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Figure 1. Factors influencing performance on neuropsychological tests in epilepsy. (From
Baxendale and Thompson 2010, see Further reading)

The overall value of a neuropsychological assessment very much depends on the validity of
the questions being asked, the cooperation of the patient on the day and the availability of
other relevant data to aid in the accurate interpretation of the test data once it has been
collected.

In patients with epilepsy, neuropsychological assessments are most frequently used to aid
diagnosis, evaluate the cognitive side effects of antiepileptic medications and monitor the
cognitive decline associated with some epileptic disorders. In conjunction with MRI and
other presurgical investigations, neuropsychological scores are also used to assess the
suitability of patients for epilepsy surgery and can be used to predict post-operative outcome,
both in terms of cognitive change and seizure control. In 2015, the ILAE Diagnostic
Commission Neuropsychology Task Force published guidelines for the minimum standards
in neuropsychological assessment for people with epilepsy.1

In an ideal world, all newly diagnosed patients with epilepsy would undergo a brief
neuropsychological screen prior to the onset of treatment to create a valuable baseline against
which future assessments can be measured. While local resources do not allow such a
specialist assessment for most patients, it is possible to have some record of memory function
at diagnosis if a self-report questionnaire is administered. Serial neuropsychological
assessments can be used to evaluate the cognitive side effects of new or existing antiepileptic
drug (AED) regimens and to monitor the cognitive deterioration that may be associated with
long-term poorly controlled epilepsy and episodes of status. They can also contribute to the
diagnostic process. However, repeated assessments over a short period of time can lead to the
development of practice effects which can mask a deterioration in function. In most cases it
is therefore recommended that there is at least a nine-month interval between assessments to
maximise the validity and utility of the results. Single assessments can be useful in the
localisation of cognitive dysfunction associated with focal pathologies and also enable the
setting of realistic education and employment goals. Single assessments may also reveal
deficits that are amenable to rehabilitation.