Nerve Conduction Studies (Ncs) In Patients With Central (Cns) And Peripheral (Pns) Nervous System Diseases With And Without Neuropathic Pain (Np)

Background: The diagnostic yield of NCS in CNS or PNS NP has not been systematically studied. Objectives: To compare the diagnostic yield of NCS in CNS and PNS disease with and without NP. Methods: Sensory NCS:sural, median,ulnar and radial. Motor:median, ulnar, peroneal and posterior tibial, Fwaves and H reflex. Contact heat evoked potentials(Cheps,Medoc)&SSEPes to painful stimulation are described elsewhere. Mean age 53.9 ± SD (range 22-83 years) Males = 48 Females = 43. PNS divided into polyneuropathies (PNP) and focal PNS involvement (OPN). Groups subdivided in with (+) and without (-) NP. Results: NCS showed in PNP(+): 24 sensori motor, 8 normal. PNP(-): 12 sensorimotor, 4 normal. OPN(+):5 mononeuropathies, 3 radiculopathies, 1 plexopathy, 2 normal. OP(-): 2 mononeuropath, 1 normal. CNS(+): 1 sensorimotor PNP, 4 OPN, 11 normal.CNS(-) 2 sensorimotor, 2 OPN , 9 normal. No significant differences (Fisher’s exact test) between with, versus without, NP in the proportions of PNP, OPN, CNS and normal findings overall, nor within the PNS sub groups. 70% of PNPs were sensorimotor. In 10 (7 with NP) of 16 patients with PNS and normal conduction findings, SSEPs or Cheps, were abnormal. NCS identified 9/29 CNS patients with unsuspected PNS pathology, five of them with NP. Conclusions: Patients with and without NP had similar proportions of PNS and CNS NCS findings. The majority of PNPs with NP were sensorimotor. The majority of small fibre PNP were identified by CHEPS or SSEPes to painful stimuli. Nerve conduction studies are indicated in patients with NP.