New research confirms that childhood onset temporal lobe epilepsy has a
significant impact on brain aging. Study findings published in Epilepsia,
a peer-reviewed journal of the International League Against Epilepsy (ILAE),
show age-accelerated ventricular expansion outside the normal range in
this patient population.
According to the Centers for Disease Control and Prevention (CDC),
epilepsy affects nearly 2 million Americans. Temporal lobe epilepsy is
the most common form of partial epilepsy, with 60% of all patients
having this form of the disease. Previous evidence suggests that
patients with childhood onset epilepsy have significant cognitive and
developmental deficiencies, which continue into adulthood, particularly
in those resistant to antiepileptic drugs.
Prior imaging studies of patients with temporal lobe epilepsy have shown
abnormalities in brain structure in hippocampus, in thalamus and other
subcortical structures, and also in cortical and white matter volume.
However, there is limited knowledge of the effects of aging on these
structural changes.
To characterize differences in brain structure and patterns of
age-related change, Dr. Bruce Hermann and colleagues from the University
of Wisconsin-Madison recruited 55 patients with chronic temporal lobe
epilepsy and 53 healthy controls for their study. Participants were
between the ages of 14 and 60, with patients having mean age of onset of
epilepsy in childhood/adolescence. Magnetic resonance imaging (MRI) was
used to measure cortical thickness, area and volume in the brains of all
subjects.
In participants with epilepsy, there were extensive abnormalities in
brain structure, involving subcortical regions, cerebellum and cortical
gray matter thickness and volume in the temporal and extratemporal
lobes. Furthermore, researchers found that increasing chronological age
was associated with progressive changes in cortical, subcortical and
cerebellar regions for both epilepsy subjects and healthy controls. The
pattern of change was similar for both groups, but epilepsy patients
always showed more extensive abnormalities. In particular, epilepsy
patients displayed age-accelerated expansion of the lateral and third
ventricles. “The anatomic abnormalities in patients with epilepsy
indicate a significant neurodevelopmental impact,” said Dr. Hermann.
“Patients with epilepsy are burdened with significant neurodevelopmental
challenges due to these cumulative brain abnormalities,” concludes Dr.
Hermann. “The consequences of these anatomical changes for epilepsy
patients as they progress into elder years remain unknown and further
study of the adverse effects in those of older chronological age is
needed.”
