A new study has shown that nerve ultrasound scores can be useful in differentiating demyelinating and axonal polyneuropathies in patients with conditions such as hereditary transthyretin amyloidosis (hATTR).
The study, published in Medicina, found no significant differences in intra- and internerve cross-sectional area (CSA) between chronic inflammatory demyelinating polyneuropathy (CIDP), acute inflammatory demyelinating neuropathy, and axonal neuropathies.
“In the current study, we aimed to evaluate the utility of the [ultrasound pattern sub-score A (UPSA)] and intra- and internerve CSA variability in differentiating demyelinating neuropathies (CIDP and AIDP) from various axonal neuropathies,” the authors wrote. “We hypothesize that the UPSA scores and intra- and internerve CSA variability are higher in demyelinating neuropathies, specifically in CIDP, as compared to axonal neuropathies.”
The research team assessed intra- and internerve CSA variability and UPSA scores in 34 patients with CIDP, 30 patients with Guillain-Barré syndrome, 4 patients with hATTR, 3 with diabetic polyneuropathy, and 1 with vasculitic neuropathy. Thirty healthy participants served as controls. Nerve ultrasound scanning was performed by 2 evaluators on both sides and at predefined nerve segments. Nerve conductions studies were also performed.
Read more about hATTR testing
The results revealed significantly higher values of CSA in peripheral nerves in patients with CIDP, and patients with both CIDP and AIDP had larger nerves than control patients. Those with CIDP had the largest nerves among all participants. UPSA was significantly higher in CIDP compared with the other groups.
However, UPSA did not consistently distinguish non-CIDP demyelinating neuropathy from axonal neuropathies or from healthy controls, unless the ultrasound pattern subscore B score was also incorporated.
The authors conclude that nerve ultrasound is useful in diagnosing CIDP, particularly in cases of nerve excitability on nerve conduction studies. They recommend quantifying the extent of nerve enlargement using USPA scores to distinguish CIDP form other types of neuropathy.
Reference
Tan C-Y, Yahya MA, Goh K-J, Shahrizaila N. Nerve ultrasound score in chronic inflammatory demyelinating polyneuropathy. Medicina. Published online April 11, 2023. doi.10.3390/medicina59040747
