Diabetic neuropathy is a complication of diabetes that can affect both the peripheral and the autonomic nervous system.
This pathological condition results, in particular, from the combination of:
- Microangiopathy, vascular alteration related to diabetes that causes ischaemia of the capillaries that supply nerves. The consequent nutritional deficiency causes a progressive demyelination of the fibers and axonal degeneration;
- Direct effect of hyperglycemia on neurons;
- Intracellular metabolic changes that compromise nerve function.
Nerve transmissions can therefore be subject to unpredictable variations and dangerous interruptions.
Most common symptoms and signs *
- Alve alterations
- Muscular atrophy and paralysis
- Muscular atrophy
- Swollen ankles
- Intermittent claudication
- Muscle cramps
- Decreased sweating
- Erectile dysfunction
- Bladder dysfunction
- Abdominal pain
- Foot pain
- Hand and wrist pain
- Retrograde ejaculation
- Tingling in the legs
- Bone fractures
- Sore legs
- Legs tired, heavy legs
- Fecal incontinence
- Orthostatic hypotension
- Muscular hypotrophy
- Vaginal dryness
- Raynaud's syndrome
- Skin Ulcers
- Double vision
- He retched
Neuropathy occurs predominantly in patients with diabetes inadequately compensated for by therapy.
There are several types of diabetic neuropathy, including:
- Symmetric polyneuropathy : it is the most common form; hits the distal part of feet and hands. It manifests itself as a reduction in muscle strength, numbness and tingling in the limbs, burning pains or a painless loss of tactile, vibratory, proprioceptive and / or thermal sensitivity. In the most distal part of the lower limbs, these symptoms can lead to a reduced perception of the traumas of the foot deriving from narrow shoes or an incorrect distribution of body weight. This predisposes to the development of ulcerations, infections or fractures, subluxations and dislocations or alteration of the normal architecture of the foot (Charcot's disease, see also diabetic foot).
- Autonomic neuropathy : this variant of diabetic neuropathy can cause orthostatic hypotension and resting tachycardia. At the level of the digestive tract, alterations of the alvus (diarrhea or constipation), dysphagia, nausea and vomiting (secondary to gastroparesis), fecal incontinence, retention and urinary incontinence may occur. Autonomic neuropathy can also cause vaginal dryness, erectile dysfunction and retrograde ejaculation.
- Radiculopathy: most often it affects the nerve roots proximal from L2 to L4 - causing pain, weakness and atrophy of the extremities of the lower limbs (diabetic amyotrophy) - or the nerve roots proximal from T4 to T12 - causing abdominal pain (thoracic polyradiculopathy).
- Cranial nerve neuropathy: this variant may result in diplopia, ptosis, anisocoria or motor paralysis.
- Mononeuropathy : can cause weakness and numbness of the fingers (median nerve) or foot fall (peroneal nerve). Patients with diabetes mellitus are also prone to the development of nerve compression disorders, such as carpal tunnel syndrome. Mononeuropathies can occur simultaneously in different locations (multiple mononeurites).
Diabetic neuropathy can be diagnosed by detecting sensory deficits and reducing reflexes in patients with overt diabetes. Electromyography and nerve conduction studies may be necessary in all forms of neuropathy and are sometimes used to rule out other causes of neuropathic symptoms, such as non-diabetic radiculopathies and carpal tunnel syndrome.
Strict glycemic control can reduce the risk of diabetic neuropathy developing.
To reduce the extent of symptoms, it is possible to apply topically a capsaicin cream or to use drugs such as tricyclic antidepressants (eg imipramine), serotonin and noradrenaline reuptake inhibitors (SNRI; eg duloxetine), anticonvulsants (eg gabapentin, carbamazepine) and antiarrhythmics (eg mexiletine).
Diabetic patients who have a loss of sensitivity must daily check their feet to detect even minor traumas and to prevent their progression to infections that put the limb at risk.