Numbness of the leg due to a herniated disc: causes of insensitivity and what to do about it?

The most unpleasant symptom of a herniated disc is intense pain. The pain is sometimes so severe that it forces a person to take a forced position, and completely, for several hours or even days, deprives him of mobility and the ability to perform familiar, everyday movements. The most formidable, alarming sign is progressive weakness in the muscles of the foot, which makes walking difficult, makes running impossible and leads to disability.

But in addition to pain and muscle disorders, and sometimes instead of them, in isolation, sensitivity disorders occur. Most often, this is numbness in the leg due to a herniated spine, or a herniated intervertebral disc, to put it correctly. This material will talk about what numbness and other types of sensitivity disorders are, why they occur with hernias, how to make a diagnosis, and how to help such a patient. After all, sensory disorders, compared to pain and paralysis, bother the patient least of all, but in vain.

Sensation in legs is normal

Sensitivity is the final process of awareness of irritation that affects receptors, is carried along sensory nerves, enters the central nervous system and is recognized by the sensitive parts of the cortex. There are several specific types of sensitivity. Which of them will be important when considering the pathology of intervertebral discs?

First of all, it is tactile sensitivity, or touch. This is the feeling of touching the skin, its intensity, localization. Pain is also one of the specific types of sensitivity, but, as a rule, it is assessed as a separate symptom. It is important to assess temperature sensitivity by alternately assessing the ability of the skin of the foot to distinguish between hot and cold shades. There is a discriminatory feeling, that is, the ability to distinguish between two simultaneous touches. This is done with a special compass. The distance at which two touches feel like one is considered the minimum discriminatory distance. These are all types of superficial sensitivity. They are determined by specific receptors located in the skin.

But there are also deep types of sensitivity. This is a joint-muscular feeling, or a sense of the position of a limb in space. Deep are the feelings of vibration, the sensation of pressure, the feeling of weight on the limb. Many of these types of sensation are impaired in the presence of herniated intervertebral discs.

How does a hernia affect sensitivity?

Between the vertebrae, on their back side, are the so-called spinal or sensory ganglia. These are the nodes in which the bodies of the first neurons are located, perceiving various types of sensitivity from the corresponding peripheral nerves. The lumbar ganglia collect all types of sensation from the lower extremities, and then, as part of the dorsal or sensory root, these nerve bundles enter the spinal cord. There, switching to the bodies of other neurons, the bundles carrying sensitive impulses rise to the central nervous system for analysis. If a hernia, that is, a defect of the intervertebral disc, is located in such a way that it squeezes or compresses the spinal ganglia or other areas in which the majority of sensitive conductors are concentrated in a bottleneck, then the patient will experience certain sensitivity disorders. What happens if a hernial protrusion compresses the anterior portions of the spinal roots, causing their swelling?

Treatment of causes of back numbness

After specialists have established an accurate diagnosis, it is necessary to begin treatment of the pathology. It depends on what disease a particular doctor discovered in the patient. But in any case, the prescriptions will most likely include therapeutic exercise and massage. It has been proven that these types of therapies have a high percentage of positive effects on improving the patient’s health. The main thing is to follow all the doctor’s recommendations and not to overdo it with physical procedures.

Damage to the anterior portion of the roots

In addition to the posterior, sensitive portions, on the right and left in each pair of spinal roots there are also anterior, motor portions. Unlike the posterior roots, the anterior roots carry orders from top to bottom, from the brain to the muscles. They regulate muscle tone, causing muscles to perform voluntary movements that obey our will.

Almost always, a hernia “indiscriminately” compresses both portions, so in the clinic of lumbar hernias, along with sensory disturbances, various muscle disorders often occur. In some cases, these are minor changes that only a doctor can determine by examining tendon reflexes. Thus, in the case of long-term chronic compression, muscle weakness, difficulty gait, “slapping” of the foot, and the inability to walk on toes and (or) heels occur. What sensitivity disorders occur in the presence of hernias of the lumbar spine?

Numbness of the thoracic spine

If there is numbness in the thoracic spine, the development of scoliosis should first be suspected. This is a curvature of the spinal column in the lateral plane. Develops with weakness of the intervertebral ligaments and violation of the rules of distribution of physical activity. Scoliosis can also occur due to sitting with the body tilted to one side, inadequate development of the muscular frame of the back, etc.

Diagnosis is carried out by a vertebrologist or orthopedist. He orders an x-ray in several projections. If a characteristic deformity is detected, the degree of curvature and the possibility of correction using manual therapy without surgery are determined.

Please note that at the early stage of scoliosis development, back numbness in the area of ​​the shoulder blades may be the only sign of the disease. Much later, different heights of the angles of the shoulder blade, skew of the shoulders, and the formation of a hump will appear. At the first stage, only the occasional feeling of numbness may bother you.

Types of sensitivity disorders in hernias

We will not describe all localizations of sensory disorders in the presence of a hernia in the lumbar spine; we will limit ourselves only to an example of a classic localization site. This is a hernia in the L5-S1 area, that is, between the last, lowest lumbar vertebra and the upper base of the sacrum. In this case:

• sensitivity disorders in the form of pain will be localized in the gluteal muscle on the affected side, but the pain can go down to the popliteal fossa, and even below the knee;
• tactile disturbances will be on the skin along the posterolateral surface of the thigh, in the calf and foot of the same name;
• Also, the most likely area of ​​loss of sensation is the area of ​​the lower leg and the dorsal, or back surface of the foot. It is possible that the change in sensitivity will also occur on the lateral surface of the calf.

Along the way, foot drop, weakness of the tibial and peroneal muscles, loss of the Achilles reflex on the side of the hernia or its weakening, and impaired plantar flexion of the foot are possible. Of course, these are symptoms of an advanced, chronic hernia. But what specific sensitivity disorders occur with hernias, which are rare, or do not occur at all? Let's list them.

Hypesthesia

Hypoesthesia, or decreased sensitivity, involves maintaining all types of sensitivity, but with an increase in the threshold of irritation. That is, a person does not feel weak tactile touches, a weak painful effect also remains unnoticed for him, and he cannot confidently determine slight differences in temperature. This type of disturbance, especially for tactile sensations, is quite typical for compression disorders.

Paresthesia

The second type, which is sometimes even more common than decreased sensitivity, is called paresthesia, or translated from Latin - paraesthesia - “near-sensation”. Unlike hypertension, paresthesia occurs when there is no irritation. This is a false sensation, and most often it manifests itself in the so-called formication, or the feeling of “creepy crawling”. Such abnormal sensations can, in principle, be extremely diverse. This is a classic numbness and tingling sensation (most often with lower back hernias in the leg), a burning or cold feeling, a feeling of heat. But all these feelings are false.

Anesthesia

Anesthesia, or the complete loss of one or another type of sensation with herniated intervertebral discs, is quite rare, and only in advanced stages, when the process has been steadily progressing over a number of years. In this case, tactile loss of sensitivity most often occurs in the corresponding radicular zone.

In almost all cases, such a deep lesion is combined with impaired movement and the development of severe peripheral deep paresis, or paralysis with gait disturbance. Since the main thing that worries the patient is paralysis, such anesthesia will always be “relegated to the background.” Such patients are now very rare for another reason. Since movement disorders progress along with anesthesia, such patients are quickly taken for surgery. Therefore, severe anesthesia most often coexists with paralysis in those patients who live in villages, are illiterate and deprived of medical care. This situation in our country, alas, is not at all uncommon.

Dissociation (splitting) of sensitivity

Dissociation, or splitting of sensory disorders, is quite typical for radicular lesions. In the event that the hernia compressed all nerve conductors without exception with equal force, then in this case, all types of sensitivity on the limbs would be lost, from tactile and temperature, to pain and joint-muscular sensation. However, in practice it is noted that some types of sensitivity are preserved, while others are impaired.

Most often, tactile and pain sensitivity is upset, but temperature conductors and conductors of deep sensitivity are preserved. This is explained by the phenomenon of eccentric arrangement of conductors. It is known that an intervertebral hernia, as a physical defect, is located more ventrally, and the pressure of the hernia goes along different parts of the arch from the outer edge of the vertebral body. The conductors of tactile and pain sensitivity are located most ventrally in the posterior portion of the root, therefore, with intervertebral hernias, these disorders most often occur.

Very rarely, with intervertebral hernias, hyperpathy occurs, when subtle irritations fall out and are not felt, and only gross ones are perceived. Such an increase in the threshold of perception allows only strong stimuli to pass through; the nature of perception in this case will be explosive, unpleasant, difficult to localize and crumbly. Such complaints are more typical with neuropathic pain. Also, with radicular disorders, the phenomenon of causalgia almost never occurs, which most often appears with injuries to the immediate peripheral nerves.

How to understand that numbness in the back is a symptom?

Let's start with a fundamentally important point: how to determine that numbness in the back is pathological? Probably everyone has experienced a similar feeling in some stressful situations: after being in a low temperature, maintaining one body position for a long time, physical overload and even nervous strain. In such cases, the manifestation will be called “physiological”, and it does not require treatment.

It is quite simple to distinguish a “physiological” feeling of numbness in the back from a “pathological” one if you pay attention to three criteria:

1. The presence of any other neurological disorders in parallel with this. This may be a feeling of stiffness in the limbs, pain in the spine, impaired movement, local cramps and much more, from a headache in the morning to a sudden deterioration in vision. Looking ahead, let's say that in almost all cases the cause of numbness is a neurological problem, so this criterion is first not only in order, but also in importance.
2. Duration of sensation. Physiological numbness will pass quickly, within a few hours. But if the feeling of numbness remains longer, then this is already a sign of its pathological nature.
3. Physiological numbness in the back hardly interferes with your life, while pathological numbness can do this quite noticeably. For example, it may cause stiffness in movements, forced body posture, and sleep disturbances.

Diagnostics

Diagnosis of sensory disorders, first of all, involves a thorough neurological examination. After the neurologist has assessed all types of sensitivity and their disorders, assessed the strength and tone of the muscles, examined the reflex sphere, volume and amplitude of movements, he can make a preliminary diagnosis taking into account the history and palpation of the back muscles.

Then, a mandatory step is imaging diagnostics, with magnetic resonance imaging being preferable to X-ray computed tomography (X-ray CT). This is due to the fact that MRI shows soft tissue formations, including cartilage tissue, much better. But RCT, for example, has an advantage in the emergency diagnosis of stroke in the first hours, since, unlike MRI, it reacts very well to free blood. In order to confidently diagnose not only the presence of a hernial protrusion, but also its localization, as well as the degree of compression of the roots, a resolution of at least 1.5-2 Tesla is required on the tomograph magnets.

Finally, once the diagnosis has been made, the extent of peripheral nerve damage can be assessed, if there is evidence for this. Electroneuromyography (ENMG) is performed. It allows you to assess the degree of nerve degeneration and make a differential diagnosis between radicular symptoms caused by a hernia and, possibly, the presence of underlying compression-ischemic neuropathy. This disorder does not directly affect the root, but a nerve, and can simulate a hernia.

How are sensory disorders treated?

The greatest concern, understandably, is intense pain, and later paralysis and muscle weakness. If sensitivity disorders occur without pain, then the Russian patient is inclined to be patient with them and get used to them. In some cases, there is a much more dangerous situation when, along with limited sensitivity disorders, a painless form of motor disorders gradually progresses, which, in the end, is fraught with peripheral paralysis and permanent disability. Therefore, such patients need to preventively check the strength of the muscles in the legs, even just by walking on their toes and heels in the morning. When weakness, uncertainty or impossibility of this test occurs, you need to urgently contact a neurologist.

Before treating sensitivity disorders with conservative methods, from physiotherapy to massage and physical therapy, it is necessary to determine whether there are indications for surgical intervention and removal of the hernial protrusion or not.

If, according to MRI, the hernia is small in size, and the pain syndrome does not last too long, just a few days against the background of maintaining strength and limited sensory disorders, then you can get by with conservative measures. When aseptic inflammation and edema are relieved, sensory disorders will disappear on their own. Moreover, the sooner treatment is started after their appearance, the greater the chance of full recovery.

In the same case, if the hernial protrusion is quite large, if there are additional factors, for example, excess body weight, old age, diabetes, then there is a high risk that the treatment will be ineffective. In this case, it is necessary to first eliminate the immediate cause of the sensory disorders, that is, mechanically release the root from the pressure of the hernia. This means that the best treatment option will be modern minimally invasive neurosurgery.

This can be laser vaporization, classic microdiscectomy, video-endoscopic microdiscectomy, or, for example, nucleoplasty, which prevents the transformation of protrusion into a hernia. Modern operations are carried out quickly, safely, and with high efficiency. They are carried out in large clinics in Russia and in Eastern European countries, such as the Czech Republic. Of course, the greatest experience has been accumulated by surgeons from the European Union, Israel and the USA. In the presence of large hernias with pronounced periodic aggravation and gradual progression, only after surgery to remove the intervertebral hernia, sensory disorders are also eliminated.

Diagnosis of back numbness

If the patient’s back is numb, the first thing to do is consult a general practitioner. At the first stage of diagnosis, the doctor assesses the patient’s condition, makes a preliminary diagnosis and prescribes additional clinical studies, which involve a narrow-profile approach to the examination. Therefore, the first stage of diagnosis is aimed at:

• studying the patient's medical history;
• clarification and analysis of information about the manifestations of the disease at the moment;
• a careful physical examination with the obligatory procedure of carefully palpating the numb areas of the back;
• a detailed survey regarding the manifestation of symptoms coupled with back numbness.

After the general practitioner carries out the first stage of diagnosis with all accompanying procedures, laboratory and other tests are prescribed to clarify the picture of the disease.

1. Computer and magnetic resonance imaging of the patient’s internal organs and head.
2. General blood test and biochemistry.
3. X-ray of the spine.
4. Dopplerography.
5. Ultrasonography.

Ultrasonography

The most commonly prescribed are CT, MRI and general clinical blood tests due to their high information content. Thanks to these studies, the presence of destruction in the spine is established, as well as the exact location of the identified disorders.

Ultrasound and radiography are prescribed to exclude diseases of the internal organs. These studies are additional diagnostic in nature, but are no less important in importance.

It should be noted that in the absence of disorders in the spinal column, ultrasound and laboratory blood tests come first in diagnosis. In this case, the involvement of back numbness in diseases that have a surgical basis is established. In this case, an accurate clinical picture is important for making a diagnosis.

In case of numbness of the back, muscle sprains or spasms are diagnosed only if no evidence of more serious pathologies in the patient’s body is identified. In this case, the medical history must establish the presence of a sedentary lifestyle, injury or hypothermia.

After the initial examination procedures and after receiving research results, patients are referred to the following specialists:

• orthopedist;
• cardiologist;
• gastroenterologist;
• infectious disease specialist;
• pulmonologist;
• gynecologist;
• urologist;
• proctologist

After this, the patient is prescribed additional specific tests depending on the treatment plan of a particular specialist to whom the patient will be referred.

Doctors of completely different specializations can supervise a patient with back numbness.

How to treat sensitivity disorders conservatively

What to do to restore sensitivity? Same as for pain relief. To do this, it is necessary to eliminate swelling and aseptic inflammation. First of all, in the first hours and days, drugs from the NSAID group are used. These are selective inhibitors of cyclooxygenase type 2, for example, ketoprofen, meloxicam or non-selective but powerful drugs - diclofenac, always covered with proton pump blockers in the presence of risk factors for erosive gastritis and gastric ulcer. Of course, if there is no pain, then the fight against sensitivity disorders is almost never carried out as quickly and energetically as when it is present. After all, relieving pain is the first task of emergency care, and not at all restoring sensitivity.

Next, you need to restore blood flow in the area of ​​the affected root, and, more importantly, increase venous outflow to relieve swelling. For this purpose, therapeutic exercises, physiotherapy, and, first of all, electrophoresis with vitamins and aminophylline are used, and in some cases, UHF is even indicated, which has a classic absorbable effect.

To resolve muscle spasms in the painful form, the use of central muscle relaxants is indicated: tolperisone and tizanidine. They also help cope with sensitivity disorders.

If sensory disorders persist after pain relief, a more thorough diagnosis is necessary, because it is possible that not only a hernia, but also other pathological conditions could lead to sensory disturbances in the patient. This could be diabetic or alcoholic polyneuropathy, or the onset of multiple sclerosis. In this case, it is necessary to treat the identified underlying pathology, and correct and timely treatment will, in most cases, lead to the return of impaired sensitivity.

Classification of causes

This problem - the occurrence of cold sensations - can be either a pathological or physiological problem. At least, that’s how doctors describe the symptoms.

Physiology

These conditions are distinguished by the presence of a clear time frame - the cold is not felt constantly, but occurs only short-term and periodically. The occurrence of this feeling is influenced by the following factors:

• externally influencing environment;
• temporarily altered state;
• stressful state;
• state of hunger;
• lack of sleep;
• uncomfortable, difficult posture;
• being motionless.

Stress can cause a cold back

As soon as the physiological impact factor disappears, the feeling of cold also disappears. This feature is not related to the pathological feeling of freezing of the back.

1. External influence from the environment is elementary hypothermia, frequent exposure to dampness, draft or wind.
2. Changes in the body can be either a manifestation of a cold, accompanied by chills, increased sweating, or vasoconstriction.
3. Stress is a cold-provoking factor because the nerve endings located around the spine react to it and hormones are released from the body of the adrenal cortex.
4. If a person remains immobile for a long time or in an uncomfortable position, the back becomes numb and feels cold.
5. This reaction of the body can also be detected during physical fatigue and heavy load on the back.

A cold back may be due to a cold.

After changing posture, resting, disappearing the feeling of hunger, eliminating external natural influences, the back quickly warms up and returns to normal temperature.

Signs of pathology

The causes of the pathological nature are more serious and deeper, since in absolutely all episodes they report the occurrence of problems in the body or a pathology already existing in it.