brief introduction
Diseases that occur in the central nervous system, peripheral nervous system and autonomic nervous system and are characterized by sensory, motor, conscious and autonomic nervous dysfunction. Also known as psycho. Diseases that occur in skeletal muscles and neuromuscular joints are often indistinguishable from diseases caused by the damage of the nervous system itself, so muscle diseases are often discussed with neuropathy. A disease in which the central nervous system is affected by pathogenic factors (especially the organic pathological changes of the nervous system cannot be detected) and is mainly manifested as mental activity disorder is called psychosis. As the saying goes, mental illness is often called "neuropathy", which is really wrong. However, neuropathy and psychosis can often coexist. For example, sporadic encephalitis often takes mental symptoms as the first symptom, and patients with paralytic dementia may also have neurological symptoms in the early stage. Some neuropathy, such as cerebrovascular disease, epilepsy, encephalitis and meningitis, are common in clinic. Chronic diseases are the majority of neuropathy, which often persist, have a great impact on patients' work and life, and have a high disability rate. Neuropathy can be caused by many reasons, many of which are unknown, and many of them are genetic diseases. The application of brain CT scanning and magnetic resonance imaging can quickly and accurately diagnose many brain and spinal cord diseases. However, because nerve cells are not easy to regenerate after injury, many neuropathy still have no effective treatment.
2 Etiology
infect
Various reasons can cause nervous system diseases. The etiology of many nervous system diseases is still unknown.
Including bacterial infections caused by various purulent bacteria, such as purulent meningitis and brain abscess; Viral infections, such as epidemic encephalitis B caused by epidemic encephalitis B virus, epidemic chest pain caused by Kutcher virus B, poliomyelitis caused by poliovirus, Kuru disease or subacute sclerosing panencephalitis caused by lentivirus infection, may be caused by measles virus mutant; Parasitic infections such as cerebral malaria, cerebral paragonimiasis and cerebral cysticercosis; Fungal infections, such as candida albicans and cryptococcal meningitis; Leptospira can also cause meningoencephalitis. Part of epilepsy is caused by local scar formation after meningeal or cerebral cortex infection.
be poisoned
Including metal poisoning, such as lead poisoning can cause peripheral motor nerve paralysis and lead poisoning encephalopathy, and mercury, arsenic and thallium poisoning also affect the nervous system; Organic poisoning, such as alcoholism and barbiturate poisoning, can inhibit the central nervous system, while organophosphorus poisoning makes cholinergic nerves excessively excited; Bacterial toxin poisoning, such as botulism, can cause cranial nerve paralysis and limb weakness, diphtheria toxin can cause nerve paralysis, and tetanus toxin can cause systemic skeletal muscle tonic spasm; Animal poisons (toxins contained in coelenterates, shellfish, poisonous mosquitoes, spiders, puffer fish, etc.). ) can also cause nervous system symptoms (muscle weakness, paralysis, convulsions, ataxia, etc. ).
genetic defect
Many metabolic diseases (such as phenylketonuria, glycogen storage disease, mucopolysaccharidosis and lipid storage disease), degenerative diseases (such as leukodystrophy, Parkinson's disease, amyotrophic lateral sclerosis, hereditary optic atrophy, etc. ) and myopathy affecting the nervous system (such as progressive muscular dystrophy) are hereditary diseases. Mostly autosomal recessive inheritance. However, hyperkalemic periodic paralysis and hypokalemic periodic paralysis are autosomal dominant inheritance.
malnutrition
Patients with Quashie's Oak's disease (a form of protein's heat malnutrition) may have neurological symptoms, such as tremor, bradykinesia and myoclonia. Vitamin A deficiency or poisoning can cause intracranial hypertension. Vitamin B deficiency will affect the nervous system. For example, vitamin B 1 deficiency (beriberi) shows most peripheral nerve damage, and vitamin B 12 deficiency can cause subacute combined degeneration.
immunologic mjury
Encephalitis after vaccination may be an allergic reaction caused by protein antigen contained in the vaccine. Infectious polyradiculoneuritis, facial paralysis, abducens nerve paralysis after infection and glossopharyngeal nerve paralysis after infection may all be allergic diseases of peripheral nerves. Connective tissue diseases such as rheumatic fever, systemic lupus erythematosus and polyarteritis nodosa are autoimmune diseases, which can involve the nervous system. For example, rheumatic fever can manifest as Sydenham's chorea. Demyelinating diseases of the central nervous system can be autoimmune diseases caused by viral infection, such as diffuse sclerosis, acute disseminated encephalomyelitis, multiple sclerosis, subacute sclerosing panencephalitis, neuromyelitis optica, transverse myelitis, acute cerebellar ataxia and central pontine myelinolysis. Myasthenia gravis is also an autoimmune disease.
metabolic disturbance
In addition to the above genetic and metabolic diseases (such as glycogen storage disease, etc.). ) can affect the nervous system, acquired metabolic diseases, such as hypoxia, hypernatremia, hyponatremia, hypocalcemia, uremia, hypoglycemia, hepatic encephalopathy and so on. , can be accompanied by neurological symptoms.
Endocrine disorder
Thyroid hormone can promote the formation of cerebral myelin sheath and stimulate the synthesis of RNA and protein. Children with cretinism may have brain retardation and cerebellar ataxia. Hyperthyroidism may be accompanied by tremor and tendon reflex. Insufficient insulin secretion in diabetes mellitus leads to demyelination of peripheral nerves and neurological disorders.
congenital malformation
Caused by teratogenic factors such as viruses or toxins, or hereditary. Such as spina bifida, congenital hydrocephalus and brain perforation.
disturbance of blood circulation
Vascular diseases, changes in blood components, hemodynamic disorders or emboli may all lead to cerebrovascular diseases.
Abnormal hyperplasia
Abnormal tissue hyperplasia can form tumors. Visible in the central nervous system and peripheral nerves.
Many nervous system diseases of unknown causes and unknown causes are often referred to as "primary".
3 classification
There are many diseases of the nervous system, the etiology is unknown, and the classification is chaotic and overlapping, which can be roughly classified according to the etiology, location and pathology.
The previous section describes the classification of causes. However, the causes of many diseases are unknown, and it is difficult to classify them into categories with clear causes.
According to the location, it can be divided into central nervous system diseases, peripheral nervous system diseases, autonomic nervous system diseases and myopathy. Diseases in different parts can be classified according to etiology and pathological changes.
According to pathological changes, it can be divided into degenerative diseases, demyelinating diseases, inflammatory diseases, deformities and bleeding.
According to the course of disease, it is divided into acute (such as epidemic encephalitis and purulent meningitis) and chronic (the majority).
4 Clinical manifestations
Symptoms of nervous system diseases can be divided into absence symptoms, release symptoms, irritation symptoms and shock symptoms. When the nervous system is damaged, its normal function is lost, which is called absence symptom. For example, when the cerebral internal capsule bleeds, the motor and sensory conduction bundles are damaged, the contralateral limb is paralyzed, and the sensation disappears. Under normal circumstances, the superior center can inhibit the activities of the lower center. After the injury of the superior center, the inhibition of the inferior center is released, and its functional activities increase, thus releasing symptoms. For example, after internal capsule hemorrhage, the inhibitory effect of cerebral cortex on subcortical motor center is released, and the activity of subcortical motor center is increased, which increases the muscle tension of paralyzed limbs (spastic paralysis). Involuntary movements (dance-like movements, limb peristalsis) during extrapyramidal diseases are also release symptoms. Stimulating symptoms refer to the intense increase of nerve cell activity caused by local or systemic lesions of the nervous system, such as burning neuralgia caused by peripheral nerve injury, and excessive cortical cell activity can cause convulsions when the brain is hypoxic. Shock symptoms refer to the temporary loss of function of the central nervous system when it is in acute lesions, such as sudden coma (concussion) when the internal capsule bleeds, and flaccid paraplegia (spinal cord shock) after spinal fracture. After the shock stage, symptoms of loss or release gradually appear.
Symptoms and signs of nervous system diseases can be manifested as disturbance of consciousness, sensory perception and movement (such as paralysis, involuntary movement, abnormal gait and ataxia). ) and abnormal muscle tone (increased muscle tone is seen in pyramidal tract diseases, extrapyramidal diseases, rigidity syndrome, tetanus, tetany and so on. The increase of muscle tension in extrapyramidal system is called myotonia; Hypotonia is found in progressive muscular dystrophy, myositis, peripheral neuropathy, gray matter lesions in the posterior root, posterior cord and anterior horn of spinal cord, amyotrophic lateral sclerosis, cerebellar lesions and so on. ), headache, dizziness, dizziness, abnormal reflexes, muscle atrophy, urination, defecation, sexual dysfunction, etc.
In addition to all kinds of abnormal signs, cerebrospinal fluid often appears abnormal when nervous system diseases occur.
Lesions in different parts of the nervous system can show different pathological syndromes.
5 diagnosis
The diagnosis of nervous system diseases includes location diagnosis, qualitative diagnosis and etiological diagnosis, and it is often necessary to make location diagnosis first, that is, to point out that the disease is in a specific part of the nervous system. The pathological syndromes of different parts are the basis of localized diagnosis. Localization diagnosis usually helps to determine the nature of the disease. The causes of many diseases are unknown, so it is difficult to make a diagnosis. In the diagnosis of nervous system diseases, medical history and physical examination are very important. Cerebrospinal fluid examination and other laboratory examinations, electromyography and electroencephalography can often provide important clues. The imaging examination of nervous system plays an important role in the diagnosis of some diseases, especially after the application of computed tomography and magnetic resonance imaging, the application of pneumoencephalography, ventriculography and cerebral angiography has been greatly reduced. Positron emission tomography, single photon emission computed tomography, transcranial Doppler ultrasound, quantitative EEG, nervous system evoked potential, digital subtraction angiography, nystagmus and other new technologies are all helpful to the diagnosis of nervous system diseases.
6. Nervous system examination and auxiliary examination
Nervous system examination can find brain, nerve, muscle and spinal cord diseases. Neurological examination includes medical history, mental state evaluation, physical examination and laboratory diagnosis. The difference between psychiatric examination and evaluation of patients' behavior is that the evaluation of neurology requires physical examination. However, abnormal behavior often suggests clues to changes in brain organs.
Medical/medical records
Before the physical examination and laboratory examination, the doctor met with the patient to learn about his medical history. Ask the patient to describe the current state, and make clear where, when, frequency, severity, duration and whether these symptoms affect daily work and life. Symptoms of the nervous system can include headache, pain, weakness, poor general condition, decreased consciousness, paresthesia, weakness and mental confusion.
Patients should inform their doctors about their past and present illness or surgical history, and in severe cases, they should know about their blood relatives, allergic symptoms and drugs currently used. In addition, doctors should also ask patients whether they have any difficulties related to work or family, or whether they have encountered any confusion, because these situations will affect patients' health and body's ability to resist diseases.
Mental examination
By asking about the medical history, doctors have a certain understanding of the mental state of patients, but the diagnosis of diseases that affect the thinking process needs further examination to determine the mental state.
physical examination
The physical examination of neurology requires a general examination, but the focus is on the nervous system. The scope of examination includes cranial nerve, motor nerve, sensory nerve and nerve reflex. In addition, it is necessary to check the patient's economic function, posture and gait, autonomic nervous system function and cerebral blood supply.
The cranial nerve examiner should check the function of 12 pairs of cranial nerves directly connected to the brain. Trauma, tumor or infection can damage any part of the brain. The exact location of the damage needs to be determined by inspection.
Examination of the motor system Motor nerves innervate voluntary muscles (voluntary muscles produce movement, such as walking leg muscles). ) motor nerve injury can lead to paralysis of its dominant muscle or decrease of muscle strength. Lack of peripheral nerve stimulation can lead to muscle atrophy (primary atrophy). The doctor asked the patient to push and pull against the resistance to understand the muscle strength of each group.
Sensory nerve Sensory nerve transmits pressure, pain, cold and heat, vibration, movement and graphic sensation to the brain.
Check whether the sensory nerve is normal by checking the body surface sensation. When numbness, tingling or pain occurs in a certain part of the patient's body surface, the doctor first gently pricks the split surface with a sharp needle, and then gently pricks the same part with a blunt needle to judge whether the patient has the ability to distinguish between sharpness and dullness. The function of sensory nerves can also be checked by using light pressure, heat or vibration. When checking the sense of movement, the doctor asked the patient to close his eyes, then gently moved the patient's fingers (toes) up and down, and asked the patient to tell the position of moving the fingers (toes).
Reflex is the body's automatic response to stimulation. For example, tapping the tendon below the knee with a percussion hammer will produce a reflex in the lower limbs. This reflex is called knee tendon reflex (this is a deep tendon reflex). Knee tendon reflex shows the same function of sensory nerve entering spinal cord, synaptic connection in spinal cord and motor nerve returning to lower limb muscles. Its reflex arc is a complete loop from the knee to the spinal cord and back to the leg, without involving the brain.
Knee tendon reflex and its similar elbow, ankle reflex and Babinsky reflex are often used for reflex examination. Babinsky reflex examination is to scrape the outer edge of the sole with a blunt instrument. Except for infants under 6 months old, the normal reflex is that the toes bend down. If the big toe bends upward and the other toes extend outward, this is a sign that the brain or the motor nerve from the brain to the spinal cord is abnormal. In addition, there are many nerve reflex tests suitable for evaluating special nerve function.
* * * Economic function, posture and gait When examining the patient's economic function, the doctor asked the patient to touch the tip of the nose with his index finger first, then touch the doctor's finger, and repeat this action repeatedly and quickly. During the first finger nose examination, the patient can open his eyes and then close them during the whole examination. The doctor told the patient to straighten his hands, close his eyes and stand upright, and then let him walk with his eyes open. These tests are used to check the functions of motor nerve, sensory nerve and brain. In addition, there are many other different simple inspection methods.
Non-brain reflex arc reflex arc is the path of nerve reflex, such as knee reflex.
1. Tap the knee to stimulate the sensory receptors and generate nerve signals.
2. The signal is transmitted to the spinal cord along the nerve pathway.
3. In the spinal cord, signals are transmitted from sensory nerves to motor nerves.
4. Motor nerves feed back signals to thigh muscles.
5. Muscle contraction causes the calf to rebound upwards. The whole reflection does not pass through the brain.
Autonomic nervous system Autonomic (involuntary) nervous system abnormalities can lead to postural hypotension, anhidrosis and erectile dysfunction. There are many experiments to check the function of autonomic nervous system. For example, a doctor can measure the patient's blood pressure while sitting, and then let the patient stand and measure his blood pressure immediately to test the patient's autonomic nervous function.
Patients with severe cerebral artery stenosis are at risk of stroke. The elderly, patients with hypertension, diabetes and cardiovascular diseases are high-risk groups of stroke. When the stethoscope is placed above the carotid artery, you can hear the murmur of blood flowing through the narrow blood vessel segment. More accurate diagnosis requires advanced examination, such as Doppler ultrasound scanning.
Diagnostic test inspection
In order to accurately diagnose the disease, doctors can ask patients to do relevant special examinations according to their medical history, mental evaluation and physical examination.
Spinal puncture
Spinal puncture (lumbar puncture) is to insert the puncture needle into the spinal canal through the intervertebral space and collect cerebrospinal fluid samples for examination. The whole puncture process can be completed in 15 minutes without general anesthesia. Normal cerebrospinal fluid is clear and colorless. Cerebrospinal fluid of different diseases has its abnormal characteristics. If there are white blood cells and bacteria in cerebrospinal fluid, it is turbid, suggesting cerebrospinal fluid infection, which is found in meningitis, Lyme disease or other infectious diseases.
Cerebrospinal fluid with high protein content, usually spinal cord tumor, is a sign of acute peripheral nerve diseases, such as polyneuritis or Guillain-Barre syndrome. Cerebrospinal fluid contains abnormal antibodies suggesting multiple sclerosis. Meningeal infection or some cancers, the sugar content in cerebrospinal fluid decreases. Bloody cerebrospinal fluid shows cerebral hemorrhage. Many diseases, including brain tumors and meningitis, will increase the pressure on cerebrospinal fluid.
Computed tomography
CT uses enhanced computer scanning technology to analyze X-rays. Computer generates two-dimensional high-resolution images, similar to anatomical slices of the brain or other organs. During the examination, the examinee must lie down quietly and comfortably. With the help of CT, doctors can widely detect diseases of the brain and spine. CT is not only used for the diagnosis of nervous system diseases, but also for monitoring the therapeutic effect. This precise technology has revolutionized the field of neurology and improved the medical quality of neurology.
Magnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI) is to place the patient's head or whole body in a strong and uniform magnetic field to obtain a clear anatomical image of the patient's examined part. There is no X-ray in MRI, which is very safe.
MRI is superior to CT in the diagnosis of old stroke, most brain tumors, brain stem and cerebellar diseases and multiple sclerosis. A clearer image can be obtained by intravenous contrast agent enhanced imaging. The new computer program of magnetic resonance imaging can measure the function of the brain.
The biggest disadvantage of MRI is that it is expensive and takes a long time (10 ~ 45 minutes), and it is not suitable for patients who use artificial respiration machines, have a serious claustrophobic tendency, and carry pacemakers or other metal objects (such as dentures).
. Cerebral echocardiographic examination
Echocardiography is a brain imaging examination using ultrasound. Because its examination process is simple, painless and relatively cheap, it is suitable for the examination of cerebral hemorrhage in children under 2 years old. Cases of ventricular enlargement (hydrocephalus) caused by hydrocephalus can be examined by bedside. This kind of examination has been replaced by CT or MRI in older children and adults.
Positron emission tomography (PET)
PET is an image of the internal structure and functional state of the brain obtained by displaying the distribution of special radionuclides in the body. The function of brain can be measured by transmitting radionuclide tracer to brain tissue through blood. For example, when candidates do mathematical calculations, PET can show that a certain part of the brain has the most active function, and PET is also suitable for checking epilepsy, brain tumor, stroke and so on. PET is mainly used for research.
Single photon emission computed tomography
SPECT uses radionuclides to understand the changes of blood supply and metabolic function of brain. Once the injected or inhaled radionuclide enters the brain tissue through blood, its intensity in different parts of the brain reflects the blood supply of the brain or the function of the neurotransmitter receptor that can absorb the radionuclide. The accuracy and specificity of this technology are worse than that of PET.
Cerebral angiography
Cerebral angiography is to inject contrast agent (visible substance under X-ray) into the blood vessels supplying cerebral blood and display the image of cerebral blood flow, so as to check abnormal cerebrovascular diseases such as aneurysm, arteritis, arteriovenous malformation and cerebral vascular occlusion. The improved MRI image can also show the blood supply of the neck and brain base, but its image is not as detailed and clear as that of cerebral angiography.
. Doppler ultrasound scanning
Doppler ultrasound scanning evaluates the risk of stroke by measuring the blood flow of carotid artery and skull base artery. Different cerebral blood flow is displayed in different colors on the monitor. The advantage of this technique is that it is painless, can be examined at the bedside, and is relatively cheap.
. Spinal myelography
Myelography is to inject contrast agent into the spinal cavity and examine the spinal cord by ct or X-ray. Myelography can detect spinal diseases, such as disc herniation or carcinomatosis. The CT scan of this technique is particularly clear. Because MRI is simple and safe, and the image is more detailed and clear, myelography is mostly replaced by MRI at present.
electroencephalogram
EEG examination is simple and painless. Electroencephalogram (EEG) is to put 20 wires on the scalp to detect and record EEG activity. EEG recording of various waveforms is helpful to diagnose epilepsy and some rare brain metabolic diseases. For some intractable epilepsy, 24-hour recording is used. But this kind of inspection can't provide obvious specific information.
. evoked response
Evoked response is the characteristic of the brain's response to certain stimuli. Visual, auditory and tactile stimuli can activate specific areas of the brain. For example, flash stimulation can cause sensory visual responses in the back of the brain. Under normal circumstances, the brain's response to a single stimulus is very small, and the EEG has not changed significantly. But after a series of stimuli are processed by computer, it can be indicated that the brain has received the stimuli. Brain evoked potential response is especially suitable for patients who can't speak. For example, doctors can check the brain's response to sound stimuli to check the baby's hearing.
Brain evoked response can reveal mild optic nerve injury in patients with multiple sclerosis. Epilepsy patients can induce abnormal discharge through deep breathing and flash stimulation.
Electromyography
Electromyography records electrical activity by inserting tiny needles into muscles. EMG activity is displayed on the oscilloscope and can be heard through the speaker. Under normal circumstances, resting muscles do not produce electrical activity. But slight muscle contraction can produce electrical activity. With the increase of muscle contraction intensity, EMG activity increases. Abnormal EMG activity in muscle, peripheral nerve and spinal motor nerve diseases.
The conduction velocity of motor nerve impulses can be measured by studying nerve conduction. Stimulating the motor nerve with a small charge can trigger nerve impulses, which spread along the nerve and eventually reach the muscle to cause muscle contraction. By measuring the time required for nerve impulses to reach muscles, the conduction velocity of nerve impulses can be calculated.
Similar examination methods are also used to examine sensory nerves. If it is muscle weakness caused by muscle diseases, the nerve impulse conduction speed remains normal. If it is myasthenia caused by neurogenic diseases, the nerve conduction speed will usually slow down.
Muscle weakness in patients with myasthenia gravis is caused by insufficient transmission of nerve impulses to muscles through synapses. Repeated nerve impulses are transmitted to muscles along nerve fibers, which leads to an increase in the tolerance of synapses to neurotransmitters and a decrease in the progressive response.
7 treatment
Diseases (such as epidemic meningitis) with clear etiology and elimination of pathogens can be cured by appropriate treatment measures. Some immune diseases can be treated with immunosuppressive drugs. Some deformities can be treated by surgery. Many degenerative diseases and metabolic diseases have no special treatment methods and need more symptomatic treatment.