Journal List > Dement Neurocogn Disord > v.13(4) > 1120741

Dement Neurocogn Disord. 2014 Dec;13(4):146-149. Korean.
Published online Dec 31, 2014.
© 2014 Korean Dementia Association
A Case of Insulinoma Presenting as Repetitive Abnormal Behavior with Amnesia
Sang Wuk Sohn, M.D.,* Byeol A Yoon, M.D.,* Hyung Jin Lee, M.D.,* Dong-Hyun Shim, M.D.,* and Kyung Won Park, M.D.*,
*Department of Neurology, Dong-A University College of Medicine, Busan, Korea.
Cognitive Disorders and Dementia Center, Dong-A University Hospital, Busan, Korea.

Address for correspondence: Kyung Won Park, M.D. Department of Neurology, Dong-A University College of Medicine, 32 Daesingongwon-ro, Seo-gu, Busan 602-715, Korea. Tel: +82-51-240-2966, Fax: +82-51-245-2966, Email:
Received Dec 01, 2014; Revised Dec 24, 2014; Accepted Dec 24, 2014.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Insulinomas are very rare tumors. Diagnosis of insulinoma is often delayed or misdiagnosed because of its various symptoms. We report a patient with hypoglycemic encephalopathy who had repetitive behavior changes, diagnosed as a pancreatic insulinoma. A 52 years old man was referred to a memory and dementia clinic for evaluation of his repetitive abnormal behavior changes. He has threatened his wife with violent acts and showed aggressive behaviors, but he couldn't remember when he was recovered to normal state. During the hospitalization, we noticed that his repetitive abnormal behaviors were correlated to severe hypoglycemia. After we corrected glucose level, his symptoms were disappeared. We performed an abdomen-pelvis CT scan, revealing pancreatic head tumor. After he took surgical treatment, His symptoms were fully recovered. Our case demonstrates that various neurological symptoms, such as abnormal behavior, rarely occur due to recurrent hypoglycemia in patient with insulinoma.

Keywords: Insulinoma; Hypoglycemic encephalopathy; Neuropsychiatric symptoms


Fig. 1
Patient's Seoul neuropsychological screening battery (SNSB) revealed multiple cognitive impairments in naming, verbal memory and inhibitory control.
Click for larger image

Fig. 2
Electroencephalogram (EEG). (A) Patient's EEG before BST control, revealed theta to delta slowing predominantly in the most of leads. (B) Theta to delta slow waves totally disappeared by intravenous glucose infusion.
Click for larger image

Fig. 3
Abdomen-Pelvis computed tomography (CT) scan. 1.7 cm sized well enhancing mass in pancreas uncinate process.
Click for larger image

1. Wilder KM, Allan FN, Power MH. Carcinoma of the island of the pancreas: hyperinsulinism and hypoglycemia. JAMA 1927;89:347–355.
2. Wang S, Hu HT, Wen SQ, Wang ZJ, Zhang BR, Ding MP. An insulinoma with clinical and electroencephalographic features resembling complex partial seizures. J Zhejiang Univ Sci B 2008;9:496–499.
3. Suzuki K, Miyamoto M, Miyamoto T, Hirata K. Insulinoma with earlymorning abnormal behavior. Intern Med 2007;46:405–408.
4. Do YR, Kwon OD, Kim JE, Do JK, Lee DK. Complex partial seizure like symptoms presented by a patient with insulinoma and hyperproinsulinemia. J Korean Epilep Soc 2004;8:167–170.
5. Cho H, Choi YH, Cho YN, Kim WJ. Insulinoma presenting as a parasomniamimic symptoms. J Korean Sleep Res Soc 2010;7:57–60.
6. Dizon AM, Kowalyk S, Hoogwerf BJ. Neuroglycopenic and other symptomsin patients with insulinomas. Am J Med 1999;106:307–310.
7. Service FJ, McMahon MM, O'Brien PC, Ballard DJ. Functioning insulinoma-incidence, recurrence, and long-term survival of patients: a 60-year study. Mayo Clin Proc 1991;66:711–719.
8. Whipple AO. Hyperinsulinism in relation to pancreatic tumors. Surgery 1944;16:677–681.
9. Shin JJ, Gorden P, Libutti SK. Insulinoma: pathophysiology, localizationand management. Future Oncol 2010;6:229–237.