DM neuropathy v CIDP

Use rules

1.  With proximal weakness and distal weakness, in absence of genetic disorder, CIDP is overwhelmingly more likely; diabetic is usually not proximal\

2.  Diabetic is sensory, CIDP is motor more

3.  Diabetic is insidious, CIDP is aggressive

4.  Distal/proximal gradient reflex loss is more common in DM

5.  Objective response to immunomodulation is much more common in CIDP

 

(Obvious but still useful)

HNPP pearls

EMG

 

1.  Median >>> ulnar,  2.  Peroneal is involved

3.  Tibial nerve is almost never involved

4.  Pathology is tomaculi

5.  ulnar slowing across elbow is 100 %

6.  peroneal slowing across knee is 85 %

7.  SNAP's are abnormal-- amplitudes always reduced, latencies may be prolonged-- have not only pressure palsies but also an age related neuropathy

 

 

Clinical

Unlike CIDP, in which patients are usually symptomatic, HNPP patients often are asymptomatic with EMG changes