Sonographic findings in the ulnar nerve according to the electrophysiologic stage of carpal tunnel syndrome

Elastography of nerves in the wrists of cyclists

Purpose

This study aimed to investigate changes in the elasticity of the median and ulnar nerves in cyclists.

Material and methods

The study included 30 cyclists and 2 non-biking reference groups that included 32 healthy volunteers and 32 individuals with ulnar nerve entrapment neuropathies. All participants underwent physical, ultrasonographic, and elastographic examinations including assessment of nerve cross-sectional area (CSA) and stiffness (SWE). The cyclists' group was tested before and after a 2-hour workout.

Results

The values of ulnar nerve CSA and stiffness in Guyon's canal in resting cyclists were 5.30 ± 1.51 mm2 and 49.05 ± 11.18 kPa, respectively. These values were significantly higher than in the healthy volunteers, but not higher than in the nerve entrapment group. Median nerve CSA and stiffness at rest were 9.10 ± 2.61 mm2 and 38.54 ± 14.87 kPa, respectively. Both values were higher than respective values in the healthy group. Cycling induced an increase in all these parameters, although the increase in nerve stiffness was more noticeable than in CSA.

Conclusions

The elasticity of the median and ulnar nerve in cyclists remains within normal limits, questioning the belief that cyclists are at risk of nerve palsy in Guyon's canal. However, cycling workout does exert compression, resulting in transient oedema of both nerves. The dynamics of changes was more noticeable in SWE examination than in conventional ultrasound, which may depend on SWE sensitivity.

Median nerve ultrasonography examination correlates with electrodiagnostic studies for the diagnosis of moderate to severe carpal tunnel syndrome

OBJECTIVE

The aim of the study was to investigate the associations of cross-sectional area (CSA) of the median nerve measured by ultrasonography, the median to ulnar nerve ratio (MUR), the median to ulnar nerve difference (MUD) and the ratio of CSA of the median nerve to height squared (MHS) in relation to electrodiagnostic classification of moderate and severe carpal tunnel syndrome (CTS) and thus to identify patients suitable for surgical treatment.

MATERIALS AND METHODS

A prospective study was conducted in patients aged ≥ 18 years who underwent both median and ulnar nerve ultrasonography and electrodiagnostic studies (EDS). 124 wrists of 62 patients were examined. The patients' characteristics were acquired through a questionnaire. CTS was diagnosed using EDS and classified according to the guidelines of the Czech Republic Association of Electrodiagnostic Medicine. The CSA of the median nerve and of the ulnar nerve were measured at the carpal tunnel inlet.

RESULTS

Median nerve CSA at the tunnel inlet ≥ 12 mm² correlates with electrodiagnostic classification of moderate to severe carpal tunnel syndrome. At this cut-off value, the sensitivity of ultrasonography is 82.4%, its specificity is 87.7%, the positive predictive value is 82.4%, the negative predictive value is 87.7%. MUD, MUR and MHS perform worse than the median nerve CSA, as shown by their lower area under the receiver operating characteristic curve.

CONCLUSIONS

Ultrasound could help us indicate surgical treatment for CTS, especially in patients with clinical findings. Our results suggest a cut-off value of CSA at the tunnel inlet of ≥ 12mm².

Diagnostic utility of median nerve CSA to ulnar nerve CSA ratio in the diagnosis of mild idiopathic carpal tunnel syndrome

Background

Ultrasonography (US) measurement of median nerve cross-sectional area (m-CSA) at pisiform is increasingly utilized in identification of carpal tunnel syndrome (CTS), but there is still no agreement about the ideal cut-off value to employ. The aim of the study was to explore whether the median CSA to ulnar CSA ratio at the level of pisiform may yield a more accurate diagnosis of CTS. The study included 50 patients with mild idiopathic CTS (ICTS), assessed clinically and by nerve conduction studies, and 50 matched controls. M-CSA, median nerve flattening ratio and swelling ratio (m-SR), palmer bowing, and median CSA to ulnar CSA ratio (m-CAS:u-CSA) were measured for patients and controls. The cutoff values for the US parameters for the diagnosis of ICTS were evaluated.

Results

Compared to the control group, the ICTS group had significantly higher m-CSA (p < 0.001), higher m-CSA:u-CSA ratio (p < 0.001), higher m-SR (p = 0.012, and higher palmar bowing (p < 0.001). Use of m-CSA cutoff value of 11.78 mm2 and CSA:u-CSA ratio cut-off point of 2.97 yielded the greatest sensitivity and specificity for the diagnosis of ICTS.

Conclusion

The m-CSA:u-CSA ratio is slightly superior to the m-CSA in the diagnosis of CTS in terms of sensitivity and specificity.

Evaluation of axonal loss in ulnar sensory nerve fibers recorded from ring and little fingers secondary to idiopathic carpal tunnel syndrome in Egyptian patients

Background

The association between carpal tunnel syndrome (CTS) and ulnar nerve entrapment is unclear, and the extra-median paresthesia in the ulnar nerve territory innervation in CTS is unexplained. Our purpose is to evaluate the neurophysiologic changes in ulnar nerve sensory fibers secondary to idiopathic CTS in comparison to normal subjects, and their relation to the severity of CTS.

Results

The difference between CTS and control hands regarding all parameters of ulnar motor nerve conduction studies (MNCS) was not statistically significant (p > 0.05). There was a statistically significant difference in all parameters of median sensory conduction study (SCS) and MNCS between CTS and control hands (p < 0.0001) except for conduction velocity and in all parameters of median and ulnar SCS recording digit 4 (D4) (p < 0.05). The mean value of abnormalities of ulnar SCS recording D4 and digit 5 (D5) was significantly higher in moderate and severe CTS hands (p < 0.05). There were significant negative correlations between median motor and sensory latency and ulnar sensory amplitude recording D4 and D5.

Conclusion

Ulnar sensory nerve abnormalities exist among CTS patients, which were more in moderate and severe grades. The drop in amplitude of ulnar nerve sensory response argues in favor of the possible impact of CTS on the ulnar nerve and did not indicate axonal deterioration of the ulnar nerve.

[Acute carpal tunnel syndrome regarding clinico-anatomical point of view in personified medicine]

Carpal tunnel syndrome (CTS) requires special attention due to its different reasons and course. Knowledge about the variability of median nerve (MN) topography in carpal canal region, features of diagnosis and treatment extends outlooks on this pathology. Aggregating rare clinical cases from the Medline and Pubmed databases is useful to form personified approach. There are 3 types of topographic variations which should be considered to prevent false-positive diagnosis of pathology: recurrent branch location, early bi- and trifurcations of MN, anastomoses. Since acute CTS is treated only by surgery, every surgical approach is aimed at minimally invasiveness and fast recovery. Endoscopic decompression (ED) is more favorable regarding these aspects. However, this method cannot be considered as perfect due to available data about incomplete decompression and certain incidence of recurrences. The last ones are absent after microsurgical decompression as a rule. It can be concluded that only individual approach is advisable for complete release of CTS without iatrogenic damage and recurrences.

Ratio and difference of the cross-sectional area of median nerve to ulnar nerve in diagnosing carpal tunnel syndrome: a case control study

Background

To evaluate the diagnostic accuracy of the median-to-ulnar nerve ratio (MUR) and the median-to-ulnar nerve difference (MUD) in patients with carpal tunnel syndrome (CTS).

Methods

In this study, 32 patients with CTS and 32 healthy volunteers were evaluated. All participants received a series of tests and ultrasound examination for the evaluation of the following criteria: cross-sectional area of the median nerve at the pisiform level (CSA-P), swelling ratio (SR), MUR, MUD, and flattening ratio (FR).

Results

CSA-P, SR, MUR, and MUD were all significantly larger in the patients with CTS than in the healthy volunteers. The areas under the receiver operator characteristic curves of MUD, MUR, CSA-P, and SR were 0.78, 0.75, 0.70, and 0.61 respectively. MUD had higher sensitivity (84%) than MUR, CSA-P, and SR (sensitivity: 63, 63, and 53%, respectively).

Conclusions

By using the ulnar nerve area at the pisiform level as an internal control parameter, the MUD and MUR methods showed higher diagnostic accuracy than SR in patients with CTS. Further application of these methods in research and clinical settings is recommended.

Trial registration

Clinicaltrial.gov NCT03033173. Registered 18 January 2017. Retrospectively registered.

Are extramedian symptoms associated with peripheral causes in patient with carpal tunnel syndrome? Electrodiagnostic and ultrasonographic study

OBJECTIVE

To evaluate the relationship between extramedian spreading of sensorial symptoms and median and ulnar nerve cross-sectional area (CSA) and to compare the ultrasonographic and electrophysiological findings in patients with carpal tunnel syndrome (CTS) with or without extramedian sensory symptoms.

DESIGN

Cross-sectional study.

MATERIALS AND METHODS

Patients with CTS were divided into two groups as with or without extramedian symptoms and were assessed clinically, electrophysiologically and ultrasonographically by three blind investigators. In electrophysiological tests, median and ulnar nerve conduction studies were performed. Nerve cross-sectional areas were measured at hook of hamate, psiform bone, radio-ulnar joint, one-third distal part of forearm, and medial epicondyle by ultrasonography.

FINDINGS

The study was completed with 61 patients (108 hands). Extramedian symptoms were present in 31 patients (54 hands). Finger grip strength was lower, pain values evaluated with visual analogue scale were higher in patients with extramedian symptoms (p<0.05). There was no statistically significant difference in electrophysiological and ultrasonographic parameters.

CONCLUSION

According to our results, extramedian symptoms are not related to nerve conduction studies or nerve ultrasonography, these symptoms may be explained with central sensitization in patient with CTS.

Diagnostic Significance of Ultrasonographic Measurements and Median-Ulnar Ratio in Carpal Tunnel Syndrome: Correlation with Nerve Conduction Studies

Background and Purpose

We determined the reliability of ultrasonography (US) measurements for diagnosing carpal tunnel syndrome (CTS) and their correlation with symptom duration and electrophysiology findings. We determined whether the ratio of the median-to-ulnar cross-sectional areas (CSAs) can support CTS diagnoses.

Methods

The pisiform CSA (CSA_pisiform), swelling ratio (SR), palmar bowing, and CSA_pisiform/ulnar CSA (CSA_ulnar) measurements made in two subgroups of CTS patients (having sensory affection alone or having both sensory and motor affection) were compared with controls. CSA_ulnar was measured in Guyon's canal at the level of most-protuberant portion of the pisiform bone.

Results

The values of all of the measured US parameters were higher in patients with CTS (n=50) than in controls (n=62). CSA_pisiform could be used to diagnose CTS of mild severity. All of the parameters were positively correlated with the distal latency of the compound muscle action potential, and all of them except for SR were negatively correlated with the sensory nerve conduction velocity. A CSA_pisiform/CSA_ulnar ratio of ≥1.79 had a sensitivity of 70% and a specificity of 76% for diagnosing CTS.

Conclusions

Only CSA_pisiform measurements were reliable for diagnosing early stages of CTS, and CSA_pisiform/CSA_ulnar had a lower diagnostic value for diagnosing CTS.