Details

Autor(en) / Beteiligte

• McCormick, Cornelia
• Quraan, Maher
• Cohn, Melanie
• Valiante, Taufik A.
• McAndrews, Mary Pat

Titel

Default mode network connectivity indicates episodic memory capacity in mesial temporal lobe epilepsy

Ist Teil von

• Epilepsia (Copenhagen), 2013-05, Vol.54 (5), p.809-818

Ort / Verlag

United States: Wiley Subscription Services, Inc

Erscheinungsjahr

2013

Link zum Volltext

Quelle

Wiley

Beschreibungen/Notizen

• Summary Purpose The clinical relevance of resting state functional connectivity in neurologic disorders, including mesial temporal lobe epilepsy (mTLE), remains unclear. This study investigated how connectivity in the default mode network changes with unilateral damage to one of its nodes, the hippocampus (HC), and how such connectivity can be exploited clinically to characterize memory deficits and indicate postsurgical memory change. Methods Functional magnetic resonance imaging (fMRI) resting state scans and neuropsychological memory assessments (Warrington Recognition Tests for Words and Faces) were performed on 19 healthy controls, 20 patients with right mTLE, and 18 patients with left mTLE. In addition, postsurgical fMRI resting state and memory change (postsurgical memory performance–presurgical memory performance) data were available for half of these patients. Key Findings Patients with mTLE showed reduced connectivity from the posterior cingulate cortex (PCC) to the epileptogenic HC and increased PCC connectivity to the contralateral HC. Stronger PCC connectivity to the epileptogenic HC was associated with better presurgical memory and with greater postsurgical memory decline. Stronger PCC connectivity to the contralateral HC was associated with less postsurgical memory decline. Following surgery, PCC connectivity to the remaining HC increased from presurgical values and showed enhanced correlation with postsurgical memory function. It is notable that this index was superior to others (hippocampal volume, preoperative memory scores) in explaining variance in memory change following surgery. Significance Our results demonstrate the striking clinical significance of the brain's intrinsic connectivity in evaluating cognitive capacity and indicating the potential of postsurgical cognitive morbidity in patients with mTLE.