Chronic inflammatory demyelinating polyneuropathy (CIDP)

Signs and symptoms

Typical presentation includes symmetric, proximal and distal sensorimotor deficits: limb weakness that worsens over time, numbness or tingling, gait disturbance, and loss of tendon reflexes. Autonomic features are less common than in acute immune neuropathies. The course may be steadily progressive, relapsing–remitting, or show a monophasic improvement after treatment.

Diagnosis

Diagnosis combines clinical findings with supportive investigations. Key elements are:

• Electrodiagnostic studies showing demyelinating features such as slowed conduction, prolonged distal latencies or conduction block.
• Cerebrospinal fluid with raised protein and normal cell count (albuminocytologic dissociation).
• Imaging (MRI) may show thickened or enhancing nerve roots; nerve biopsy can demonstrate demyelination and remyelination with characteristic changes.

Criteria and classification systems are used to distinguish CIDP from related disorders, particularly the acute Guillain–Barré syndrome and hereditary neuropathies. When onset or features are atypical, other causes such as diabetic, vasculitic or paraproteinemic neuropathies must be considered.

Variants and pathophysiology

Several clinical variants exist: typical symmetric sensorimotor CIDP, multifocal acquired demyelinating sensory and motor neuropathy (MADSAM or Lewis–Sumner syndrome), purely motor or purely sensory forms, and distal-predominant subtypes. Recent research has identified antibodies against nodal and paranodal proteins in some patients, which can influence prognosis and treatment response.

Treatment and prognosis

First-line therapies include intravenous immunoglobulin (IVIG), corticosteroids and plasma exchange. Many patients improve with immunotherapy, especially when treatment begins early, but relapses and residual disability are common. Refractory cases may require immunosuppressive agents or targeted biologic therapies. Long-term follow-up is important to adjust treatment and manage complications.

For clinical overviews and guidance on management, see summaries of inflammatory neuropathies and their relation to acute syndromes: further reading.