An Overview of Diabetic Neuropathy
Peripheral neuropathy is a disorder of the peripheral
nerves. In diabetics these disorders are called diabetic peripheral
neuropathy. The iteology of diabetic neuropathies involves a thickening of
the walls of the blood vessels that supply the nerves, resulting in a
decrease of important nutrients; demyelinization of the Schwann cells that
surround and insulate nerves, slowing the nerve conduction; and the
formation and accumulation of sorbitol within the Schwann cells, impairing
nerve conduction. The manifestations of diabetic neuropathy depend on the
locations in which the lesions form.
The peripheral neuropathies include polynueropathies and mononeuropathies.
The most common of the two neuropathies found in diabetics is polyneuropathy
which is a bilateral sensory disorder. The symptoms of diabetic peripheral
neuropathy first appear in the toes and feet and work their way upward in
the body. In the later stages of diabetes the fingers and hands may also
become involved. Where the symptoms hit depends on the nerve fibers
involved.
The diabetic who suffers from polyneuropathy will usually experience a
subjective change in sensation, such as numbness and tingling, an aching
pain, burning, shooting pain and feelings of cold feet. Other symptoms that
may be experienced include impaired sensations of pain, temperature, light
touch, two-point discrimination, and vibration. There is no specific
treatment for poly-neuropathy.
Isolated peripheral neuropathies that affect single nerves are
mononeuropathies. The symptoms of this form of diabetic neuropathy depend on
the nerve involved and can include the following:
• Palsy of the third cranial (oculomotor) nerve, with headache, eye pain,
and an inability to move the eye up, down, or side to side.
• Radiculopathy, with pain over a dermatome and a loss of cutaneous
sensation, most often located in the chest.
• Diabetic femoral neuropathy, with motor and sensory deficits of pain,
weakness, and areflexia) in the anterior thigh and medial calf.
• Entrapment or compression of the medial nerve at the wrist, resulting in
carpal tunnel syndrome with pain and weakness of the hand, the ulnar nerve
at the elbow, with weakness and loss of sensation over the palmar surface of
the fourth and fifth fingers, and the peroneal nerve at the head of the
fibula, with foot drop. | 
