Central Nervous System Tuberculosis in Immunocompromised Patients: A Case Report Emphasizing Immune Status and Early...

Tuberculosis (TB) remains a global health challenge. Although pulmonary TB is the most frequent presentation, extrapulmonary involvement can occur, especially in immunocompromised patients. HIV-positive individuals are particularly vulnerable to opportunistic infections, such as TB, and CNS involvement is more prevalent in these patients, often leading to a poorer prognosis. CNS TB management is challenging due to nonspecific symptoms and delayed diagnosis, contributing to high mortality. It can manifest diffusely as tuberculous meningitis (TBM), localized as tuberculoma or tuberculous abscess, or as extradural and intradural spinal infections. TBM is the primary CNS manifestation, bearing significant morbidity and mortality, and rarely complicates with involvement of the spinal cord, termed tuberculous myelitis, which is associated with an unfavorable prognosis. A 61-year-old male, smoker with a history of substance abuse, undergoing seven months of antiretroviral therapy (ART) for HIV-1, presented with a two-day history of altered consciousness, sphincter incontinence, and fever. He also reported headaches, dizziness, and sleep disturbances over the past months. The examination revealed fever, asthenia, prostration, disorientation, neck rigidity, and bilateral lower limb weakness. Initial tests indicated lymphopenia, hyponatremia, and a slightly elevated C-reactive protein. Cranial CT showed no abnormalities. Lumbar puncture yielded abnormal cerebrospinal fluid (CSF), xanthochromic, hyperproteinorrheic (2316 g/L), hypoglycorrhagic (24mg/dl), with pleocytosis predominantly of mononuclear cells (98%). Compared to the values prior to ART treatment, the patient had a decreased HIV-1 viral (44 copies/ml) load but also a decreased CD4+ cell count (43 cells/mm³). Given the patient's rapid clinical deterioration, immunosuppression history, and a positive interferon-gamma release assay (IGRA) prior to ART, treatment with antituberculous drugs and dexamethasone was started at admission. Subsequently, Mycobacterium tuberculosis was identified through polymerase chain reaction (PCR) of the CSF. Cranial and spinal MRI revealed leptomeningeal enhancement from C2-C3 to the cauda equina, consistent with meningitis, without intracranial extension, and findings suggestive of myelitis, without evidence of tuberculomas or spinal cord osseous involvement. One week after treatment, the recovery of higher neurological functions became evident. Improvement in lower limb motor deficits had a delayed trajectory, with marginal progress observed at discharge. After an eight-week incubation, CSF mycobacterial culture analysis yielded negative results. This case discusses the importance of early suspicion and intervention in CNS infection prognosis. Attention to signs and symptoms beyond the most frequent ones is crucial, particularly in immunocompromised individuals like HIV patients. Identifying CSF features in different CNS infections and group-specific particulars facilitates the prompt initiation of treatment. Additionally, in co-infected patients (HIV and CNS TB), considering factors such as ART duration, CD4+ cell count, and viral load is important, in influencing the disease's incidence, course, and prognosis.