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Chapter 10

The significance of the syndromic diagnosis of the epilepsies

CHRYSOTOMOS P. PANAYIOTOPOULOS and MICHALIS KOUTROUMANIDIS

Department of Clinical Neurophysiology and Epilepsies, St Thomas’ Hospital, Guy’s and St
Thomas’ NHS Foundation Trust, London

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Classification of epileptic syndromes and diseases

Medical diagnosis is defined as:1
‘The identification of a disease by investigation of its symptoms and history,
which provides a solid basis for the treatment and prognosis of the individual
patient’.

The most significant advance in modern epileptology has been the recognition of epileptic
syndromes and diseases, which provides a proper medical diagnosis for patients with
epileptic disorders26. The inclusive term ‘epilepsy’ is unacceptable because such
generalisation defies diagnostic precision, which is the golden rule in medicine5.

‘Epilepsy’ is not a single disease entity. Epilepsies are hundreds of diseases with different
causes, natural histories and prognoses, requiring different short-term and long-term
management. Using the inclusive diagnostic label of ‘epilepsy’ instead of a precise seizure
and syndrome categorisation endangers patients with epileptic seizures both medically and
socially5. It is medically incorrect to label a child with temporal lobe epilepsy and a child
with childhood absence epilepsy as simply having ‘epilepsy’ just because they both have
seizures. This is as unsatisfactory as giving a diagnosis of ‘febrile illness’, irrespective of
whether this is due to influenza, tuberculosis, bacterial meningitis, collagen disease, or
malignancy.

Despite significant progress in the diagnosis and management of epilepsies, there are many
reports in which patients with epileptic seizures are erroneously categorised as having
‘epilepsy’. This situation has to change. Patients with epileptic seizures and their families are
entitled to a diagnosis, prognosis, and management that is specific and precise.

In addition, new antiepileptic drugs (AEDs) are predominantly tested in partial epilepsies and
inappropriate generalisations may be made about their use in other epilepsies such as
idiopathic generalised epilepsies (IGE). The clinical significance of this is clearly
demonstrated by vigabatrin and tiagabine, two of the new generation drugs for partial
epilepsies. Both are potent drugs that induce absence seizures and absence status7. As such,
they are contraindicated in IGE which make up one-third of ‘epilepsy’ cases5 yet this fact is
not even mentioned in the British National Formulary on ‘The control of epilepsy’. Many
patients with IGE are treated incorrectly with these drugs as a result of such generalisations.
Identification of the type of epilepsy is of utmost clinical importance, especially as
satisfactory diagnostic precision is possible even after the first recognisable seizure8.