The initial use of arterial spin labeling perfusion and diffusion-weighted magnetic resonance images in the diagnosis of nonconvulsive partial status epileptics

Takafumi Shimogawa; Takato Morioka; Tetsuro Sayama; Sei Haga; Yuka Kanazawa; Kei Murao; Shuji Arakawa; Ayumi Sakata; Koji Iihara

doi:10.1016/j.eplepsyres.2016.12.008

The initial use of arterial spin labeling perfusion and diffusion-weighted magnetic resonance images in the diagnosis of nonconvulsive partial status epileptics

Epilepsy Res. 2017 Jan:129:162-173. doi: 10.1016/j.eplepsyres.2016.12.008. Epub 2016 Dec 21.

Authors

Takafumi Shimogawa¹, Takato Morioka², Tetsuro Sayama³, Sei Haga⁴, Yuka Kanazawa⁵, Kei Murao⁶, Shuji Arakawa⁷, Ayumi Sakata⁸, Koji Iihara⁹

Affiliations

¹ Department of Neurosurgery, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan; Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Department of Neurosurgery, Fukuoka Children's Hospital, 5-1-1 Kashiiteriha, Higashi-ku, Fukuoka 813-0017, Japan. Electronic address: shimogawa28@gmail.com.
² Department of Neurosurgery, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan; Department of Neurosurgery, Fukuoka Children's Hospital, 5-1-1 Kashiiteriha, Higashi-ku, Fukuoka 813-0017, Japan. Electronic address: takato@ns.med.kyushu-u.ac.jp.
³ Department of Neurosurgery, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan; Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: tsayama@ns.med.kyushu-u.ac.jp.
⁴ Department of Neurosurgery, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan. Electronic address: sei.haga@gmail.com.
⁵ Department of Cerebrovascular Disease, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan. Electronic address: yu8850@gmail.com.
⁶ Department of Cerebrovascular Disease, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan. Electronic address: mrok19840314@gmail.com.
⁷ Department of Cerebrovascular Disease, Kyushu Rosai Hospital, 1-1 Sonekitamachi, Kokura Minami-Ku, Kitakyushu 800-0296, Japan. Electronic address: shuji6031@gmail.com.
⁸ Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: asakata@med.kyushu-u.ac.jp.
⁹ Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: kiihara@ns.med.kyushu-u.ac.jp.

PMID: 28092848
DOI: 10.1016/j.eplepsyres.2016.12.008

Abstract

Background: In the diagnosis of nonconvulsive status epilepticus (NCSE), capture of ongoing ictal electroencephalographic (EEG) findings is the gold standard; however, this is practically difficult without continuous EEG monitoring facilities. Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) and perfusion MRI with arterial spin labeling (ASL), have been applied mainly in emergency situations. Recent reports have described that ictal MRI findings, including ictal hyperperfusion on ASL and cortical hyperintensity of cytotoxic edema on DWI, can be obtained from epileptically activated cortex. We demonstrate the characteristics and clinical value of ictal MRI findings.

Methods: Fifteen patients diagnosed as having NCSE (eight had complex partial status epilepticus (SE) and seven subtle SE) who underwent an initial MRI and subsequent EEG confrmation, participated in this study. Follow-up MRI and repeated routine EEG were performed.

Results: In 11 patients (73%), ictal MRI findings were obtained on both DWI and ASL, while in four (27%) patients, ictal hyperperfusion was found on ASL without any DWI findings being obtained. In all 10 patients with an epileptogenic lesion, there was a tight topographical relationship between the lesion and the localization of ictal MRI findings. In the other five patients, ictal MRI findings were useful to demonstrate the pathophysiological mechanism of NCSE of non-lesional elderly epilepsy, or 'de novo' NCSE of frontal origin as situation-related NCSE. Ictal MRI findings are generally transient; however, in three cases they still persisted, even though ictal EEG findings had completely improved.

Conclusion: The present study clearly demonstrates that the initial use of ASL and DWI could help to diagnose partial NCSE and also combined use of the MRI and EEG allows documentation of the pathophysiological mechanism in each patient.

Keywords: Arterial spin labeling; Cytotoxic edema; Diffusion-weighted image; Ictal hyperperfusion; Nonconvulsive status epilepticus.

MeSH terms

Adult
Aged
Aged, 80 and over
Brain / diagnostic imaging*
Brain / physiopathology*
Electroencephalography
Female
Follow-Up Studies
Humans
Magnetic Resonance Imaging* / methods
Male
Middle Aged
Retrospective Studies
Status Epilepticus / diagnostic imaging*
Status Epilepticus / physiopathology*
Status Epilepticus / therapy
Time Factors
Treatment Outcome