Symptom >> Internal Medicine >> Neurology

Sensory disturbance

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction The sensation is a direct reflection of the various stimuli in the human brain. Sensory disturbance is one of the common symptoms in neurological diseases. Perceptual disorder refers to abnormal psychological phenomena that appear difficult and abnormal in the process of reflecting the individual attributes of stimuli. Common sensory disorders are: 1 feeling allergic. The ability to feel external stimuli is abnormally high. 2 feelings of loss and loss of feeling. The ability to feel external stimuli is abnormally reduced. 3 feels wrong. It gives a false impression of the nature of external stimuli. 4 internal sensibility discomfort. It produces a strange discomfort to the stimulus from the inside of the body. Psychological studies on the brain mechanisms of sensory disturbances have confirmed that damage to the posterior region of the central sulcus of the human cerebral cortex is associated with the development of sensory disturbances. Sensory disturbances can have a wide-ranging impact on various psychological processes of human beings, and can cause perceptual obstacles, which can lead to disturbances in motor feedback and lead to motor dysfunction. Clinically, both neuropathy and psychosis can have symptoms of sensory impairment, and the former is more common.

Cause

Cause

Causes:

1. Peripheral infection disorder

Common in ulnar nerve, median nerve, spinal nerve damage, peripheral neuritis, toxic neuritis, metabolic neuritis, lateral femoral cutaneous neuritis, polyneuritis.

2, the latter type

Common in disc herniation, extraspinal tumor, syringomyelia, trauma and so on.

3, spinal cord type

Common in transverse myelitis, spinal cord tumors, extramedullary tumors, trauma, spinal vascular disease, spinal cord compression. Subacute combined degeneration, syringomyelia, optic neuromyelitis, etc.

4, brain stem type

Common in brain stem vascular disease, brain stem tumor, brain stem inflammation, congenital malformation, cerebellopontine angle lesions, brain stem cavity disease.

5, thalamic type

Common in cerebrovascular disease, tumors, epilepsy and so on.

6, inner capsule type

Common in cerebrovascular diseases, tumors and so on.

7, cortical type

Common in cerebrovascular disease, tumor, sensory epileptic seizures, inflammation, trauma and so on.

8. Adenopathic sensory disturbances are common in people with excessive sensitivity to mental trauma and mental stimulation.

Pathogenesis:

(a) sensory conduction path

The sensation begins with the characteristic receptors of the distal end, and is transmitted to the central center respectively. The conduction pathway is composed of three-level sensory neurons, which are generally crossed at the second level, so the relationship between the central and peripheral is the opposite of the motion system.

1. Pain and temperature party

The first level of neurons are located in the spinal nerves; the peripheral branches are distributed in the skin, due to membrane receptors (free nerve endings, sensory end spheres, etc.), and the central branch of the spinal cord, the posterior root of the spinal cord, rises 1 to 2 spinal segments and enters the posterior horn. After the replacement, the second-order neurons are axons that cross the white matter anterior commissure to the contralateral lateral cord, forming a side of the spinal thalamus and ending in the lateral nucleus of the thalamus. After the meta-combine, they form a third-order neuron, and its axons The thalamic cortical bundle is composed, and the posterior limb of the internal capsule is finally projected to the posterior portion of the middle, upper, and lateral central lobules.

2, touch

The first-order neurons are in the spinal ganglia, and the surrounding fibers that make up the spinal nerve are distributed in the skin tactile receptors (tactile bodies, ring-layer bodies, etc.). After the central branch enters the spinal cord, the fine tactile sense (recognitional touch) is transmitted upwards in the thin bundle and the wedge bundle, which is the same as the deep sensory conduction pathway; the coarse tactile fiber is transmitted after the posterior cord rises 1 to 2 spinal segments and enters the human The horn, which terminates in the posterior horn cells, constitutes the second-order neuron crossing to the contralateral side to form the anterior tract of the spinal thalamus. After the lateral nucleus of the thalamus, the third-order neurons form the posterior limb of the sac to the cerebral cortex.

3, deep feeling

The first neuron is located in the spinal ganglia, and the sensory fibers that make up the spinal nerve are distributed in the deep receptors and fine tactile receptors of the muscle, the periosteum, the joints, etc., and the medial part of the posterior root of the central branch enters the spinal cord and is divided into long. Ascending branches and short descending branches, which emit collaterals on both the ascending and descending directions, form synapses directly with the anterior horn cells directly or through interneurons, forming spinal cord reflexes. The ascending fibers can reach the medulla, and the fibers from the lower part of the trunk and the lower limbs are arranged in a thin bundle at the inner side of the rear cable, and the fibers from the upper part of the trunk and the upper limbs are arranged at the outer side of the rear cable to form a wedge bundle. The thin beam and the wedge beam rise in the back cable, and the medulla finally has a thin bundle nucleus and a wedge bundle nucleus. Here, there is no formation of the second-order nerve fibers to bypass the ventral side of the central gray matter, and the left-right cross, that is, the mound system crosses to the contralateral side to form the medial collateral, and terminates in the lateral nucleus of the thalamus, and then the third-order nerve The nucleus fibers are terminated in the middle and upper part of the cerebral cortex by the posterior limb of the inner capsule, and the posterior central lobule and the central anterior gyrus. A part of the sense of touch is also transmitted through the wedge beam and the thin beam.

(2) Segmental feeling dominance

The inferior fibers of the posterior root of each spinal nerve dominate a certain area, and this segmental dominance is evident in the thoracic segment. The body surface markers are the nipple plane for the chest 4, the rib arch plane for the chest 8, the umbilical plane for the chest 10, the groin plane for the chest 12 and the waist 1 dominating. The nerve distribution in other parts is more complicated. The neck is from the front of the ear to the clavicle and the upper edge of the sternum is distributed by the neck 2 ~ 4, the upper limb is the neck 5 ~ chest 2, the front of the lower limb is the waist 1 ~ 5, the anal saddle area is able to 4 ~5 distribution. Each sensory nerve root or segment of the spinal cord dominates the sensation of a skin, called the dermis. Most dermatomes are dominated by 2 to 3 posterior roots or segments, so when determining the true upper bound of spinal cord damage, it must be calculated 1 to 2 segments higher than the level of spinal cord damage.

(3) Arrangement level of inner sensory conduction beam

The ridges of the thalamus bundle are arranged in fibers from the outside to the inside in the order of the tendon, the waist, the chest, and the neck. That is, the outer portion transmits the sensation from the lower segment (the lumbar energy segment), while the inner portion transmits the sensation from the upper segment (the cervical thoracic segment), which is the same as the arrangement of the pyramidal bundles. This is so because the spinal thalamus bundle fibers from the upper segment progressively push the fibers from the lower segment outward. The fibers in the posterior bundle are arranged from the inside to the outside in the order of the fibers of the tendon, the waist, the chest, and the neck, just opposite to the spinal thalamus bundle. The posterior bundle fibers (wedge bundles) from the upper segment will successively come from the posterior bundle of the lower segment. The fiber (thin bundle) is pushed to the inside. This arrangement rule, especially in the case of pain and temperature disturbance, identifies intramedullary and extraluminal swelling. Tumors are of particular importance. For example, in the intramedullary tumor of the cervical segment, the superficial sensory disorder begins to develop from the top to the bottom of the lesion, that is, according to the neck, chest, waist, and order; the extramedullary tumor of the cervical segment. The order of development of the disorder of shallow sensory dysfunction is just the opposite. The former is mostly bilateral symmetry, and the latter is mostly the contralateral side of the lesion in the early stage of the lesion.

Examine

an examination

Related inspection

Deep reflex examination chest and abdomen bolster test compound sensation examination deep sensation examination brain ultrasound examination

First, medical history

Should pay attention to the age, the location of the disease, the speed of onset, the length of the disease, and so on. Such as the elderly have a history of hypertension, sudden onset, there is a partial sensory disturbance, more common cerebrovascular disease; chronic disease is more likely to be a tumor. Young people have physical pain and loss of sense of temperature, and the normal movement and touch should consider the possibility of syringomyelia. Peripheral neuritis should be considered when the numbness of the extremities is weak. Subacute combined degeneration should be considered when the congenital sign of the spinal cord is associated with deep sensory disturbances of the lower limbs. When inquiring about medical history, pay attention to past history, such as hypertension, diabetes, uremia, trauma, tumor, drinking, poisoning, headache, dizziness, disc herniation, myelitis, neuritis, cerebrovascular disease, epilepsy, mental stimulation, etc. .

Second, physical examination

The examination of the sensation is cumbersome and prone to errors in the examination of the nervous system diseases. It requires patience and meticulousness, and sometimes it is necessary to repeatedly check and falsify the truth to obtain diagnostic data of great value. Attention should be paid during the examination: the patient's mental state is good, the consciousness is clear, and the ability to have normal expression can be checked. Before the examination, the patient should be made aware of the method and significance of the examination, and strive for full cooperation of the patient; the patient should be closed or covered during the examination. The location of the examination; the order of examination is generally from the sensory missing area to the normal area; in the examination, pay attention to the comparison between the corresponding parts of the left and right sides and the far and near end, repeat the examination if necessary; avoid suggestive questions in the examination, so as not to affect the judgment of the patient; The subjective prejudice of the examiner; when using the sensory disorder, it is advisable to use the chart and the human body contour map to compare the reference when repeating the examination; pay attention to distinguish the type of sensory disorder, such as conduction beam type, segmental type, nerve root type or distal type. Waiting for the degree of sensory disturbance; excessive fatigue can increase the patient's sensory area, and the time of one examination should not be too long. If necessary, the examination can be completed several times.

(a) shallow feeling check

1, touch

Gently wipe the skin with cotton wool, and touch the hair in areas covered with hair.

2, shallow pain

You can use an ordinary acupuncture needle or a small needle on the stalk of the sputum to gently prick the skin. The sputum patient makes a sound when he feels a slight pain. The well determines that the patient feels pain rather than the touch of the pointed object. If necessary, alternate the blunt ends of the needle. Stimulus to verify. If an area with a shallow sensory abnormality is found, a multi-directional inspection verification range is required.

3, temperature sense

Use a test tube filled with cold water (5 ~ 10 °C) and hot water (40 ~ 50 °C) to alternately contact the skin, and the patient will report cold or heat.

(2) Deep feeling check

1, joint position sense

The examiner passively moves the patient's joint and asks the patient where his limb is. The examiner can also place the patient's limb in a posture and maintain it, and mimic the contralateral limb.

2, sports sense

The examiner gently moves the patient's fingers and toes, asking the patient to say the direction of movement, moving about 50 degrees up and down, and then increasing the obstacles. Note that the examiner's fingers should be placed on both sides of the moving direction, and the action should be slow. Otherwise, the patient may indirectly judge the direction of the toe movement by pressure, resulting in the illusion of movement sensibility.

3, vibration sense

Use a vibrating tuning fork handle, usually 128 Hz, placed at the patient's bone protuberance, asking for the presence or absence of vibration, paying attention to the time limit of the feeling, and contrasting on both sides. It is also possible to alternate the vibrating and non-vibrating tuning forks to check their discriminating ability.

4, pressure

The patient's skin is alternately touched and pressed with a blunt object, and the patient is identified.

5, deep pain

Squeeze muscles or tendons, or compress the main nerve trunks, ask if there is any pain, and observe whether there is painful expression.

(3) Examination of complex sensation

1. Positioning

When the patient closes the eye, the examiner touches the patient's skin with a finger or a pen, and the patient clicks the finger to the stimulation site.

2, two points of discrimination

When the patient closes his eyes, use a special obtuse-angled two-footed ruler to separate the two feet to a certain distance, contact the patient's skin, and gradually reduce the distance. If the patient still feels two points, then reduce the distance. Normally, the sensitivity of the whole body is different, the fingertips are the most sensitive, and the back, the thighs and the legs are the worst. Normal fingertips 2-4mm, palm 8-12mm, back 2-3mm, forearm and upper arm 7-8cm.

3, shape sense

When the patient closes his eyes, put items such as pens, keys, coins, etc. in the patient's hand so that they can only be touched with one hand, and then the item name is spoken. Can be tested separately.

4, weight sense

The two objects with at least one time difference in weight are placed in one hand one by one, and the patient is distinguished. Can be compared on both sides. This test is meaningless when there is a deep sensory disturbance.

Third, auxiliary inspection

According to the distribution of the location of the sensory disturbance, the nature of the selection of appropriate detection of peripheral infection disorders should choose EMG, lumbar cerebrospinal fluid dynamics examination and routine examination. If necessary, a nerve biopsy should be performed; the posterior root type and the spinal cord type should be selected according to the sensory plane: CT or MRI, lumbar puncture for cerebrospinal fluid dynamics, spinal canal angiography, etc.; brain stem type, thalamus type, internal capsule type, cortical type Should choose brain CT or MRI, EEG, cerebral angiography and other examinations; disease-type sensory impairment should be checked from the psychological aspect.

Diagnosis

Differential diagnosis

The diagnosis should be differentiated from the following symptoms:

1. Sensory disturbance and function limitation on the lateral side of the shoulder arm: Quadrilateral space syndrome is a series of clinical syndromes caused by the compression of the posterior circumflex artery and the phrenic nerve at the four-sided hole. Its main manifestation is the sensory disturbance of the lateral arm of the sacral nerve and the limitation of deltoid function. When the shoulder joint is abducted and externally rotated, the muscles that make up the four-sided hole are pulled, and the four sides are squeezed from three directions to cause the disease.

2. Gloves or short socks are shallow and deep sensory disorders: one of the symptoms of cancerous neuromuscular disease. Different degrees of numbness, pain, or abnormal sensation at the distal end of the extremities. Gradually proceed and develop towards the near end.

3. Deep feeling disorder: "deep feeling" refers to the positional sense of muscles and joints, movement and vibration. If the nerve fibers or brain-sensing central lesions that transmit deep sensations are present, muscle and joint positional sensation, motor sensation, and vibration dysfunction are deep sensory disturbances. The patient is asked to close his eyes during the examination. The examiner touches one of his fingers or a toe and asks him to answer which one he is touching. If the answer is correct, the position is normal. If the answer is incorrect, it is a positional disorder. Or slightly up, down or left, move the patient's finger toe to the right, ask them to answer the direction of the activity, and answer correctly to indicate that the motor is normal. If the answer is incorrect, it is a motor impairment. The vibration test is to place the vibrating tuning fork on the protruding part of the bone. Ask the patient to answer the vibration feeling. If there is vibration, the vibration is normal. If there is no vibration, it is a vibration disorder.

4. Segmental dissociative sensory disturbance: Syringomyelia is often characterized by segmental dissociative sensory disturbance. Due to a variety of reasons, a tubular cavity is formed in the spinal cord, called syringomyelia, and there is often gliosis around the cavity. The incidence of this disease is relatively slow, the clinical manifestations of the affected spinal cord segmental nerve damage symptoms, characterized by pain, temperature loss and disappearance, and deep sensory preservation of the sensory disturbance, combined with dyskinesia and nerve damage Nutritional disorders.

5. Partial sensory disturbance: refers to the pain, temperature and body disorders of the patient's side. The nerve fibers of the conduction painful party from the skin receptor to the nerve endings to the posterior horn of the afferent spinal cord, crossed to the contralateral lateral cord, and then passed through the inner capsule to the center of the cerebral cortex and then returned to the sensory center. The sensory center makes a comprehensive analysis of the incoming stimuli to make a judgment that is hot, cold, or painful. If the internal part is damaged, the contralateral side pain is transmitted and the temperature is disturbed. The receptors that transmit the proprioceptive sensation are stimulated and then afferent into the spinal cord and then lifted up to the medullary wedge nucleus and the thin bundle nucleus, and then the nerve fibers from the two nucleus intersect to the contralateral superior sac to the central posterior gyrus. If the internal capsule is damaged, the conduction of the sense of the partial body is interrupted, and the proprioception is lost such as loss of position.

6. The use of no movement or sensory disturbance can not be: the use of aphasia is not possible, it is a situation in which there is no ability to perform a purposeful or fine movement when there is no movement or feeling of difficulty, and sometimes it means that the movement cannot be coordinated in the whole body. Next, use some of the limbs correctly to make a habitual action.

diagnosis: