CIDP & NCS protocol

Shehzad Hussain

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.

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

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.

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.

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

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.

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’sand 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.

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

Nerve Conduction Study Protocol….cont’d

• Cranial segmentMotor:

o Bilateral Facial Motor Nerveo Bilateral Phrenic Nerve (In respiratory compromised patients)

Blink Study:o Trigeminal & facial nerve sensory studies

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

CIDP Electrodiagnostic Findings

• NCS Findings:– Similar findings with GBS except:

• Secondary axonal changes– Abnormalities can be asymmetric.

– “Conduction block is an important parameter todifferentiate acquired demyelinating polyneuropathies

from congenital ones”

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

Nerve Biopsy Findings• Nerve Biopsy

– Teased Fiber: Segmental demyelination– Onion Bulb formation– Inflammation: Epineurial & endoneurial

Nerve biopsy is not essential for the diagnosis ofCIDP; however, if there remains a question of the diagnosis, nerve biopsy remains a usefuldiagnostic tool.

Sural Nerve Biopsy

THE END

• Without knowledge action is useless and knowledge without action is futile.

HAZRAT ABU BAKAR (R.A)