Vasculitic neuropathy can be a part of systemic vasculitis. It also
can present as a nonsystemic vasculitic neuropathy, without any
constitutional symptoms or serologic abnormalities. The clinical and
pathologic features are those of an ischemic neuropathy caused by a
necrotizing vasculitis of small arterioles.
vasculitic neuropathy may present with either mononeuritis multiplex
or asymmetric sensorimotor neuropathy. Symmetric neuropathy is rare.
It can present as acute/subacute relapsing, progressive, or
relapsing progressive neuropathy.
Asymmetric or multifocal
painful sensorimotor neuropathy is the most common presentation.
Asymmetry and length-independent involvement are the hallmarks of
mononeuritis multiplex, which is the most common presenting feature
of vasculitic neuropathy.
Less than 3% of the world's population is affected but is found that
over half of the people suffering from diabetics will develop some
degree of nerve damage. The symptoms of neuropathy are usually the
only method of diagnosis. Symptoms may involve tingling sensations
similar to decreased circulation in the extremities such as numbness
or even and pins and needles. A person's limbs may feel
alternately burning hot and icy cold, accompanied by sharp or dull
pain and muscle fatigue. These feelings are associated with reduced
fine motor coordination, possibly leading to paralysis in extreme
easy to diagnose neuropathy based on the pain suffered by a patient
but it is difficult to treat because neuropathy is so commonly
idiopathic, which means the doctor doesn't know why the patient has
developed peripheral nerve damage. However, some of the causes
identified include malnutrition, repetitive motion resulting in
carpal tunnel syndrome, herpes virus, HIV/AIDS, exposure to toxins
such as alcohol and inherited genetic disorders. When a doctor can
identify one of these causes, they can treat the pain at the source
by correcting malnutrition or treating diabetes for example.
Unfortunately, if the neuropathy is idiopathic, the only available
treatment is ongoing, temporary pain management usually with
pharmaceutical products. Researchers are still pursuing many paths
of study to better understand the process that leads to such
Wallerian degeneration of nerves results
from ischemic infarction caused by inflammatory occlusion of the
blood vessels. Segmental fibrinoid necrosis of a vessel wall and
transmural inflammatory cell infiltration are the main pathologic
features of vasculitis. Leukocytoclastic reaction traditionally has
been considered the primary mechanism of vessel injury in these
diseases, although more recent evidence suggests that
cellular-mediated mechanisms may be more important in the peripheral
Immune complexes are formed as a result of antibodies
reacting with antigen found within the blood vessel walls. These
immune complexes within the circulation activate the complement
cascade, generating chemotactic factors responsible for recruitment
of polymorphonuclear leukocytes at the local site of deposition of
the complex. Degranulation of the polymorphonuclear leukocytes
releases proteolytic enzymes, which, along with free radicals,
disrupt cell membranes and damage blood vessels. T cell–mediated
processes against epineurial and endoneurial vessels likely are also
important in the pathogenesis of vasculitic neuropathies.
Necrotizing vasculitis causes neuropathy through ischemic injury to
the vessels supplying the nerve. Poor collateral circulation in the
nerves makes them susceptible to ischemic injuries. Commonly
involved nerves with these features tend to be in the mid upper arm
and mid thigh in the "watershed zone."
most often presents as mononeuropathy multiplex (ie, in more than
60% of patients), with the peroneal nerve most commonly affected
(89% of patients), followed by the sural nerve (84%), tibial nerve
(68%), ulnar nerve (42%), and median nerve (26%).
symmetric polyneuropathy is the second most common presentation,
seen in less than one third of patients. The nerves most often
affected clinically are a diffuse mix of distal more than proximal
lower limb nerves, arising either from the lumbosacral plexus or
from widespread multifocal nerve involvement (ie, summation of
existing patchy lesions).
involvement also has been reported in systemic vasculitis. Facial
nerve neuropathy is observed most commonly, occasionally accompanied
by abnormalities in cranial nerve III, VI, or X.