Tuberculous Meningitis – How can imaging help in the diagnosis
Tuberculosis remains a clinical health problem worldwide and tuberculous meningitis (TBM) constitutes one of its most dreadful forms of presentation. Its global burden is thought to be 100000 cases per year.
We describe a case of an early diagnosis of TBM due to brain magnetic resonance (MR) imaging findings.
Materials and Methods:
A 30-year-old female with history of type 1 diabetes mellitus and episodic migraine presented multiple times to the emergency department in a period of one week with complaints of bilateral frontal headache, vertigo, vomits and photo- and phonophobia, initially described as a typical migraine but progressively worse and refractory to analgesic treatment. Upon admission, she was afebrile, and disclosed cognitive slowing as well as spontaneous bidirectional horizontal nystagmus, normal head-impulse test and skew deviation.
Laboratory work-up showed mild elevation of C-RP. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis (20 cells/µL), hypoglicorrhachia of 42% and hyperproteinorrhachia. Head CT was unremarkable. She started empiric treatment for bacterial meningitis, without clinical improvement in the following days. Brain MR study revealed, in the post-contrast sequences, an infratentorial leptomeningeal enhancement mainly in the sulci of both cerebellar hemispheres, with involvement of the vermis. At the supratentorial region, there was also enhancement of the infundibulum of the pituitary stalk and also leptomeningeal enhancement of some sulci. Due to these image findings, the hypothesis of meningitis, mainly TBM, neurosarcoidosis and leptomeningeal carcinomatosis were considered. She started anti-tuberculosis treatment and corticosteroids, and TBM was later confirmed by detection of Mycobacterium Tuberculosis in CSF by polymerase chain reaction.
The diagnosis of TBM is difficult to ascertain, being a rare condition. Imaging studies, mainly brain MR, can demonstrate key imaging features in suspicious cases of TBM diagnosis, allowing the introduction of early treatment.