Symptoms of diabetic neuropathy

Symptoms of autonomic diabetic neuropathy are determined by the location of the lesion.

Autonomic diabetic neuropathy of the cardiovascular system is characterized by:

• painless ischemia and myocardial infarction (detected only by ECG);
• reduced heart rate variability, including the absence of an adequate increase in heart rate during exercise, the absence of changes in heart rate during deep breathing, the Valsalva maneuver, and the orthostatic test;
• tachycardia at rest (vagus nerve damage);
• Orthostatic hypotension (sympathetic innervation damage).

Autonomic diabetic neuropathy of the gastrointestinal tract is characterized by:

• dysphagia (disorder of esophageal motility);
• a feeling of fullness in the stomach, sometimes nausea, postprandial hypoglycemia is possible (due to impaired evacuation from the stomach);
• nocturnal and postprandial diarrhea, alternating with constipation (as a result of damage to the intestinal innervation);
• fecal incontinence (dysfunction of the anal sphincter).

In case of autonomic diabetic neuropathy of the genitourinary system, the following is noted:

• impaired bladder emptying, vesicoureteral reflux and bladder atony, accompanied by an increased risk of developing urinary tract infection;
• erectile dysfunction;
• retrograde ejaculation.

With autonomic diabetic neuropathy of other organs and systems, the following is possible:

• impaired pupillary reflex;
• impaired adaptation to darkness;
• sweating disorder (increased sweating when eating, decreased sweating in the distal parts of the extremities);
• absence of hypoglycemia symptoms.

Focal neuropathies

The clinical manifestations of these rare types of neuropathies are determined by the localization of the lesion. These include focal neuropathies of ischemic etiology and tunnel neuropathies.

Diabetic amyotrophy (proximal neuropathy) is characterized by:

• sudden onset, more often in older men;
• It is often accompanied by anorexia and depression.

Clinical manifestations include:

• weakness and atrophy of the thigh muscles;
• pain in the back and hips;
• difficulty rising from a sitting position;
• usually asymmetrical in nature or onset on one side, followed by involvement of the other limb;
• improvement of the condition with normalization of glycemia.

Diabetic radiculoplexopathy most often develops in type 2 diabetes mellitus.

Clinical features include:

• one-sided progressive pain in the chest area;
• possible disturbances of sensitivity in the area of innervation of the affected nerve.
• spontaneous recovery.

Mononeuropathies usually develop in people over 40-45 years of age. Characteristic signs of mononeuropathy include:

• acute or subacute onset;
• asymmetry of the process;
• damage to the cranial nerves (abducens and oculomotor, distal parts of the facial nerve) with the development of corresponding symptoms (most often double vision, paresis);
• sometimes pain in the eye area, headaches,
• spontaneous recovery.

Tunnel neuropathies are primarily associated not with a disruption of the blood supply or metabolism of the nerves, but with their compression in anatomically determined "tunnels". Tunnel syndromes with compression of the median, ulnar, radial, femoral, lateral cutaneous nerve of the thigh, peroneal, as well as medial and lateral plantar nerves are possible. The most common syndrome in diabetes mellitus is the carpal tunnel syndrome (compression of the median nerve).

Tunnel syndromes are characterized by:

• slow start;
• gradual progression and absence of spontaneous recovery (unlike typical mononeuropathies).

Clinical symptoms of carpal tunnel syndrome include:

• paresthesia of the thumb, index and middle fingers;
• As the disease progresses, there is a decrease in pain sensitivity in these fingers, atrophy of the short muscle that abducts the thumb.

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Subclinical stage of diabetic neuropathy

There are no clinical manifestations. Neuropathy is detected only with the help of special research methods. In this case, it is possible:

• changes in electrodiagnostic test results:
  • decreased conductivity of nerve impulses in sensory and motor peripheral nerves;
  • decrease in the amplitude of induced neuromuscular potentials,
• changes in sensitivity test results;
  • vibration;
  • tactile;
  • temperature;
• changes in the results of functional tests characterizing the activity of the autonomic nervous system:
  • dysfunction of the sinus node and heart rhythm,
  • impaired pupillary reflex.

Clinical stage of diabetic neuropathy

Diffuse neuropathy

In distal symmetrical neuropathy, patient complaints include:

• pain (usually moderate, dull and aching, mainly in the feet and shins, increasing at rest, especially in the evening and at night, and decreasing with physical activity);
• numbness, paresthesia (including a crawling sensation, "superficial tingling"), dysesthesia (unpleasant and painful sensations from any touch of clothing, bedding), hyperesthesia, burning sensation (usually in the soles).

Physical examination also reveals:

• disturbances of sensitivity (vibrational - the earliest manifestations, tactile, pain, temperature, muscle-joint sense or proprioception - in the joints of the distal phalanges of the big toes of both feet);
• areflexia (usually loss of the Achilles reflex on both sides),
• disturbance of muscle-articular sense in the distal interphalangeal joints of the big toes;
• movement disorders are possible later.

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