Use of Distribution of F-Latency (DFL) in the Detection of Cervical Spondylotic Neuropathy

Abstract

Distribution of F-latencies (DFL) is a new nerve conduction parameter introduced by our laboratory to give a distribution of the conduction velocity (DCV) of motor nerve fibres in a peripheral nerve trunk simply as its mirror image. Earlier work revealed an association between Cervical Spondylotic (CS) neuropathy and DFL patterns obtained from the thenar muscle at the base of the thumb by artificially stimulating the median nerve. DFL froom normal subjects had a single peaked pattern, while that from subjects with CS had double or triple peaks, or a broad peak. The broad peak was suggested to be an indicator of early CS, even when the symptoms are not fully apparent. This led to some hypotheses based on physics, physiology and statistics, in order to explain such patterns. In order to verify these hypotheses, experiments need to be carried out carefully, and the present work is a step towards that goal. In this work DFL of the median nerve was obtained from 15 subjects, 6 normal, and 9 with diagnosed cervical spondylosis. The latter were subjected to further X-ray and MRI investigations, performed blindly at regular clinics. All of the 9 subjects were identified with either compression of nerve roots (radiculopathy), or spinal cord compression due to the bulging of the inter-vertebral discs (myelopathy). This shows with confidence that double or triple peaks of DFL indeed relates to CS, and broad peaks indicate their early stage. The same concept may be extended to other peripheral nerves, both in the hands and legs. Thus DFL may become an important screening test for neuropathy, as a first choice, offering a low cost and widely available test compared to the only other alternative, MRI, for such diagnosis. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14676 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 37-42

Identification of cervical radiculo-myelopathy using Distribution of F-Latency (DFL), a new nerve conduction parameter

“…Nine of them showing double or broad peaks were subject to X-ray or MRI investigation at regular clinics, where the radiologist gave reports without knowing the purpose of this study, or without any knowledge of the DFL findings. It was found that almost all of these cases had some pathology in the cervical region, whether radiculopathy or myelopathy (Hossain MI et al, 2011). X-ray assessment of one subject who had a single peak of DFL came out normal which agreed to the contention held by the above analysis of DFL.…”

“…However, while trying to establish the above hypothesis it was observed that double peaks of DFL were present in some cases where radiculopathy seemed to be absent, as determined from X-ray images. Further MRI scans of these cases revealed that there was myelopathy through disc bulging and compression of the spinal cord at one or more of the higher intervertebral levels (C4/5 and C5/6) (Hossain MI et al, 2011).…”

A double blind study to evaluate the efficacy of Distribution of F-Latency (DFL) in the detection of cervical radiculopathy and myelopathy

“…This indicates that it is potentially very suitable as a clinical test. It has been possible to detect subclinical cases of cervical radiculopathy and myelopathy where the patients did not have any complain or symptoms to suggest the clinical condition but after a suggestion from DFL, X-ray or MRI revealed the presence of neuropathy (Hossain et al 2011). All these findings indicate that DFL could be very useful as a screening test for CRM, for subjects without any history of nerve injury.…”

Changes in the distribution of F-latency (DFL) for different postures of head and neck

“…DFL has been found to be a sensitive parameter in the detection of radiculopathy (compression of nerve roots near the vertebra) or myelopathy (compression of the spinal cord) in the cervical regions, even at a subclinical stage [Alam and Rabbani 2010, Hossain et al 2011, Chowdhury et al 2014. Routine clinical investigations carried out by the group also indicated similar patterns for radiculopathy in lumbosacral regions.…”