Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired lesion of the peripheral nervous system of an autoimmune nature. In the classical version, it is manifested by a typical clinic of symmetrical sensorimotor polyneuropathy with slow monotonous or stepwise progress. CIDP is diagnosed according to clinical data, ENMG criteria, MRI results of the spine or ultrasound of nerve trunks. Treatment is carried out for a long time with the use of glucocorticosteroids, plasmapheresis sessions and intravenous immunotherapy. In most cases of CIDP, the prognosis is favorable.
ICD 10
G61.8 Other inflammatory polyneuropathies
General information
Chronic inflammatory demyelinating polyneuropathy (CIDP) finally got its name in 1982. Before that, various terms were used in relation to it. Because of the similarity of symptoms, clinicians have long considered CIDP to be a chronic form of Guillain-Barre syndrome. At the end of the XX century, specialists in the field of clinical neurology identified clear neurophysiological signs and developed diagnostic criteria for CIDP.
The disease occurs mainly in adulthood. The frequency in children is 0.5 cases per 100 thousand people, in adults — 1-2 cases per 100 thousand. Males get sick more often. The peak incidence of chronic inflammatory demyelinating polyneuropathy occurs at the age of 40-50 years. Moreover, people over 50 years of age have a more severe course and a smaller response to therapy. CIDP is often combined with other diseases: HIV infection, sarcoidosis, rheumatoid arthritis, SLE, amyloidosis, chronic glomerulonephritis, diabetes mellitus, tumor lesions. Along with other symptoms, chronic inflammatory demyelinating polyneuropathy may constitute a clinic for paraneoplastic syndrome.
Causes
CIDP refers to inflammatory polyneuropathies. The basis of the pathological process is inflammation of the peripheral nerve trunks. Its autoimmune nature is beyond doubt, but its etiopathogenesis has not yet been sufficiently studied. HLA genes are often detected in patients with CIDP, and antibodies to p-tubulin are detected in 70%.
Unlike Guillain-Barre syndrome, in most cases of CIDP, there is no connection of the debut with any previous disease or condition (ARI, vaccination, surgery, etc.). Perhaps such a connection exists, but due to the latent slow onset of CIDP, it is difficult to trace it.
Pathogenesis
Autoimmune inflammation leads to the destruction of the myelin sheath of the nerve. Demyelination in CIDP is diffuse in nature: individual nerve sites are affected; the process spreads along the diameter, then along the length of the nerve trunk; changes can affect either sensory or motor fibers. This causes a large polymorphism of clinical manifestations and certain difficulties in the diagnosis of CIDP.
Classification
In connection with the polymorphism of symptoms, a typical (classical) form and atypical variants of CIDP are distinguished.
1 The classical form of CIDP implies symmetrical muscle weakness of both distal and proximal parts of all 4 limbs, combined with sensory disturbances and increasing over a period of more than 2 months. It has a monotonous or gradual slowly progressing course, against which individual exacerbations are possible.
2 Atypical forms of CIDP include:
- distal with a predominant lesion of the hands, feet, forearms and shins;
- asymmetric with asymmetric involvement of the limbs;
- focal — an isolated lesion of one or more nerves, brachial or lumbosacral plexus;
- isolated motor — damage to only motor fibers;
- isolated sensitive — damage to only sensory fibers.
About 70-75% of cases of CIDP are variants with monophasic and chronic course. In the first case, the symptoms slowly progress to a maximum, and then its complete or partial regression is observed without subsequent recurrence.
The chronic progressive course of chronic inflammatory demyelinating polyneuropathy is characterized by a continuous smooth or gradual aggravation of symptoms. In 25-30% of patients, there is a relapsing-remitting course with clearly distinguished periods of exacerbation.
Separately, there is a variant of CIDP with acute onset, which is often diagnosed as Guillain-Barre syndrome (acute inflammatory demyelinating polyneuropathy). However, its subsequent chronic progressive course makes it possible to finally diagnose CIDP.
Symptoms
The basis of the clinical picture of CIDP is sensorimotor polyneuropathy. It develops gradually, often patients cannot even approximately indicate the onset of the disease. The first visit to the doctor is usually dictated by weakness in the limbs, which makes it difficult to walk up the stairs, climb on the running board in public transport, minor finger work, etc. Patients note shakiness and numbness of the limbs. Usually, with CIDP, muscle weakness is symmetrical and progresses in an ascending type. In most cases, its slow growth takes more than 2 months. However, 16-20% of patients with CIDP have a more acute onset with the development of weakness in the period up to a month.
Motor disorders progress and capture the proximal parts of the extremities. Accompanied by a decrease and loss of reflexes, most often – Achilles. Muscle atrophy does not develop immediately, but only with a prolonged course of CIDP without treatment. Sensory disorders are noted in 85% of cases of CIDP. They prevail over motor ones only in 10% of patients. As a rule, numbness of the feet and hands is noted. In a number of cases of CIDP, due to the defeat of deep types of sensitivity, sensitive ataxia develops. Some patients have pain syndrome.
Often, with CIDP, there is a postural tremor of the hands — trembling when holding the hands in a certain position. Possible damage to the cranial nerves: oculomotor, facial, trigeminal. Bulbar paralysis in CIDP rarely develops. Involvement of the respiratory muscles with the development of respiratory failure is observed only in some cases. Vegetative disorders are not typical for CIDP.
Diagnostics
Patients with symptoms of polyneuropathy are examined by a neurologist. In the neurological status, they have muscle weakness of the distal extremities, decreased sensitivity (hypesthesia) of the “stockings and gloves” type, loss of tendon reflexes. In atypical forms of CIDP, the changes may be asymmetric in nature or be detected only in the innervation zone of individual nerves or plexuses. Diagnosis of the type of polyneuropathy is carried out using electroneuromyography (ENMG), magnetic resonance imaging and examination of cerebrospinal fluid.
- ENMG. It is carried out by a neurophysiologist and in most cases diagnoses changes typical for demyelination of peripheral nerves. In the future, signs of axonal damage may be detected on the stimulation EMG. The initial ENMG study should include at least 4 nerves.
- Lumbar puncture with cerebrospinal fluid analysis. With HVDP, it is now carried out less and less often. In the classic version, it allows you to exclude an infectious lesion of the central nervous system. A high level of protein (> 1 g/l) in the cerebrospinal fluid is typical for CIDP in the absence of cytosis (increased content of cellular elements). The presence of cytosis indicates, first of all, the likelihood of HIV or Lyme disease.
- MRI of the spine. In patients with CIDP, it reveals an amplification of the MR signal from the spinal roots, branches of the lumbar or brachial plexus, which indicates their thickening. Almost 50% of patients with cerebral MRI are diagnosed with cerebral foci of demyelination.
- Sonography. Currently, nerve ultrasound is increasingly used in the diagnosis of polyneuropathies. This method is much simpler and cheaper than MRI. It also allows to detect thickening of the nerve trunk and can be used in the differential diagnosis of CIDP with multifocal motor neuropathy.
Since in 10-20% of chronic inflammatory demyelinating polyneuropathy is secondary, concomitant with systemic disease, it is necessary to carefully examine patients to exclude such an option. In some cases, signs of the underlying disease appear several months after the onset of chronic inflammatory demyelinating polyneuropathy. Therefore, the examination of patients must be repeated. Comprehensive examination includes blood glucose analysis, protein spectrum, antinuclear antibodies, liver tests, cancer markers; diagnosis of HIV and viral hepatitis, lung radiography, etc.
Treatment
To date, chronic inflammatory demyelinating polyneuropathy therapy has 3 components: corticosteroid administration, immunoglobulin administration and plasmapheresis. Corticosteroid therapy usually begins with a large dose of prednisone. If there is an effect, the dose is gradually reduced and switched to taking it every other day. In the period from 1 to 1.5 years of therapy, almost complete regression of symptoms is observed in most patients with CIDP. To prevent relapses, corticosteroid therapy is extended for several more years. In some patients, even after 2-3 years, relapses of CIDP occur against the background of attempts to cancel therapy, and then treatment must be continued.
Long-term use of corticosteroids should be controlled by blood pressure, bone density (densitometry), blood sugar, cholesterol, potassium and calcium levels. Accompanying courses of gastroprotectors, calcium preparations are mandatory. Immunosuppressants are an alternative to corticosteroids in CIDP. They are used in cases of low effectiveness of steroids, if they are poorly tolerated or if it is impossible to reduce the dosage.
The additional use of plasmapheresis and immunoglobulin allows to reduce the dose and duration of glucocorticoid therapy in patients with CIDP. Intravenous immunoglobulin therapy is effective in 50% of patients with chronic inflammatory demyelinating polyneuropathy. However, its effect is short-lived, so the courses of immunotherapy must be constantly repeated. Plasmapheresis is performed at a frequency of 2 times a week until clinical improvement (approximately 1.5 months). Then the sessions are gradually reduced to 1 time per month.
Forecast
Adequate treatment of chronic inflammatory demyelinating polyneuropathy makes it possible to achieve complete or almost complete regression of symptoms of polyneuropathy. Only 10% of patients have the preservation or aggravation of the clinic. In 85% of cases, 5 years after the debut, there is a minimal neurological deficit.
An important prognostic value is the duration of the primary increase in symptoms of CIDP. If it is more than 3 months, then recovery may take only 1 year. However, most patients with CIDP need long-term treatment and face a return of symptoms when it is canceled.