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Seizures in the oncology patient

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Shared care information

Paediatric oncology patients may fit, or present with an altered level of consciousness, for a variety of reasons (see below).

As for other children, stabilisation of the "ABC" is the first priority. A diagnostic work up should be performed on patients who are not suitable for transfer after discussion with the paediatric oncologist on call, looking for reversible causes. Rectal medications should be avoided in patients who may be neutropenic.


  • Infection: usually in patients on therapy. Immunocompromised patients may develop typical or atypical infections including fungal, viral, and parasitic.
  • Drugs: Chemotherapeutics intrathecal or systemic especially methotrexate but also ifosfamide, vincristine, cisplatin.
  • Neoplasm: primary or secondary. This can be meningeal infiltration without mass effect and so MRI may be required. CNS leukaemia can also present with seizures.
  • Metabolic: hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, hyperammonia.
  • Vascular: intracranial haemorrhage, sinus venous thrombosis (especially if child is on L-asparaginase), CVA.
  • Other: raised ICP secondary to space occupying lesions, blocked VP shunts, Posterior reversible encephalopathy syndrome (PRES).

Clinical presentation

Seizures may be:

  • Generalised
  • Focal (especially with CNS tumours) +/- secondary generalisation
  • Non convulsive.


Investigations such as imaging to determine the underlying cause should be delayed until the patient has been stabilised if they are still fitting.

All children with seizures should have:

  • CBC, full biochemistry including glucose, calcium, magnesium, LFTs, blood gas, ammonia (on ice), coag screen.
  • Full infection screen - write clearly on form what organisms are being considered, e.g., fungus, so that microbiology can process appropriately. Do not attempt LP without cranial imaging first in this setting.
  • Viral serology/PCR should be taken when bloods are taken off but results will take several days to come back.
  • Drug history.
  • Tox screen (including alcohol in older children).
  • CSF for cytospin to haematology (leukaemia/lymphoma) or cytology (solid tumours). Do not attempt LP without cranial imaging first in this setting.

Once the child is stable:

  • MRI preferably, but CT may be more readily available after hours. In semi-conscious children this often requires a general anaesthetic.
  • Consider EEG if available for repeated seizures or if herpes encephalopathy is suspected.


  • ABC - if convulsions are severe, anaesthetic help may be required to manage the airway. Make sure you chase the results of rapidly reversible causes such as glucose and calcium. Secure IV access if there is no CVL.
  • Treat seizures that last > 5min following the local protocol for status epilepticus but avoid rectal medications where possible.
  • Full history, physical and neurological exam looking for: signs of infection, skin lesions (herpes, bacterial infection), bruising (abnormal coag), localising neurological signs.
  • If there is any fever or other signs of infection, consider first line antibiotic therapy, antifungals or antivirals, as indicated after discussion with the treating oncologist.
  • Consider methylene blue if there has been recent ifosfamide therapy.

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  • Date last published: 01 December 2010
  • Document type: Clinical Guideline
  • Services responsible: National Child Cancer Network