Herpes simplex encephalitis
Herpes simplex encephalitis Causes
HSE is thought to be the result of the retrograde transmission of virus from a peripheral site on the face to the brain along a nerve axon following HSV-1 reactivation. In children older than 3 months and in adult patients, HSV-1 is responsible for virtually all cases. HSV-2 causes a small number of cases, most particularly in the immunocompromised host.
Herpes simplex encephalitis Definition
Herpes simplex encephalitis (HSE) is a very serious disorder and one of the most severe viral infections affecting the human central nervous system.
Herpes simplex encephalitis Diagnosis
Most hospitals perform an EEG (an electro-encephalogram to monitor the brains electrical activity), plus brain imaging by a CT scan ( computerised tomography), or, for a clearer picture, an MRI (magnetic resonance imaging). These procedures, combined with careful and continuous clinical assessment provide data which may be suggestive of HSE and, importantly, may exclude other conditions. However the diagnostic procedure now more widely-accepted as providing an aetiological diagnosis of HSE is the polymerase chain reaction (PCR). This has been developed using the methods of modern molecular biology.
Herpes simplex encephalitis Symptoms and Signs
Most individuals with HSE display a decrease in their level of consciousness and an altered mental state presenting as confusion and changes in personality. Increased numbers of white blood cells can be detected in their cerebrospinal fluid without the presence of pathogenic bacteria and fungi, and they typically have a fever. Some patients with HSE will undergo seizures.
Herpes simplex encephalitis Treatment
The role of Acyclovir is crucial to the treatment of HSE. If therapy can be initiated during the first few days of the illness there is a dramatic reduction in the mortality rate - c.80% down to 25%.