Case History

A 28-year-old man from India developed cranial nerve deficits and soon became encephalopathic.

Diagnosis: Tuberculous Meningitis

Images 9.6A–9.6C: Postcontrast axial and sagittal T1-weighted images demonstrate extensive ring-enhancing lesions in the basal meninges in a patient with tuberculosis, representing tuberculomas. Images 9.6D–9.6F: Axial FLAIR images show significant edema and mass effect associated with the lesions.

Introduction

  Infection with Mycobacterium tuberculosis occurs from person to person by infected respiratory droplets. It is not common in Western countries except in the setting of an immunocompromised state, especially in patients with AIDS. The most common route of infection of the CNS is hematogenous spread from a systemic source. Approximately 10% of patients develop neurological complications.

Clinical Presentation

  It most commonly affects the basal meninges, manifesting with cranial neuropathies, primarily of the abducens nerve, and altered mental status. Other presentations include seizures, vasculitis with subsequent infarction, hydrocephalus, and focal neurological deficits if there are tuberculomas within the brain.

  Patients with tuberculous meningitis are categorized by stage on presentation, based upon mental status and focal neurological signs as follows:

       1.  Stage I: Patients are lucid with no focal neurological signs or evidence of hydrocephalus.

       2.  Stage II: Patients exhibit lethargy and confusion. They may have mild focal signs, such as cranial nerve palsy or hemiparesis.

       3.  Stage III: Represents advanced illness with delirium, stupor, coma, seizures, multiple cranial nerve palsies, and/or dense hemiplegia.

  Myelopathy can occur due to infection of the vertebral body (Pott disease) or due to direct infection of the spinal canal and spinal cord with tuberculomas in the absence of any lesion to the bone. There can be both intraspinal granulomatous tissue, which compresses the cord from the outside, or intramedullary tuberculomas. Pott disease arises from the vertebral body, usually in the thoracic or lumbar spine, which then invades the epidural space. Patients present with the subacute onset of severe, localized pain and fever. Myelopathic signs develop if there is compression of the spinal cord.

Radiographic Appearance and Diagnosis

Image 9.6G: Gross pathology demonstrates a thick basal exudate in a patient with tuberculosis (image credit Yale Rosen).

Images 9.6H–9.6K: Postcontrast axial T1-weighted and FLAIR images demonstrate innumerable ring-enhancing lesions throughout the brainstem and brain with surrounding edema and mass effect from tuberculomas.

Images 9.6L and 9.6M: Postcontrast axial and sagittal T1-weighted images of the cervical spine demonstrate thin linear enhancement of the meninges (red arrow) and a larger lesion at C2 with cord compression. On the axial image, the spinal cord is indicated by the yellow arrow, while the large tubercular lesion is indicated by the blue arrow. Image 9.6N: Sagittal T2-weighted image demonstrates hyperintensity throughout the cervical cord.

Images 9.6O and 9.6P: Sagittal T2-weighted and postcontrast TI-weighted images demonstrate a severe compression fracture of the L1 vertebral body with retropulsion of bone into the spinal canal indenting the tip of the conus medullaris in a patient with Pott disease. Image 9.6Q: Gross pathology of Pott disease (image credit Dr. Yale Rosen).

Images 9.6R and 9.6S: Chest radiograph and axial CT image demonstrate miliary tuberculosis.

  The illness is universally fatal in 1 to 2 months without treatment, and fatal in about 25% of those with treatment. Immunocompromised patients fare worse.

  For patients with Pott disease, the same antitubercular treatment is indicated as for tuberculous meningitis, though neurosurgical debridement and stabilization of the spine may be required in patients with acute neurological deterioration, spinal deformity with instability, resistance to drug therapy, or paravertebral abscess.

References

1.  Bernaerts A, Vanhoenacker FM, Parizel PM, et al. Tuberculosis of the central nervous system: overview of neuroradiological findings. Eur Radiol. August 2003;13(8):1876–1890.

2.  Sahu SK, Giri S, Gupta N. Longitudinal extensive transverse myelitis due to tuberculosis: a report of four cases. Postgrad Med. October–December 2014;60(4):409–412.

3.  Sanei Taheri M, Karimi MA, Haghighatkhah H, Pourghorban R, Samadian M, Delavar Kasmaei H. Central nervous system tuberculosis: an imaging-focused review of a reemerging disease. Radiol Res Pract. 2015;2015:202806.

4.  Mondol BA, Siddiqui MR, Mohammad QD, Saha NC, Hoque MA, Uddin MJ. Tuberculosis of the central nervous system. Mymensingh Med J. April 2010;19(2):312–322.