encephalitisencephalitisencephalitis

1. ENCEPHALITIS
28/12/2017

2.  The inflammation of the brain substance may be
caused by viruses- bacteria- fungi-drugs –post
infectious and radiation.
 This is mostly due to herpes simplex virus
followed by Japanese encephalitis.
 The liable part of the brain are the temporal
lobes.

4.  Clinical features:
 It affects young adults usually. The clinical suspicion
will be directed by a careful history to indentify the
sequence of:
 Fever
 Headache
 Confusion
 convulsions

5.  It is important to enquire about behavioral
changes that are easily observed by the family
members or friends.
 Travelling history (epidemics) is important as
well as recent vaccination co morbid conditions
like DM.

6.  The main features in the acute phase may be
only a toxic febrile patient who has confusion
(low GCS). Focal signs may appear i.e. cranial
neuropathy or papilloedema.
 Detailed medical examination is essential
including the general and all systems.
 Temperature charts and other vitals.

7.  Routine blood tests are essential.
 CBC-ESR- CRP- U&Es- RBS- viral screening-
Urine analysis plus, CXR & U/S abdomen and
pelvis.

8.  The plan of investigations must include:
 Brain MRI
 LP and CSF analysis

9.  Other diseases that that may present like this
includes:
 Vascular events : Stroke- SDH- AVM
 SOL: Tumors- Granulmoa-Abscesses
 Chronic infections: TB Meningitis
 Chronic inflammation: Sarcoidosis- SLE

10.  All these diseases as well as viral encephalitis
may show focal signs or cranial nerve’s palsy at
presentation.
 Viral encephalitis may end with weakness,
dystonia or cognitive disability.

11.  MRI Brain is abnormal specially at day 3
onwards.
 Bilateral or unilateral temporal signals are
characteristic. Other areas may be affected in
other viruses or medical diseases.

14. THIS IS AN ESSENTIAL TEST
FOR THE DIAGNOSIS
 CSF analysis:
 Clear fluid
 May be under tension
 High number of lymphocytes over 5 cells-1000 mainly
lymphocytes. May be normal count or neutrophils early in
the course.
 Raised proteins 0.5-1g/dl
 Glucose may be normal / mild reduction.
 Negative Gram stain ZN stain and culture.
 PCR for HSV 95% sensitivity and specificity.

15.  Management:
 These patients are in great need of
vital signs assessment and
management.
 They are liable to arrhythmias, breathing
abnormalities up to respiratory failure, central
temperature issues and fluctuation of BP.
 They are usually managed in the ICU with full
support in the case of low GCS. This includes
mechanical ventilation as elective or emergency.

16.  The low GCS and seizures much compromise
their breathing and the hypoxia will worsen the
cerebral damage hence worsening the outcome.
 Antibiotics must be introduced for documented
infections.

17. BAD OUTCOME IS ASSOCIATED
WITH 2 DAYS OR MORE DELAY
IN TREATMENT
 Time is brain
 Time is memory
 Time is knowledge
 Time is concept
 Time is vision
 Time is hearing

18. UNTREATED HSV ENCEPHALITIS
MORTALITY IS 40-70%
SURVIVORS MAY HAVE LONG TERM
DISABILITY.
 The drug of choice is aciclovir infusion as
10mg/kg 8 hourly infused in normal saline over
40-0 minutes.
 Duration of treatment is 2-3 weeks.
 Dose must be adjusted in renal impairment.
 Antiepileptic drugs are usually needed in these
patients in the form of phenytoin infusion 100mg
8 hourly plus oral carbamazepine or lamotigene
or valproate.

19.  Antipyretics are essential.
 Cold sponging and low room temperature.
 Well balanced nutrition and hydration to face the
high metabolic needs.

20. OTHER LESS COMMON TYPES
 ADEM: Acute disseminated encephalomyelitis
is a disease of children and adolescents. It shows
similar lesions on MRI to multiple sclerosis but is
monphasic condition and lesions are larger than
MS plaques.

21. HIV ENCEPHALITIS
 Associated with high vial loads. Needs HAART.

22. HEMORRHAGIC POST INFECTIOUS ENCEPHALITIS HURT’S DISEASE:
 A very serious type of encephalitis that is post
infectious with extensive brain substance
bleeding. Mortality rate reaches 85%.

23. NMDA RECEPTOR ENCEPHALITIS
 A rare disease of young females. It is related to
the presence of ovarian teratoma that secrets
antibodies. Only removal of the tumor is
associated with remission of the condition.

24.  THE END