided into several categories:

Motor Symptoms

• Convulsions (Tonic-Clonic Movements): These are often dramatic, involving stiffening (tonic) and rhythmic jerking (clonic) of the limbs. They usually occur when large brain areas are affected, as in generalized seizures 3 5 8.
• Focal Motor Movements: Jerking or twitching may occur in only one part of the body if the seizure starts in a specific brain region 3 5.

Sensory Symptoms

• Auras: Before a seizure spreads, some people experience warning signs—known as auras—including tingling, numbness, seeing lights, or hearing sounds that aren’t there. These can help pinpoint where the seizure begins in the brain 3 5.
• Unusual Perceptions: Smelling burnt toast or tasting something metallic are classic examples 3 5.

Autonomic Symptoms

• Cardiovascular: Fluctuations in heart rate or blood pressure.
• Gastrointestinal: Nausea, vomiting, or an urge to urinate.
• Other: Sweating, changes in skin color, pupillary changes, or even sexual/genital sensations 1 2.
• Autonomic symptoms can sometimes be so subtle that only careful observation or specialized testing reveals them. In rare cases, they may be the only sign of a seizure 1 2.

Cognitive and Emotional Symptoms

• Confusion and Memory Lapses: People may appear dazed, confused, or unresponsive.
• Emotional Changes: Sudden fear, déjà vu, or even laughter can occur if emotional centers are involved 3 5 8.

Changes in Awareness

• Loss of Consciousness: Common in generalized seizures and some focal seizures.
• Impaired Awareness: The person may be unaware of their environment but not fully unconscious 3 5 8.
• Post-ictal Effects: After a seizure, confusion, tiredness, headache, or even injuries like tongue-biting may be noted 3.

Types of Seizure

Seizures are classified by how and where they start in the brain, as well as their main features. The International League Against Epilepsy (ILAE) has developed a modern classification system to aid diagnosis and treatment.

Type	Description	Key Features	Source
Focal	Start in one hemisphere	Awareness may be affected	4 5 8
Generalized	Involve both hemispheres from onset	Immediate loss of awareness	4 5 8
Unknown Onset	Origin unclear	Classified by observed signs	4 5 8
Motor/Non-Motor	Movement or other symptoms dominate	E.g., tonic-clonic, absence	5 8

Table 2: Seizure Classification

The ILAE 2017 Seizure Classification

Seizures are divided into three main groups:

Focal Seizures

• Start in one hemisphere and can be further categorized by:
  • Awareness: Retained (aware) or impaired (impaired awareness) 4 5 8.
  • Motor Onset: Movements such as jerking, stiffening, or automatisms (repetitive movements).
  • Non-Motor Onset: Changes in mood, sensation, cognition, autonomic symptoms (e.g., nausea or palpitations), or arrest of activity 4 5 8.
• Focal to Bilateral Tonic-Clonic: Sometimes, a focal seizure spreads to both hemispheres, causing a generalized tonic-clonic seizure 4 5 8.

Generalized Seizures

• Involve both hemispheres from the start.
• Types include:
  • Motor seizures: Tonic-clonic (classic convulsions), tonic (stiffening), myoclonic (brief jerks), atonic (loss of muscle tone), and others.
  • Non-motor (absence) seizures: Brief lapses in awareness, sometimes with subtle movements like eyelid fluttering 5 8.

Unknown Onset Seizures

• When the beginning of the seizure is not observed (e.g., unwitnessed events), the seizure is classified by its most prominent feature (motor, non-motor, etc.) 4 5 8.

Subtypes and Variations

• Autonomic Seizures: Where autonomic symptoms (like vomiting, sweating, or heart racing) are the main feature 1 2 5.
• Status Epilepticus: A prolonged seizure (or series of seizures without recovery) lasting longer than 5 minutes, requiring emergency treatment 17 18.
• The distribution of seizure types varies by age and underlying cause. Tonic-clonic seizures are the most common generalized type, while focal seizures are more common overall, especially in adults 7.

Causes of Seizure

Seizures can be triggered or caused by a broad range of factors, from underlying medical conditions to acute injuries or metabolic disturbances.

Cause	Description	Typical Context	Source
Structural	Brain injury, tumor, stroke, developmental issues	Often underlying epilepsy	11 12
Infectious	CNS infections (e.g., meningitis, encephalitis)	Common in developing countries	11 13
Genetic	Inherited or de novo mutations	Often in childhood/adolescence	11
Metabolic	Electrolyte imbalance, organ failure	May cause single/provoked seizure	12
Inflammatory	Autoimmune or post-infectious brain inflammation	May trigger epilepsy	9 11
Drugs/Toxins	Medication, intoxication, withdrawal	Drug-induced seizures	12 18
Unknown	No clear cause identified	"Idiopathic" or "cryptogenic"	11

Table 3: Major Causes of Seizures

Understanding Seizure Causes

Structural and Developmental Causes

• Brain Injuries: Trauma, stroke, tumors, or congenital malformations can disrupt brain networks and trigger seizures 11 12.
• Developmental Disorders: Conditions like cortical dysplasia or perinatal brain injury may lead to epilepsy in children 11.

Infectious Causes

• Central Nervous System (CNS) Infections: Meningitis, encephalitis, malaria, and neurocysticercosis are major contributors worldwide, especially in resource-poor regions 11 13.
• Acute seizures are common during severe CNS infections, and a significant proportion of survivors develop epilepsy later 13.

Genetic Causes

• Inherited or De Novo Mutations: Many childhood epilepsies have a genetic basis, sometimes with specific syndromes 11.

Metabolic and Medical Causes

• Electrolyte Imbalances: Low sodium, calcium, or other metabolic disturbances can provoke acute (often reversible) seizures 12.
• Organ Failure: Kidney or liver failure can cause metabolic encephalopathy, predisposing to seizures 12.
• These are often single, "provoked" seizures, not true epilepsy 12.

Inflammatory and Autoimmune Causes

• Brain Inflammation: Both infectious (e.g., viral, bacterial) and non-infectious (e.g., autoimmune) inflammation can trigger seizures 9 11.
• Inflammatory mediators may both result from and contribute to seizures, and chronic inflammation can make the brain more seizure-prone 9.

Drugs, Toxins, and Withdrawal

• Drug-Induced Seizures: Overdose or adverse effects of medications (antidepressants, stimulants, antihistamines) can cause seizures 18.
• Withdrawal: Sudden cessation of alcohol or certain drugs is a common cause 12 18.
• Poisoning: Some toxins directly lower the seizure threshold 18.

Unknown Causes

• In many cases, especially in adults, no clear cause is found—these are labeled as idiopathic or cryptogenic seizures 11.

Treatment of Seizure

Effective seizure management is tailored to the underlying cause, seizure type, and individual needs. The majority of people with epilepsy achieve good control with medication, but some require additional interventions.

Treatment	Key Features	Context/Use	Source
Antiepileptic Drugs (AEDs)	Mainstay for most seizures	Monotherapy preferred	14 15
First-Line AEDs	Carbamazepine, lamotrigine, sodium valproate	Varies by seizure type	15
Emergency Drugs	Benzodiazepines (e.g., intranasal)	Status epilepticus, acute events	17 18
Treat Underlying Cause	Correct metabolic, infectious, toxic issues	For provoked seizures	12 13 18
Surgery	For drug-resistant, focal epilepsy	Selected cases	6 14
Other Therapies	Dietary (ketogenic), neurostimulation	Drug-resistant cases	14

Table 4: Seizure Treatments

Approaches to Seizure Treatment

Antiepileptic Medications

• Mainstay for Epilepsy: Most people with ongoing ("unprovoked") seizures or epilepsy are started on a single AED (monotherapy) 14 15.
• Drug Choices:
  • Partial (Focal) Seizures: Carbamazepine, lamotrigine, or levetiracetam are preferred 15.
  • Generalized Seizures: Sodium valproate is first-line, with lamotrigine or levetiracetam as alternatives—especially for women of childbearing age due to valproate’s teratogenic risks 15.
• Effectiveness: About 60-70% achieve long-term seizure freedom, often with the first or second medication tried 14.
• Adverse Effects: Drowsiness, headache, gastrointestinal upset, rash; side effects vary by drug 15.

Emergency Treatment

• Status Epilepticus: Prolonged seizures are a medical emergency. Benzodiazepines (e.g., intranasal midazolam, lorazepam) are first-line for rapid control 17 18.
• Drug-Induced Seizures: Benzodiazepines are also first-line; if ineffective, barbiturates or propofol may be used. Some toxins (e.g., isoniazid) require specific antidotes (pyridoxine) 18.
• Intranasal Delivery: Offers rapid, non-invasive administration for seizure emergencies 17.

Treating the Underlying Cause

• Provoked Seizures: When seizures are due to infection, metabolic disturbances, or toxic exposure, correcting the underlying issue is paramount 12 13 18.
• Withdrawal of offending drugs, electrolyte correction, or management of organ failure can resolve seizures without long-term AEDs 12.

Non-Pharmacological Treatments

• Surgery: For focal epilepsy unresponsive to medication, surgical removal of the seizure focus may be curative 6 14.
• Dietary Therapies: The ketogenic diet and similar approaches are options for drug-resistant epilepsy, especially in children 14.
• Neurostimulation: Vagus nerve stimulation or responsive neurostimulation may help in refractory cases 14.

Special Considerations

• First Unprovoked Seizure: Immediate AED treatment reduces short-term recurrence but does not impact long-term remission; decisions should be individualized 16.
• Drug Resistance: If seizures persist after two appropriate AEDs, the likelihood of further success with medications drops, and alternative therapies should be considered 14.

Conclusion

Seizures are complex events with diverse symptoms, numerous types, varied causes, and a range of treatment options. Understanding these aspects is vital for effective management and improved outcomes.

Main points:

• Symptoms range from dramatic convulsions to subtle changes in sensation, cognition, or autonomic function.
• Types of seizures are classified by onset (focal, generalized, unknown) and main features (motor, non-motor, autonomic, etc.).
• Causes include structural brain disease, infections, genetic factors, metabolic disturbances, inflammation, drugs, and sometimes remain unknown.
• Treatment is tailored to the cause and seizure type, with most patients benefiting from antiepileptic drugs; others may require surgery, dietary therapy, or emergency interventions.

A comprehensive, individualized approach—grounded in the latest research and clinical guidelines—remains the cornerstone of optimal seizure management.