The rate-dependent depression (RDD) of the Hoffmann (H) wave was examined as a predictor of therapy success in individuals with painful diabetic peripheral neuropathy (DPN).  About 73 healthy patients, 50 with type 2 diabetes and painless DPN, and 71 with type 2 diabetes and painful DPN provided general medical information, scales, and nerve conduction data. RDD was estimated by the decrease in amplitude of the third H wave relative to the first one after stimulating the left tibial nerve. Following the baseline examination, gabapentin therapy was started, and the RDD and visual analog scale (VAS) scores were both examined on a regular basis over the 2-week trial period. 

The unpleasant DPN group had considerable RDD impairment across all stimulation frequencies at baseline. During the 2-week observation period, gabapentin therapy dramatically lowered the VAS score and restored RDD. RDD was discovered to be an independent determinant of modest VAS score improvement, with the benefit increasing 1.27 times for every 1% drop in RDD value. In conclusion, the investigation showed that gabapentin can modify diabetes-induced loss of RDD and implies that RDD may be useful for predicting the early success of gabapentin treatment in patients with painful DPN.

Reference:diabetesjournals.org/diabetes/article-abstract/71/6/1272/144634/Rate-Dependent-Depression-A-Predictor-of-the?redirectedFrom=fulltext