Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

A case of Hashimoto's encephalopathy with diffuse white matter lesions on diffusion-weighted MRI

Kensho Okamoto, M.D., Chiaki Mori, M.D., Kenji Kamogawa, M.D., Kayo Tominaga* and Bungo Okuda, M.D.

Department of Neurology, Ehime Prefectural Central Hospital
*Department of Neurology, National Hospital Organization, Ehime National Hospital

A 65-year-old woman was admitted to our hospital because of subacute deterioration of cognitive function. On admission, she presented with marked disorientation of time and place and inability to carry out commands. Mini-Mental State Examination score was 5/30. Although routine laboratory examinations including thyroid function, vitamin B1 and B12, serum syphilitic reaction, sIL-2 receptor level, titers of herpes simplex and zoster viruses, and HIV antibody were normal, titers of anti-thyroglobulin (TG) antibodies and thyroid peroxidase (TPO) antibodies were elevated. Cerebrospinal fluid showed normal findings. Brain MRI revealed diffuse high intensity in the white matter on diffusion- and T2-weighted images, mimicking leukoencephalopathy. We made a diagnosis of Hashimoto's encephalopathy, based on clinical features and high titers of anti-thyroid antibodies. Following administration of steroid hormone, her cognitive impairment gradually improved, associated with decrease of the white matter abnormality on MRI. Hashimoto's encephalopathy should be kept in mind in the differential diagnosis of subacute leukoencephalopathy with cognitive decline.

(CLINICA NEUROL, 47: 112|115, 2007)
key words: Hashimoto's encephalopathy, diffusion-weighted images, cognitive impairment, MRI, leukoencephalopathy

(Received: 21-Aug-06)