VIRAL MENINGOENCEPHALITIS CSF PRESSURE : Normal or Slightly raised (80-150 mm of H20) LEUCOCYTES : few-1000 cells/mm3 - Initially poly morpho nuclear later mononuclear cells predominate PROTEIN : Usually 50 -200 mg/dL GLUCOSE : Normal or slightly reduced ACUTE DISSEMINATED ENCEPHALOMYELITIS CSF PRESSURE : Normal or Slightly raised LEUCOCYTES: 100 cells/mm3, lymphocytosis PROTEIN : Mildly elevated GLUCOSE : Normal

1. ENCEPHALITIS
INVESTIGATIONS
R SANJAY KUMAR
IV YEAR

2. INVESTIGATIONS
Careful history should be taken to arrive at
precise etiological diagnosis
Complete systemic examination should be done
Exposure to toxins should be carefully assessed

3. LUMBAR PUNCTURE
After excluding papilledema
Lumbar puncture is done to assess the cerebro-
spinal fluid
CSF- cytology, biochemistry, serology and cultures
are mandatory to assess the etiological agents in
causing encephalitis

4. CSF FINDINGS
VIRAL MENINGOENCEPHALITIS
 CSF PRESSURE : Normal or Slightly raised
(80-150 mm of H20)
 LEUCOCYTES : few-1000 cells/mm3 - Initially poly
morpho nuclear later mononuclear cells predominate
 PROTEIN : Usually 50 -200 mg/dL
 GLUCOSE : Normal or slightly reduced

5. SPECIFIC CSFFINDINGS
ACUTE DISSEMINATED ENCEPHALOMYELITIS
 CSF PRESSURE : Normal or Slightly raised
 LEUCOCYTES: 100 cells/mm3, lymphocytosis
 PROTEIN : Mildly elevated
 GLUCOSE : Normal

6. SPECIFIC FEATURES
 Herpes simplex virus-encephalitis
Is suggested by focal findings in CT OR MRI OR EEG
 Herpes simplex virus and enteroviruses
are detected by polymerase chain reaction of the CSF

7. INVESTIGATIONS
ELECTROENCEPHALOGRAM
EEG typically shows diffuse slow wave
activity usually without focal changes
 NEURO IMAGING STUDIES
CT OR MRI may show swelling of the
brain parenchyma

8. ISOLATION OF VIRUS
SITES FOR SPECIMEN FOR CULTURE:
1) Nasopharyngeal swabs 2) urine 3) feces
 Detection of viral DNA or RNA by PCR is the test of
choice in the diagnosis of encephalitis caused by
Herpes simplex, parecho virus and enteroviruses
 CSF serology is the diagnostic test for west nile virus

9. CT AND MRI IMAGING
 To exclude intracranial tumour or abscess
 MRI is the imaging of choice
IN HERPES SIMPLEX VIRUS ENCEPHALITIS
 MRI is senstitive in early stages
 Typical features:
# Areas of focal oedema in temporal lobes and orbital
surface of frontal lobes
# Abnormal areas may show enhancement with gadolinium

11. BRAIN BIOPSY
Brain biopsy is rarely performed but useful in
patients with focal neurological findings
Brain biopsy may be helpful to identify
Arbovirus,enteroviruses,tuberculosis and
malignancies

12. OTHER INVESTIGATIONS
 Serum electrolytes
 Blood sugar
 Urea
 Blood ammonia
 Metabolic screening

13. Arterial blood gas analysis
Serum lactate
Urinary ketones
Urinalysis
Toxicological studies
Serum lead level –in case of poisoning

14. THANK Y0U