CC BY-NC-ND 4.0 · Indian J Radiol Imaging 2021; 31(01): 109-115
DOI: 10.1055/s-0041-1729672
Original Article

Magnetic Resonance Imaging Characterization of the Hippocampi in Temporal Lobe Epilepsy: Correlation of Volumetry and Apparent Diffusion Coefficient with Laterality and Duration of Seizures

Apoorva Muralidhar
1   Department of Radio-diagnosis, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
,
Ashok Kumar
1   Department of Radio-diagnosis, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
,
Arjun Prakash
2   Department of Radio-diagnosis, Bangalore Medical College & Research Institute, Bengaluru, Karnataka, India
,
Umesh Krishnamurthy
1   Department of Radio-diagnosis, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
,
Manjunath S.
1   Department of Radio-diagnosis, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
,
Roshni Majeed
1   Department of Radio-diagnosis, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
› Author Affiliations

Abstract

Background and Purpose It is estimated that hippocampal damage is seen in 50 to 70% of patients with temporal lobe epilepsy (TLE). Although most magnetic resonance imaging (MRI) studies are adequate to detect gross hippocampal atrophy, subtle changes that may characterize early disease in TLE, such as visually nonappreciable volume loss, may often be missed if objective volumetric analysis is not undertaken.

Materials and Methods We conducted a hospital-based prospective analytical study in which 40 patients with partial seizures of temporal lobe origin were included and their hippocampal volumes (HVs) were determined by manual volumetric analysis. The findings were recorded and correlated with the side of seizure and its duration. The quantitative assessment was allotted different grades accordingly. Also, the apparent diffusion coefficient (ADC) values of bilateral hippocampi were estimated and their correlation with the side of seizure was determined.

Results Most patients in the study were in the age group of 11 to 20 years (37.5%). In total, 57.5% had seizures for a period of 1 to 5 years. While 67.5% (n = 27) had seizure on the right, 32.5% (n = 13) had on the left. The mean HV estimated on the right and left were correlated with the side of seizure and found to be statistically significant (p < 0.001 in those with right-sided seizures and p = 0.02 in those with left-sided seizures). Simultaneously the ADC values estimated were found to correlate with the laterality of seizures with a statistical difference (p < 0.01). Duration of seizures however did not show a positive correlation with the HV.

Conclusion MRI with quantitative estimation of HV and ADC values can depict the presence and laterality in TLE with accuracy rates that exceed those achieved by visual inspection alone. Thus, quantitative MRI provides a useful means for translating volumetric analysis into clinical practice.



Publication History

Article published online:
31 May 2021

© 2021. Indian Radiological Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Thieme Medical and Scientific Publishers Private Ltd.
A-12, Second Floor, Sector -2, NOIDA -201301, India

 
  • References

  • 1 Engel Jr J. Report of the ILAE classification core group. Epilepsia 2006; 47 (09) 1558-1568
  • 2 French JA, Williamson PD, Thadani VM. et al. Characteristics of medial temporal lobe epilepsy: I. Results of history and physical examination. Ann Neurol 1993; 34 (06) 774-780
  • 3 Kobayashi E, D’Agostino MD, Lopes-Cendes I. et al. Hippocampal atrophy and T2-weighted signal changes in familial mesial temporal lobe epilepsy. Neurology 2003; 60 (03) 405-409
  • 4 Zarow C, Wang L, Chui HC, Weiner MW, Csernansky JG. MRI shows more severe hippocampal atrophy and shape deformation in hippocampal sclerosis than in Alzheimer’s disease. Int J Alzheimers Dis 2011; 2011: 483972
  • 5 Lüders H, Acharya J, Baumgartner C. et al. Semiological seizure classification. Epilepsia 1998; 39 (09) 1006-1013
  • 6 Quigg M, Bertram EH, Jackson T, Laws E. Volumetric magnetic resonance imaging evidence of bilateral hippocampal atrophy in mesial temporal lobe epilepsy. Epilepsia 1997; 38 (05) 588-594
  • 7 Jackson GD, Kuzniecky RI, Cascino GD. Hippocampal sclerosis without detectable hippocampal atrophy. Neurology 1994; 44 (01) 42-46
  • 8 Kim JA, Chung JI, Yoon PH. et al. Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging. AJNR Am J Neuroradiol 2001; 22 (06) 1149-1160
  • 9 Honeycutt NA, Smith CD. Hippocampal volume measurements using magnetic resonance imaging in normal young adults. J Neuroimaging 1995; 5 (02) 95-100
  • 10 Bhatia S, Bookheimer SY, Gaillard WD, Theodore WH. Measurement of whole temporal lobe and hippocampus for MR volumetry: normative data. Neurology 1993; 43 (10) 2006-2010
  • 11 Dhikav V, Duraisamy S, Anand KS, Garga UC. Hippocampal volumes among older Indian adults: comparison with Alzheimer’s disease and mild cognitive impairment. Ann Indian Acad Neurol 2016; 19 (02) 195-200
  • 12 Jack Jr CR, Theodore WH, Cook M, McCarthy G. MRI-based hippocampal volumetrics: data acquisition, normal ranges, and optimal protocol. Magn Reson Imaging 1995; 13 (08) 1057-1064
  • 13 Jack Jr CR, Twomey CK, Zinsmeister AR, Sharbrough FW, Petersen RC, Cascino GD. Anterior temporal lobes and hippocampal formations: normative volumetric measurements from MR images in young adults. Radiology 1989; 172 (02) 549-554
  • 14 Wahlund LO, Julin P, Johansson SE, Scheltens P. Visual rating and volumetry of the medial temporal lobe on magnetic resonance imaging in dementia: a comparative study. J Neurol Neurosurg Psychiatry 2000; 69 (05) 630-635
  • 15 Mohandas AN, Bharath RD, Prathyusha PV, Gupta AK. Hippocampal volumetry: normative data in the Indian population. Ann Indian Acad Neurol 2014; 17 (03) 267-271
  • 16 Hakyemez B, Yucel K, Yildirim N, Erdogan C, Bora I, Parlak M. Morphologic and volumetric analysis of amygdala, hippocampus, fornix and mamillary body with MRI in patients with temporal lobe epilepsy. Neuroradiol J 2006; 19 (03) 289-296
  • 17 García-Fiñana M, Denby CE, Keller SS, Wieshmann UC, Roberts N. Degree of hippocampal atrophy is related to side of seizure onset in temporal lobe epilepsy. AJNR Am J Neuroradiol 2006; 27 (05) 1046-1052
  • 18 Londoño A, Castillo M, Lee YZ, Smith JK. Apparent diffusion coefficient measurements in the hippocampi in patients with temporal lobe seizures. AJNR Am J Neuroradiol 2003; 24 (08) 1582-1586
  • 19 Yoo SY, Chang KH, Song IC. et al. Apparent diffusion coefficient value of the hippocampus in patients with hippocampal sclerosis and in healthy volunteers. AJNR Am J Neuroradiol 2002; 23 (05) 809-812
  • 20 Diehl B, Najm I, Ruggieri P. et al. Postictal diffusion-weighted imaging for the localization of focal epileptic areas in temporal lobe epilepsy. Epilepsia 2001; 42 (01) 21-28
  • 21 Ramey WL, Martirosyan NL, Lieu CM. Hasham HA, Lemole GM Jr, Weinand ME. Current management and surgical outcomes of medically intractable epilepsy. Clin Neurol Neurosurg 2013; 115 (12) 2411-2418