A 57-year-old man, previously treated for tuberculosis, was admitted to a Korean clinic with complaints of headache, neck pain, and tingling in the right hand for two weeks. Physical examination revealed decreased grip strength in the right hand. A chest CT scan revealed miliary nodules. A contrast-enhanced MRI of the head revealed a "starry sky" phenomenon—numerous small spherical nodules with peripheral signal enhancement in the cerebral hemispheres, basal ganglia, cerebellum, and brainstem, as well as in the upper spinal cord with surrounding edema. No meningeal involvement was observed. Cerebrospinal fluid analysis was normal, and bacteria were not cultured. Sputum culture was positive for Mycobacterium tuberculosis. Doctors In-Suk Bae and Yung Ki Park from Eulji Medical Center in Nowon and Uijeongbu described the case in the New England Journal of Medicine.
Based on the examination results, the patient was diagnosed with central nervous system tuberculomas secondary to miliary pulmonary tuberculosis. Central nervous system tuberculomas are foci of granulomatous inflammation at the sites of mycobacterial bloodstream entry from the primary lesion. Without treatment, they enlarge over time and undergo caseous necrosis and calcification. They may or may not be accompanied by tuberculous meningitis (as in this case). The man was prescribed an antimycobacterial therapy regimen and dexamethasone. After about a month, the symptoms began to subside; at a follow-up examination 18 months later, they were completely absent, and an MRI of the head was normal. The "starry sky" phenomenon on MRI is most often observed in cysticercosis—an invasion of the brain by the larvae of the pork tapeworm, which inhabits the intestines—but can also occur in tuberculosis, schistosomiasis, Rocky Mountain fever, Japanese encephalitis, and some other central nervous system disorders. Inflammation of the dura mater can also manifest on MRI as the Eiffel Tower sign at night.
