A slowly progressive disease of the central nervous system, characterized by demyelinating plaques scattered in the brain and spinal cord, leads to a variety of neurological symptoms and signs, and often relieves and recurs repeatedly.

Etiology and incidence

The cause is unknown, and immune abnormality is suspected. One hypothesis is that the cause is caused by latent virus (possibly human herpesvirus or retrovirus) infection, and the virus infection and expression stimulate the secondary immune response. The incidence of this disease in patients' families is increasing. Correlation with some HLA allotypes indicates genetic susceptibility. Environmental factors also have some influence. The incidence of multiple sclerosis (MS) in temperate regions (1/2000) is higher than that in tropical regions (110000). The risk of MS is related to the area where the patient lived before 15. /kloc-moving to another place after 0/5 years old cannot change the tendency of onset. The onset age is generally 20~40 years old, and there are more female cases than male cases.

pathology

There are disseminated demyelinating plaques in the central nervous system, accompanied by oligodendrocyte destruction and perivascular inflammation. The lesions mainly occurred in white matter. The most common sites are lateral column and posterior column of spinal cord (especially in cervical and thoracic segments), optic nerve and paraventricular region. The conduction bundles of midbrain, pons and cerebellum may also be involved, as well as gray matter and spinal cord. The cell bodies and axons of neurons are usually intact. Especially in new lesions, axons may be destroyed in the later stage, especially the long conduction bundle, and the secondary fibroglial hyperplasia makes the conduction bundle harden. New and old lesions can coexist. Chemical changes can be found in the lipid and protein components of myelin sheath around demyelinated plaques and plaques.

Symptoms and signs

This disease is characterized by diversified symptoms and signs of central nervous system dysfunction, repeated remission and recurrence. The most common symptom is paresthesia, which appears in one or more limbs, trunk or one face. Weakness or clumsiness in legs or hands; Or visual impairment, such as partial blindness in one eye and pain (retrobulbar optic neuritis) during eye movement, blur or dark spots. Other common early symptoms include diplopia caused by ophthalmoplegia, temporary weakness of one or more limbs, slight gait disorder, slight stiffness and abnormal fatigue of one limb, difficulty in bladder control, dizziness and mild emotional disorder; All these symptoms reflect disseminated lesions in the central nervous system, and usually occur several months or years before the disease is diagnosed. Elevated body temperature (such as hot climate, hot bath and fever) can aggravate symptoms and signs.

Mental state can be manifested as indifference, lack of judgment and inattention. Emotional fluctuations are very common, and it is easy to be mistaken for hysteria at first. Some patients have euphoria, while others have reactive depression. Sudden crying or laughing (a symptom of pseudobulbar palsy) indicates that the cortibulbar pathway that controls emotions has been involved. Seizures are rare. Serious mental disorders (such as mania, dementia, etc.) may occur in the later stage of the disease.

In addition to optic neuritis, cranial nerves can usually see one or more of the following eye signs in the course of the disease: partial atrophy of optic nerve with temporal pallor of optic disc, change of visual field (central scotoma or overall reduction of visual field), or temporary ophthalmoplegia with diplopia (due to the involvement of conduction bundle connecting the 3rd, 4th and 6th brain nuclei in brain stem). When optic neuritis occurs, papillae edema with visual impairment may occur, and the direct response of the pupil to light is also weakened. However, other pupil changes, argyle Robertson's pupil and total blindness, are rare. Nystagmus is a common sign, which may be caused by the damage of cerebellum or vestibular nucleus. Other manifestations of cranial nerve damage are rare. If it happens, it is usually caused by the damage of the corresponding cranial nerve nucleus in the brain stem. Deafness is rare, but dizziness is not uncommon. Occasionally, unilateral facial numbness or pain (similar to trigeminal neuralgia) and unilateral paralysis or spasm may occur.

Motor tendon reflexes (such as knee reflexes and ankle reflexes) are generally hyperactive; Babinski's sign and knee-ankle clonus. Shallow reflexes, especially upper and lower abdominal wall reflexes, are reduced or disappeared. Usually, patients only complain about unilateral symptoms, but physical examination can find signs of bilateral pyramidal tract. Intentional tremor caused by cerebellar lesions is common, and it is aggravated by continuous purposeful exertion. The movement is characterized by ataxia: jitter, irregularity, trembling and ineffectiveness. Tremors may occur when the head is still. In addition, rigidity and cerebellar ataxia will make the patient unable to move. Brain lesions can lead to hemiplegia, sometimes manifested as symptoms. Painful flexor spasm caused by sensory stimulation (such as contact with bed quilt) may occur in the later stage of illness.

There is a subtype of optic neuromyelitis, which can cause optic neuritis, sometimes bilateral, with demyelinating lesions in the cervical or thoracic spinal cord. The clinical manifestations are blindness and paraplegia of both lower limbs. Charcot triad (nystagmus, intentional tremor and poetic speech) is a common cerebellar sign in advanced cases. Minor brain injury, cortical control disorder or medullary nucleus injury can all lead to mild anorexia.

The complete loss of any kind of epidermal sensation is rare, but it can cause abnormal sensation, numbness and insensitivity (such as the decrease of pain and temperature sense, the obstacle of vibration sensation and position sensation), which is often confined to the hands or legs. Objective sensory changes are short-lived and can only be induced by careful examination. Various painful sensory disorders (such as burning sensation, electric shock or paroxysmal pain) may occur, especially in the case of demyelinating lesions of the spinal cord.

Autonomic nerve When the spinal cord is involved in time, it is common to have urgent urination, dysuria, partial urinary retention or mild urinary incontinence and constipation, which can cause impotence in men and sensory loss in female reproductive organs. In advanced cases, urinary incontinence will occur.

course of a disease

The course of the disease varies greatly and is unpredictable. In most cases, remission and recurrence will occur. Except for the most serious cases, the life expectancy of most patients has not been shortened. At first, there may be a remission period of several months or years between recurrence, especially in patients with retrobulbar optic neuritis. The remission period may exceed 10 years. However, some cases may recur frequently and soon become disabled. In a few cases, especially middle-aged men, the process of disease can develop and deteriorate rapidly. The increase of body temperature and ambient temperature caused by fever sometimes aggravates symptoms.

diagnose

According to the clinical manifestations and laboratory examination results, the diagnosis is made by indirect inference. Typical cases can usually be diagnosed with confidence according to clinical signs. After the first attack, it can only be suspected as Ms. In the later stage, the medical history has been repeatedly relieved and relapsed. In addition, there are many clinical evidences that the lesions are scattered in many areas of the central nervous system, which highly suggests that it is Ms., but other possibilities must be considered (Table 180- 1).

MRI is the most sensitive brain imaging technique for diagnosing MS, which can display multiple demyelinating plaques. It can also show some treatable non-demyelinating lesions at the junction of medulla oblongata and spinal cord (such as arachnoid cyst and tumor in foramen magnum), which can occasionally cause uncertainty and fluctuation spectrum of motor and sensory symptoms, so gadolinium-enhanced MRI can distinguish acute inflammatory areas from old brain plaques. Enhanced CT scan can also show multiple sclerosis lesions. Double iodine dose and delay scanning time ("double dose delayed CT scanning") can improve the detection rate of lesions.

In most cases, cerebrospinal fluid is abnormal. IgG can be > 13%, lymphocyte count and protein content can be slightly increased, but these changes are not disease-specific. In up to 90% of MS cases, CSF agar gel electrophoresis showed few bands, suggesting that IgG was synthesized in the brain, but the absence of few bands could not rule out that the level of MS.IgG was related to the severity of the disease. In the process of acute demyelination.

Evoked potentials (see section 165, neurological auxiliary diagnostic measures) are records of potential responses in the brain after sensory system is stimulated. In the early stage of the disease, the mode-switching visual evoked potential, brainstem auditory evoked potential and somatosensory evoked potential all appear abnormal delay, because demyelination can slow down the electrical pulse conduction in these sensory pathways.

treat cordially

Spontaneous remission and symptom fluctuation make it difficult to evaluate the therapeutic effect. Adrenal cortical hormone (oral prednisone 60 ~ 1000mg/d, reduced for 2~3 weeks until withdrawal, or intravenous methylprednisolone 500~ 1000mg/d, 3~5 days) is the main treatment scheme at present. They can shorten the duration of symptoms during an acute attack. Although they are unlikely to affect the final long-term dysfunction, taking acute severe optic neuritis as the onset case, intravenous injection of high-dose adrenocortical hormone may delay the onset of MS. There is little need for long-term treatment with adrenocortical hormone, and there will be many medical complications, such as osteoporosis, ulcers and diabetes. Intramuscular injection of ACTH40~80u/d for 5 days, and withdrawal within 2~3 weeks, sometimes optional.

Immunomodulatory therapy with interferon-β can reduce the recurrence frequency of MS and may help to delay the final dysfunction. * * * Polymer I(glatiramer) may have similar benefits for early and mild MS. Intravenous injection of γ-globulin, once a month 1 time, may be helpful to control some recurrent MS that are ineffective in conventional treatment. For more severe progressive MS, immunosuppressive drug (A) can be used.

Symptomatic treatment is helpful to relieve stiffness, fatigue, bladder dysfunction and some uncomfortable sensory symptoms. Regular exercise (for example, stationary bicycle exercise, pedaling, swimming and stretching exercise) is beneficial. Even in the relatively late disease series, it can adjust the heart and muscle functions, reduce stiffness and improve psychological factors. Drugs for rigidity (baclofen 10~20mg orally, daily 1 time) and tizanidine 4~8mg orally, three times a day) should be used in small doses at the beginning, and the dosage should be carefully increased until the effect appears. Physical therapy of gait training is helpful to improve the range of motion of weak and stiff limbs. Sensory symptoms of pain may require many drugs, including oral amitriptyline 25~75mg before going to bed, oral carbamazepine 200mg three times a day, and narcotic analgesics. Patients should try to keep it.

For bedridden patients, attention should be paid to preventing bedsores and urinary tract infections, and the needs of patients with intermittent catheterization at home should be carefully evaluated. Encouragement and comfort are very important. Clinical symptoms of depression should be induced and treated with antidepressants.