Encephalitis among children, Child Health Nursing

encephalitis

1. Encephalitis LAXMI DAHAL Assistant Professor Department of Child Health Nursing

2. DEFINITION Encephalitis is an inflammatory process of the central nervous system that affects brain parenchyma. Encephalopathy implies cerebral dysfunction due to circulating toxins, poisons, abnormal metabolites or intrinsic biochemical disorders affecting neurons but without inflammatory response.

3. DEFINITION Encephalitis is almost always accompanied of the adjacent meninges, thus termed as meningoencephalitis.

4. INCIDENCE Epidemiologic studies estimate the incidence of viral encephalitis at  3.5-7.4 per 100,000 persons per year . Overall, viruses are the most common cause of encephalitis.

5. Classification Acute encephalitis may be: 1. Primary: Direct invasion and replication of the virus leading to tissue necrosis, e.g. encephalitis due to herpes simplex, Arbo viruses and Rabies

6. Classification 2. Para infectious encephalitis (PIE) : post-infectious inflammatory responses characterized by immune mediated central nervous system damage, demyelination with preservation of neurons and their axons. Distinction between primary infection and Para infection is however difficult.

7. Etiology The common etiologic agents for acute encephalitis and acute meningoencephalitis are listed below: 1. Viruses: Herpes simplex 1 and 2, Varicella zoster virus, Mumps virus, Measles virus, Japanese B encephalitis virus, Rabies virus, Ebstein - bar virus, Influenza virus, Enteroviruses, Adenovirus, HIV, etc. 2. Bacteria: H. influenza, N. meningitides, S. pneumoniae, M. tuberculosis,

8. Etiology 3. Spirochetes: Borrelia , Leptospira , Treponema pallidum 4. Fungi: Cryptococcus neoformans , coccidioidomycosis , blastomycosis histoplasmosis , Aspergillus , Candida. 5. Protozoal: Plasmodium falciparum , Naegleria , Acanthamoeba , Toxoplasma 6. Helminths : Schistosoma 7. Others : Chlamydia, rickettsia , mycoplasma

9. PATHOGENESIS: Portals of entry are virus specific. i.e. mosquito bite, animal bite, exposure to secretions of animals, etc. Virus then replicates outside the CNS but later gains entry to the CNS either by hematogenous spread or neural pathways. This leads to disruption in neural cell functioning ultimately results in perivascular congestion, hemorrhage & a diffuse inflammatory response affecting gray matter.

10. CLINICAL MANIFESTATIONS Antecedent history of viral infections, exanthema or vaccination Fever Sensorial alterations ranging from irritability to deep coma Seizures

11. CLINICAL MANIFESTATIONS Neurologic defects Extrapyramidal symptoms may be present in Japanese encephalitis Mumps encephalitis can precede or be associated with parotitis.

12. DIAGNOSTIC INVESTIGATIONS Lumbar puncture: Mild pleocytosis, slightly elevated protein and normal sugar. Red blood cells in a non- traumatic lumbar puncture is characteristic of herpes simplex virus encephalitis. Viral cultures, serology and PCR may be performed.

13. DIAGNOSTIC INVESTIGATIONS… 2. Electroencephalogram: Diffuse slow wave activity indicating cerebral dysfunction. Periodic lateralized epileptiform discharges (PLED) is a characteristic EEG finding in HSV and other focal encephalitis.

14. DIAGNOSTIC INVESTIGATIONS… 3. Neuroimaging: CT and MRI of the brain can help to differentiate viral encephalitis from metabolic or toxic disorders and acute disseminated encephalomyelitis.

15. DIFFERENTIAL DIAGNOSIS Acute Hypoglycemia Brain Abscess in Emergency Medicine Herpes Simplex Encephalitis Meningitis Status Epilepticus Systemic Lupus Erythematosus (SLE) Toxoplasmosis Tuberculosis (TB)

16. Emergency Management Airway: Maintain patency and provide assisted ventilation if necessary. Hyperpyrexia: Cold sponging and antipyretics Shock: Vasopressors (Dopamine and Dobutamine ) ABC’s (airway, breathing, circulation) must be immediately evaluated & stabilized.

17. Emergency Management … Place the patient on non-invasive monitors, such as pulse oximeter & cardiorespiratory monitor. Initially administer 100% supplemental oxygen via face mask or nasal cannula .

18. Emergency Management … If the child is in respiratory failure, intubation should be considered. Fluid resuscitation: 20ml/kg of an isotonic crystalloid infusion, such as 0.9% isotonic NaCl or RL over 5 minutes or less. Re-evaluate the patient and repeat the same dose if still in shock.

19. Emergency Management … Seizures: Intravenous lorazepam (0.05-0.1 mg/kg IV slowly infused over 2-5 min) and phenytoin (20 mg/kg IV ) Raised intracranial pressure: IV infusion of 20% mannitol solution and corticosteroid.

20. Supportive Management Analgesics and antipyretics for viral meningoencephalitis. Hydration with plenty oral fluids. Airway protection, prevention of aspiration, Prompt treatment of seizures and lowering the raised intracranial pressure.

21. Pharmacological management 1. Specific therapy : Acyclovir (10 mg/kg IV, TDS in children with normal renal function; 20 mg/kg IV, TDS in neonates) Should be initiated in all patients with suspected encephalitis as soon as possible, pending results of diagnostic studies. 

22. Nursing management 1. Nursing assessment Fever, headache, nausea and vomiting, mental status changes. Meningeal signs – nuchal rigidity (stiff neck), photophobia. Seizures, motor deficits, personality changes.

23. Nursing assessment… Signs of brain stem involvement, such as nystagmus, extraocular nerve palsies, hearing loss, dysphagia, and respiratory dysfunction. Patients with hypothalamic-pituitary involvement may develop diabetes insipidus , hypothermia, or SIADH

24. Nursing diagnosis Acute pain related to irritation of encephalon. Ineffective cerebral tissue perfusion related to inflammatory process, increased intracranial pressure.

25. Nursing diagnosis… Altered thought process related to changes in the level of consciousness. Imbalanced nutrition: less than body requirement related to anorexia, fatigue, nausea and vomiting Risk for injury related to disorientation, seizures and unfamiliar environment.

26. COMPLICATIONS Seizures Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) Increased intracranial pressure (ICP) Coma Brain edema Personality changes

27. COMPLICATIONS… Epilepsy Paralysis Hearing or vision defects Speech impairments

28. PROGNOSIS Ten to forty percent of patients die during the acute stage. Many of the survivors have severe neurological sequel in the form of cognitive impairment, behavioral abnormality, focal weakness, language impairment, seizures and a variety of movement disorders especially following Japanese encephalitis.

29. PROGNOSIS… In 5- 30% of children with Herpes encephalitis, the neurological evolution of the disease is characterized by acute clinical relapse in which the resurgence of cerebral viral replication or an immune-inflammatory disorder is implicated.

30. PREVENTION CNS viral infections by measles, mumps, polio and varicella are preventable through appropriate vaccination against these viruses.

31. PREVENTION… Control of insect vectors and adequate personal protection reduce the incidence of arboviral infections. There are 3 types of JE vaccines, mouse-brain derived inactivated vaccine, cell culture derived inactivated vaccine and cell-culture derived live attenuated JE vaccine. Among them live attenuated vaccine is the most efficacious.

32. Reference Datta P. Pediatric nursing. 3 rd ed. New Delhi: Jaypee Brothers Medical Publishers (P) Ltd; 2014. Gupta P. Textbook of Pediatrics.1 st ed. New Delhi: CBS Publishers and Distributors Pvt. Ltd; 2016. Paul V K. Bagga A. Ghai Essential Pediatrics. 8 th ed. New Delhi: CBS Publishers and Distributors Pvt. Ltd; 2014. Shrestha T. Essential of child health nursing. 2 nd ed. Kathmandu: Medhavi Publication; 2016.

33. Reference… Encephalitis - Symptoms and causes [Internet]. Mayo Clinic. 2021 [cited 12 April 2021]. Available from: https://www.mayoclinic.org/diseases-conditions/encephalitis/symptoms-causes/syc-20356136 Encephalitis: Types, symptoms, causes, and treatment [Internet]. Medicalnewstoday.com. 2021 [cited 12 April 2021]. Available from: https://www.medicalnewstoday.com/articles/168997 4. A summary of encephalitis research in 2019 [Internet]. The Encephalitis Society. 2021 [cited 12 April 2021]. Available from: https://www.encephalitis.info/blog/encephalitis-research-2019

34. Reference… Shresta S, Awale P, Neupane S, Adhikari N, Yadav B. Japanese Encephalitis in Children admitted at Patan Hospital. Journal of Nepal Paediatric Society. 1970;29(1):17-21.