Seizures occur in approximately 10–15% of patients in advanced illness most commonly due to primary or secondary brain tumours, cerebrovascular disease, pre-existing epilepsy, or metabolic disturbances (e.g. severe hyponatraemia).
Up to 70% of patients with brain tumours will experience seizures during their illness.
Investigations and management should be tailored according to stage of illness.
An initial approach to treatment
- Protect from injury; position in recovery position and maintain airway
- If seizure lasts >5 minutes give Buccal Midazolam 10 mg if available or subcutaneous Midazolam, starting with 5mg.
(Alternative: rectal diazepam 10–20 mg).Repeat after 10 minutes if seizure persists. - Address reversible causes e.g. infection, metabolic disturbance, drug toxicity or recent medication changes, anticonvulsant concordance and potential drug interactions
Red Flags
- New onset seizures or change in pattern/frequency
- Seizure >5 minutes (status epilepticus) or recurrent seizures without recovery
- Persistent neurological deficit post-seizure
- Reduced consciousness or airway compromise
- Signs of infection, raised intracranial pressure or metabolic disturbance
Key clinical features for a clinician to assess in the community
- Establish background: Ask about previous seizures, epilepsy, known brain disease (e.g. brain tumour, stroke, metastases), alcohol misuse
- Diagnose seizure type: Sudden unresponsiveness, involuntary limb or facial movements, or new confusion or restlessness. These may represent generalised, focal, or non-convulsive seizures. Subtle behavioural or cognitive changes can also indicate seizure activity
- Temperature, blood pressure, pulse, blood sugar. Consider blood tests for U&E/Ca2+
- Consider other causes of seizure like episodes e.g. vasovagal syncope, postural hypotension, cardiac arrhythmia, hypoglycaemia, or extrapyramidal side effects from dopamine antagonists e.g. Metoclopramide
- Review medications: Check adherence to prescribed anticonvulsants, and review for drug interactions or recent dose changes
- Note that steroids reduce plasma concentrations of Carbamazepine and Phenytoin - doses may need increasing
Specialist care
Further tests according to stage of illness e.g. CT brain
Ongoing Management
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Oral route available:
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Continue or initiate regular anticonvulsant therapy (e.g. Levetiracetam, Sodium Valproate, Lamotrigine, depending on prior history and tolerance)
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Levetiracetam is often used in palliative settings as has minimal interactions and a non-sedating profile
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Oral route not available:
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Midazolam 10–20 mg/24h SC via syringe pump (titrate to effect)
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If seizures persist, consider adding Phenobarbital starting with 600 mg/24h SC for comfort in the terminal phase
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- Consider need for steroids, or increased steroid dose, if a brain tumour is the cause of seizures
Top Tips
- Ensure carers have access to rescue medication (e.g. buccal Midazolam or rectal Diazepam) and know how to use it/when to call for help
- Seizures are frightening for patients and their families. Educate family about the risk of seizure recurrence if anti-epileptic drugs are stopped, for example due to swallowing difficulties
- Ensure there is an up to date Advance Care Plan
- Consider driving advice
- Levetiracetam can cause behavioural problems - anger and impulsiveness - medication might need to be switched if this occurs