Diagnosis of diabetic neuropathy

The diagnosis of diabetic neuropathy is based on the corresponding complaints, anamnesis of type 1 or type 2 diabetes, data from a standardized clinical examination and instrumental research methods (including quantitative sensory, electrophysiological (electromyography) and autofunctional tests).

[1], [2], [3], [4], [5], [6], [7], [8]

Complaints and standardized clinical examination

To measure the intensity of pain, special scales are used (TSS - general scale of symptoms, VAS - visual analog scale, McGill scale, HPAL - Hamburg symptom questionnaire).

[9], [10], [11], [12], [13], [14], [15],

Instrumental Research Methods

The great importance of methods for studying sensitivity disorders lies in the fact that they make it possible to diagnose diabetic neuropathy before the onset of clinical manifestations. The disadvantages of all the studies listed below are their non-specificity: these disorders are possible with neuropathies not associated with diabetes mellitus.

Assessment of vibration sensitivity. It is carried out by a graduated tuning fork of Riedel-Seifert with a frequency of oscillations of 128 Hz on the tip of the thumbs of both feet three times, with the calculation of the average value (in the norm> 6 conventional units out of 8).

Evaluation of tactile sensitivity. Monfilament Sernmes-Weinstein is used with a force of 1, 2, 5, 10 g. The monofilament is touched perpendicular to the skin surface for 1.5 seconds with a pressure sufficient for the monofilament to curl. The absence of sensation of touch in the patient indicates a violation of tactile sensitivity.

Assessment of pain sensitivity. Apply light pricks with a blunt needle. The sample is considered positive if the patient has painful sensations.

Assessment of temperature sensitivity. Produced using a Tip-Therm. The metal and plastic ends of the device alternately touch the patient's skin. The sample is considered positive if the patient feels a difference in the temperature of the surface of the device.

Electromyography. This method allows to assess the state of peripheral nerves of motor and sensory nerves of the upper and lower extremities. With stimulation neuromyography, we study such parameters as the amplitude of the M-response, the rate of propagation of excitation, residual latency, which allow us to evaluate the severity of neuropathy. Allows diagnosing diabetic neuropathy at an early stage.

Autonomous functional tests. For the diagnosis of autonomic diabetic neuropathy, cardiovascular tests are most often used, in particular:

• quantitative determination of heart rate variability with deep breathing (normal difference between heart rate on inhalation and exhalation> 10 beats / min);
• orthostatic test (measurements in the supine position and after standing). With a violation of sympathetic innervation, systolic blood pressure decreases more than in healthy people. The patient lies calmly on his back for 10 minutes, after which blood pressure is measured. The patient then rises, and blood pressure is measured at 2, 4, 6, 8 and 10 minutes. Systolic pressure drop> 30 mm. Gt; is considered pathological and testifies to vegetative cardiac neuropathy with violation of sympathetic innervation;
• measurement of blood pressure in isotonic muscular load. After determining the initial blood pressure of the patient, ask for 5 minutes to compress the hand dynamometer to 1/2 the maximum strength of the hand. If the diastolic pressure increases, then <10 mm. Gt; st., This indicates a vegetative neuropathy with a defeat of sympathetic innervation;
• ECG with a Valsalva test. Normally, with increased intrapulmonary pressure (straining), heart rate increases. If there is a violation of parasympathetic regulation of heart rate this phenomenon falls out. The smallest and largest RR intervals are determined on the ECG. The ratio of the maximum RR to the minimum <1.2 indicates autonomic neuropathy.

Additional methods for diagnosing autonomic diabetic neuropathy are daily monitoring of the ECG according to Holter and daily monitoring of arterial pressure, x-ray of the stomach with and without contrast, ultrasound of the abdominal cavity organs, intravenous urography, cystoscopy, etc.

Differential Diagnosis of Diabetic Neuropathy

Diabetic neuropathy must be differentiated with neuropathies of a different genesis, including with alcoholic neuropathy, neuropathy with the use of nsrotoxic drugs (nitrofurans, barbiturates, cytostatics, etc.) or exposure to chemicals (some solvents, heavy metals, insecticides), neuropathies within the paraneoplastic syndrome or malabsorption syndrome, nodular periarteritis. In this case, the main role is played by the detailed collection of anamnesis.

In the clinical picture, the manifestations of autonomic diabetic neuropathy come to the fore. Diagnosis of the dysfunction of an organ or system as a result of autonomic neuropathy is the diagnosis of an exception.

In patients with type 2 diabetes mellitus with diabetic radioplexopathy, in which there is a possibility of bilateral progressive pain in the chest with spontaneous disappearance, it is necessary to take into account the possibility of diseases of the heart and abdominal organs.

[16], [17], [18], [19],