[Brain stem glioma presenting with contralateral sensory impairment of ascending nature]

A case of brain stem glioma, presenting with impairment of contralateral pain-temperature sense of ascending nature, is reported. A 38-year-old woman with documented neurofibromatosis type 1 (NF-1) was admitted to our hospital for treatment, complaining of diminished pain-temperature sense in the left lower extremity. On admission, the symptom was first evaluated to be due to cervical myelopathy although motor involvement was absent. An MRI, myelography and CT-myelography of the cervical spine were done, demonstrating no abnormality. Shortly after the admission the sensory impairment progressed to the upper chest level and then to the upper extremity on the left. Because of her documented NF-1 a brain CT was checked, revealing a small mass with ring enhancement in the dorsal midbrain on the right. On MRI, the tumor location was at the right dorsolateral tectal region of superficial situation. Under the diagnosis of midbrain glioma the tumor was partially removed by the occipital transtentorial approach. At operation, the tumor has grown intraaxially, having pinkish-gray color and central necrosis. Histologically the tumor was diagnosed as glioblastoma multiforme. Postoperatively she presented a definite improvement of the sensory impairment in the reverse order, that is from upper extremity and then to the lower extremity. Progression and post-treatment improvement of the impaired pain-temperature sense in this case suggested that the topography and lamination of the lateral spinothalamic tract might be present even in the dorsal midbrain, namely the posterior-superficial layer to be sacral segment and the anterior-deep layer to be cervical one.