Herpes simplex encephalitis (also known as HSV encephalitis for short) is an inflammation of the brain caused by herpes simplex viruses. After a phase of nonspecific flu-like symptoms, the patient presents with characteristic neurological and neuropsychological symptoms as the disease progresses. With early treatment, the prognosis is good.
What is herpes simplex encephalitis?
Herpes simplex encephalitis is an inflammation of the brain (encephalitis) that results from infection with herpes simplex viruses. It is usually herpes simplex virus type 1 (oral strain), very rarely herpes simplex type 2 (genital strain). The disease affects women as well as men. It occurs most frequently between the ages of 20 and 30 and worldwide. The viruses have usually been latent in the body since childhood. In herpes simplex encephalitis, they enter the brain via nerve cords. There, they lead to hemorrhages, necrosis (death of tissue) and swelling. The result is characteristic neurological and neuropsychological symptoms emanating from the respective focus of infection (so-called “focus symptoms”). With early treatment, the prognosis is good. If the inflammation also affects the meninges (meninges), doctors refer to it as herpes simplex meningoencephalitis.
Causes
Herpes simplex encephalitis is caused by infection with herpes simplex virus (usually type 1). Initial infection with herpes simplex virus type 1 usually occurs in childhood. The pathogen remains unnoticed in the body for a long time. However, it can become active again at any time and trigger the typical vesicular rash around the lips. If the immune system is weak, the viruses can migrate through the nose via the olfactory mucosa and the olfactory nerves into the central nervous system. From there, they enter the frontal lobe and temporal lobe of the brain. This usually occurs first on one side, and later on the other. In the affected brain regions, hemorrhages and necrosis occur, as well as swelling around the affected area of the brain (cerebral edema). This leads to the characteristic neurological and neuropsychological symptoms.
Symptoms, complaints, and signs
Herpes simplex encephalitis progresses rapidly and in several stages. Initially, the patient presents with nonspecific flu-like symptoms such as severe headache and high fever for several days. After a temporary improvement, the affected person shows psychomotor and mental changes. Behavioral changes, confusion, disorientation, and perceptual disturbances may occur. Often, the patient is unable to speak after some time (aphasia). Mild hemiplegia may develop. Epileptic seizures occur in more than half of the cases. These are initially confined to one area of the brain (focal seizures), but may then spread to both sides of the brain (generalized seizures). This may be accompanied by painful neck stiffness and clouding of consciousness. Without treatment, coma may result. If the intracranial pressure rises too high, the patient may die from it.
Diagnosis and course
Part of the basic diagnosis is an examination of the cerebrospinal fluid (CSF), which is obtained during a lumbar puncture. The cerebrospinal fluid is examined for certain values that, if abnormal, may indicate herpes simplex encephalitis. If necessary, it is also examined for the genetic material of the virus. However, it usually takes several days before the result is available. After about a week, the body produces antibodies against the herpes simplex virus type 1, which can then be detected in the blood and also in the cerebrospinal fluid. In addition to the nerve fluid examination, a CT (computer tomography) or an MRI (magnetic resonance imaging) of the skull is performed. MRI will show necrosis and swelling. A CT is usually still unremarkable within the first few days that symptoms appear. An EEG (electroencephalography) may show evidence of damage in the affected brain regions. Differential diagnoses should exclude septic sinus thrombosis (blood clot in the brain), cerebral infarction, and intracerebral hemorrhage (bleeding in the brain with the source of bleeding in brain tissue) with associated infection. Herpes simplex encephalitis progresses rapidly in several stages.Since it is often fatal if left untreated, treatment must be initiated even before the final diagnosis is made. If the disease is treated early, about 80 percent of patients survive. About half of the survivors are left with neurological sequelae such as memory impairment or paresis (paralysis). Furthermore, there is an increased risk of permanent seizure disorders originating from the brain region that was affected by herpes simplex encephalitis.
Complications
Herpes simplex encephalitis usually causes inflammation in the brain. This inflammation is recognized late, because the initial symptoms and signs are not particularly characteristic of the disease. In the further course, psychological and neurological restrictions of the patient may occur if the herpes simplex encephalitis is not treated immediately. The affected person primarily suffers from fever and headaches. Furthermore, the inflammation in the brain leads to a severe disorientation and changes in behavior. There are disturbances in thinking and in orientation. The patient’s actions are also severely restricted. Furthermore, speech disorders occur and the affected person can no longer speak during the course of the disease. The quality of life is extremely reduced by herpes simplex encephalitis. As a rule, the disease makes the patient dependent on the help of other people. Without treatment, loss of consciousness and further coma will occur. The affected person will die if the intracranial pressure is not reduced. Treatment of herpes simplex encephalitis is not possible in every case. In most cases, patients die from the disease. However, treatment with antibiotics may be possible, but the course of the disease cannot be predicted.
When should you go to the doctor?
Even a classic herpes infection should be treated medically. The typical vesicular rash around the lips requires diagnosis and treatment to prevent the development of herpes simplex encephalitis. If headache, high fever and other flu-like symptoms are noticed, the virus may have already spread to the central nervous system. In this case, the family doctor must be consulted immediately. If the symptoms recur after a temporary improvement, usually accompanied by psychological complaints, herpes simplex encephalitis is suspected. A visit to the doctor is indicated if behavioral abnormalities, perceptual disturbances or orientation disorders are noticed. Typical of encephalitis is hemiplegia, often accompanied by epileptic seizures. In the event of these symptoms, the emergency physician must be called. At the latest when a stiffening of the neck is noticed, the disease must be medically clarified and treated. Herpes simplex encephalitis is a serious disease that can be fatal without medical care. Therefore, the warning signs mentioned should be clarified quickly. Especially at-risk groups such as people with a weakened immune system should go to the doctor immediately with the signs of HSV encephalitis.
Treatment and therapy
Because 70 percent of patients die if untreated, therapy with aciclovir must be initiated immediately if there is a reasonable suspicion of herpes simplex encephalitis. This applies even if the pathogen has not yet been identified beyond doubt at this point. Aciclovir stops the multiplication of the herpes simplex viruses. In the event that the brain inflammation is not due to herpes simplex viruses but is due to a bacterial disease, a broad-spectrum penicillin is also initially given. The brain edema is treated with osmotherapy. This involves giving the patient a highly concentrated sugar solution that binds water from the edema due to osmosis. The epileptic seizures are also treated with medication. Further therapeutic measures depend on the patient’s condition, what other symptoms he or she is suffering from, and what other findings the examinations reveal.
Outlook and prognosis
In contrast to bacterial meningitis, viral brain infection tends to be associated with lower mortality. However, there is a risk of recurrence, as the affected virus can lodge in the body and break out again after a period of dormancy. Treatment as soon as possible determines the chances of recovery from encephalitis.The rather aggressive herpes simplex virus poses a great danger to life and limb if left untreated. Statistically, about 70 percent of patients succumb to the consequences of the disease if timely therapy is not administered. Accurate identification of the pathogen and appropriate medication significantly increases the likelihood of survival. Although approximately 80 out of 100 patients recover, this does not eliminate the risk of sequelae. The risk from TBE viruses is much lower, with a 98 percent probability of recovery. Consequences of encephalitis caused by herpes viruses often impair former patients in their everyday life. Cognitive impairments and manifesting muscle weakness are particularly common in severe courses. Children tend to develop hydrocephalus and suffer additional hearing damage. Depending on the affected area, personality changes may be observed. A particularly risky course is pending in the case of a permanent tendency to convulsions (status epilepticus). The spontaneous occurrence of cerebral edema is also life-threatening. Such consequences make successful therapy immensely difficult and require long-term follow-up care for the patient. The earlier the disease is detected, the more likely long-term complications will not occur. A complete recovery without brain damage is then within the realm of possibility.
Prevention
While vaccination can be given against many other agents that cause encephalitis, this is not possible with herpes simplex virus. Nor is there any other drug treatment that can prevent the virus from reemerging after initial infection. A strong immune system is considered the best protection. A healthy lifestyle with a balanced diet and exercise supports this.
Follow-up care
It is crucial for follow-up care to begin as early as possible. In the early stages, the patient is still very weak and lacks strength and already has great difficulty sitting by himself. Exercises by occupational and physical therapists are adapted to this situation and the patient is encouraged in a targeted and slow manner. As the patient’s mobility increases, the intensity and duration of the exercises are increased. It is important that the patient himself also performs small exercises outside the therapy sessions and does not allow himself to be discouraged by the lack of strength. Under certain circumstances, additional psychotherapy can help to find the necessary patience for oneself and one’s body and to act with a lot of mindfulness and iron will. Even after discharge from the hospital, both physical and occupational therapy must continue, with the goal of the patient being able to manage his or her own daily life on his or her own as soon as possible. Once this interim goal is achieved, the next step is to work on restoring the patient’s ability to work so that he or she can also regain financial independence. There is no fixed schedule for rehabilitation. The patient decides together with the attending physician when the personal goals set have been reached and the affected person can also manage without outside help.
What you can do yourself
In the case of herpes simplex encephalitis, no self-help options exist apart from medical options for therapies. There are no alternatives to immediate medical treatment for this condition. Nevertheless, the quality of life of survivors after herpes simplex encephalitis can be significantly improved by certain measures. Those affected can find help in this regard primarily in self-help groups, which exist in various larger cities, but also in social networks. There are also a number of books on the subject of herpes simplex encephalitis and living with the long-term consequences of such a disease, most of which have been written by sufferers. Helpful testimonials can also be found in various Internet forums. In many cases, survivors of herpes simplex encephalitis suffer from cognitive deficits such as memory disorders or behavioral problems. Family members of those affected must be particularly understanding in this situation. They can help by involving the affected person in everyday life and challenging him or her physically and cognitively as far as possible. Apart from further treatment and therapy of the late effects of herpes simplex encephalitis, psychotherapeutic help can also be sought.
