SPECTにて一過性全般性脳血流低下を示した非ヘルペス性ウイルス性脳症の1症例

Abstract

Elderly persons have a tendency to present with mental disorders such as delirium. Environmental changes are known to induce mental disorders such as delirium in elderly persons. At the time of acute mental sorder or impalrment, we need to take encephalitis or encephalopathy into consideration. In particular, evere encephalitis may cause sequelae such as dementia, personality change or disturbance of cerebral blood flow; these patients need to receive treatment at an early stage. We report a case of non-herpes viral encephalopathy with a transient diffuse decrease in cerebral blood flow on brain SPECT during antiviral therapy. After the 72-year-old female had a tooth extracted, she gradually demonstrated psychiatric symptoms, which consisted of insomnia, delusion of persecution, delusion of observation and disorientation. Finally, she was complicated with disturbance of consciousness and admitted to our psychiatric ward. She was suspected of having encephalopathy, and treated mainly with acyclovir. She temporarily improved, but after a while her consciousness deteriorated again. Brain MRI showed normal findings, whereas brain SPECT (99mTc-ECD) showed a diffuse decrease in cerebral blood flow. Therefore, she was treated with oxygen inhalation and therapeutic agents which improved cerebral blood flow. As result, she completely recovered and has had not any sequela such as dementia or personality change. It was suggested that brain SPECT is useful to evaluate the pathology and decide the treatment for patients who demonstrate acute eterioration of consciousness during antiviral therapy.