Herpes simplex encephalitis in the elderly
Introduction
Introduction to herpes simplex encephalitis in the elderly Herpessimplex encephalitis (herpessimplexencephalitis) is a common sporadic viral encephalitis, also known as herpessimplexvirus encephalitis, which can be found in both hereditary herpes simplex virus infections and in recurrent patients. The pathogen herpes simplex virus (HSV) is divided into type I and type II. After inoculation in the peripheral part, the virus is detected by PCR technology, which proves to be latent in the body. Type I HSV is lurking in the olfactory bulb, olfactory tract and trigeminal sensory ganglia and is easy to induce encephalitis. Type II HSV is latent in the posterior root of the medullary nucleus and easily induces genital herpes simplex infection. Therefore, HSV often becomes the host immunosuppressive state. One of the pathogens that induce opportunistic infections. basic knowledge The proportion of illness: 0.001-0.003% Susceptible people: the elderly Mode of transmission: sexual transmission, contact transmission, mother-to-child transmission Complications: cerebral edema, coma
Cause
The cause of herpes simplex encephalitis in the elderly
Viral infection (55%):
Herpes simplex encephalitis is caused by herpes simplex virus invading the brain parenchyma and meninges. Herpes simplex virus is divided into two types, I and II, and type I is the pathogen of adult and elderly patients. Most cases are caused by herpes simplex virus type I.
Herpes simplex virus is a neurotropic DNA virus, surrounded by a stereo-symmetric protein capsid, surrounded by a lipid-like capsule, with a diameter of about 150-200 nm and a rectangular shape under electron microscopy. Nearly 90% of HSE is caused by HSV-I type, and only 6% to 15% is caused by HSV-II type. HSV-I is transmitted through respiratory or saliva contact, often without clinical symptoms or only as stomatitis, pharyngitis or respiratory diseases. The detection rate of antibodies in adults is as high as 90%.
Personal physique (10%):
Traditional Chinese medicine believes that the cause of this disease is due to the human body's qi deficiency, warm epidemic and damp heat epidemic.
Pathogenesis
Adults often have skin, mucosal herpes simplex virus infection, and lurk in the trigeminal semilunar or spinal ganglia, sometimes recurrent herpes simplex around the lips or sexual organs, only a few people in the body's immune function is reduced, latent virus activation, Along the axons into the brain, herpes simplex virus encephalitis occurs, and the lesions invade the cerebral hemispheres on both sides, often with temporal lobe and the frontal lobe.
Prevention
Herpes simplex virus encephalitis prevention in the elderly
Usually exercise more, improve disease resistance, prevent colds and intestinal infections, and treat them promptly and effectively.
It is necessary to pay attention to the elimination of mosquitoes, to maintain a healthy living environment, to pay attention to food hygiene, air-conditioned rooms should always open windows to ventilate.
Avoid direct contact with herpes simplex infections. Medical staff should wear gloves and should be isolated for close contacts.
Complication
Elderly herpes simplex encephalitis complications Complications, brain edema, coma
Concurrent cerebral edema, intracranial hypertension, coma and so on.
Symptom
Herpes simplex virus encephalitis symptoms in the elderly Common symptoms High fever meninges irritation personality changes herpes herpes convulsions coma
Symptoms and signs: The clinical symptoms of this disease vary greatly. The mild cases may only manifest as mild meningitis symptoms, signs, headache, fever, meningeal irritation or signs of mild brain damage, while typical herpes simplex encephalitis is often abrupt. Severe encephalitis with high onset and high mortality; sudden high fever, headache, due to temporal lobe and frontal lobe damage, the patient's personality changes, memory loss, mental symptoms, and soon develops to convulsions, coma within a few days. Meningeal irritation signs and focal signs are more obvious, and some patients may be accompanied by herpes on the skin mucosa.
Examine
Examination of herpes simplex virus encephalitis in the elderly
Cerebrospinal fluid examination: the pressure is often increased, the number of white blood cells is increased, mainly lymphocytes, some patients may have a large number of red blood cells in the cerebrospinal fluid, cerebrospinal fluid yellowing, reflecting the hemorrhage and necrosis of the brain parenchyma.
EEG
EEG is helpful for early diagnosis. On the basis of diffuse slow wave background, the slower frequency delta wave limited to temporal lobe and pathological wave are the characteristics of this disease.
2. CT and MRI scan
CT scans can show low-density lesions on one or both temporal lobe, while MRI suggests long-T1 and long-T2 signals dominated by the above-mentioned sites, which show inflammatory changes about 3 days earlier than CT.
Diagnosis
Diagnosis and diagnosis of herpes simplex encephalitis in the elderly
Diagnostic criteria
The early diagnosis of herpes simplex encephalitis is very important. It is directly related to the prognosis of this disease. It is generally manifested in encephalitis, EEG and CT, MRI suggests bilateral temporal lobe involvement, and can exclude other brain diseases. This disease can be considered. If there is a history of herpes labialis, the diagnosis is more adequate. The diagnosis requires virological examination: double cerebrospinal fluid herpes simplex virus antibody or serum complement-binding antibody titration is increased by more than 4 times; polymerase chain reaction , PCR); brain tissue biopsy to observe the inclusion bodies in the nuclear cells, or to observe the virus particles under electron microscope.
Differential diagnosis
1. Other viral encephalitis
The pathogens of viral encephalitis are diverse, mainly including herpes virus, arbovirus and enterovirus, but in addition to a few epidemic encephalitis such as Japanese encephalitis, the clinical manifestations of other sporadic viral encephalitis are relatively Lighter, there are few signs of significant damage to the temporal lobe and frontal lobe; serum and cerebrospinal fluid to detect the specific antibodies of the corresponding virus is helpful for identification.
Japanese encephalitis is very serious and progresses rapidly. It often starts with sudden high fever, and rapidly manifests symptoms of disturbance of consciousness, convulsions, convulsions, etc.; and the incidence is concentrated in the summer and autumn mosquito season, patients are not vaccinated with JE. Can help diagnose.
2. Suppurative meningoencephalitis
Suppurative meningoencephalitis is characterized by severe systemic infection symptoms, peripheral blood leukocytes are significantly increased, cerebrospinal fluid is purulent, bacterial smear or culture positive.
3. Acute disseminated encephalomyelitis
The disease has received increasing attention and is found in the course of acute estrus virus infections (such as measles, rubella, smallpox, chickenpox, etc.); it can also be seen in other acute viral infections (eg infectious mononucleosis, influenza, etc.) The recovery period is called encephalitis after viral infection; it is still occurring within 2 to 3 weeks after vaccination such as whooping cough and rabies, and it is called encephalitis after vaccination; it may even occur due to deworming treatment, such as Levamisole encephalitis may be associated with an immune response.
The pathological features are the demyelinating changes of the disseminated brain and spinal cord, and the infiltration of inflammatory cells distributed around the small veins. The clinical manifestations vary with the location and severity of the lesion, and may have high fever, headache, vomiting, convulsions, Insanity, coma, meningeal irritation and signs of focal damage; cerebrospinal fluid detection of protein and cell number increased, pay attention to identify the time of the patient's neurological symptoms, often suggest the significance of clinical diagnosis.
4. Infectious toxic encephalopathy
Often in the early or extreme stage of acute bacterial infection, more common in sepsis, pneumonia, bacterial dysentery, typhoid, diphtheria, whooping cough, etc., patients with sputum mainly from 2 to 10 years old, due to the body's allergic reaction to infectious toxins, resulting in Cerebral congestion and edema; clinical manifestations of high fever, headache, vomiting, convulsions, convulsions, coma, meningeal irritation, etc.; cerebrospinal fluid pressure increased, protein can be slightly increased, cells generally do not increase, sugar and chloride normal, primary disease After getting better, the brain symptoms will gradually disappear, and there is generally no sequelae.
