Encephalitis Flashcards
What is herpes simplex encephalitis?
Herpes simplex (HSV) encephalitis is a common topic in the exam, typically affecting the temporal lobes.
What are the common features of herpes simplex encephalitis?
Fever, headache, psychiatric symptoms, seizures, vomiting, and focal features such as aphasia.
Do peripheral lesions relate to HSV encephalitis?
Peripheral lesions (e.g. cold sores) have no relation to the presence of HSV encephalitis.
Which virus is responsible for the majority of HSV encephalitis cases in adults?
HSV-1 is responsible for 95% of cases in adults.
Which brain regions are typically affected by HSV encephalitis?
Typically affects the temporal and inferior frontal lobes.
What are the CSF findings in HSV encephalitis?
Lymphocytosis and elevated protein.
What is the preferred imaging technique for investigating HSV encephalitis?
MRI is better than CT for detecting changes.
What EEG pattern is associated with HSV encephalitis?
Lateralised periodic discharges at 2 Hz.
What is the treatment for herpes simplex encephalitis?
Intravenous aciclovir.
How does the timing of aciclovir treatment affect prognosis?
If treatment is started promptly, the mortality is 10-20%; left untreated, it approaches 80%.
MRI of a patient with HSV encephalitis. There is hyperintensity of the affected white matter and cortex in the medial temporal lobes and insular cortex.
MRI brain showing ring-enhancing lesion in the right frontal lobe with surrounding oedema
