F wave

This article is about the term as it applies to neuroscience. For the type of electronic wavefunction in atomic physics, see atomic orbital.

In neuroscience, an F wave is one of several motor responses which may follow the direct motor response (M) evoked by electrical stimulation of peripheral motor or mixed (sensory and motor) nerves.[1] F-waves are the second of two late voltage changes observed after stimulation is applied to the skin surface above the distal region of a nerve, in addition to the H-reflex (Hoffman's Reflex) which is a muscle reaction in response to electrical stimulation of innervating sensory fibers.[2][3] Traversal of F-waves along the entire length of peripheral nerves between the spinal cord and muscle, allows for assessment of motor nerve conduction between distal stimulation sites in the arm and leg, and related motoneurons (MN's) in the cervical and lumbosacral cord.[4] F-waves are able to assess both afferent and efferent loops of the alpha motor neuron in its entirety.[5] As such, various properties of F-wave motor nerve conduction are analyzed in nerve conduction studies (NCS),[6] and often used to assess polyneuropathies, resulting from states of neuronal demyelination and loss of peripheral axonal integrity.[1][7][8]

With respect to its nomenclature, the F-wave is so named as it was initially studied in the smaller muscles of the foot.[9] The observation of F-waves in the same motor units (MU) as those present in the direct motor response (M),[10] along with the presence of F-waves in deafferented animal and human models,[11] indicates that F-waves require direct activation of motor axons to be elicited,[12] and do not involve conduction along afferent sensory nerves. Thus, the F-wave is considered a wave, as opposed to a reflex.

  1. ^ a b Neuromuscular function and disease : basic, clinical, and electrodiagnostic aspects. Brown, William F. (William Frederick), 1939-, Bolton, Charles Francis, 1932-, Aminoff, Michael J. (Michael Jeffrey) (1st ed.). Philadelphia: Saunders. 2002. ISBN 0-7216-8922-1. OCLC 46873002.{{cite book}}: CS1 maint: others (link)
  2. ^ Smith, M; Kofke, WA; Citerio, G (2016). Oxford Textbook of Neurocritical Care. Oxford University Press. p. 175.
  3. ^ Jerath, Nivedita; Kimura, Jun (2019). "F wave, A wave, H reflex, and blink reflex". Clinical Neurophysiology: Basis and Technical Aspects. Handbook of Clinical Neurology. Vol. 160. pp. 225–239. doi:10.1016/B978-0-444-64032-1.00015-1. ISBN 9780444640321. ISSN 0072-9752. PMID 31277850. S2CID 195813560.
  4. ^ Fisher, Morris A. (2007-02-02). "F-waves--physiology and clinical uses". TheScientificWorldJournal. 7: 144–160. doi:10.1100/tsw.2007.49. ISSN 1537-744X. PMC 5901048. PMID 17334607.
  5. ^ Katirji, Bashar. (2007). Electromyography in clinical practice : a case study approach (2nd ed.). Philadelphia: Mosby Elsevier. ISBN 978-0-323-07034-8. OCLC 324995633.
  6. ^ Mallik, A.; Weir, A. I. (2005). "Nerve conduction studies: essentials and pitfalls in practice". Journal of Neurology, Neurosurgery, and Psychiatry. 76 (Suppl 2): ii23–31. doi:10.1136/jnnp.2005.069138. ISSN 0022-3050. PMC 1765692. PMID 15961865.
  7. ^ Fisher, Morris A. (1992). "AAEM minimonograph #13: H reflexes and F waves: Physiology and clinical indications". Muscle & Nerve. 15 (11): 1223–1233. doi:10.1002/mus.880151102. ISSN 1097-4598. PMID 1488060. S2CID 6174526.
  8. ^ Lachman, T; Shahani, B T; Young, R R (1980). "Late responses as aids to diagnosis in peripheral neuropathy". Journal of Neurology, Neurosurgery, and Psychiatry. 43 (2): 156–162. doi:10.1136/jnnp.43.2.156. ISSN 0022-3050. PMC 490491. PMID 6244369.
  9. ^ Magladery, J. W.; McDOUGAL, D. B. (1950). "Electrophysiological studies of nerve and reflex activity in normal man. I. Identification of certain reflexes in the electromyogram and the conduction velocity of peripheral nerve fibers". Bulletin of the Johns Hopkins Hospital. 86 (5): 265–290. ISSN 0097-1383. PMID 15414383.
  10. ^ Wulff, C. H.; Gilliatt, R. W. (1979). "F waves in patients with hand wasting caused by a cervical rib and band". Muscle & Nerve. 2 (6): 452–457. doi:10.1002/mus.880020606. ISSN 0148-639X. PMID 514311. S2CID 2423723.
  11. ^ Fox, J E; Hitchcock, E R (1987). "F wave size as a monitor of motor neuron excitability: the effect of deafferentation". Journal of Neurology, Neurosurgery, and Psychiatry. 50 (4): 453–459. doi:10.1136/jnnp.50.4.453. ISSN 0022-3050. PMC 1031882. PMID 3585357.
  12. ^ Trontelj, JV (1973). A study of the F response by single fiber electromyography, in Desmedt JE (ed): New Developments in Electromyography and Clinical Neurophysiology. Basel: Karger. pp. 318–322.