When evaluating patients with convulsions, it is also important to exclude the causes of syncope (p. 443). An accurate description from an observer is invaluable for documentation and may help in differentiating the forms of epileptic seizures. A prodrome or aura may be associated with the onset of a seizure.

Precipitating factors

The history should start with precipitating factors, e.g. causes such as trauma, surgery, or drug overdose. Flashing lights may precipitate a seizure in patients with a past history of epilepsy.

Headache

Convulsions associated with headaches may be due to trauma, subarachnoid haemorrhage, meningitis or raised intracranial pressure from a tumour. Patients with subarachnoid haemorrhage may also complain of sudden onset of blinding headache. The headache associated with meningitis is often accompanied with neck stiffness and photophobia. In the presence of raised intracranial pressure, the headache tends to be worse in the mornings and on coughing or sneezing. It may be associated with nausea or vomiting. For a fuller description, see p. 221.

Associated neurology

Pre-existing neurological impairment before the onset of convulsions has important implications. A stroke, subarachnoid haemorrhage or intracranial bleed may precipitate neurological impairment preceding a convulsion. Chronic progressive impairment preceding a seizure may be a result of tumour growth. In the post-ictal period, transient motor weakness may accompany epilepsy (Todd’s palsy). Permanent neurological deficit can be induced by cerebral anoxia from prolonged seizures.

Past medical and drug history

Co-existing disease such as diabetes will predispose to abnormalities of serum glucose concentrations. A drug history should be obtained and specific enquiries undertaken regarding illicit drug use. Alcohol consumption should be documented. In epileptics, poor drug compliance may lead to seizure control failure.

Examination

Temperature

The presence of pyrexia usually suggests an infective aetiology, such as meningitis or cerebral abscess. Examination should also be undertaken to look for the primary focus, such as otitis media or mastoiditis. Convulsions may result as a complication of a pyrexia alone, especially in children.

General examination

A general examination is performed to look for the presence of head injury and also any damage resulting as a consequence of the convulsion.

Neurological examination

The primary aim of a neurological examination following a convulsion is to determine the presence of residual neurological deficit. The neurological assessment should include mental state and higher cortical function. If an abnormality is detected, the location may be determined by clinical examination to allow focussed investigation. However, neurological abnormalities present immediately after a seizure, may resolve completely. Todd’s palsy may occur post-ictally.