CASE 17395 Published on 18.08.2021

A case of intracranial miliary tuberculosis

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Jagannathan K, Nisha D Bhojwani, Sanjay R Gadhvi

Department of Radiology, Civil Hospital, B. J. Medical College, Ahmedabad, Gujarat, India

Patient

23 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR
Clinical History

A 23-year-old male patient was brought with complaints of headache and vomiting for 3 days. He had complaints of dry cough for 15 days. He also had complaints of loss of appetite and weight loss.

Imaging Findings

MRI study of the cranium is performed on a 1.5 T Philips MR scanner, with SE T1, FSE T2, FLAIR, and post-gadolinium SE T1 weighted sequences on three planes. MRI study reveals multiple nodular and ring-enhancing lesions in bilateral cerebral and cerebellar hemispheres, left side of midbrain which appear hypointense and hyperintense to brain parenchyma on T1 and T2 weighted images respectively (Figures 1 and 2). Few foci of diffusion restriction are noted in left parietal parafalcine region possiblity of Vasculitic infarcts. (Figure 3)
 

On computed tomography (CT) of thorax, multiple miliary nodular lesions are noted diffusely in bilateral lung fields. (Figure 4)

Discussion

The most common manifestation of tuberculosis (TB) is pulmonary. Central nervous system (CNS) TB is rare and often due to hematogenous spread from the lung and most severe form of human mycobacterial infection. CNS TB accounts for 1 % of all TB cases and 5% of extrapulmonary TB cases [1,2]. The bacteria reaches CNS through hematogenous spread, usually from a pulmonary focus. Blood-brain barrier(BBB) offers protection to CNS against the entry of pathogens. However several microorganisms can pass through the BBB and deposit in the brain layers during the bacteremic phase. "Rich foci" develop around these deposits, the rupture of these foci lead to dissemination of the organism into subarachnoid space or brain parenchyma [3]. The disease, therefore, manifests in CNS as meningitis, tuberculoma and tubercular abscess [4,6]. Although the appearance of CNS TB on MR is not absolutely specific, it is important in the proper clinical setting to recognize the range of possible patterns that can be observed on images [5,6]. The presence of TB elsewhere in the body favours the diagnosis although its absence does not exclude it. Miliary lesions are usually diffusely scattered in the brain parenchyma, measuring less the 2-3 mm in size, and they are predominantly located at the grey-white matter junction. These show homogeneous post-contrast enhancement. On non-contrast scans, they may or may not be visible. Caseating lesions appear hypointense on T2-weighted sequences [6].
            

In our case, the patient had multiple nodular and ring-enhancing lesions in cerebral parenchyma, cerebellum and brainstem. Miliary tuberculomas can have a variety of unusual presentations and there is no mass effect and may present with headaches, seizures and meningeal signs. CT chest revealed diffuse miliary opacities in bilateral lung fields. CBNAAT of CSF revealed tuberculous bacilli. Sputum Acid-fast staining revealed Acid-fast bacilli. Fundus examination also revealed choroid tuberculomas in both eyes.

Differential Diagnosis List
Intracranial miliary tuberculosis
Neurocysticercosis
Cerebral abscess
Metastasis
Lymphoma
Final Diagnosis
Intracranial miliary tuberculosis
Case information
URL: https://www.eurorad.org/case/17395
DOI: 10.35100/eurorad/case.17395
ISSN: 1563-4086
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