Applying Diagnostic Criteria in Clinical Practice
Carol L. Koski, M.D. and Richard A. Lewis, M.D., Principal Authors
One of the critical issues facing the practicing neurologist is early recognition and treatment of CIDP patients when they are more likely to respond and, in some cases, go into remission. Unfortunately, there is no definitive diagnostic test for CIDP.
Diagnosis is based on
- the clinical history,
- neurological examination and supported by electrodiagnostic studies,
- cerebrospinal fluid (CSF) findings,
- blood studies to exclude other disorders, and
- nerve biopsy (infrequently performed).
Particularly, patients with early symptoms of the disorder may have predominantly sensory episodes of paresthesia prior to the onset of motor weakness. However, even then nerve conduction studies can display features of peripheral nerve demyelination with partial motor conduction block at other than compression points, temporal dispersion of compound action potentials, prolonged distal and F wave latencies, and reduced conduction velocities that involve at least two and frequently more nerves as the course extends over time. Identification of these changes in even one nerve at a non-compression area would indicate the need for close follow up and, with more widespread clinical progression, the institution of a therapeutic measure.
Increased protein and normal cell counts in the CSF can be used to support the diagnosis and confirm the disorder. Nerve biopsy is usually not required but should be considered in cases were the diagnosis is in question for example with pure sensory syndromes or where other etiologies such as vasculitis are suspected.
