Dynamic Two-point Discrimination Research Articles

Mid-term outcomes of digital nerve injuries treated with Renerve® synthetic collagen nerve conduits: A retrospective single-center study

BackgroundBiodegradable synthetic nerve conduits have become widely used for peripheral nerve injuries. Recently, bioabsorbable collagen conduits filled with collagen fibers (Renerve®) are commercially available in Japan. We investigated the clinical efficacy and safety of Renerve® conduits for digital nerve repair. Patients and methodsWe retrospectively reviewed data of patients who underwent digital nerve repair using Renerve® conduits between August 2017 and February 2022 at our hospital and were followed up for at least 12 months. Seventeen patients (20 nerves) with a median age of 46.5 years (interquartile rage: 26–48 years) were included in the analysis. We analyzed sensory nerve function recovery and residual pain or uncomfortable tingling, as well as safety outcomes. The relationship between nerve defect length and sensory function data was assessed using Spearman's rank correlation. ResultsSensory nerve function at 12 months postoperatively was excellent in six, good in 10, and poor in four nerves, and that at the final follow-up (median period, 24 months; range, 12–30 months) was excellent in nine, good in 10, and poor in one nerve. All nerves with a defect length of <12 mm had excellent or good sensory outcomes. At 12 months postoperatively, the correlation coefficients between nerve defect length and Semmes-Weinstein monofilament test results, static two-point discrimination, and dynamic two-point discrimination were 0.35 (p = 0.131), 0.397 (p = 0.0827), and 0.451 (p = 0.0461), respectively. Residual pain or tingling sensation were observed in four nerves at the final follow-up. No postoperative complications were observed in any of the patients. ConclusionsThis study demonstrated the clinical efficacy and safety of Renerve® conduits for digital nerve repair. Our results will be useful in clinical practice because of the scarcity of real-world data on the use of Renerve® conduits for digital nerve repair.

Effects of Cognitive Exercise Therapy on Tactile Sensations of the Hands and Activities of Daily Living in Stroke Patients

Background/Objectives: The aim of present study was to evaluate the effects of cognitive exercise therapy (CET) on tactile sensations of the hands and activities of daily living in stroke patients.Method/Statistical Analysis: A total of 14 stroke patients with impaired hand sensations were participated and were randomly assigned to the CET group or the traditional occupational therapy (TOT) group. Patients in the CET group performed cognitive tasks using their spatial and tactile senses, whereas those in the TOT group received traditional occupational therapy. The intervention periods of the two groups were 30 min per day, five-times per week for four weeks. All participations were assessed before and after intervention with light touch sensation using the Mono-Filament, two-point discrimination sensation using the Disk-Criminator (static and dynamic tactile sensations), and the modified Barthel index (MBI) for activities of daily living ability.Findings: The CET group appeared significant improvements in static and dynamic two-point discrimination, and the MBI before and after the intervention. Also, the TOT group showed a significant improvement in MBI after intervention. At post-test, the CET group showed significant improvements in two-point discrimination and light touch compared to the TOT group.Improvements/Applications: These findings suggest that CET can induce improvement of the tactile sensations of the hands in stroke patients. Thus, we suggest that CET can be used for tactile-sensory rehabilitation of patients with stroke in clinic.

Reconstruction of fingertip with hypothenar free perforator flaps

Introduction: In fingertip injuries where replantation is not possible, options for reconstructing the fingertip with similar type of tissue are limited. Palmar and plantar regions are the donor sites that offer similar characteristics. In this study, we aim to evaluate the clinical outcomes of the hypothenar perforator free flap from the palmar region, compare this flap with the reports available in the literature, and share our experience regarding the practicality of the flap. Patients and Methods: The two-center retrospective clinical study included 15 patients who were operated on between 1 June 2015 and 31 December 2017. All patients were analyzed according to their demographic characteristics, mode and level of injury. Perforator flaps used in fingertip reconstruction were analyzed for skin island size, number of anastomosed arteries and veins, and number of reconstructed nerves. Static and dynamic two-point discrimination tests were applied, and grip strength and pulp-to-pulp pinch measurements were performed in the 13th-month visit of each patient. Surgical results were assessed with the Michigan Hand Outcomes Questionnaire (MHQ). Results: Mean age of the 15 patients was 39.1 years (range: 27-61). While majority of the injuries were of crush type, 8 cases were classified as Ishikawa subzone 2 and 3 cases as Ishikawa subzone 1. One perforator artery and 2 veins were anastomosed in 13 cases. Neural reconstruction was performed in all of the cases. Mean dynamic two-point discrimination value was 3.0 mm (range: 2.8-3.2). Mean grip strength was 42.5 kg (range: 17.7-74.8) and mean pulp-to-pulp pinch strength was 10.7 kg (range: 5-19). MHQ results were 90% in subgroup 1, 95.3% in subgroup 2, 79.5% in subgroup 3, 92.9% in subgroup 5, and 93% in subgroup 6. Conclusion: In cases of fingertip injuries where replantation is not possible, hypothenar free perforator flaps come forth as a sophisticated reconstruction option with favorable outcomes suitable to the similar tissue principle.

Evaluation of discriminative sensibility recovery in patients with buccinator myomucosal flap oral cavity reconstructions

Background Sensitive restoration is the primary aim of oral reconstructive surgery. Discriminative sensibility is an important index of innervation density of a tissue. Instruments normally used to assess this type of skin sensibility are bulky and difficult to introduce in the oral cavity, even in healthy patients with a normal mouth opening. This study was intended to evaluate the recovery of static and dynamic two-point discrimination sensitivity of the reconstructed areas of the oral cavity.

Innervated Free Groin Flap.

Innervated Free Groin Flap.

Quantitative assessment of sural nerve donor site sensitivity: one week and one year after surgery

Background The use of autologous nerve material has become the gold standard for reconstructing peripheral nerve defects. For various applications, nerve grafting is required to restore nerve continuity, and the sural nerve may be considered the best option for such purposes. The aim of this study was to quantitatively assess the recovery of donor site sensory deficit following sural nerve harvest. Methods This descriptive study was performed on 30 patients in the first week after surgery and 23 patients 1 year after sural nerve harvest. Mapping of the affected area was performed using Semmes–Weinstein monofilaments. Then, the areas of diminished or loss of sensation were evaluated with monofilament test, static and dynamic two-point discrimination, and temperature sensitivity. Also, the complaints of paresthesia, numbness, and pain were measured. The results were compared in the two groups. Results The area of diminished or loss of sensation 1 week after surgery was significantly reduced after 1 year (p00.000). A reduction was observed in the patients' complaints, especially in numbness and paresthesia, and better results were obtained in clinical findings, significantly in dynamic two-point discrimination and temperature sensation. Conclusion In this study, donor site adverse effects of sural nerve harvest decreased over time, and improvements in sensory tests were observed; however, more studies should be performed on this topic. Level of Evidence: Level III, diagnostic study.

PROSPECTIVE STUDY ON TACTILE SENSITIVITY IN THE HANDS OF A BRAZILIAN POPULATION USING THE PRESSURE-SPECIFIED SENSORY DEVICE

Objective: To evaluate the pressure perception thresholds on the pulp of two fingers (index and little fingers), among a Brazilian population with no nerve injury or neuropathy. Methods: We used the Pressure-Specified Sensory Device (a computerized device) to derive static and dynamic normal pressure perception thresholds and two-point discrimination distances. Results: We tested finger sensitivity on 30 volunteers. Significance analyses were performed using the Student t test. The mean values (g/mm2) for static one and two-point pressure thresholds (s1PD, s2PD) and dynamic one and two-point discrimination (m1PD, m2PD) in the dominant index finger were: s1PD = 0.4, m1PD = 0.4, s2PD = 0.48, m2PD = 0.51. Conclusion: There was no significant difference in sensitivity between the dominant and nondominant hands.

Evaluation of neurosensory alterations via clinical neurosensory tests following anterior maxillary osteotomy (Bell technique)

Neurosensory deficits are the most common complication following orthognathic surgery. Le Fort I and sagittal split ramus osteotomies have been widely studied but there is a lack of data about the neurosensory alterations resulting from anterior maxillary osteotomy (AMO). This paper evaluates the neurosensory alterations in cutaneous regions including lower eyelid, cheek, nose, upper lip and vestibular and palatal mucosal areas using simple clinical tests following AMO performed with Bell's incision so patients can be properly informed about the extent of sensory loss and its rate of recovery following AMO. Twenty-four sides of 12 patients (eight females; four males) with a mean age of 14.20±1.86 years (range 12–17 years) were examined. Pin prick sensation, light touch sensation, static and dynamic two-point discrimination tests were used. Following AMO, vestibular mucosa, upper lip, nose and cheek were the most commonly affected sites. No alterations were detected in lower eyelid and palatal mucosa. The neurosensory deficits in cheek, nose and upper lip resolved 10 days after surgery. The vestibular mucosa showed normal sensation on day 30. In conclusion, following AMO, neurosensory alterations can occur, but it will resolve spontaneously in 30 days.

Successful replantation in ten-digit amputation

Amputations involving ten digits are very rare because of different lengths of the digits. A 34-year-old man working in a printing house presented one hour after guillotine amputation involving all ten digits. Surgery was initiated 80 minutes after admission and took seven hours. Under axillary anesthesia, the operation was performed by two teams each consisting of two microsurgeons and two assistants. Replantation was completed without the use of any skin graft or flap. Fingertip examination showed poor arterial circulation in the second, third, and fourth digits of the left hand after 24 hours of replantation and surgical exploration was performed, during which anastomosis of the ulnar digital artery of the second digit was re-established and a Y-shaped vein graft was placed at the level of the third web to restore revascularization of the third and fourth digits. However, these interventions did not prevent the development of necrosis in the distal segment of the fourth digit which resulted in dry gangrene that required amputation. After 38 months of replantation, radiographic examination showed complete union in all fingers without malunion or damage to the joint surface and about 8 degrees of medial angulation in the proximal phalanx of the fourth digit of the right hand. The patient did not have difficulty in performing daily activities and had a considerably good pinching. Losses of active range of motion of the metacarpophalangeal and interphalangeal joints were within the rage of 10 to 30 degrees in both hands. In the assessment of sensation, static and dynamic two-point discrimination test results were 6.1 mm and 4.0 mm, respectively.

Sensory outcome of fingertip replantations without nerve repair

The sensory recovery outcomes of fingertip replantations without nerve repair were retrospectively studied. Between 2000 and 2006, 112 fingertip replantations with only arterial repair were carried out in 98 patients. About 76 of the replants survived totally, with a success rate of 67.8%. Evaluation of sensory recovery was possible in 31 patients (38 replantations). Sensory evaluation was made with Semmes-Weinstein, static and dynamic two-point discrimination, and vibration sense tests. Fingertip atrophy, nail deformities, and return to work were also evaluated. According to the Semmes-Weinstein test, 29.0% (11/38) of the fingers had normal sense, 60.5% (23/38) had diminished light touch, 7.9% (3/38) had diminished protective sensation, and 2.6% (1/38) had loss of protective sensation. Mean static and dynamic two-point discriminations were 7.2 mm (3-11 mm), and 4.60 mm (3-6 mm), respectively. Vibratory testing revealed increased vibration in 42.1% of the fingers, decreased vibration in 36.8%, and equal vibration when compared with the non-injured fingers in 21.1%. Atrophy was present in 14 (36.8%) fingers and negatively affected the results. Nail deformities, cold intolerance, return to work, and the effect of sensory education were investigated. Comparison of crush and clean cut injuries did not yield any significant difference in any of the parameters. Patients who received sensory education had significantly better results in sensory testing. The results were classified as excellent, good, and poor based on results of two-point discrimination tests. The outcome was excellent in 18 fingers and good in 20 fingers. Overall, satisfactory sensory recovery was achieved in fingertip replantations without nerve repair.

Use of two‐point discrimination as a nerve repair assessment tool: preliminary report

Two-point discrimination, static and dynamic, has long been used as an assessment tool for tactile gnosis, and to assess recovery after repair of a peripheral nerve. While use of a bent paperclip with a specified intertip distance as the assessment device has been described, no research has been performed on the accuracy of setting this distance by hand and eye alone. The aim of the present study was to demonstrate this accuracy. Five orthopaedic registrars, four residents and three clinic nurses performed static and dynamic two-point discrimination testing on each other. They set the tip distance by hand and eye by bending a paperclip such that the distance between the two ends was their best approximation of 5 mm and then 10 mm. The testing was repeated after 7 days, n = 264 for each tip distance. Two-sample t-tests showed no significant difference (P > 0.53-0.93) between tip distance setting performed by registrars, nurses and residents; while single sample t-test showed a statistically significant difference (P < 0.0001) between the attempted tip distance and the overall mean tip distance achieved at 5 mm and 10 mm. Statistical analysis showed that the single sample t-test could be discarded. Static and dynamic two-point discrimination testing with a paperclip set by hand and eye is therefore an accurate and reproducible test capable of being administered by both medical and non-medical staff, and is suitable for inclusion in a peripheral nerve repair testing protocol.

End-to-side neurorrhaphy of sensory nerves

One century passed before end-to-side neurorrhaphy was rediscovered, and now it finds more frequent use in clinical practice. Experimental studies have improved our understanding of the underlying mechanism and its potential. However, still discussed is whether reinnervation by end-to-side neurorrhaphy works as well in sensory nerves as in motor nerves. The digital nerves are sensory nerves and therefore an ideal model to investigate this question. Two cases of successful sensory reinnervation by end-to-side nerve suture are reported. We began to use end-to-side nerve repair clinically in 1995 and have used it for motor or sensory reinnervation in a total of 13 cases. In two patients primary nerve repair using end-to-side neurorrhaphy was performed in digital avulsion injuries. In one patient the avulsed ulnar nerve of the thumb was sutured end-to-side to the median nerve; in the other the ulnar digital nerve of the ring finger had been destroyed over a distance of 20 mm, and the distal stump was joined end-to-side to the radial nerve of the same finger. Sensory recovery was obtained in both patients. The static two-point discrimination was 3.0 mm, and dynamic two-point discrimination was 2–3 mm for the reinnervated finger compared to 2 mm for static and dynamic two-point discrimination in the adjacent "donor" finger. The sensation of the finger supplied by the "donor nerve" was not altered in relation to the corresponding contralateral finger site. Excellent sensory reinnervation is possible through an end-to-side nerve suture. Proximal avulsion, missing proximal nerve stumps, partial recovery, and prevention of nerve grafts are good indications for resensitization using end-to-side neurorrhaphy. No harm to the donor nerve is expected. Preference should be given to donor nerves that supply skin areas near to the anesthetic area.

The Alderson-McGall hand function questionnaire for patients with carpal tunnel syndrome: A pilot evaluation of a future outcome measure

The Alderson-McGall hand function questionnaire (AMHFQ) was developed to evaluate outcomes for patients with carpal tunnel syndrome (CTS). This pilot evaluation of 17 subjects with CTS involved the same battery completed twice prior to CTS release. The complete battery included evaluation of grip and pinch strength, static and dynamic two-point discrimination, dexterity using the Valpar Worksample for upper extremity range of motion, pain and hand function using visual analog scales (VASs), and the AMHFQ. The results indicated high internal consistency, with a Cronbach alpha value of 0.97. Intraclass correlation showed test-retest reliability in the 95th percentile for all items except one. Validity was demonstrated by AMHFQ correlations with all other battery items in the correct direction and significant correlations with dynamic two-point discrimination (r = −0.32), functional VAS (r = 0.3688), pain VAS (r = 0.36), and grip strength (r = 0.3867). These results suggest that the AMHFQ has clinical utility for patients with CTS. Further research to confirm these findings and determine sensitivity to change is required.

Evaluation of the improvement of sensibility after primary median nerve repair at the wrist.

In the Istanbul Hand Surgery and Microsurgery Centre, between 1991-1996, 28 out of 54 patients who had clean-cut median nerve laceration at the wrist level were evaluated in a detailed manner regarding the improvement of sensibility following primary repair. Semmes-Weinstein monofilament and vibration tests form the group of threshold tests, and static and dynamic two-point discrimination tests and the Moberg pick-up test form the group of functional tests which were applied to the patients. Follow-up was from 1 to 5 years. Moreover, subjective findings such as cold intolerance, pain, and paraesthesia were also evaluated. All the results obtained were evaluated in relation to the SO-S4 sensibility improvement criterion which Waylett-Rendall recommended. The following results were obtained: S4 in 35.7% of the patients, S3+ in 28.5%, S3 in 14.2%, S2+ in 7.14%, S2 in 10.7%, and S1 in 3.5%. In our opinion the most important reason for the high rate of success was the fact that we worked with a highly selective group of patients and the fact that there was a high rate of young patients in this group (21.4% of them were under the age of 15). It was observed that there was a significant correlation between age and functional sensibility improvement (P = 0.04). Moreover, when we observed the relation between age and Semmes-Weinstein monofilament, static two-point discrimination, and dynamic two-point discrimination tests, it was seen that age had a significant correlation with each of the parameters (r = 0.61, P = 0.001; r = 0.58, P = 0.002; r = 0.57, P = 0.002). There was a clear decline in the intensity of the paraesthesia in S3+ and S4 group (X2 = 4.7, P = 0.02) and in these groups the period of Moberg pick-up test was meaningfully short (P < 0.05).

Replantation in childhood and adolescence. Long-term outcome

In 31 (out of 48) patients with 43 (out of 63) replanted or revascularized digits or parts of the extremities a study of long-term results was performed. Their ages were below 16 years at the time of injury. The results concerning function, sensitivity, cold intolerance, growth disturbance, patient acceptance and occupational changes were evaluated. Early complications consisted of venous stasis in 10.6% (n = 4), skin necrosis of the wound margin in 5.3% (n = 2) and in finger-tip necrosis in 5.3% (n = 2). One lower arm and one finger replanted (5.3%, n = 2) were lost after several revisions due to venous problems. In no case did arterial problems occur. Tendon adhesions were the most common complication in 28.9% (n = 11), followed by deviation of the axis in a frontal plane of more than 20 degrees in 13.3% (n = 5) and by joint instability in 5.3% (n = 2). Only twice (5.3%) did ankylosis or in another case osteomyelitis of the proximal phalanx result. At amputation level II (between the DIP joint and the nail root), 37.5% (n = 3) developed a reduction of range of active movement (RAM) with a mean of 31.7 degrees, and once an arthrodesis was necessary, whereas 50% (n = 4) of the patients have full range of active motion. At amputation level III (between the MP and DIP joint) 52.7% (n = 10) developed a reduction of RAM at the PIP joint with a mean of 29.5 degrees, and twice an arthrodesis was necessary, whereas 26.4% (n = 5) of the patients have full range of active motion. Of the patients 78.9% (n = 15) developed a reduction of RAM at the DIP joint with a mean of 35.7 degrees, and twice an arthrodesis was necessary. Only twice was ankylosis present, but 10.5% (n = 2) of the patients have full range of active motion. Excellent sensory recovery was observed with a mean dynamic two-point discrimination of 4.8 mm. In addition, only 29% (n = 9) of the patients report a surprisingly low incidence of cold intolerance, which is in contrast to adults with up to 100% cold intolerance in replanted digits. In 67.7% a radiologically measured difference of length with a mean of 3.8 mm and clinically measured a difference in the length of the digits with a mean of 4.9 mm was observed without complaints by the patients, instead, there was moderate discontent with the aesthetically disturbing fingertip atrophy, which was up to 30% in 48.4% of the patients. Of the patients who are now adult, 16.7% (n = 4) changed their choice of profession due to the trauma or because of the dissatisfactory result. These results and the success rate of 94.7% suggest the conclusion that one should not hesitate to perform a replantation or revascularization in children with even multiple amputations as the results are excellent.

Regeneration of sudomotor and sensory nerve fibres after digital replantation and microneurovascular toe-to-hand transfer

The end-stage sudomotor and sensory recovery in patients with replanted fingers and patients after microneurovascular toe-to-hand transfer was studied using quantitative electrophysiological investigations (recovery of sensory nerve action potentials and the sympathetic skin response), the ninhydrin test and clinical testing of sensory regeneration (light touch, pain, static and dynamic two-point discrimination). 13 adult patients with 22 replanted digits (11 males, 2 females) aged 21–58 years (mean 42.2 years) and 12 adults and adolescents (8 males, 4 females) aged 13–45 years, (mean 26.8 years) following 14 microneurovascular great and/or second toe-to-hand transfers were studied. The replanted fingers were examined 2–7 years after injury and replantation. The toe-to-hand transfers were examined 2–12 years after injury and transfer. The results show better end-stage recovery of sudomotor and sensory function following finger replantation when compared to microneurovascular toe-to-hand transfer.

Results of open carpal tunnel release: a comprehensive, retrospective study of 188 hands.

Many recent reports of the results of decompression of the median nerve in the carpal tunnel have concentrated on only one aspect of recovery (numbness, grip etc.), and there are no reports of a comprehensive study of outcome. The aim of the present study was to review comprehensively the results of the direct visualization method of decompression of the carpal tunnel and to compare them with the published results of endoscopic release. Patients' perceptions of the severity of pain, numbness and paraesthesiae due to carpal tunnel syndrome (CTS), before and after open carpal tunnel release (CTR) in 188 hands were reviewed retrospectively at a minimum time of follow-up of 18 months. Motor and sensory testing, provocation testing and measurement of scar tenderness in 135 hands were performed at a clinical review. Subjective results showed that 70% experienced a reduction in the severity of pain after CTR, 78% of hands experienced a reduction in the severity of paraesthesiae and 77% experienced a reduction in the severity of numbness. A total of 49% had improvements in all three symptoms after CTR. At the clinical review, sensory testing revealed that 59% of hands had normal or slightly diminished light touch, 35% had normal static two-point discrimination and 61% had normal dynamic two-point discrimination. Results for Tinel's test, Phalen's test and pressure provocation testing were positive in 10% of hands. There was no scar tenderness in 38%, no persisting thenar atrophy in 90%. Normal grip strength was found in 93% and 91% had normal pinch strength. It was concluded that open carpal tunnel release remains a safe and reliable treatment for carpal tunnel syndrome. The very low incidence of serious complications from the open technique of CTR, when compared with endoscopic CTR as published by different authors in the literature, and the comparable clinical results, appears to make the open technique a safer and preferable option. However, a properly controlled trial of both techniques is necessary to compare them.