Acute onset of somnolence and amnesia due to cerebral infarction of bilateral thalamus accompanied with tuberculous meningitis: a case report

A 55-year-old man was admitted to our hospital because of somnolence and aspontaneity. He was hospitalized in the psychopathic ward under the initial diagnosis of depression. Chest X-ray showed infiltration in both upper lobe. Twelve days later, Mycobacterium tuberculosis was detected from his sputum and was confirmed by RT-PCR. Cerebrospinal fluid findings showed elevated ADA and mononuclear cells, suggesting the presence of tuberculous meningitis. However, the brain CT revealed no abnormal findings. By applying antituberculous treatment the pulmonary lesion improved but psychological symptoms remained. Three months later follow-up brain MRI was examined. Contrast enhanced granuloma was detected in the ambiens, suprasellar and quadrigeminal cisterns. A strong signal was seen in the left frontal thalamus and a weak enhanced lesion was detected in the right frontal thalamus on a T2 enhanced image. These lesions showed low intensity on a T1 enhanced image, suggesting cerebral infarction affecting the bilateral thalamus. Somnolence and memory disorder was due to cerebral infarction of the bilateral thalamus and tuberculous meningitis contributed to form the intracranial lesion. From the experience of this case, it is needed to consider cerebral infarction (especially the thalamus) due to tuberculous meningitis when we examine the patients with acute onset of psychological symptoms.