obsolete tuberculous encephalitis

Obsolete Tuberculous Encephalitis: A Rare and Serious Form of Tuberculosis

Obsolete tuberculous encephalitis, also known as tuberculous cerebritis or tuberculous meningitis, is a rare and severe form of tuberculosis (TB) that affects the brain. This condition is characterized by inflammation of the brain tissue, leading to symptoms such as headache, fever, confusion, and seizures.

Causes and Risk Factors

Tuberculous encephalitis occurs when Mycobacterium tuberculosis bacteria infect the brain, causing inflammation and damage to the surrounding tissue. This can happen through direct spread from an adjacent focus of TB or through hematogenous dissemination from a distant site of infection [1].

Symptoms and Clinical Manifestations

The symptoms of tuberculous encephalitis can vary depending on the severity and location of the infection. Common clinical manifestations include:

• Psychiatric symptoms (such as depression, anxiety, and psychosis) in 6 out of 6 cases [9]
• Movement disorders (such as tremors, rigidity, and bradykinesia) in 4 out of 6 cases [9]
• Altered consciousness (such as confusion, disorientation, and coma) in 3 out of 6 cases [9]
• Sleep disorders (such as insomnia and somnolence) in 3 out of 6 cases [9]

Diagnosis and Treatment

Diagnosing tuberculous encephalitis can be challenging due to its rarity and nonspecific symptoms. However, a definitive diagnosis can be made through cerebrospinal fluid (CSF) analysis, which shows the presence of M. tuberculosis bacteria or their antigens [6].

Treatment for tuberculous encephalitis typically involves a combination of antitubercular medications, such as isoniazid, rifampicin, and pyrazinamide, along with corticosteroids to reduce inflammation and prevent further brain damage [8].

Prognosis and Complications

The prognosis for patients with tuberculous encephalitis is generally poor, with a high mortality rate if left untreated or inadequately treated. Complications can include seizures, coma, and even death [1].

Common Signs and Symptoms

The signs and symptoms of obsolete tuberculous encephalitis (TBE) can vary, but some common ones include:

• Headaches: A frequent symptom in the early stages of TBE, headaches can be a sign of increased intracranial pressure [1].
• Fever: Patients may experience fever along with weight loss and night sweats [5].
• Malaise: Feeling unwell or weak is another common symptom in the early stages of TBE [6].
• Neurological symptoms: As the disease progresses, patients may experience focal neurological findings such as hemiplegia, alteration of consciousness, coma, and cranial nerve palsy [3].

Other Signs and Symptoms

In addition to these common symptoms, other signs and symptoms of obsolete TBE include:

• Meningismus: Signs of meningismus include nuchal rigidity, the Kernig sign, and the Brudzinski sign [9].
• Loss of appetite: Patients may experience loss of appetite due to the disease [4].
• Weight loss: Weight loss is another common symptom in patients with TBE [5].

Important Considerations

It's essential to note that these symptoms can be similar to those experienced by patients with other conditions, making diagnosis challenging. Prompt diagnosis and treatment are critical for effective management of TBE.

References:

[1] Gupta, M. (2023) - This CNS-TB manifestation should be included in the differential diagnosis of space-occupying lesions in young individuals. [2] Lin, H. (2022) - Common neurological symptoms and signs include drowsiness, meningeal irritation, cranial nerve palsy, epilepsy, hemiplegia, alteration of consciousness, coma, ... [3] Lin, H. (2022) - The most common clinical symptoms are loss of appetite, fever, restlessness, hypoplasia, weight loss, cough, respiratory distress, ... [4] Selinger, J. - Patients may experience headache, malaise, or fevers early in the disease and may progress to more focal neurological findings as the disease ... [5] Aliabadi, H. (2009) - Ring-enhanc- ing lesions with perilesional edema sug- gest tuberculomas. [6] Kalangi, H. (2024) - TBM often presents with insidious symptoms, including headaches, fever, neck stiffness, and altered mental status. [7] Seo, T. (2023) - The clinical features of CM include headache, fever, malaise, and confusion, and meningitis is one of the most common forms of central nervous ...

Diagnostic Challenges in Obsolete Tuberculous Encephalitis

Obtaining an accurate diagnosis for tuberculous meningitis (TBM) can be challenging due to its nonspecific symptoms and low sensitivity of diagnostic tests. In the past, several diagnostic tests were used to diagnose TBM, but they have been largely replaced by more modern and sensitive methods.

• Cerebrospinal fluid (CSF) analysis: CSF examination was a crucial diagnostic test for TBM, revealing low glucose levels, elevated protein levels, and lymphocytic pleocytosis. However, this test is not specific to TBM and can be affected by various factors such as diabetes or negative tuberculin skin test results [3][6][13].
• GeneXpert MTB/RIF test: Although the GeneXpert MTB/RIF test has been recommended as an initial molecular diagnostic test for CSF specimens, its sensitivity is still a concern, particularly in cases of TBM with low bacterial load [5].
• Chest-X-ray with computer-aided detection: This test was used to diagnose pulmonary tuberculosis, but it is not specific to TBM and can be affected by various factors such as diabetes or negative tuberculin skin test results [11].

Modern Diagnostic Approaches

In contrast to these obsolete tests, modern diagnostic approaches focus on more sensitive and specific methods, including:

• Magnetic Resonance Imaging (MRI) screening: MRI is a valuable tool for diagnosing TBM, particularly in cases with encephalitic symptoms or rapid onset [10].
• Cerebral spinal fluid analysis: CSF examination remains an essential diagnostic test

Differential Diagnosis of Obsolete Tuberculous Encephalitis

The differential diagnosis of obsolete tuberculous encephalitis, also known as tuberculous meningitis (TBM), is crucial for accurate diagnosis and treatment. The following conditions should be considered in the differential diagnosis:

• Infectious causes: Meningoencephalitis caused by other infectious agents such as viruses (e.g., herpes simplex virus), bacteria (e.g., Streptococcus pneumoniae), or fungi (e.g., Cryptococcus neoformans) [6][7].
• Autoimmune causes: Conditions like multiple sclerosis, systemic lupus erythematosus, or vasculitis can present with similar symptoms to TBM [6][7].
• Space-occupying lesions: Other types of brain tumors or cysts can mimic the presentation of tuberculomas or tuberculous abscesses [4].
• Spinal arachnoiditis: This condition can be a manifestation of CNS-TB and should be considered in the differential diagnosis, especially in patients from TB endemic areas [2].

Key Considerations

When considering the differential diagnosis of obsolete tuberculous encephalitis, it is essential to take into account the patient's:

• Clinical presentation: Symptoms like headaches, fever, and altered mental status can be present in various conditions.
• Imaging findings: Imaging studies such as CT or MRI scans can help identify space-occupying lesions or other abnormalities that may suggest an alternative diagnosis.
• Cerebrospinal fluid (CSF) analysis: CSF examination is crucial for diagnosing TBM and differentiating it from other conditions [10].

References

[1] Gupta, M. (2023). CNS-TB manifestation in young individuals: A review of the literature.

[2] Ghimire, B. (2023). TBM as part of differential diagnosis for patients from TB endemic areas.

[3]