The etiological spectrum of miliary brain lesions: A systematic review of published cases and case series.

Objective: This systematic review aimed to evaluate the published cases with miliary brain lesions and their etiological factors, clinical manifestations, diagnostic procedures, and outcomes.

Methods: A comprehensive search of PubMed, Scopus, Embase, and Google Scholar was conducted using the specified search strategy. Eligibility criteria included cases with miliary lesions in the brain confirmed through neuroimaging and various diagnostic procedures. The PRISMA guidelines were followed, and the PROSPERO registration number for the protocol is CRD42023445849.

Results: Data from 130 records provided details of 140 patients. Tuberculosis was the primary cause in 93 cases (66.4%), malignancies in 36 cases (25.7%), and other causes accounted for the remaining 11% cases. Tuberculosis patients averaged 35.7 years old, while those with malignancies averaged 55.44 years. Tuberculosis symptoms primarily included fever, headache, and altered sensorium, whereas malignant cases often exhibited progressive encephalopathy, headache, and specific neurological deficits. Distinctive indicators for CNS tuberculosis were choroidal tubercles and paradoxical reactions. Additionally, 63 tuberculosis patients showed miliary lung shadows and 49 had abnormal CSF findings. For the malignancy group, 13 exhibited miliary lung lesions, and 8 had CSF abnormalities. Regarding outcomes, a significant mortality disparity was observed, with 58.3% in the malignancy group, compared to 10.8% in the tuberculosis group and 27.3% in other cases.

Conclusion: Miliary brain lesions are a crucial imaging abnormality that necessitates prompt work up. In an immunocompromised state, diagnostic possibilities of miliary brain lesions are more varied and often pose a bigger challenge.