Herpes Simplex Encephalitis (HSE) is a rare but severe infection of the central nervous system associated with the presence of the ‘Herpes Simplex Virus Type 1’ (HSV-1). It usually leads to inflammation of the brain, leading to several cerebral dysfunctions. To learn more, read on…
The human body is constantly exposed to infections by numerous viruses and bacteria that co-exist in the ecosystem around us. One such virus, the herpes virus is transmitted through oral contact with an affected person. Essentially, two members of the herpes virus family commonly affect humans. These include Herpes Simplex Virus 1 (HSV-1) and Herpes Simplex Virus 2 (HSV-2).
The infection caused by these viruses could be symptomatic or asymptomatic, making diagnosis difficult. Herpes simplex commonly affects the face and mouth region, and in some cases the genitals. It also manifests in the form of herpetic whitlow, gladiatorum, ocular herpes, and cerebral herpes infection. Bell’s palsy, Mollaret’s meningitis, and neonatal herpes, are all different manifestations of the herpes simplex virus.
What is Herpes Simplex Encephalitis
The term encephalitis refers to the inflammation of the brain. Herpes simplex encephalitis refers to the viral infection that affects the central nervous system. It is thought to be the direct effect of HSV-1 infection, and is commonly observed in adolescents (under 18 years of age), people who are above 50 years, and seropositive patients who have a family history of orofacial herpes.
The infection is spread via retrograde transmission. It passes along the nerve axon, and gradually moves towards the brain. Initially, the virus remains dormant in the trigeminal cranial nerve ganglion, before lodging itself within the temporal lobes of the brain. However, in case of neonates, viral encephalitis is caused due to the presence of HSV-2, during the delivery of the infant.
The viral attack causes the neurons to be subjected to a hemorrhagic process, throughout the inferior frontal lobes and medial temporal. The mechanisms of cellular damage are viral and immune-mediated processes. Brain infection is the result of direct neuronal transmission of the herpes simplex virus from some peripheral site. The virus is known to affect people across the continents, irrespective of race, sex, or previous clinical history. Once contracted, the symptoms need to be addressed in time to restrict the deterioration of the central nervous system, and/or any fatality associated with the condition.
HSE results in general as well as focal cerebral dysfunction. The sporadic attack does not follow a seasonal pattern. The classic symptoms are as follows.
- Behavioral changes, like a show of confusion
- Memory loss
- An altered level of consciousness
- Dysphasia, which is a condition, wherein an individual experiences trouble while communicating, be it written, oral, or verbal
- Visual field loss
- Papilledema, which is caused due to increased intracranial pressure, leading to swelling of the optic disc
- Anorexia, which makes the patient restrict his/her food intake, with a general fear of gaining weight
- Muscle weakness on one side of the body
- Cranial nerve deficits
- Partial paralysis
- Loss of consciousness, and even coma
- Sensitivity to light
Certain signs that are noted and studied by a medical practitioner/doctor may help in diagnosing the condition. These include:
- Increased protein in cerebrospinal fluid, and lymphocytes in blood
- Temporal lobe swelling
- Viral cultures of cold sores, if present
The symptoms are quite like those associated with meningitis. Though the condition does not surface with skin lesions, the causal virus is the same (in basic genre), which causes the herpes simplex. The treatment involves:
- A dedicated nutritional support. A diet rich in arginine, like chocolates, nuts, oats, should be avoided as this amino acid helps the virus grow, divide, and be active. Lysine-rich food like mangoes, fish, chicken, eggs, help to restrict the virus from further growth, aiding in a faster healing process.
- The patient has to be regularly monitored for intracranial pressure and seizures. The dedicated treatment options to address the increased intracranial pressure range from elevating the ‘head’ of the bed, to administration of mannitol, and steroids.
- Seizures are commonly managed with the help of anticonvulsant therapy, and administration of benzodiazepines.
- Doctors resort to biopsy and lumbar puncture only in the absence of non-toxic, antiviral medication. This neurological emergency demands a proper evaluation for timely rehabilitation.
- Pharmacotherapy involves the use of acyclovir and vidarabine. Antivirals help to shorten the course of clinical approach, preventing the development of latency.
The goal of therapies and medication is to prevent the development of further complications, and reduce morbidity. In the absence of timely treatment, HSE results in long-term neurological damage, and even death.
Disclaimer: This article is for informative purposes only, and does not in any way attempt to replace the advice offered by an expert on the subject.