Tuberculous Meningitis – Diagnosis and Treatment

The causative agent is Mycobacterium tuberculosis, the bacteria that causes tuberculosis.

Tuberculous meningitis is usually secondary to Tuberculosis in some other part of the body. Most commonly, pulmonary tuberculosis, when left unchecked, becomes miliary and spreads to other parts of the body. The spread to the brain is usually via blood stream.

Meninges are the system of membranes which envelops the central nervous system. Blood infected with this bacteria moves all around the body. As it comes in touch with the meninges, they get infected.

Risk Factors

Risk factors include a history of:

  • AIDS
  • Excessive alcohol use
  • Pulmonary tuberculosis
  • Weakened immune system

Symptoms

The symptoms usually begin gradually, and may include:

  • Fever and chills
  • Mental status changes
  • Nausea and vomiting
  • Sensitivity to light (photophobia)
  • Severe headache
  • Stiff neck (meningismus)
  • Agitation
  • Bulging fontanelles
  • Decreased consciousness
  • Poor feeding or irritability in children
  • Unusual posture, with the head and neck arched backwards (opisthotonos)

Fever and headache are the cardinal features. Confusion is a late feature. The patient may even go into coma, which bears a poor prognosis. Patients may also have focal neurological deficits.

Diagnosis

Diagnosis of TB meningitis is made by analyzing cerebrospinal fluid collected by lumbar puncture. The CSF usually has a high protein, low glucose and a raised number of lymphocytes. Acid-fast bacilli are sometimes seen on a CSF smear, but more commonly, M. tuberculosis is grown in culture. A spiderweb clot in the collected CSF is characteristic of TB meningitis, but is a rare finding.

More than half of cases of TB meningitis cannot be confirmed microbiologically, and these patients are treated on the basis of clinical suspicion only. The culture of TB from CSF takes a minimum of two weeks, and therefore the majority of patients with TB meningitis are started on treatment before the diagnosis is confirmed.

Imaging studies such as CT or MRI may show features strongly suggestive of TB meningitis, but cannot diagnose it.

Treatment

The treatment of TB meningitis is isoniazid, rifampicin, pyrazinamide and ethambutol for two months, followed by isoniazid and rifampicin alone for a further ten months. Steroids are always used in the first six weeks of treatment (and sometimes for longer). A few patients may require immunomodulatory agents such as thalidomide.

Complications of Tuberculous Meningitis

  • Brain damage
  • Build-up of fluid between the skull and brain (subdural effusion)
  • Hearing loss
  • Seizures
  • Hydrocephalus: This requires a ventricular shunt as treatment.

Medical Advice (Q&As) on “Tuberculous Meningitis – Diagnosis and Treatment

  1. Dammy

    My 5 years old son (I had him through normal delivery and his development milestones are normal) started to complain about abdominal pain around 2 years ago. The episodes of the groaning and pain last usually few minutes and then he feels better or sleep and it can occur up to 3 times a week. We’ve seen doctors and nothing could be traced to be the cause. Last year the child behave a bit violent during the pain. An EEG was done April 2013 and a temporal lobe epilepsy was suspected and a follow up CT scan showed an appearance of a mass at the temporal lobe. We saw the neuro pediatrician in June 2013 and he was placed on tegretol twice daily had relief for about 3 months then it started again. The doctors have been varying the doses of the tegretol but the symptoms persist. We saw the neuro 2 weeks ago and he recommended an MRI. I just saw the results. It reads something like lesion involving left prepontine, left cerebello-pontine angle cistern, left peri – mesencephalic cistern, left peri-mesencephalic cistern, left thalamus and mesial temporal lobe appearing hyperintense on T2 and isointence on T1 and is showing mild restricted diffusion. Few area of necrosis is seen within lesion. The report suggested infective (granulomatous) etiology? Koch’s (Tuberculoma). I saw the neuro with the result we are given another appointment. I’m scared. Is my son case curable? What’s his chances of survival? I live in part of Africa where advance medical services is not readily available.

    Reply
    1. Buddy M.D. Post author

      This does sound like an infective pathology.

      The condition is medically complicated. Tubercular bacteria is very resistant to treat, especially in the brain, where penetration of most of the anti tubercular drugs is very poor.

      You need a good hospital set up. Your son does have good chances of survival, if treated well and early.

      He would require strong anti tubercular medicines and may be a drainage operation in the brain.

      Reply
      1. dammy

        Please, I need more advice. After seeing my son’s doctor with the MRI results the doctor said he would want another radiologist and neurosurgeon’s opinion on the MRI. Finally yesterday, I was told both the radiologist and neurosurgeon believe my son is not having granulomatous tuberculoma but he’s having tumor in the brain and would require surgery. His doctor also feel my son does not seem to have TB. I’m so confused. Which opinion I’m to go with. How do radiologist differentiate between a tuberculoma and a tumor? Why can’t they agree?
        If my son has a brain surgery, will he survive and without mental illness?
        To get proper care, I was told I may have to fly him outside Nigeria to a country where medical service is developed. Please can you also advise me on average cost of taking care of my son’s case and where. The MRI report reads a lobulated ill-defined soft tissue lesion (29x 58 x 32mm) involving left prepontine, left cerebello-pontine angle cistern, left peri-mesencephalic cistern, left half of midbrain, left thalamus and mesial temporal lobe appearing hyperintense on T2 and isointence on T1 and is showing mild restricted diffusion. Few area of necrosis is seen within lesion.

        Reply
        1. Buddy M.D. Post author

          It is very difficult to differentiate between a tumor and a T.B. lesion. Both of them look alike on CT and behave similarly. Read here on tumor v/s tubercular lesion..

          Surgery seems to be inevitable. Cost would be around $40,000 to $50,000. You may try getting him operated in India, where the cost is less with no compromise in medical care.

          Reply