Vasculitic peripheral neuropathy

Introduction to vasculitic peripheral neuropathy Vasculitic peripheral neuropathy refers to the inflammatory occlusion of the nourishing blood vessels of the peripheral nerves, resulting in one or more nerve infarcts or ischemic lesions. The pathological feature of vasculitis is segmental fibrinoid necrosis or transmural inflammatory cell infiltration of the vessel wall. basic knowledge The proportion of illness: the incidence rate is about 0.04%-0.08% Susceptible people: no special people Mode of infection: non-infectious Complications: nodular polyarteritis lupus erythematosus

Causes of vasculitic peripheral neuropathy

Disease factors (45%):

Vasculitic peripheral neuropathy can occur in connective tissue disease with vasculitis, such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome (sjogren's syndrome), and sarcoidosis, etc., can also occur in primary Vasculitis, such as nodular polyarteritis, Churg-Strauss syndrome, Wegner granulomatosis, etc.

Self-factor (45%):

A considerable part of vasculitis peripheral neuropathy confirmed by sural nerve biopsy, without associated connective tissue disease, nor evidence of primary systemic vasculitis, is a peripheral vasculitis peripheral neuropathy.

Pathogenesis

The occurrence of vasculitis has long been thought to be mediated by immune complexes deposited in the vessel wall, but in recent years this immunopathology has been challenged. Detailed immunohistochemical studies have shown that inflammatory infiltration of the vessel wall is based on T lymphocytes. Mainly, not polymorphonuclear leukocytes, suggesting that cellular immunity may also play a role. Although the pathogenesis of vasculitis is still unclear, it is certain that peripheral nerve damage is due to occlusion of small artery with a diameter of 75-200 m. Caused by distal ischemia.

1. Pathological changes of peripheral nerve vessels: pathological studies of autopsy and sural nerve biopsy confirmed that the vascular inflammation process of peripheral nerve mainly involves the small artery of the epicardium, and the diameter of the affected artery is 30-300 m. The endarterial artery is very Less affected, although the pathological changes of vasculitis vary depending on the type of vasculitis, the site of the disease, the length of the disease, and the treatment, but the clinical type of vasculitis cannot be distinguished only by the histopathological features of vasculitis.

The pathological manifestations of acute vasculitis are fibrinous necrosis of the arterial wall, neutrophils, lymphocytes and eosinophil infiltration. The subacute and chronic phases are characterized by internal elastic layer and intimal hyperplasia, vascular wall and surrounding tissue fibers. Differentiation, thickening, stenosis or occlusion of the lumen, the lumen of the vasculitis can be recanalized during the recovery period, and vasculitis in different periods can occur in the neuromuscular biopsy of the same patient.

Guo Yuxi (1988) reported the results of 21 cases of nodular neuroarthritis with nodular polyarteritis and peripheral neuropathy. 12 cases showed acute or subacute pathological changes, 3 cases showed chronic or convalescent pathological findings, and 5 cases were transitional. Type vasculitis, characterized by inflammation of the small arteries or small veins with intimal thickening, and the vascular adventitia may also have inflammatory cell infiltration.

Peripheral nerve biopsy of Churg-Strauss syndrome often shows necrotizing vasculitis with a large number of eosinophilic infiltration, pathological differences between nodular polyarteritis and microscopic polyarteritis, in which the former only involves the middle arteries and does not involve the capillaries. Arteries, capillaries and venules, the latter mainly involving the anterior capillaries, capillaries and venules, sometimes involving moderate arteries, leukocyte vasculitis can be seen in Wegener granulomatosis, Churg-Strauss syndrome, Henoch- Scholein purpura and idiopathic cryoglobulinemia vasculitis.

Immunofluorescence of sural nerve biopsy specimens is of great significance for the pathological diagnosis of vasculitic neuropathy. Almost all patients with vasculitic neuropathy have immunoglobulin, C3 complement and fibrinogen deposition, or only C3 complement or fibrinogen deposition, IgA-based immune complex deposition around the vessel wall or blood vessels is a pathological feature of Henoch-Scholein purpura.

2. Peripheral neuropathological changes: vascular inflammatory peripheral neuropathy The prominent feature of nerve fiber injury is axonal degeneration, which is manifested by the reduction or loss of myelinated fibers, the density of nerve fibers is significantly reduced, and the axis of visible and extracted single nerve fibers is visible. Distortion and medullary formation, the above changes are consistent with the pathological features of Wallerian degeneration (Waller's degeneration), demyelinating changes are relatively light, occasionally regenerative plexus, 34 cases of vasculitis peripheral neuropathy reported by Hawke, axonal degeneration There were 21 cases in more than 80%, and 7 cases in which all axons were degenerated.

3. Muscle biopsy pathology of peripheral neuropathy: In addition to visible vasculitis or perivascular inflammation, muscle changes are mainly selective type II muscle fiber atrophy, which may be related to muscle denervation and chronic depletion, because there is no peripheral nerve concurrency Type II muscle fiber atrophy is also common in muscle biopsy in patients with collagen vascular disease.

Vascular inflammatory peripheral neuropathy prevention

There is no good preventive method for autoimmune diseases. Early diagnosis and treatment of primary diseases leading to vasculitis is the main measure to prevent vascular inflammatory peripheral neuropathy.

Vascular inflammatory peripheral neuropathy Complications nodular polyarteritis lupus erythematosus

In addition to the clinical manifestations of peripheral nerve involvement, depending on the primary disease, various types of vasculitis (such as nodular polyarteritis, rheumatoid vasculitis, systemic lupus erythematosus) are also accompanied by other systemic manifestations, such as generalized weakness , weight loss, loss of appetite, joint pain, skin damage and clinical symptoms of kidney, respiratory, digestive tract and heart involvement.

Symptoms of vasculitic peripheral neuropathy Common symptoms Loss of appetite, joint pain, weakness, fatigue, or short socks... Deep feeling disorder, sensory ataxia

Vasculitic peripheral neuropathy can occur in connective tissue disease with vasculitis, such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, and sarcoidosis, etc., can also occur in primary vasculitis, such as knots Segmental polyarteritis, Churg-Strauss syndrome, Wegner granulomatosis, etc.

There is also a considerable part of vasculitis peripheral neuropathy confirmed by sural nerve biopsy, neither associated with connective tissue disease nor evidence of primary systemic vasculitis, is a peripheral vasculitis peripheral neuropathy.

According to the distribution of affected nerves, vascular inflammatory peripheral neuropathy can be divided into the following types:

1. Distal symmetry (glove socks) motor sensory neuropathy.

2. Single neuropathy / multiple mononeuropathy.

3. Asymmetric peripheral neuropathy.

4. Neural root syndrome and plexus disease.

5. Simple sensory peripheral neuropathy.

The onset of vasculitic peripheral neuropathy can be acute, subacute or chronic insidious onset, often manifested as multiple mononeuropathy in the early stage of the disease, and later with the evolution of the course, it is more common with symmetric or asymmetric peripheral neuropathy. The most commonly affected nerves are the common peroneal nerve, the sural nerve, the radial nerve, the ulnar nerve, the median nerve and the radial nerve. The clinical manifestations are intense burning of the affected nerve or limbs with pain, dullness, pain, and deep feeling. Deletion, abnormal sensation, in addition to muscle weakness, muscle atrophy and sensory ataxia, in addition to the clinical manifestations of peripheral nerve involvement, often accompanied by other systemic manifestations such as generalized weakness, weight loss, loss of appetite, joints Pain, skin damage and clinical symptoms of kidney, respiratory, digestive tract and heart involvement.

Examination of vasculitic peripheral neuropathy

1. Blood test: including blood sugar, liver function, kidney function, routine examination of erythrocyte sedimentation rate; rheumatism series, immunoglobulin electrophoresis, cryoglobulin, M protein, anti-GM-1 antibody, anti-GD1a antibody, anti-MAG antibody, tumor-associated antibody (Anti-Hu, Yo, Ri antibody) and other serological tests related to autoimmunity; serum heavy metal (lead, mercury, arsenic, antimony, etc.) concentration detection.

2. Urine examination: including urine routine, this-week protein, urinary porphyrin and heavy metal excretion in the urine.

3. Cerebrospinal fluid: In addition to routine cerebrospinal fluid, anti-GM-1, GD1b antibodies should also be investigated.

4. Angiography.

5. When there is suspected vasculitis with peripheral neuropathy, EMG and neurophysiological examination should be performed.

6. Tissue biopsy (including skin, sural nerve, muscle, nasal mucosa and kidney).

Diagnosis and differentiation of vascular inflammatory peripheral neuropathy

Neuromuscular electrophysiological examination: Almost all patients have abnormal nerve conduction velocity, mainly manifested by mild to moderate slowing of motor conduction velocity and decreased amplitude of muscle action potential. Some patients may have nerve conduction block, about In more than one third of patients, the action potential of lower extremity muscles completely disappeared, and the action potential of the sural nerve disappeared in 4/5 patients. Most patients had abnormal sensory conduction velocity, mainly manifested by the disappearance of one or more sensory nerve action potentials, electromyography Most patients have a denervated potential in the distal muscles.

1. Vasculitis with peripheral neuropathy, clinically combined with the presence of various types of vasculitis (such as nodular polyarteritis, rheumatoid vasculitis, systemic lupus erythematosus, etc.) and peripheral neuropathy.

2. For patients with suspected vasculitis, first determine the extent of damage to each system and organ based on medical history and detailed clinical examination, and then perform corresponding examinations, such as angiography, tissue biopsy (including skin, sural nerve, muscle, Nasal mucosa and kidney), suspected vasculitis with peripheral neuropathy, EMG and neurophysiological examination should be performed to determine the spatial distribution and severity of peripheral nerve involvement.

3. Sural nerve biopsy is the most direct and reliable method for diagnosing vasculitis peripheral neuropathy. About 50% of patients with suspected vasculitis peripheral neuropathy can find vascular lesions through sural nerve biopsy, even electrophysiological examination shows calf The nerves are normal and vasculitis may still be found after biopsy.

Isolated vascular inflammatory neuropathy is difficult to diagnose and needs to be differentiated from a variety of other peripheral neuropathies. At this time, sural nerve biopsy is particularly important.

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