Makindo Medical Notes Comprehensive Medical Encyclopedia | Education for Healthcare Professionals

Makindo Medical Notes "One small step for man, one large step for Makindo"
Download all this content in the Apps now Android App and Apple iPhone/Pad App

MEDICAL DISCLAIMER: The contents are under continuing development and improvements and despite all efforts may contain errors of omission or fact. This is not to be used for the assessment, diagnosis, or management of patients. It should not be regarded as medical advice by healthcare workers or laypeople. It is for educational purposes only. Please adhere to your local protocols. Use the BNF for drug information. If you are unwell please seek urgent healthcare advice. If you do not accept this then please do not use the website. Makindo Ltd.

Acute Encephalitis

About

Anaesthetics and Critical Care

Obstetrics Gynaecology

Oncology

Ophthalmology

Oral Medicine and Dentistry

Statistics and Research

Stroke

Surgery

Toxicology

Trauma and Orthopaedics

Twitter

Urology

Acute encephalitis constitutes a neurological emergency, and it is imperative that appropriate treatment is started as soon as possible based on the likely clinical diagnosis. Take expert neurological advice.

Initial Encephalitis Management Summary
ABC, Admit for LP. CT if any signs suggesting SOL, Bloods +/- CSF cultures. Start IV Aciclovir 10 mg/kg TDS initially if HSV Encephalitis is considered. MRI is useful to support diagnosis. Neurology consult. Start IV Cefotaxime if Meningitis is considered while awaiting results.

About

Viral encephalitis is a medical emergency requiring prompt diagnosis and treatment.
It involves inflammation of brain parenchyma, typically due to viral invasion.
The prognosis varies based on the pathogen type and the patient's immune status.
Early diagnosis and treatment with antiviral therapy significantly improve outcomes in HSV encephalitis.

Causes

Cause	Clinical Features	Investigations	Treatment
Viral Encephalitis (e.g., HSV-1, HSV-2, Varicella Zoster Virus)	Fever Headache Altered mental status Seizures Focal neurological deficits (e.g., hemiparesis, aphasia)	CSF analysis: Elevated WBCs, protein, normal glucose; PCR for viral DNA MRI brain: Temporal lobe hyperintensities (common in HSV) EEG: Temporal lobe epileptiform activity	IV Aciclovir (especially for HSV, VZV) Supportive care (hydration, antipyretics) Anticonvulsants for seizure management
Autoimmune Encephalitis (e.g., Anti-NMDA receptor encephalitis)	Psychiatric symptoms (e.g., agitation, hallucinations) Memory deficits Seizures Dyskinesias Autonomic instability	CSF: Mild pleocytosis, elevated protein, oligoclonal bands Anti-NMDA receptor antibodies in serum/CSF MRI: Often normal or nonspecific changes EEG: Diffuse slowing, epileptiform discharges	Corticosteroids, IVIG, or plasmapheresis Second-line: Rituximab, cyclophosphamide if refractory Treat underlying neoplasm if present
Bacterial Encephalitis (e.g., Listeria, Mycoplasma)	Fever Headache Confusion Focal neurological signs Seizures (less common than viral causes)	CSF: Elevated WBCs, high protein, low glucose, Gram stain, and culture MRI: Focal lesions or abscesses Blood cultures to identify causative organism	IV antibiotics (e.g., ampicillin for Listeria) Supportive care (hydration, monitoring) Treat complications like increased intracranial pressure (ICP)
Fungal Encephalitis (e.g., Cryptococcus, Aspergillus)	Fever Headache Meningismus Altered mental status Cranial nerve palsies	CSF: Elevated WBCs, high protein, low glucose; India ink stain for Cryptococcus Cryptococcal antigen test in CSF or serum MRI: Nodular lesions or abscesses	Antifungal therapy (e.g., amphotericin B plus flucytosine for Cryptococcus) Long-term oral fluconazole for maintenance Management of increased ICP if present

Clinical Presentation (Emphasis on HSV Encephalitis)

Wide range of symptoms, from mild confusion to severe coma.
Seizures (especially temporal lobe), fever, headache, and focal neurological signs like aphasia or hemiparesis.
Specific signs like rigidity or chorea (e.g., in Japanese encephalitis).
Rashes in HHV6 or Zoster infections.

Investigations

FBC: Raised WBC count, raised CRP.
U&E: Assess renal function before starting Aciclovir.
CSF analysis: Typically shows clear fluid with 10-700 lymphocytes, raised protein, positive PCR for HSV or other viruses.
MRI: Hyperintensities in temporal lobes, cingulate gyrus, or insular cortex (characteristic of HSV).
EEG: Temporal lobe involvement.

Management

Stabilize ABCs and consider ITU if there is raised ICP or severe disease.
Aciclovir 10 mg/kg IV every 8 hours for 14-21 days depending on immune status and PCR results.
Monitor renal function and ensure adequate hydration during Aciclovir therapy.
Use anticonvulsants for seizure control (e.g., Levetiracetam or Phenytoin).
For raised ICP, consider IV mannitol or mechanical hyperventilation.

Poor Prognostic Features

Age > 30 years
Coma at presentation
Bilateral abnormalities on EEG
High CNS viral load
Delay in treatment (>4 days from symptom onset)
Abnormal findings on CT scan

Late Complications

Cognitive deficits: Memory impairment, poor concentration.
Emotional changes: Irritability, depression, and mood swings.

References

PLEASE NOTE LEGAL ADVICE: The contents are under continuing development and improvements and may contain errors of omission or fact. Feedback vital and always welcome at drokane at gmail.com. This is not to be used for the assessment, diagnosis or management of patients. It should not be regarded as medical advice. It is only for educational purposes. Please adhere to your local protocols. If you are unwell please seek healthcare advice from your doctor. This does not replace senior or specialist advice. If you do not accept this then please do not use the website. If you need medical advice, please consult a doctor or other appropriate medical professional. If you are a medical professional and you need advice then speak to your senior or colleagues.

Edit