Primary Bilateral Thalamic Astrocytoma Presenting With Head Tremor, Ataxia, and Dementia

Case Report A 42-year-old woman was seen for 6-month progressive behavioral disturbances. At that time she started being unusually aggressive and impatient, complaining of headaches, aching pain in the right leg, and head tremor. The behavioral changes worsened slowly, and she grew incapable of doing things she previously did, such as cooking, cleaning the house, administering medicine to her mother, and caring for her 13-yearold daughter. Relatives reported that she walked with poor balance. When seen, she thought she was in 1970 and in another hospital and that the reason for the consultation was a bloody nipple discharge. Ocular movements were uncoordinated, and she had a rhythmic nodding head tremor, choreoathetoid movement of the right hand, and bilateral cerebellar signs. Muscle strength and sensory functions, as well as visual fields, were normal. Neuropsychological assessment showed moderate to severe impairment of executive function, language, semantic and episodic memory, and visuospatial abilities. Noticeable was a severe involvement of temporoparietal cortical functions, with Gerstmann and Balint syndromes. Patient brain MRI (Figure 1, panels A and B) disclosed a bithalamic diffuse homogeneous lesion, hyperintense on T2 and iso-intense on T1-weighted images, without restricted diffusivity or gadolinium uptake. EEG showed an 8-Hz background activity. Electromyography characterized the head tremor as rhythmic at 3 Hz. A stereotaxic biopsy was performed, with removal of tissue from the right thalamus. Histological examination showed astrocytosis with minor nuclear anaplasia and inconspicuous cytoplasm. A few normal large thalamic neurons were found. Spongiform changes were absent, as were mitotic figures. Numerous GFAPpositive processes were present. The diagnosis was of astrocytoma, grade 2 (WHO). On an oncology consultation, only palliative care was proposed. The patient died 3 months later.