Overview
Intracranial infections refer to intracranial inflammation caused by an infectious agent. The brain parenchyma, meninges, and blood vessels within the skull can be infected. Intracranial infections are categorized according to the site of infection as being in the subarachnoid space (meningitis), the brain parenchyma (encephalitis), or confined to the brain or meninges and forming an encompassing area (brain abscess). Mental disorders due to intracranial infections are those caused by direct invasion of brain tissue by viruses, bacteria, spirochetes, fungi, protozoa or other microorganisms and parasites. Among them, viral encephalitis, epidemic encephalitis and tuberculous meningitis are more common.
Etiology
Mental disorders caused by direct invasion of brain tissue by viruses, bacteria, spirochetes, fungi, protozoa or other microorganisms, parasites, etc.
Symptoms
1. Viral encephalitis:
Mostly acute or subacute onset, most symptoms peak within two weeks.
(1) Prodromal symptoms: some cases have upper respiratory or gastrointestinal symptoms before the onset of the disease.
(2) Mental symptoms: (1) impaired consciousness: the most common, some of which are the first symptoms; (2) schizophrenic-like symptoms: the most common inhibitory symptoms; (3) mental retardation.
(3) Physical and neurological symptoms and signs: cerebral nerve damage, motor dysfunction, meningeal irritation, autonomic dysfunction.
2. Epidemic encephalitis B:
The onset of the disease is rapid, generally divided into acute and chronic phases.
(1) acute stage: ① mental symptoms: disorders of consciousness, hallucinations and delusions, perceptual syndrome, nervousness syndrome, mostly in children, a few patients have brain weakness syndrome; ② neurological symptoms and signs.
(2) chronic stage: ① mental symptoms: personality changes, mental retardation, behavioral abnormalities, common in children; ② neurological symptoms and signs: seizures, Parkinson’s syndrome, speech disorders.
3. Epidemic encephalitis A: the onset of the disease is more acute.
(1) acute stage: ① mental symptoms: disorders of consciousness, delirium is more common, sleep disorders are more prominent, characterized by lethargy, hallucinations, more and more with disorders of consciousness at the same time, some appear depressed;
② neurological symptoms and signs: eye muscle paralysis, especially common in the early stage, can appear a variety of eye muscle paralysis and incomplete paralysis. Motor disorders. Sensory disorders, manifested as sensory abnormalities with centralized pain sensations. Autonomic disorder. At the beginning, there may be generalized discomfort, headache, lethargy and high fever.
(2) Chronic phase: (1) mental retardation; (2) pseudopathic personality, mostly seen in children; (3) Parkinson’s syndrome is the most common and more serious; (4) hallucinatory delusional state is relatively rare, and there is occasional catatonic syndrome.
4. Tuberculous meningitis: relatively slow onset.
(1) Mental symptoms: (1) cerebral debility syndrome: in the early stage of the disease for 1 to 2 weeks, the patient manifests mental depression, short-temperedness, irritability, sleep disturbance, etc., especially in the past, the quieter children become irritable and cry, easy to rage or shouting for no reason. Children who used to be active in the past are sluggish and do not like to play. Adults in the early stages of the disease to headache is more common. (2) Impaired consciousness: different degrees of impaired consciousness may occur.
(2) Physical, including neurological symptoms: mild meningeal irritation in the early stage, gradual increase in body temperature, anorexia, mild headache, vomiting, and so on.
Examination
1. General physical examination and neurological examination
General examination includes observation of consciousness, body temperature, pulse, blood pressure, respiration, etc., to find out whether there are signs of organic diseases such as serious infections, severe and serious physical diseases and craniocerebral trauma. Neurological examination should be emphasized to look for evidence of organic brain diseases.
2. Psychiatric examination
Comprehensive mental examination, including appearance and behavior, speech and thinking, emotional state, perception, cognitive function, self-awareness and motor behavior.
3. Auxiliary examination
Routine laboratory tests such as blood routine, blood biochemistry, thyroid hormone, etc., electroencephalogram, brain CT, brain MRI, pathogenetic examination, cerebrospinal fluid examination and other auxiliary examinations to understand whether there are somatic diseases and organic lesions in the brain.
4. Psychological assessment
Personality tests, such as the Retrospective Personality Development Inventory (WMPI), Minnesota Multi-Personality Inventory (MMPI), and Eysenck Personality Questionnaire developed by Prof. Wang Weidong, and the Symptom Self-Assessment Scale (SSAS). Self-Depression Scale (SDS) and Hamilton Depression Scale (HAMD), etc.
Diagnosis
According to the diagnostic criteria of the third edition of the Chinese Classification and Diagnostic Criteria for Mental Disorders:
1. Meet the diagnostic criteria of cerebral organic mental disorder.
2. Physical, neurological and laboratory examination proves that it is caused by related intracranial infection.
3. cerebrospinal fluid and electroencephalogram have corresponding abnormal changes.
3. There is no sufficient evidence that the mental disorder is due to other causes.
4. the onset, development, and course of the mental disorder are associated with an intracerebral infection.
5. impaired daily living or social functioning.
Differential Diagnosis
1. schizophrenia: schizophrenia may present with mental symptoms such as hallucinations, delusions and depression in the early stage of disease onset, which can be easily misdiagnosed as schizophrenia. However, this type of disease is often accompanied by obvious physical symptoms and abnormalities in neurological examination, and laboratory tests such as routine blood tests, cerebrospinal fluid, and cranial CT can assist in the diagnosis.
2. Intracranial space-occupying lesions: brain CT examination can find limited hyperdense shadows.
Treatment
1. Drug treatment: anti-viral and anti-inflammatory treatment for the cause of infection, anti-viral treatment is the key for viral meningitis. Aggressive symptomatic treatment is very important, and interventions are needed for life-threatening symptoms such as severe cerebral edema, acute respiratory failure, and high fever. Short-term use of high-dose corticosteroids to combat inflammation, edema, and inhibit the antibody response reduces neurologic damage. For tuberculous encephalitis, early, moderate, combined, full and regular anti-tuberculous treatment is needed.
2. Symptomatic treatment of mental symptoms: small doses of antipsychotic drugs can be given orally to those with symptoms of excitability and agitation, hallucinations, delusions, etc., such as olanzapine and quetiapine, and small doses of haloperidol injection can be considered for severe excitability and agitation.
3. Support nutritional therapy.
4. Strengthen exercise, enhance physical fitness, prevent infection is the most important and basic preventive measures.