Korean Journal of Radiology

The Korean Society of Radiology (대한영상의학회)
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Hippocampal Sclerosis: Correlation of MR Imaging Findings with Surgical Outcome

  • Yoon Hee Kim (Department of Radiology, Seoul National University College of Medicine) ;
  • Kee-Hyun Chang (Department of Radiology, Seoul National University College of Medicine) ;
  • Sun-Won Park (Department of Radiology, Seoul National University College of Medicine) ;
  • Young Whan Koh (Department of Radiology, Seoul National University College of Medicine) ;
  • Sang Hyun Lee (Department of Radiology, Seoul National University College of Medicine) ;
  • In Kyu Yu (Department of Radiology, Seoul National University College of Medicine) ;
  • Moon Hee Han (Department of Radiology, Seoul National University College of Medicine) ;
  • Sang Kun Lee (Department of Neurology, Seoul National University College of Medicine) ;
  • Chun-Kee Chung (Department of Neurosurgery, Seoul National University College of Medicine)
  • Received : 2000.11.29
  • Accepted : 2001.02.22
  • Published : 2001.06.30
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Abstract

Objective: Atrophy and a high T2 signal of the hippocampus are known to be the principal MR imaging findings of hippocampal sclerosis. The purpose of this study was to determine whether or not individual MRI findings correlate with surgical outcome in patients with this condition. Materials and Methods: Preoperative MR imaging findings in 57 consecutive patients with pathologically-proven hippocampal sclerosis who underwent anterior temporal lobectomy and were followed-up for 24 months or more were retrospectively reviewed, and the results were compared with the postsurgical outcome (Engel classification). The MR images included routine sagittal T1-weighted and axial T2-weighted spin-echo images, and oblique coronal T1-weighted 3D gradient-echo and T2-weighted 2D fast spin-echo images obtained on either a 1.5 T or 1.0 T unit. The images were visually evaluated by two neuroradiologists blinded to the outcome; their focus was the presence or absence of atrophy and a high T2 hippocampal signal. Results: Hippocampal atrophy was seen in 96% of cases (55/57) [100% (53/53) of the good outcome group (Engel class I and II), and 50% (2/4) of the poor outcome group (class III and IV)]. A high T2 hippocampal signal was seen in 61% of cases (35/57) [62% (33/53) of the good outcome group and 50% (2/4) of the poor outcome group]. All 35 patients with a high T2 signal had hippocampal atrophy. 'Normal' hippocampus, as revealed by MR imaging, occurred in 4% of patients (2/57), both of whom showed a poor outcome (Engel class III). The presence or absence of hippocampal atrophy correlated well with surgical outcome (p<0.01). High T2 signal intensity did not, however, significantly correlate with surgical outcome (p>0.05). Conclusion: Compared with a high T2 hippocampal signal, hippocampal atrophy is more common and correlates better with surgical outcome. For the prediction of this, it thus appears to be the more useful indicator.

Keywords

Acknowledgement

This work was supported by grant number HMP-99-N-02-0003 from the Ministry of Health and Welfare, Korea.

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