Page 276 - ILAE_Lectures_2015

underlying cause of the epilepsy itself, and therefore should be regarded as another symptom
of the underlying brain disorder. Cognitive problems can be very obvious, as in patients with
learning disability, but in many cases can be subtle. There is mounting evidence that cognitive
problems occur even in the so-called idiopathic epilepsies, where brain structure and function
has traditionally been thought to be normal18. Advanced neuroimaging has identified
structural correlates of cognitive deficits in patients with IGE syndromes. Similarly, patients
with temporal lobe epilepsy (TLE) often describe memory problems, which can take the form
of accelerated long-term forgetting (ALF), transient epileptic amnesia (TEA) and remote
memory impairment19.

In addition to fixed deficits related to the underlying brain disorder, patients with epilepsy
also experience dynamic changes, associated with seizures and inter-ictal epileptiform
activity, as well as adverse effects of AED. Many patients with apparently well controlled
seizures and cognitive impairment show ongoing inter-ictal discharges, abolition of which
may improve cognitive profile20. Older AEDs, especially barbiturates, and topiramate among
newer AEDs, are most likely to cause cognitive adverse effects21. Services of a
neuropsychologist, ideally with expertise in epilepsy, can be extremely helpful in
characterising cognitive difficulties and suggesting compensatory strategies for patients.

Metabolic disorders
AEDs can have a variety of metabolic effects which need to be monitored in patients on long-
term AED therapy. These include effects on bone metabolism, reproductive function
(including sexual dysfunction, contraceptive and pregnancy issues) and cardiovascular risk.
Many of these effects are mediated through the induction of hepatic microsomal enzymes,
and can be minimised by avoiding the use of such AEDs22. Valproate, which is a hepatic
enzyme inhibitor, constitutes a special case when it comes to metabolic effects23. Impairment
of glucose metabolism, weight gain, tremor (including Parkinsonism) and high teratogenicity
are particular features of this drug.

Lifestyle issues
The impact of refractory epilepsy on the individual’s life can be highly variable. Depending
on their individual circumstances, the majority of patients will benefit from support with
education, employment, leisure etc. The services of an epilepsy specialist nurse, ideally
community based, with links to neurology services, would be invaluable in this regard.

Optimise quality of life

The overall objective of the various management strategies outlined above is to optimise
patients’ quality of life. Seizure freedom correlates most strongly with improvement in
quality of life for people with epilepsy, but in the population of patients under discussion this
is sadly unlikely to be achieved. The physician has to identify the specific areas where help
can be provided, being aware that this involves much more than prescribing drugs. Providing
a sympathetic ear, practical advice and directing to external agencies such as voluntary
organisations can be equally if not more appreciated by the patients.

References

1. KWAN P, ARZIMANOGLOU A, BERG AT et al. Definition of drug resistant epilepsy: consensus proposal by
the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia 2010; 51: 1069-1077.

2. MOHANRAJ R, BRODIE MJ. Early predictors of outcome in newly diagnosed epilepsy. Seizure 2013; 22: 333-
344.

3. DE BOER HM, MULA M, SANDER JW. The global burden and stigma of epilepsy. Epilepsy Behav 2008; 12:
540-546.

4. MCCAGH J, FISK JE, BAKER GA. Epilepsy, psychosocial and cognitive functioning. Epilepsy Res 2009; 86:
1-14.