Seizures

Definition | Types of Seizures | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Example Management | References

Definition

Seizures are sudden, uncontrolled electrical disturbances in the brain that can cause changes in behaviour, movements, feelings, and levels of consciousness. Seizures can be classified into different types, including focal seizures, generalised seizures, and status epilepticus.

Types of Seizures

Focal Seizures

Focal seizures, also known as partial seizures, originate in a specific area of the brain. They can be further classified into:

• Focal aware seizures: The person is conscious and aware during the seizure.
• Focal impaired awareness seizures: The person has altered consciousness or awareness during the seizure.

Generalised Seizures

Generalised seizures affect both sides of the brain simultaneously. They include various types, such as:

• Tonic-clonic seizures: Characterised by stiffening (tonic) and rhythmic jerking (clonic) movements.
• Absence seizures: Brief lapses in awareness, often seen as staring spells.
• Myoclonic seizures: Sudden, brief jerks or twitches of the muscles.
• Atonic seizures: Sudden loss of muscle tone, causing the person to collapse.
• Tonic seizures: Increased muscle tone leading to rigidity.
• Clonic seizures: Repeated rhythmic jerking movements.

Status Epilepticus

Status epilepticus is a medical emergency characterised by a seizure lasting more than 5 minutes or multiple seizures occurring close together without recovery of consciousness between them. It requires immediate medical intervention.

Aetiology

Seizures can be caused by various factors, including:

• Genetic predisposition
• Brain injury or trauma
• Infections affecting the brain (e.g., meningitis, encephalitis)
• Brain tumours
• Stroke
• Metabolic imbalances (e.g., low blood sugar, electrolyte imbalances)
• Drug or alcohol withdrawal
• High fever, particularly in children

Pathophysiology

Seizures result from abnormal, excessive, and synchronous neuronal activity in the brain. Depending on the type and location of the seizure, this can lead to a variety of clinical manifestations. Focal seizures involve a specific area of the brain, while generalised seizures involve widespread neuronal activity affecting both hemispheres simultaneously.

Risk Factors

• Family history of seizures or epilepsy
• Previous head injury or brain trauma
• History of stroke or cerebrovascular disease
• Neurodevelopmental disorders
• Chronic alcohol or drug use
• Infections affecting the central nervous system
• Metabolic disorders

Signs and Symptoms

• Temporary confusion
• Staring spells
• Uncontrollable jerking movements of the arms and legs
• Loss of consciousness or awareness
• Cognitive or emotional symptoms, such as fear or anxiety

Investigations

• Clinical history and physical examination
• Electroencephalogram (EEG) to detect abnormal electrical activity in the brain
• Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan of the brain to identify structural abnormalities
• Blood tests to identify metabolic imbalances or infections
• Lumbar puncture if infection is suspected

Management

Primary Care Management

• Initial assessment and stabilisation of the patient
• Referral to a neurologist for further evaluation and diagnosis
• Education on seizure first aid and safety precautions
• Monitoring and managing comorbid conditions

Specialist Management

• Anti-seizure medications (e.g., carbamazepine, levetiracetam) to control seizures
• Surgical intervention for refractory epilepsy (e.g., resective surgery, vagus nerve stimulation)
• Ketogenic diet in certain cases, particularly in children with drug-resistant epilepsy
• Management of status epilepticus with intravenous medications (e.g., lorazepam, diazepam)
• Regular follow-up and monitoring of medication effectiveness and side effects

Example Management for Seizures

A patient presenting with a new onset of seizures should be referred to a neurologist for a comprehensive evaluation, including EEG and MRI. If diagnosed with focal epilepsy, the patient may be started on an anti-seizure medication such as carbamazepine. For generalised epilepsy, medications like valproate or levetiracetam may be used. In cases of status epilepticus, immediate administration of intravenous benzodiazepines is required, followed by further management in an intensive care setting if necessary. Long-term management includes regular follow-up, medication adjustments, and lifestyle modifications to reduce seizure triggers.

References

1. NICE. (2024). Epilepsies: Diagnosis and Management. Retrieved from NICE
2. NHS. (2023). Seizures (Fits). Retrieved from NHS
3. Fisher, R. S., et al. (2017). Operational Classification of Seizure Types by the International League Against Epilepsy. Epilepsia.
4. Trinka, E., et al. (2015). A Definition and Classification of Status Epilepticus. Neurology.
5. Engel, J. (2013). Seizures and Epilepsy. Oxford University Press.

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