The chronic inflammation of the meninges is known as chronic meningitis. Among the pathologic agents that can cause this disease is Mycobacterium tuberculosis. A case of tuberculous meningitis is reported here. A 46-year old male presented with recurrent headache accompanied by vomiting and body weakness. Physical examination was unremarkable except for bilateral cervical lymphadenopathy and harsh breath sounds on both lung fields. Kernig’s sign was positive for meningeal irritation. Lumbar puncture revealed cerebrospinal fluid (CSF) pleocytosis with predominance of mononuclear cells, low CSF glucose and elevated protein.
The patient has a good prognosis provided there is proper compliance to anti-TB medication which has a treatment duration lasting six to twelve months and a combination of 3 or more anti-TB drugs.
Introduction of Case/Pathology
The chronic inflammation of the meninges is known as chronic meningitis. It can manifest profound neurologic deficit and can be fatal if not treated promptly and successfully (Braunwald, Fauci, Kasper, Hauser, Longo & Jameson, 2001). Among the pathologic agents that can cause this disease is Mycobacterium tuberculosis. Tuberculous meningitis (TBM) is one of the most common chronic infections of the central nervous system (CNS) (Katti, 2001). A rapid diagnosis is essential for a favorable treatment outcome. A case of tuberculous meningitis is reported here. A 46-year old male had recurrent headache for over a month. He tolerated his condition by self-medicating with analgesics which afforded temporary pain relief.
However, persistence of severe headache accompanied by vomiting and body weakness prompted the patient to seek medical consult. Past medical history revealed the patient had been diagnosed with pulmonary tuberculosis but had poor compliance with his anti-TB medication. At the emergency department, the patient was drowsy and disoriented.
Physical examination was unremarkable except for bilateral cervical lymphadenopathy and harsh breath sounds on both lung fields. Kernig’s sign was positive for meningeal irritation. Chest x-ray revealed bilateral opacities at the hilar and apical area. A CT scan of the head was indicated which did not reveal any sign of increased intracranial pressure and no evidence of a space-occupying lesion. Routine laboratory test were unremarkable. Lumbar puncture revealed cerebrospinal fluid (CSF) pleocytosis with predominance of mononuclear cells, low CSF glucose and elevated protein.
Specifics of Case/Pathology
The initial impression in this case was chronic meningitis based on the patient’s presenting history. Patients with chronic meningitis usually present with the following cardinal features: persistent headache with or without nuchal rigidity, cranial neuropathies, radiculopathies, and alteration of mental status (Braunwald et al., 2001). Physical examination should have emphasis on looking for signs of neck pain and rigidity secondary to meningeal irritation, changes in mental status such as drowsiness, inattention, disorientation and memory loss and cranial nerve involvement such as facial weakness, double vision, and visual and hearing loss (Braunwald et al., 2001).
The clinical assessment and physical examination should lead the physician to request for the most significant diagnostic test in this case which is the lumbar tap. In this test, CSF is drawn and examined for signs of inflammation. The elevated WBC count of the CSF with low levels of glucose and elevated protein indicated chronic meningitis (Braunwald et al., 2001).
Further CSF analysis such as CSF culture and staining techniques can be helpful in identifying the etiology of the disease whether it was bacterial, viral, fungal, or protozoal in origin. In this case, the presence of acid-fast bacilli from the culture will indicate Mycobacterium tuberculosis as the etiologic agent.
Presentation of Case/Pathology
The lumbar tap or puncture was done by passing a needle below or above the fourth spine while the patient is in lateral decubitus position. CSF was drawn and analyzed for WBC count, glucose and protein levels. The radiographic studies used include contrast-enhanced CT scan and MRI.
These brain imaging studies helped identify if the intracranial pressure was elevated which would have carried a potential risk of brain herniation when lumbar puncture was done (Braunwald et al., 2001). They also provided direct visualization of the meninges, the anatomical part involved in this case. The meninges are made up of three distinct connective tissues, the dura, arachnoid, and pia mater, which provide protection to the brain and the spinal cord.
In chronic meningitis, the meninges become inflamed which explains the neck pain or rigidity of the patient since neck movement stretches the meniges. The most common pattern of involvement is a diffuse meningoencephalitis although arteries running through the arachnoid space may also be involved leading to obliterative endarteritis (Cotran, Kumar, & Collins, 1999). Both the direct brain involvement and the ischemia induced by arterial obstruction can account for the neurologic deficits found in the patient.
Since the patient had already been diagnosed with pulmonary tuberculosis, chest x-ray is a significant diagnostic procedure to assess the status of the patient. However, pulmonary findings may be inconclusive especially if the pulmonary TB was properly managed therefore it is essential that the x-ray film is of good quality. According to Pust (2004), the three technical quality indicators are the inspiration of the patient, rotation of the spinous process and penetration of the radiation.
The differential diagnosis include brain tumor such as meningioma can also present with the same features as the case presented here. A meningioma is a benign tumor that arises from the meninges. It can put pressure on the brain can mimics the neurologic symptoms in meningitis. However, unlike in meningitis which usually involves the the subarachnoid space, menigiomas usually involve the dura mater. A cerebrovascular accident can also present with a severe headache and neurologic deficits. It is ruled out because of the acuteness of this event against the chronicity of the symptoms presented by the index patient.
This is a case of chronic tuberculous meningitis. The presumptive test is the identification of acid-fast bacilli on AFB microscopy from the CSF. The definitive diagnosis is the isolation andidentification of Mycobacteriem tuberculosis from the CSF culture. The prognosis is usually good provided there is proper compliance to anti-TB medication which has a treatment duration lasting six to twelve months and a combination of 3 or more anti-TB drugs.
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