Dr Ira Shah
Editor - Pediatric Oncall
What is meningitis?
Inflammation of the lining of the brain (meninges) is called as meningitis. This meningitis can be due to infection or due to certain drugs (chemical meningitis) or due to other diseases such as autoimmune diseases where the body’s own cells attack the meninges or cancer. However the term meningitis is commonly used for infection of the meninges.
What is the commonest cause of infective meningitis?
The common causes of meningitis are infections with bacteria (bacterial meningitis), tuberculosis (TB meningitis), fungal meningitis and viral meningitis. Of the bacteria that cause meningitis, common germs are Neisseria, streptococcus and hemophilus influenzae. However any organism can cause meningitis. Among the fungal organisms, common fungi causing meningitis are Candida and Cryptococcus. However fungal meningitis usually does not occur in persons with good immunity. It is more common in patients with poor immunity such as patients on treatment for cancer or HIV infected patients. Among the viruses that can cause meningitis, common viruses are enteroviruses, arboviruses, mumps virus, measles virus, rubella virus, influenza and parainfluenza viruses. Other viruses can rarely cause meningitis. Rarely parasites such as amoeba can cause meningitis.
What are the symptoms of meningitis?
In most patients, symptoms are acute and are characterized by irritability, vomiting, headache, neck pain or neck stiffness. Fever is usually present. In young children and infants, they may cry excessively and the soft spot on the head (anterior fontanelle) may start bulging. Occasionally, a patient may have seizures (fits) or there may be drowsiness and patients may even become comatose. Rarely, stroke and paralysis may occur.
Patients with TB meningitis or fungal meningitis have a prolonged duration of illness and may present with low grade fever for few weeks prior to above mentioned symptoms.
Which patients are more prone to meningitis?
Meningitis can occur in any person. However patients with severe malnutrition, patients with poor immunity, patients with skull fractures or having a sinus in contact with brain, those with head injury or brain surgery are more prone to get meningitis. Patients on chemotherapy (anti cancer treatment), those having diabetes mellitus, ear infections are more susceptible to develop meningitis with unusual organisms.
How is diagnosis of meningitis made?
Diagnosis of meningitis is made by doing a lumbar puncture. Lumbar puncture is a procedure by which fluid from the brain (cerebrospinal fluid) is removed and sent for testing under microscope to look for cells and germs. Lumbar puncture is done by inserting a needle into the back where the tip of the needle goes into the space in the spinal column where the cerebrospinal fluid is present and then the fluid is removed for analysis. Other tests done are either CT scan or MRI of the brain. These are done to look for complications such as brain abscess, pus in the brain or look for increase in size of ventricles (hydrocephalus). Ventricles are the areas in which cerebrospinal fluid is present in the brain. If there is lot of infection or the cerebrospinal fluid has lot of pressure inside, then the ventricles enlarge which in turn can increase the pressure on the brain and can cause more damage.
What are the complications of meningitis?
Untreated bacterial, TB or fungal meningitis can lead to increase coma and death. Viral meningitis most often improves on its own. Meningitis can often be complicated with brain abscess or increase ventricle size. Patients may develop stroke and paralysis. Occasionally squint and vision impairment can occur. Common long term sequelae can occur in 30 percent of patients and include learning disabilities, hearing loss, vision impairment, paralysis and epilepsy.
What is the treatment of meningitis?
Treatment of meningitis should be prompt. Complications such as increased pressure in the brain, fits are treated promptly. Antibiotics for 10-21 days are required for bacterial meningitis. For TB meningitis, anti TB drugs are required and for fungal meningitis, antifungals are required. For viral meningitis, acyclovir is required for infection due to herpes virus. In case of brain abscess or hydrocephalus, surgery is required to drain the abscess or increased fluid (shunt surgery).
What is the long term outcome of patients with meningitis?
Prompt treatment improves survival and decreases long term sequelae. However 30% still have long term sequelae such as learning disability, hearing loss, vision impairment, difficulty in walking and or fits.
Last updated on 1-07-2010