Limitaciones:

One definition of ‘seizure’ is the ‘uncontrolled electri- cal activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances or a combination of symptoms’. ‘Epilepsy’ is a pattern of repeated seizures. The occurrence of a seizure or ‘fit’ is a common mode of presentation to the emer- gency department. In most cases, the final diagnosis will not be epilepsy.

If the patient is actively having a seizure, the ‘ABC’ of resuscitation should be meticulously followed. Intravenous anticonvulsant agents should be admin- istered promptly, within the constraints of formulary guidelines. The aim should be to suppress the seizure as quickly as possible. If there is no success with standard anticonvulsants, the administration of a general anaesthetic (together with intubation, ventila- tion and admission to intensive care) should be considered. The definition of ‘status epilepticus’ is under continuous scrutiny (Table 9.14).

If the patient is not actively having a seizure at the time of clinical assessment, the task is to identify whether the episode preceding admission was a seizure

Table 9.14 Simple terminology for seizures

Term Description

Generalized seizure

Involvement of the whole cerebral cortex and therefore abnormalities (e.g. convulsions) may be seen in the whole of the body

Consciousness is always impaired Focal

(partial) seizure

Involvement of a focus in the cerebral cortex and therefore abnormalities (e.g. convulsions) may be seen in one part of the body

Consciousness may be retained (simple partial seizure) or impaired (complex partial seizure)

There may be secondary generalization (i.e. a focal seizure leading on to a generalized seizure) Convulsive

seizure For example tonic-clonic, tonic and clonic Non-

convulsive seizure

The term ‘absence seizure’ should generally be avoided unless a specific syndromic diagnosis is being made by a clinician experienced in epilepsy Status

epilepticus Historically, one definition has been ‘prolonged seizures for more than 30 minutes’, although in modern times it is more sensible to accept that ‘any prolonged seizure’ may be classified as status epilepticus

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contractions. Persistent fever together with other abnormal observation such as tachycardia and raised respiratory rate may suggest the presence of an infection. If there is genuine doubt as to whether the fever is related to the seizure or an infection, one should look vigorously for a source of infection (including performing a lumbar puncture) and consider administering empirical intravenous antibiot- ics while awaiting investigations. One should examine for evidence of cranial trauma, alcoholic foetor and severe hypertension.

In the drowsy postictal patient, some aspects of neurological examination such as visual fields, vol- untary eye movements, cerebellar function, power and sensory deficits will be difficult or impossible to ascertain. However, the following should be performed to a high standard: fundoscopy; pupillary, corneal and gag reflexes; limb tone; limb reflexes; and spontaneous limb movement. Any asymmetry should be noted and it may prompt urgent investigations.

Blood sugar should be performed urgently, as hypoglycaemia may be quickly reversed and brain injury prevented. Plasma biochemistry and liver function tests will identify reversible electrolyte deficiencies and features of liver disease. Possible infections should be identified with the help of white cell count, blood culture and urinalysis. Toxicology tests may include blood alcohol and urine drug analysis. Women of childbearing age should have a pregnancy test. Patients with unexplained seizures and a history of travel abroad should have parasite analysis. If the patient has no known identity and therefore no known past history, plasma anticonvulsant analysis may lend support to recent ingestion and therefore the possibility of previously diagnosed epilepsy.

A cranial CT scan will be required if one or more of the following are present: the seizure is unexplained, there are features of cranial trauma, there are focal or lateralizing features, there are fundoscopic features of raised intracranial pressure and there are features of infection. The gross features uncovered by a cranial CT may include intracranial haemorrhage or space- occupying lesions. Although it is a misconception that a CT scan is always required prior to lumbar puncture, it is overwhelmingly recognized that lumbar puncture for the investigation of meningitis in the patient with seizures should always be preceded by a cranial CT. The cerebrospinal fluid from the lumbar puncture should be analysed for meningitis and for subarachnoid haemorrhage. An EEG may be per- formed acutely to lend support to the diagnosis of a postictal state and occasionally to identify features of herpes encephalitis.

Once a seizure is diagnosed, the clinician should advise the patient of his duty to contact the driving licensing authority, who in turn will issue guidelines for cessation of driving for a defined period. The diagnosis of epilepsy should be made by an expert in epilepsy, as this diagnosis will have social and In history taking, there is considerable overlap with

the principles described for the patient with syncope. It is essential that witnesses are available to give a collateral history, as the seizure itself will not be recalled by the patient. However, on recovery, the events preceding and following the seizure may be recounted by the patient. As with syncope, dramatic sequelae such as motor vehicle accidents or personal injury should be taken seriously. It should be estab- lished whether there is a known history of epilepsy. In patients with known epilepsy, a history should be taken for compliance, anticonvulsant changes, concur- rent illnesses, alcohol intake and lifestyle issues. In other cases, specifically ask about alcohol intake, recreational drug usage, diabetes, head injury, foreign travel and pregnancy.

General examination will include the assessment of features of infection. Mild, transient, fever is a common phenomenon after seizures from muscle

Table 9.15 Awareness of conditions commonly

misdiagnosed as seizures

Condition Awareness

Pseudoseizure The reasons for patients presenting with contrived movements mimicking seizures are complex. They often occur in known epileptics. The risk of death is significantly higher in epileptic patients with pseudoseizures, and so the latter needs to be taken seriously and not merely dismissed as a non-organic event. Many epilepsy experts maintain that with increasing clinical experience, there is increased awareness of the difficulty in the differentiation of seizures from pseudoseizures. There are, however, some features which may lend support to the diagnosis of pseudoseizures: resistance to attempted eye opening by the clinician, limb thrashing and pelvic thrusting, full alertness immediately after the event (i.e. lack of postictal drowsiness) and down-going plantar responses during attack

Vasovagal

episode Prolonged vasovagal episodes may lead to cerebral hypoperfusion and brief, self-limiting convulsive-type movements Cranial

trauma This is particularly seen in sports events, where cranial trauma may lead to brief, self-limiting convulsive-type movements, similar to those seen in vasovagal episodes

Extrapyramidal

disease Patients may present with worsening or poorly controlled Parkinson’s disease, manifested as severe coarse tremor which, to the untrained eye, may resemble myoclonus

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drug-therapy implications. The epilepsy expert will also decide, together with the patient, on the clinical value of prescription of anticonvulsants after a first seizure.