Encephalitis overview and Definition

Encephalitis is inflammation of the active tissues of the brain caused by an infection or an autoimmune response. The inflammation causes the brain to swell, which can lead to headache, stiff neck, sensitivity to light, mental confusion and seizures. The disease might be due to infectious or Autoimmune

Clinical signs & symptoms






Cerebral edema


Febrile illness

Heamorrhagic fever which results in damage to the blood vessels. severe bleeding is manifested.

Excessive sleepiness

Confusion and disorientation





Memory loss

Other behavioral changes

Cognitive impairment



Differential Diagnosis

Detection of virus-neutralizing antibodies in combination with recent travel history to an endemic area may be meaningful.

Immunosorbent assay:

 Detect the virus specific IgM or IgG antibodies.

Greater than fourfold rise in titer between acute and convalescent sera  and  cerebo spinal fluid containing virus specific IgG or IgM or both are the diagnostic features.

Real-time polymerase chain reaction (RT-PCR):

 It is valuable in the early confirmation of arbovirus infections. However, the value of RT-PCR is limited to diagnosis in the viraemic phase, with later infection requiring serology.

Direct immunofluorescence assay :

to detect IgM has a high sensitivity and specificity and is used in the latter stages. However, the use of these tests in the tropics may be limited by financial constraints.

A normal erythrocyte sedimentation rate- and a negative rheumatoid factor are useful to differentiate virus arthritis from rheumatoid arthritis. Extensive, symmetrical joint involvement, particularly of the metacarpophalangeal and proximal joints, the presence of rheumatoid nodules or anti-cyclic citrullinated peptide (anti-CCP) antibodies favours rheumatoid arthritis over  with chronic arthropathy. The presence of lower limb asymmetrical joint involvement with axial skeletal affliction favours the diagnosis of spondyloarthropathy

Lumbar puncture:

The spinal fluid is tapped and it is sent to the laboratory for further investigations.

Needle biopsy:

It can be used to collect the brain tissue and examination is done under microscope.

Imaging tests: CT scan, MRI scan SPECTs and  PET scans help doctors locate the tumor and determine if it is cancerous or benign. Your doctor may also look at other parts of the body, such as the lungs, colon or breasts, to identify where the tumor started.

Neurological exam: During a neurological exam, your doctor will look for changes in your balance, coordination, mental status, hearing, vision and reflexes. These changes can point to the part of your brain that may be affected by a tumor.

Intracranial pressure monitoring:

The ICP measures the pressure created inside the skull.



  • Keep your vaccinations up to date, especially while travelling to the areas of encephalitis virus prone.
  • Use proper hygiene and hand-washing to help prevent the spread of viruses and bacteria.
  •  Avoid mosquito and tick exposure