By Ritika Sakhuja
New Delhi: Annual outbreaks of encephalitis, or inflammation of the brain, across the country pose a major health burden in India. Encephalitis can severely impact the brain, opening a gateway for extreme neurological disorders and causing cognitive impairment that can lead to permanent brain damage. Hence, timely diagnosis and effective treatment are of prime importance to tackle this life-threatening disease.
However, the causative agent in most cases of acute encephalitis syndrome can range from a viral infection due to a mosquito bite to autoimmune disorders, making diagnosis and appropriate treatment a big challenge. According to the World Health Organisation (WHO), the case-fatality rate among those with encephalitis can be as high as 30 per cent. While permanent neurologic or psychiatric sequelae can occur in 30-50 per cent of those with encephalitis.
The lack of a single cause and neurological disorders that can lead to confusing brain-related symptoms has largely contributed to the usual case of late diagnosis in encephalitis patients. On the occasion of World Encephalitis Day, ETHealthworld spoke to neurologists to explore the screening measures employed to ensure timely and correct diagnosis of this debilitating disease and the challenges posed by this complicated disease that can hinder effective treatment.
Varied neurological symptoms trigger misdiagnosis
Encephalitis most commonly presents itself through a constellation of symptoms such as headache, generalised weakness, malaise, fever, severe lethargy, loss of weight, loss of appetite, vomiting, and seizures. Patients often also experience becoming progressively drowsy and inability to respond to commands. However, these symptoms can occur in a myriad of diseases and can lead to a misdiagnosis.
Speaking about the most common case resulting in misdiagnosis, Dr Anil Venkatachalam, Neurologist, Zen Multispecialty Hospital, Chembur, said, “Not every patient with encephalitis presents with fever. Often these patients present with nonspecific symptoms like headache, loss of appetite, loss of weight, or intractable vomiting. These patients are often taken to other specialists where they are labelled as having a normal headache due to ageing, not eating, or just a routine headache due to exertion. In the absence of fever, it is very difficult to make a diagnosis of encephalitis.”
Listing out the most common symptoms of encephalitis, Dr Pavan Pai, Consultant Interventional Neurologist, and Stroke Specialist, Wockhardt Hospitals Mira Road, said, “Daze, vomiting, paralysis, fever, disorientation, stiff neck, weakness, emotional disbalance, headaches, anxiety, irritation, and memory loss are some of the symptoms that can overlap with other problems and lead to misdiagnosis.”
Another contributing factor to the late diagnosis of encephalitis is that in the starting stage the disease projects mild to almost no symptoms, presenting mild flu-like signs and symptoms such as a fever or headache at the beginning. However, the disease rears its ugly head with rapidly progressing acute symptoms when it is too late for the patient.
Advocating for immediate medical intervention in case of extreme neurological symptoms, Dr Pankaj Agarwal, Senior Consultant – Neurology, Head – Movement Disorders Clinic and In- charge – DBS programme, Global Hospital, Mumbai, mentioned, “Symptoms can be anything from a headache, altered sensorium, which is confusion, unresponsiveness to commands, seizures, small movements or jerks where one part of the body may be shaking, or it may be a generalised seizure, where the whole body is convulsing. So if there is an acute onset of this in any person of any age, especially in combination, these signs should alert a patient to immediately rush to a doctor to get evaluated.”
“If there is an acute onset of these symptoms, the patient needs to be admitted immediately to the hospital. If multiple seizures are occurring, the patient could go into a condition called status epilepticus, which means that there are so many seizures that there are hardly any gaps between them. In this case, the patient needs ICU, where they will be put on a ventilator, anticonvulsants, and immune-mediated treatments,” added Dr Agarwal.
Thorough screening & effective treatment: need of the hour
There are multitudes of psychological ailments that can cause neurological symptoms. In such patients, an added ailment of encephalitis may be overlooked. In such cases, thorough screening becomes the need of the hour.
Informing about the common diagnostic practices in patients with prior neurological ailments, Dr Pai suggested, “Various tools such as an MRI, CT scan, lumbar puncture to look for the signs of infection in the brain or spinal cord, electroencephalogram (EEG) for seizures or specific patterns of electrical activity in the brain, and blood, urine or stool tests to check for the antibodies responsible for infection can be advised to such patients.”
Recommending paying close attention to the behaviour of those with prior psychotic issues, Dr Venkatachalam advised, “If you have prior neurological symptoms, it is generally challenging. But in the case of encephalitis, there will be a sudden deterioration from baseline. So if a patient has a history of psychotic problems, and suddenly there is a change in behaviour or an increase in seizures or headaches, the doctors should be alerted to conduct neuroimaging. The patient should get a brain MRI with contrast, where you give an injection and look for inflammation in the brain.”
“Sometimes the neurologist will also recommend a cerebrospinal fluid analysis where a needle is inserted into the spine to test the spinal fluid. This test is often not prescribed and patients are straightaway started on antibiotics or an antiviral agent, without getting an accurate diagnosis. A CSF test is an extremely important step in the diagnosis of encephalitis,” added Dr Venkatachalam.
Expanding on the views of Dr Pai and Dr Venkatachalam, Dr Agarwal informed, “A brain MRI is very helpful in finding out which area and to what extent the damage has occurred. Then you will need a lumbar puncture in which some fluid is removed from the spinal canal. This is the normal fluid that is around the brain. The examination of this fluid enables you to find out if there is inflammation in the brain, and again if there is any virus or any antibody that is causing this inflammation. The type of encephalitis is often diagnosed through this important test. The third test is an electroencephalogram or an EEG to test for intra-seizures and the extent or frequency of the seizures, which can help a neurologist deduce the type of medicines and their quantity that needs to be administered to the patient.”
Dr Venkatachalam informed that the onus of correct diagnosis and timely treatment lies on the doctor, as it is their responsibility to accurately identify the disease and refer the patient to a higher centre for further evaluation. Generally, the symptoms of encephalitis could be life-threatening so one shouldn’t be managing them at home with oral medication, Dr Venkatachalam suggested, “Patients will need intravenous medication and ICU monitoring. The patient also needs to complete their therapy and then only these patients need to be discharged. Very often the patients get better with one or two days of antiviral or antibiotics and then they feel fit to go home. We sometimes actually have to convince them that you have to complete the course of your antiviral or your antibiotics because recurrences can happen, or it will flare up again.”
However, even after prolonged targeted therapy, the inflammation in the brain as a result of encephalitis may persist, even after the patient has stopped displaying debilitating symptoms. This could lead to an enhancement of the patient’s poor condition and may cause them to relapse.
To tackle this issue, Dr Agarwal advised, “After the acute phase of encephalitis is over, there may be residual damage in the brain leading to complications. This residual damage may cause dementia. Even though the patient has recovered enough to get back home, they may have difficulty with memory or behaviour. Subsequently, the patient will require multiple medicines to control this condition, which they may need to continue for many years.”
Tackling rampant Japanese encephalitis outbreaks
The two most common causes of encephalitis are viral encephalitis which is due to infection, and the other is autoimmune encephalitis. In India, a lot of parasitic infections are extremely common. Infections that can cause encephalitis are herpes, Japanese encephalitis, dengue, and even measles. Cases of Japanese encephalitis are very common in rural areas of India, especially where there are many crops and paddy cultivation that foster mosquitoes which can spread viral infections that can cause encephalitis.
Japanese encephalitis cases account for around 15 per cent of the reported encephalitis cases, with 68,000 clinical cases reported annually across Asia, as informed by the National Health Mission.
To tackle this rampant outbreak of Japanese encephalitis, Dr Pai advised, “The best way to deal with Japanese encephalitis virus infection is to safeguard oneself from mosquito bites. One should use insect repellent, wear long-sleeved clothes and full pants, and get vaccinated as suggested by the doctor. Effective programmes and campaigns should be conducted regarding this fatal condition and the importance of vaccination.”
Urging public health organisations to intervene to contain the outbreak of encephalitis causing infections, Dr Venkatachalam recommended, “Try to find out what is the source and try to restrict that outbreak to that location itself. In such scenarios, preventive measures must be employed. See that the environment is properly sanitised, the mosquitoes are eliminated, the larvae are eliminated, and regular fumigation practices are being conducted. Usually what we do as doctors is notify public health organisations about the probable cause behind such outbreaks and what to look for.”
“In northern India, regular outbreaks of Japanese encephalitis seem to happen, a vaccine is available against Japanese encephalitis, but it is not so commonly used in our country because at this point it is not an endemic disease, we have sporadic outbreaks,” added Dr Venkatachalam.
“Containing Japanese encephalitis and similar encephalitis causing infections requires an epidemiological approach where rather than treat one patient, organisations have to act on another level where control of these mosquitoes from breeding needs to be conducted at government level by providing education, sanitation, and vaccination to enable symptom recognition, timely diagnosis, and quick treatment, through a multi-pronged attack,” concluded Dr Agarwal.
The burden of encephalitis in India can be tackled only through effective surveillance and controlled breeding of infection-causing mosquitoes, especially in rural parts of India. Additionally, the masses need to be made aware of this lesser-known, yet commonly occurring disease that plagues thousands of patients every year across India so that they can seek timely intervention from a neurologist and receive effective treatment before it’s too late.