Dysesthesia

Among the various neurological symptoms and signs of sensory disorders, dysesthesia stands out, defined as a change in sensations with the onset of a feeling of pain and an increased tactile response, which may not be clearly associated with damaging factors.

This condition is considered a type of neuropathic (neurogenic) pain in various diseases; dysesthesia code according to ICD-10 (in the section of symptoms, signs and deviations from the norm) - R20.8. [1]

Epidemiology

As noted by clinical statistics, in diabetic neuropathy, a change in sensitivity with the onset of pain is observed in 25% of patients.

In multiple sclerosis, burning, tingling or aching pain - as a manifestation of dysesthesia - is observed in 15-28% of patients.

And the prevalence of this symptom after a stroke is estimated at 7.5-8.6%.

 

Causes dysesthesia

The main causes of dysesthesia are impaired nerve conduction, leading to  peripheral  sensory neuropathy.

Diabetic neuropathy , which is noted in almost half of patients with hyperglycemia, is of metabolic origin, and along with dysesthesia, itching, tingling and numbness (paresthesia), muscle weakness are observed.

Most often, dysesthesia is clinically manifested:

• in patients with  multiple sclerosis ;
• as one of the symptoms of a  post-stroke condition ;
• with  Guillain-Barré syndrome ;
• with  fibromyalgia ;
• in cancer patients - with the development of progressive  polyneuropathy after chemotherapy
• in cases of  alcoholic polyneuropathy  in chronic alcoholism.

Risk factors

Experts, calling dysesthesia neuropathic or neurogenic pain, attribute all of the above diseases and conditions to factors that increase the likelihood of developing this symptom.

The risk of disorders of the somatosensory nervous system is increased with any damage to the nerves associated with various injuries and problems with the cervical spine; endocrine, autoimmune and oncological diseases; herpes virus and HIV; deficiency of calcium, magnesium, vitamins D and group B. [2]

In addition, risk factors include psychogenic conditions such as anxiety and  obsessive-compulsive disorder , hypochondria and depression, and somatoform disorder with  psychogenic pain .

Read more about the relationship between depression and abnormal pain syndrome in the publication -  Chronic pain and comorbid conditions .

Pathogenesis

The pathogenesis of dysesthesia is explained by nerve damage, impaired transmission of nerve impulses along the spinothalamic tract (transmitting somatosensory information about pain and itching) and spontaneous inadequate excitation of nociceptors (pain receptors).

Violation of receptor excitation causes a response in the corresponding areas of the cerebral cortex in the form of altered sensations - from slight tingling to pain of varying intensity.

In the case of multiple sclerosis, the mechanism of dysesthesia development is due to autoimmune destruction of the  myelin of the  protective sheath of nerve fibers, which leads to a violation of the transmission of afferent nerve impulses.

As a result of damage to the peripheral or central somatosensory nervous system, as well as complete or partial interruption of the transmission of afferent nerve signals (transmitting sensory information to the central nervous system), so-called deafferent pain occurs, which is usually accompanied by such abnormal manifestations as dysesthesia. [3]

More information in the articles:

• Anatomy of the nociceptive system
• Sensory neuropathies

Symptoms dysesthesia

As a rule, the symptoms of dysesthesia associated with alteration of peripheral or central sensory pathways appear locally - with varying degrees of intensity depending on the diagnosis.

The usual first signs are painful burning (burning sensation under the skin), tingling or aching pain. [4]

This is how dysesthesia of the extremities manifests itself - in the legs (especially in the feet), as well as dysesthesia of the hands (most often of the hands and forearms). The sensations of pain can be sharp - stabbing or similar to an electric shock - or prolonged with intensification when the ambient temperature changes, after exercise, or when falling asleep. For more information, see -  Sensory Neuropathy of the Upper and Lower Extremities

Nocturnal dysesthesias - when neuropathic pain worsens at night - is characteristic not only of multiple sclerosis and diabetes, since their occurrence after falling asleep is associated with a decrease in body temperature and a slowdown in blood flow during sleep. [5]

Generalized cutaneous dysesthesia, affecting most or all of the skin surface, may present with a painful burning sensation that is aggravated by changes in temperature, heat, or touching clothing. Local cutaneous dysesthesia is manifested by a painful sensation of subcutaneous burning or severe itching of the scalp.

People with multiple sclerosis sometimes have a feeling of compression (general tension) in the chest and ribs. [6]

Dysesthesia of the oral cavity causes discomfort in the mouth in the form of: a burning sensation, the presence of a foreign body, an increase or decrease in salivation, a sour or metallic taste. Pain is also possible, affecting the tongue, lips, jaw, mucous membrane of the cheeks and the bottom of the mouth. Bite discomfort for no apparent reason is defined as occlusive dysesthesia. Some experts associate the occurrence of these sensations with  neuropathy of the branches of the trigeminal nerve , which can be damaged by injury or during dental procedures.

Complications and consequences

Persistent dysesthesia can have negative consequences and complications. For example, the burning and itching sensation of scalp dysesthesia can lead to scratching, damage to the hair follicles and hair loss. Dermatological complications associated with itching are skin inflammation, hyperpigmentation and / or lichenification. [7]

In addition, dysesthesias at night due to sleep disturbance lead to chronic daytime fatigue, irritability and depression. [8]

In any case, this symptom reduces the quality of life of patients.

Diagnostics dysesthesia

With the development of dysesthesia against the background of obvious neurological damage, its diagnosis is carried out on the basis of anamnesis, physical examination of the patient and fixing his complaints and accompanying symptoms.

However, there are many diagnostic problems that blood tests help to solve (for HIV, C-reactive protein, glycosylated hemoglobin, antinuclear and antineutrophilic antibodies, iron, folic acid and cobalamin); analysis of cerebrospinal fluid; skin biopsy.  [9]

Instrumental diagnostics includes: study of nerve conduction (electroneuromyography), ultrasound of nerves, magnetic resonance imaging (MRI) of the brain and cervical spine. [10]

If there is a suspicion of a connection between dysesthesia and somatoform disorder, it is necessary to  study the neuropsychic sphere  with the involvement of a psychotherapist.

Differential diagnosis

Differential diagnosis is also needed to distinguish dysesthesia from paresthesia (painless tingling and numbness, creeping sensations on the skin), hyperalgesia (increased sensitivity to painful stimuli), allodynia (pain caused by a stimulus that is usually painless).

Treatment dysesthesia

For mild dysesthesia, treatment may not be necessary. In other cases, antidepressants are prescribed, and most often they are Maprotiline (Maprotibene),  Depress  (Fluoxetine), Venlafaxine (Venlaxor,  Velaksin ), Zolomax, Duloxetine, Citalopram.

It is also possible to use such anticonvulsants as Pregabalin,  Gabapentin  (Gabalept, Gabantin, Neuralgin),  Carbamazepine .

Dysesthesia in diabetic patients can be relieved with topical creams containing capsaicin or lidocaine. [11]

Also read:

• Sensory neuropathy treatment
• Treating neuropathic pain

Prevention

Comprehensive measures that could prevent the occurrence of this symptom are currently lacking. [12]

Forecast

For life expectancy, dysesthesia symptom has a good prognosis. However, in many cases it occurs due to progressive diseases and conditions, so over time, the condition of patients can worsen.