Neuropsychiatric Symptoms of Epilepsy

17 The Role of Epilepsy Surgery
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The concept of forced normalization, however, remains controversial due to a
paucity of both systemic research and direct empirical evidence for any of its putative
mechanisms.
Summary: Psychosis
• ~6 % of surgical candidates have a lifetime history of psychotic disorder.
• Epilepsy patients with comorbid psychosis commonly experience meaningful
seizure improvement after surgery, and no worsening of their psychotic
symptoms.
• De novo psychosis emerges in ~3–5 % patients after anterior temporal
lobectomy.
• Putative neurobiological mechanisms for psychosis after surgery include
so-called “forced normalization,” preoperative bilateral functional, and
structural brain abnormalities.
• Other Risk factors for postsurgery psychosis include a family history of
psychosis, undergoing surgery after the age of 30, and preexisting schizoid
or schizotypal personality traits.
• De novo psychosis after epilepsy surgery is linked to seizure freedom.
Somatic Symptom and Related Disorders
Presurgery Prevalence
A psychogenic nonepileptic seizure (PNES) is typically defined as a paroxysmal
event that resembles an epileptogenic seizure to the observer, but is not accompanied
by changes in EEG activity. Instead, psychological and emotional factors are
strongly suspected to have caused the event [ 97 ]. Of the 41 studies reviewed here,
three examined the occurrence of PNES before or after surgery (Table S17.4). In
one study of 58 surgical candidates, PNES was evident in 3 % of TLE patients and
19 % of extratemporal patients before surgery. These patients were predominantly
female (~75 %) and had risk factors typical of PNES, including a history of sexual
and physical abuse, family and relationship problems, aggression, low IQ, as well
as poor visual memory [ 98 ].
Postsurgery Course
Initial evidence suggests that preexisting PNES should not be considered a contraindication
to epilepsy surgery in patients who also experience epileptogenic seizures.
Reuber et al. [ 99 ] followed up 13 adult epilepsy patients with comorbid PNES and
found that epilepsy surgery led to meaningful improvements in 11 patients. Seven