Neuropsychiatric Symptoms of Epilepsy

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M. Yogarajah and M. Mula
HRSA
LAC
LEV
LTG
OXC
PGB
PHT
RTG
RUF
STP
TGB
TPM
VGB
VPA
ZNS
Hamilton Rating Scale for Anxiety
Lacosamide
Levetiracetam
Lamotrigine
Oxcarbazepine
Pregabalin
Phenytoin
Retigabine
Rufinamide
Stiripentol
Tiagabine
Topiramate
Vigabatrin
Valproate
Zonisamide
Introduction
The introduction of nearly 15 new antiepileptic drugs (AEDs) in the past 20 years
has significantly expanded the pharmacological armamentarium for epilepsy [ 1 ].
Although some of these agents offer appreciable advantages in terms of pharmacokinetics,
tolerability, and lower drug interaction potential, improvements in
clinical outcome have fallen short of expectations, with no more than 15–20 % of
patients refractory to older AEDs attaining seizure freedom without unacceptable
toxicity [ 2 ]. In addition, AEDs are still characterized by treatment-emergent psychiatric
adverse effects that have a considerable impact on quality of life and
compliance to treatment [ 3 ]. However, AEDs have also potential positive effects
as demonstrated by the wide use in psychiatric practice for a broad spectrum of
psychiatric disorders. The primary application is in mood stabilization [ 4 ] but
interesting data are also emerging for anxiety disorders [ 5 ] and withdrawal syndromes
[ 6 ].
Any discussion of the psychotropic effect of AEDs must acknowledge that psychopathology
in epilepsy has a multifactorial, biopsychosocial etiology, and AEDs
constitute only one of several factors. In fact, it is often difficult to determine which
psychopathological manifestations are due specifically to the drug therapy, and which
may be due to other factors that can affect the patient. In addition, the mechanisms of
action of several AEDs are not fully understood, and several AEDs have a diverse
array of actions on biological systems, only some of which may be related to the
desired antiseizure effect. In summary, therefore, the psychotropic effects of AEDs in
epilepsy derive from a number of variables related to the single compound (i.e.,
mechanism of action), to the underling neurological condition (i.e., neurobiology of