2. What is CIDP???
• Chronic inflammatory demyelinating polyneuropathy (CIDP)
is an immune-mediated inflammatory disorder of the
peripheral nervous system.
• CIDP is an autoimmune diseases where the body's immune
system attacks its own nerves.
• normally the body learns not to attack itself; It also knows
when a foreign object like a virus or a bacteria has entered
the body which needs to be destroyed. In autoimmune
diseases, the recognition of self is lost and the body attacks
itself. The nerves of the body are seen as a foreign object
and attacked. If this occurs acutely then the illness is called
Guillain-Barré and if it becomes chronic then it is
called Chronic Inflammatory Demyelinating Polyneuropathy
or CIDP.
3. Cont…
• The nerve itself acts like the copper wire, and
there is an insulation around the wire that is
called myelin. In CIDP, it is the myelin that is
affected first and in later stages of the disease
the nerve itself is attacked
4. Clinical:
• CIDP is an acquired, demyelinating, motor and sensory
neuropathy that is presumed to be immune mediated.
All ages can be affected, but most patients present in
their fifth to sixth decade. Both proximal and distal
muscles are affected.
• The time course in CIDP is longer than AIDP (>6 six
weeks)
and may follow a monophasic progression, a stepwise
progression or a relapsing and remitting course.
• Early in the illness, it may be impossible to differentiate
AIDP from the initial presentation of CIDP.
5.
6.
7. Symptoms:
• The symptoms of Chronic Inflammatory
Demyelinating Polyneuropathy include numbing,
tingling, pain, progressive muscle weakness, loss of
deep tendon reflexes (areflexia), fatigue, and
abnormal sensations. One of the first signs that could
develop is a foot drop, where patients developed
weakness in their ankles and as a result tend to trip
over their feet, or they could develop numbness and
tingling in the feet and toes which gradually spreads
to the other parts of the body.
8. CLINICAL MENIFESTATION
• Demyelination
– May be detected on nerve conduction studies or
nerve biopsy
– Multifocal demyelination is a diagnostic hallmark of
CIDP, but distribution of demyelinative lesions varies
among patients
• Weakness
– Characteristically, involves both proximal and distal
muscles
– Typically symmetric, but can begin asymmetrically
• Sensory symptoms are common but motor symptoms
usually predominate
• Autonomic system dysfunction can occur
9. Cont…
• Slow progressive course is seen in approximately 2/3 of cases
• Children usually have a more precipitous onset of symptoms
• Relapsing course with partial or complete recovery between
recurrences is seen in approximately 1/3 of cases
– Periods of worsening and improvement usually last weeks or
months
– Patients with a younger age of onset are said to have a
higher frequency of relapsing course
• CIDP typically is a very slowly progressive, predominantly sensory
polyneuropathy and is more common in older patients, especially men.
Patients usually present with gait ataxia and marked large-fiber
sensory loss. Some patients have a prominent action tremor.
10. American Association of Neurology
ELECTROPHYSIOLOGIC
CIDP DIAGNOSIS CRITERIA
• AAN has developed Electrophysiologic criteria for the identification
of patients with CIDP ;
• Electrophysiologic Criteria:
According to AAN to diagnose the CIDP patients following NCV’s
and EMG findings should be fulfilled;
– Require 3 demyelinating range abnormalities
• Prolonged distal latencies (two or more nerves)
• Slow conduction velocity in two or more nerves (not across
the entrapment sites).
• Prolonged F wave latencies & H reflexes in one or more
nerves.
• Conduction block/ temporal dispersion in one or more
nerves.
11. Nerve Conduction Study Protocol
• Motor Nerve Conduction Studies:
– Bilateral Median (APB) & Ulnar (ADQ) motor nerves
Bilateral Posterior Tibial (AH) & Peroneal (EDB) motor
nerves (If low amplitudes in Peroneal (EDB) then we have
to record the peroneal motor nerve from Tibialis anterior
muscle).
• Late Reponses Studies:
– Bilateral f-wave responses in all motor nerves performed
in upper and lower limbs.
– Bilateral H-reflex studies at the same distances
• Sensory Nerve Conduction Studies:
– Bilateral Median (F2) ,Ulnar (F5) & Radial in upper limbs
– Bilateral sural in lower limbs
12. Nerve Conduction Study Protocol….cont’d
• Cranial segment
Motor:
o Bilateral Facial Motor Nerve
o Bilateral Phrenic Nerve (In respiratory compromised patients)
Blink Study:
o Trigeminal & facial nerve sensory studies
13. EMG Recommended Protocol
• These are the muscles which should be sampled routinely for
polyneuropathy:
• Upper limb muscles:
– First dorsal interosseous
– Extensor indicis proprius
– Forearm muscles (pronator teres or flexor carpi radialis)
– Biceps brachii
– Cervical Paraspinal muscles
• Lower Limb Muscles:
– Extensor Hallucis Longus
– Tibialis anterior
– Soleus/medial gastrocnemius
– Quadriceps
– Gluteal muscles or tensor fascia latae
– Lumber Paraspinal muscles
Weaker muscles should be sampled first for better yield & to
increase the sensitivity of the EMG study
14. CIDP Electrodiagnostic Findings
• NCS Findings:
– Similar findings with GBS except:
• Secondary axonal changes
– Abnormalities can be asymmetric.
– “Conduction block is an important parameter to
differentiate acquired demyelinating polyneuropathies
from congenital ones”
15. EMG PARAMETERS & FINDINGS
• Parameters assessed (on EMG)
– Insertional activity
– Spontaneous activity
– Motor unit potentials (MUPs)
• Morphology (duration, amplitude and complexity)
• Recruitment and firing rate
• Interference pattern
• EMG Findings:
– Neuropathic pattern
• Positive sharp waves
• Fibrillations potentials
• Large MUAPs
• Reduced recruitment
• Paraspinal muscles also involved showing the abnormal
spontaneous activity
16. Nerve Biopsy Findings
• Nerve Biopsy
– Teased Fiber: Segmental demyelination
– Onion Bulb formation
– Inflammation: Epineurial & endoneurial
Nerve biopsy is not essential for the diagnosis of
CIDP; however, if there remains a question of
the diagnosis, nerve biopsy remains a useful
diagnostic tool.
