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Information ⬇

Author: Bridget MacDonald

Generalised Tonic-Clonic Seizure

Priorities ⬆ ⬇

Outline

Airway, Breathing and Circulation!!navigator!!

  • Clear the airway. Place a nasopharyngeal airway if needed to maintain a clear airway (Chapter 112).
  • Put the patient in the lateral semiprone position. Attach an ECG monitor and oxygen saturation monitor.
  • Give high-flow oxygen and obtain IV access.
  • Take blood for urgent investigation (Table 16.1).

Exclude Hypoglycaemia!!navigator!!

Check blood glucose immediately by stick test. If blood glucose is <4.0 mmol/L:

  • Give 100 mL of 20% glucose (or 200 mL of 10% glucose) over 15–30 min IV, or glucagon 1 mg IV/IM/SC.
  • Recheck blood glucose after 10 min; if still <4.0 mmol/L, repeat the above IV glucose treatment.
  • In patients with malnourishment or alcohol use disorder, there is a remote risk of precipitating Wernicke's encephalopathy by a glucose load; prevent this by giving thiamine 100 mg IV before or shortly after glucose administration.

See Chapter 81 for further management of hypoglycaemia.

Give a Benzodiazepine!!navigator!!

  • Take into account pre-hospital treatment. Give lorazepam (which is less likely to cause respiratory suppression) 0.1 mg/kg (typically 4–8 mg) IV over 5–10 min (Table 16.2), midazolam 10 mg buccally (NICE-recommended, but only licensed in patients <18 years), or diazepam 10–20 mg IV at a rate of <2.5 mg/min (faster injection rates carry the risk of sudden apnoea).
What is the likely cause of the seizure? (Table 16.3)What is the likely cause of the seizure? (Table 16.3)

Obtain the history from all available sources including emergency information or health app on mobile telephone, and make a systematic examination of the patient. Check the blood results.

  • Correct severe hyponatraemia (plasma sodium <120 mmol/L) with hypertonic saline (Chapter 85).
  • Correct severe hypocalcaemia (plasma total calcium <1.5 mmol/L) with calcium gluconate 1g IV (10 mL of 10% solution) (Chapter 87).
  • Correct hypomagnesaemia (Chapter 88)
  • Give dexamethasone 10 mg IV if the patient is known to have a brain tumour or active vasculitis.
  • If patient is known to have epilepsy, restart any antiepileptic medication stopped within the last three weeks (via a nasogastric tube if IV or rectal preparations are not available).

Further Management ⬆ ⬇

Outline

If fitting continues:

  • Transfer the patient to the ICU and discuss management with an anaesthetist and neurologist.
  • Consider the possibility of psychogenic status epilepticus (Table 16.4), which is not uncommon. Definitive diagnosis may require EEG.
  • Give either phenobarbital or phenytoin (Table 16.2) (please note the difference in time to treatment dose being given – many experts prefer phenobarbital for this reason).

If there is refractory status epilepticus

If fitting continues despite phenytoin or phenobarbital IV:

  • The patient should be intubated and ventilated.
  • Midazolam, propofol or thiopentone should be given (Table 16.2), preferably with EEG monitoring.

Once fitting has stopped

  • Determine the cause (Table 16.3).
  • Ask advice from a neurologist on further management; in complex patients with a past history of epilepsy, speak to their usual consultant where possible.

After a First Generalized Tonic–clonic Seizure!!navigator!!

Was it a seizure? (Table 16.5)Was it a seizure? (Table 16.5)

Distinguishing between a seizure and syncope requires a detailed history, taken from the patient and any eyewitnesses. Points to cover include the following:

Background

  • Any previous similar attacks (including partial seizures such as déjà vu or myoclonic jerks in morning)
  • Previous significant acquired brain injury (i.e. complicated or premature birth, trauma with skull fracture or loss of consciousness >1h, meningitis or encephalitis, stroke)
  • Febrile seizures in childhood (age six months to six years)
  • Family history of epilepsy
  • Cardiac disease (previous myocardial infarction, hypertrophic or dilated cardiomyopathy, long QT interval (at risk of ventricular tachycardia))
  • Drug therapy
  • Alcohol or substance use
  • Sleep deprivation

Before the attack

  • Prodromal symptoms: were these cardiovascular (e.g. dizziness, palpitation, chest pain) or focal neurological (aura)?
  • Circumstances, for example exercising, standing, sitting or lying, asleep
  • Precipitants, for example coughing, micturition, head-turning

The attack

  • Were there any focal neurological features at the onset: sustained deviation of the head or eyes or unilateral jerking of the limbs (bilateral ‘twitching’ is common in syncope)?
  • Was there a cry (may occur in tonic phase of seizure)?
  • Duration of seizure (must be assessed in relation to the reliability of the witness).
  • Associated tongue biting, urinary or faecal incontinence or injury.
  • Facial colour changes (pallor common in syncope, uncommon with a seizure).
  • Abnormal pulse (must be assessed in relation to the reliability of the witness).
  • Eyes rolled up consistent with syncope, eyes open and staring in any direction consistent with seizure.
  • Waxing and waning of long duration consistent with non-epileptic attack (dissociative seizure).

After the attack

  • Immediately well or delayed recovery with confusion or headache? (fatigue common after syncope, somnolence more common after seizure).
  • Was speech normal?

Is there evidence of an underlying cause of seizure?

  • Are there any focal neurological signs? Like an aura preceding the seizure, these indicate a structural cause.
  • Are there features of meningitis (Chapter 68), encephalitis (Chapter 69) or subarachnoid haemorrhage (Chapter 67)?
  • Does the patient have a systemic disease requiring urgent treatment, for example acute liver failure, hyperosmolar hyperglycaemic state?

If the patient is well

  • Discharge if fully recovered and supervision by an adult for the next 24h can be arranged.
  • Advise the patient not to drive (in writing, as memory may be impaired after a seizure).
  • Give first aid advice for seizure recurrence, also bathing and kitchen safety advice (see ‘epilepsy app’ from Epilepsy Action or National Society for Epilepsy).
  • Outpatient investigation (CT if indicated) and follow-up by a neurologist should be arranged. EEG is not routine but is likely to be needed if seizure, not syncope, suspected in a person <23 years.
  • In general, anticonvulsant therapy should be started after a second seizure (not a first one) – local advice should be sought for choice of starting medication (which will be carbamazepine, lamotrigine or valproate).

After a Generalized Seizure in a Patient with Known Epilepsy!!navigator!!

  • Take blood for anticonvulsant levels.
  • If the current history deviates from the usual pattern of seizures, consider intercurrent infection, alcohol use or poor compliance with therapy (an ‘epilepsy app’ can help with compliance).
  • If the patient has had a typical seizure and is fully recovered, CT is not necessary.
  • Discharge (with outpatient follow-up arranged) if the patient is fully recovered and has no evidence of acute illness. Advise the patient not to drive.

Alcohol withdrawal seizures

  • Alcohol withdrawal seizures consist of 1–6 tonic-clonic seizures without focal features, which begin within 48h of stopping drinking (although may occur up to seven days after stopping drinking if the patient has been taking a benzodiazepine). They are usually brief and self-limiting.
  • Patients who have had withdrawal seizures once are highly likely to have a recurrence if they withdraw again.
  • Patients with alcoholic hepatitis or chronic liver disease may have coagulation abnormalities, and if so, subdural haematoma should be excluded by CT.
  • Cranial CT scan is not needed after suspected withdrawal seizures if:
    • A clear history of alcohol withdrawal is obtained
    • The seizures have no focal features
    • There is no evidence of head injury
    • There are no more than six seizures
    • The seizures do not occur over a period >6h
    • Post-ictal confusion is brief
  • Management of alcohol withdrawal is described in Chapter 106.

Further Reading ⬆

Betjemann JP, Lowenstein DH (2015) Status epilepticus in adults. Lancet Neurol 14, 615–624.

Glauser T, Shinnar S, Gloss D, et al. (2016) Evidence-Based Guideline: Treatment of convulsive status epilepticus in children and adults: Report of the Guideline Committee of the American Epilepsy Society. Epilepsy Currents 16, 48–61. http://dx.doi.org/10.5698/1535-7597-16.1.48.