NCS-CIP & CIM NCS FINDINGS

SUMMARY

1. A normal NCS study by day 7 would rule out CIP and CIM.

CIM
2. Abnormalities seen a few days after onset of symptoms.
3. Low amplitude, prolonged CMAP.
4. Phrenic motor amplitudes may be low.
5. Sensory responses are normal.

CIP
6. Generalized axonal sensorimotor polyneuropathy with low motor & sensory amplitudes.

7. Over 2-3 weeks fibrillation potentials will be evident on EMG.
8. Phrenic motor amplitudes may be low.
9. Demyelination is not seen in CIP and would exclude the diagnosis.
10. Direct muscle stimulation may elicit a relatively higher amplitude compared with nerve stimulation.

Reference(s)

Lacomis, D., 2021. Neuromuscular weakness related to critical illness. [online] Uptodate.com. Available at: illness polyneuropathy in ICU,caused by reduced sodium permeability. UpToDate.com [Accessed 20 March 2021].
Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].