Chronic infectious demyelinating polyradiculoneuropathy, also known as chronic Guillain-Barre syndrome, is a chronic acquired demyelinating polyradiculoneuropathy. CIDP is an autoimmune motor-sensory peripheral neuropathy with chronic demyelination of the proximal peripheral nerves as the main lesion, and is the most common type of CADP, with a chronic progressive or remission-relapse course.
CIDP is an autoimmune motor-sensory peripheral neuropathy with chronic demyelination of the proximal peripheral nerves as the main lesion. It is a chronic acquired demyelinating polyneuropathy (ADP) and is the most common type of CADP with a chronic progressive or remission-relapse course. The etiology of the disease is unclear. It is now recognized that AIDP is associated with infectious prodromal diseases, most commonly upper respiratory tract infectious diseases (viral or bacterial) and gastrointestinal inflammatory diseases (Campylobacter jejuni).
Clinical presentation
The disease can be seen mainly in adults, but children can also be affected, with peak age of onset at 40-60 years. The natural course of the disease includes stepwise progression, stable progression and remission-relapse. The progression period ranges from months to years, with an average of 3 months, with no significant improvement within 6 months of onset and a progressive course of more than 8 weeks, which can be differentiated from GBS.
1.CIDP classic
CIDP is seen in all age groups, and is more common in 40-60 years old, with similar incidence rates in men and women. Less often there is a clear history of antecedent infection. The symptoms of CIDP are limited to the peripheral nervous system and are mainly manifested as follows
(1) muscle weakness Most patients present with muscle weakness, which can involve the proximal and distal extremities, but proximal muscle weakness is the prominent feature. Typical weakness manifests as symmetrical proximal and distal limb weakness, usually starting from both lower limbs and progressing from distal to proximal; respiratory muscle involvement is less common.
(2) Sensory impairment Most patients show numbness in the extremities, partly with pain. There may be glove and glove-like hyperalgesia, and also hyperalgesia of deep sensation, and in severe cases, sensory ataxia. However, objective sensory impairment on sensory examination is generally not prominent.
(3) Tendon reflex abnormalities tendon reflexes are diminished or absent, even in those with normal muscle strength.
(4) Abnormal cerebral nerves A small percentage of patients may develop facial palsy or ophthalmoplegia. The cerebral nerves innervating the medulla oblongata muscle may occasionally be involved, and dysarthria and dysphagia may occur.
(5) Autonomic dysfunction may manifest as postural hypotension, sphincter dysfunction, and cardiac arrhythmias. A few patients develop Horner’s sign, impotence, urinary incontinence, optic disc edema, and decreased visual acuity. About 5% of CIDP patients may also develop CNS damage, demyelinating lesions are seen in the brain and cerebellum, similar to multiple sclerosis, and CNS symptoms and brain imaging changes may disappear after immunotherapy.
2.CIDP variants
(1) Pure motor type selectively involves motor fibers, conduction block is more common, and responds better to intravenous immunoglobulin than hormone.
(2)Sensory CIDP or chronic sensory demyelinating neuropathy starts with terminal sensory disorders of the limbs, and even sensory ataxia, although only sensory symptoms, but electrophysiology suggests the presence of nerve conduction velocity typical of CIDP with impaired motor fibers, and symptoms of motor involvement can occur as the disease progresses.
(3) Light muscle strength is usually normal, and symptoms include distal numbness, tingling, or weakness, which can progress with disease progression.
(4) Multifocal type (multifocal acquired demyelinating sensorimotor neuropathy) has a multifocal clinical presentation with conduction block in the affected nerve, evidence of sensory impairment, and a good hormonal response.
(5) The distal type (distal acquired demyelinating symmetrical neuropathy) does not involve proximal musculature, no monoclonal protein is found, and the response to treatment is similar to that of classic CIDP.
(6) Chronic immune sensory polyneuropathy clinically presents with sensory ataxia and large fiber sensory deficits. Electrophysiological examination of somatosensory evoked potentials suggests sensory nerve root involvement but normal nerve conduction velocity. The histological pattern is similar to that of CIDP.
Auxiliary examinations
1. Electrophysiological examination suggests demyelinating neuropathy with axonal degeneration – multifocal conduction block, prolonged distal latency, prolonged F-wave latency, reduced nerve conduction velocity (NCV) to less than 80% of normal, and discrete muscle loading action potentials.