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obyn m. Busch, phd
memory decline following temporal lobe resection for
Intractable Epilepsy: the role of presurgical depression
By robyn m. Busch, phd
epilepsy
depressive disorders are the most frequently observed psychiatric disturbances in patients with epilepsy. rates
of depression among patients with intractable epilepsy range from 20 percent to 55 percent, approximately 5
to 10 times greater than rates in the general population. 1-3
There is also a high prevalence of cognitive problems
in individuals with epilepsy. Several studies have
found that patients with temporal lobe epilepsy (TLE)
who report greater depressive symptoms demonstrate
reduced memory scores as compared with
patients who have fewer depressive symptoms,
particularly if seizures arise from the left temporal
lobe. This relationship also appears to hold after
anterior temporal lobe resection such that patients
with left TLE and emotional disturbance following
surgery demonstrate lower memory scores than
nondepressed left TLE patients and right TLE
patients. 4 However, no study had examined presurgical
depressed mood state as a moderator of change in
memory functioning following surgical intervention
for the treatment of medically intractable epilepsy.
This is an important issue given that presurgical
indicators can help to identify patients who are at risk
for memory decline following epilepsy surgery.
We recently completed a retrospective study to
evaluate mood state as a moderator of change in
memory abilities following temporal lobe resection
for the treatment of intractable epilepsy.* We found
that patients who underwent left temporal lobe
resections and who had depressed mood prior to
surgery demonstrated the largest declines on
measures of general and verbal memory after surgery
compared with left or right temporal lobectomy
patients without depression and right temporal lobectomy
patients with depression. The change in general
memory is depicted in the chart. These differences
could not be attributed to an increase in depressive
symptoms or to poorer seizure outcome after surgery.
These results suggest that depressed mood should be
taken into account when evaluating and providing
feedback to patients about the cognitive risks
associated with temporal lobectomy.
*This research was conducted in collaboration with Mario F. Dulay,
PhD, Kevin H. Kim, PhD, Jessica S. Chapin, PhD, Colleen Kalman,
BA, Richard I. Naugle, PhD, and Imad M. Najm, MD.
Robyn M. Busch, PhD, is a neuropsychologist with joint
appointments in Cleveland Clinic’s Epilepsy Center and
the Department of Psychiatry and Psychology. Fifty
percent of her time is devoted to research regarding
cognition and behavior in surgical epilepsy patients. The
remainder of Dr. Busch’s time is spent providing clinical
services to adults, primarily patients with epilepsy. She
can be contacted at 216.444.9042 or buschr@ccf.org.
REFERENCES
1. Hermann B, Seidenberg M, Bell B. Psychiatric
comorbidity in chronic epilepsy: identification,
consequences, and treatment of major depression.
Epilepsia. 2000;41:S31-S41.
2. Jacoby A, Baker GA, Steen N, et al. The clinical
course of epilepsy and its psychosocial correlates:
findings from a U.K. community study. Epilepsia.
1996;37:148-161.
3. Gilliam F, Kanner AM. Treatment of depressive
disorders in epilepsy patients. Epilepsy Behav.
2002;3:S2-S9.
4. Dulay MF, York MK, Soety EM et al. Memory,
emotional and vocational impairments before and
after anterior temporal lobectomy for complex
partial seizures. Epilepsia. 2006;47:1922-1930.
6 INsIghts | ClEvElaNd ClINIC dEpartmENt of psyChIatry aNd psyChology