Polyneuropathy (
poly- +
neuro- +
-pathy) is damage or disease affecting peripheral nerves (
peripheral neuropathy) in roughly the same areas on both sides of the body, featuring weakness, numbness, and burning pain.[1] It usually begins in the hands and feet and may progress to the arms and legs and sometimes to other parts of the body where it may affect the
autonomic nervous system. It may be
acute or
chronic. A number of different disorders may cause polyneuropathy, including
diabetes and some types of
Guillain–Barré syndrome.[4][5][6]
Classification
Polyneuropathies may be classified in different ways, such as by cause,[2] by presentation,[1] or by classes of polyneuropathy, in terms of which part of the nerve cell is affected mainly: the
axon, the
myelin sheath, or the
cell body.[7][8]
Distal axonopathy, is the result of interrupted function of the peripheral nerves.[9] It is the most common response of neurons to metabolic or toxic disturbances, and may be caused by metabolic diseases such as
diabetes,
kidney failure,
connective tissue disease, deficiency syndromes such as
malnutrition and
alcoholism, or the effects of
toxins or
drugs such as
chemotherapy. They may be divided according to the type of axon affected (large-fiber,
small-fiber, or both), the most distal portions of axons are usually the first to degenerate, and axonal atrophy advances slowly toward the nerve's cell body. However, if the cause is removed, then regeneration is possible, although the prognosis depends on the duration and severity of the original stimulus[medical citation needed]. People with distal axonopathies usually present with sensorimotor disturbances such as amyotrophic lateral sclerosis[10]
The diagnosis of polyneuropathy begins with a history (anamnesis) and
physical examination to ascertain the pattern of the disease process (such as arms, legs, distal, proximal), if they fluctuate, and what deficits and pain are involved. If pain is a factor, determining where and how long it has been present is important; one also needs to know what disorders are present within the family and what diseases the person may have. Although diseases often are suggested by the physical examination and history alone, tests that may be employed include electrodiagnostic testing, serum protein
electrophoresis,
nerve conduction studies,
urinalysis, serum
creatine kinase (CK) and
antibody testing; nerve biopsy is done sometimes.[1][3]
Other tests may be used, especially tests for specific disorders associated with polyneuropathies; quality measures have been developed to diagnose patients with distal symmetrical polyneuropathy (DSP).[17]
Differential diagnosis
In terms of the differential diagnosis for polyneuropathy, the following must be considered:
In the treatment of polyneuropathies one must ascertain and manage the cause, among management activities are: weight decrease, use of a walking aid, and
occupational therapist assistance. Additionally, BP control in those with diabetes is helpful, while intravenous
immunoglobulin is used for multifocal motor neuropathy.[1]
According to Lopate, et al.,
methylprednisolone is a viable treatment for chronic inflammatory demyelinative polyneuropathy (which can also be treated with intravenous immunoglobulin). The authors also indicate that
prednisone has greater adverse effects in such treatment, as opposed to intermittent (high-doses) of the aforementioned medication.[1][21]