Persistence of Abnormal Electrophysiological Findings after Carpal Tunnel Release

Abstract

Practitioners may refer to experienced hand surgeons to differentiate a recurrence in carpal tunnel syndrome (CTS) from a failed carpal tunnel release. The patient may complain about the reappearance of symptoms, whatever is the cause. Nerve conduction studies (NCS) are often required by the practitioner to assist the final diagnosis. We observed abnormal values in NCS in patients who were clinically healed from CTS. We evaluated the changes preoperatively and, then, at 1, 3, 6, 9, and 12 month postoperatively. At the same time, we performed a retrospective study on a group of 37 clinically healed patients. Follow-up ranged from 2 to 20 years. Surgical treatment let the electrophysiological parameters to improve toward physiological values; however, normality is hardly ever reached. This sort of ‘‘electrophysiological scar’' is true for all the parameters measured. In presence of CTS, the latency difference between the radial and median sensory nerve action potentials, recorded following thumb stimulation, produces a double peak shift. The ‘‘double peak shift’' best described this ‘‘electrophysiological scar,’' being a parameter that should measure about zero in the normal population. In conclusion, abnormal postoperative electrophysiological findings cannot substantiate the diagnosis of a poor outcome of a carpal tunnel release nor a recurrence of CTS.

Keywords

carpal tunnel syndrome - nerve conduction studies - prospective study - retrospective study

Note

This manuscript was presented as a Podium Presentation during the ASPN meeting in 2011.

• References

• 1 Jones NF, Ahn HC, Eo S. Revision surgery for persistent and recurrent carpal tunnel syndrome and for failed carpal tunnel release. Plast Reconstr Surg 2012; 129 (3) 683-692
• 2 American Association of Electrodiagnostic Medicine, American Academy of Neurology, and American Academy of Physical Medicine and Rehabilitation. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Muscle Nerve 2002; 25 (6) 918-922
• 3 Hobson-Webb LD, Padua L. Median nerve ultrasonography in carpal tunnel syndrome: findings from two laboratories. Muscle Nerve 2009; 40 (1) 94-97
• 4 Atroshi I, Gummesson C, Johnsson R, Ornstein E. Diagnostic properties of nerve conduction tests in population-based carpal tunnel syndrome. BMC Musculoskelet Disord 2003; 4: 9
• 5 El-Hajj T, Tohme R, Sawaya R. Changes in electrophysiological parameters after surgery for the carpal tunnel syndrome. J Clin Neurophysiol 2010; 27 (3) 224-226
• 6 Ginanneschi F, Milani P, Reale F, Rossi A. Short-term electrophysiological conduction change in median nerve fibres after carpal tunnel release. Clin Neurol Neurosurg 2008; 110 (10) 1025-1030
• 7 Mondelli M, Reale F, Sicurelli F, Padua L. Relationship between the self-administered Boston questionnaire and electrophysiological findings in follow-up of surgically-treated carpal tunnel syndrome. J Hand Surg [Br] 2000; 25 (2) 128-134
• 8 Alfonso C, Jann S, Massa R, Torreggiani A. Diagnosis, treatment and follow-up of the carpal tunnel syndrome: a review. Neurol Sci 2010; 31 (3) 243-252
• 9 Pazzaglia C, Caliandro P, Granata G, Tonali P, Padua L. ‘‘Dropping objects’': a potential index of severe carpal tunnel syndrome. Neurol Sci 2010; 31 (4) 437-439
• 10 Padua L, LoMonaco M, Gregori B, Valente EM, Padua R, Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997; 96 (4) 211-217
• 11 Luigetti M, Quaranta D, Modoni A, Mereu ML, Lo Monaco M. Nerve conduction studies of the sural nerve: normative data from a single-center experience. Clin Neurophysiol 2012; 123 (9) 1891-1892 DOI: 10.1016/j.clinph.2012.02.075.
• 12 Padua L, LoMonaco M, Gregori B, Valente EM, Tonali P. Double-peaked potential in the neurophysiological evaluation of carpal tunnel syndrome. Muscle Nerve 1996; 19 (5) 679-680
• 13 Cassvan A, Ralescu S, Shapiro E, Moshkovski FG, Weiss J. Median and radial sensory latencies to digit I as compared with other screening tests in carpal tunnel syndrome. Am J Phys Med Rehabil 1988; 67 (5) 221-224
• 14 Johnson EW. The Bactrian Sign. Am J Phys Med Rehabil 1998; 77 (4) 275
• 15 Zyluk A, Szlosser Z. [Are conduction studies in the median nerve obligatory for the diagnosis of the carpal tunnel syndrome: a review]. Chir Narzadow Ruchu Ortop Pol 2009; 74 (3) 174-179
• 16 Robinson LR. Electrodiagnosis of carpal tunnel syndrome. Phys Med Rehabil Clin N Am 2007; 18 (4) 733-746 , vi
• 17 Schrijver HM, Gerritsen AA, Strijers RL , et al. Correlating nerve conduction studies and clinical outcome measures on carpal tunnel syndrome: lessons from a randomized controlled trial. J Clin Neurophysiol 2005; 22 (3) 216-221