Carpal tunnel syndrome and the "double crush" hypothesis: a review and implications for chiropractic

Effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers

OBJECTIVES

To compare the effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers with symptomatic neck pain and asymptomatic office workers.

METHODS

A total of 40 participants, both male and female office workers, with symptomatic neck pain (n = 20) and asymptomatic (n = 20), were recruited. Pain intensity, ulnar nerve conduction velocity, median nerve conduction velocity, and muscle activity were determined before and after 1 hour of computer use.

RESULTS

There was a significant increase in pain intensity in the neck area in both groups (P < .001). The symptomatic neck pain group revealed a significant decrease in the sensory nerve conduction velocity of the ulnar nerve (P = .008), whereas there was no difference in the median nerve conduction velocity (P > .05). Comparing before and after computer use, the symptomatic neck pain group had less activity of the semispinalis muscles and higher activity of the anterior scalene muscle than the asymptomatic group (P < .05). The trapezius and wrist extensor muscles showed no significant differences in either group (P > .05).

CONCLUSIONS

This study found signs of neuromuscular deficit of the ulnar nerve, semispinalis muscle, and anterior scalene muscle after 1 hour of computer use among office workers with symptomatic neck pain, which may indicate the risk of neuromuscular impairment of the upper extremities. The recommendation of resting, and encouraging function and flexibility of the neuromuscular system after 1 hour of computer use should be considered.

Current Insights into Carpal Tunnel Syndrome: Clinical Strategies for Prevention and Treatment

BACKGROUND

Carpal tunnel syndrome (CTS) is a condition that is caused by medial nerve compression, resulting in symptoms such as numbness, tightness, or weakness in the hand.

OBJECTIVES

The aim of the study was to find out the genetic modulation, mechanism, available treatment, and recommendation for carpal tunnel syndrome at its specific stage.

METHODS

Almost 200 papers were searched for this review article, and 145 articles were selected. The literature was collected from different sources like Google scholar, PubMed, a directory of open-access journals, and science.gov by using keywords, such as treatment, risk factors, recommendation, and clinical features of carpal tunnel syndrome.

RESULTS

The most efficient non-surgical treatment is methylprednisolone acetate, which reduces inflammation by acting on the glucocorticoid receptor in conjunction with immunofilling. It has also been used successfully as a second-line drug for the treatment of patients with mild or moderate conditions in order to provide relief. New non-pharmacological options include laser therapy in acupuncture, transcutaneous electric nerve stimulation (TENS), and sham therapy. Modern treatments like TENS, laser therapy, splints, and injections of methylprednisolone acetate have been demonstrated to be helpful in sporadic situations. For patients with mild and moderate problems, more research should be conducted that includes the combination of these surgical and non-surgical treatments.

CONCLUSION

We propose a multifunctional panel construct and define standard data items for future research into carpal tunnel syndrome. A discussion on idiopathic carpal tunnel syndrome, risk factors, combination of therapies, using guidelines-based recommendations and treatment should be initiated.

The prevalence of double- and multiple crush syndromes in patients surgically treated for peripheral nerve compression in the upper limb

OBJECTIVE

The double crush syndrome describes a condition characterized by multifocal entrapment of a nerve. In the upper limb, the high prevalence of carpal tunnel syndrome makes it a common diagnosis of assumption in the setting of median neuropathy. More proximal compressions may tend to be overlooked, under-diagnosed and under-treated in the population. This study aims to map the prevalence of peripheral upper limb nerve compressions among patients undergoing peripheral nerve decompression.

METHODS

A prospective case series was conducted on 183 patients undergoing peripheral nerve decompression in a private hand surgery clinic. Level(s) of nerve compression in the median, ulnar and radial nerves were determined by history and physical examination. The prevalence of each nerve compression syndrome or combination of syndromes was analyzed.

RESULTS

A total of 320 upper limbs in 183 patients were analyzed. A double crush of the median nerve at the levels of the lacertus fibrosus and carpal tunnel was identified in 78% of upper limbs with median neuropathy, whereas isolated lacertus syndrome and carpal tunnel syndrome were present in only 5% and 17% of affected limbs respectively. Cubital tunnel syndrome affected 12.5% of upper limbs, and 80% of these had concomitant lacertus and carpal tunnel syndromes, compared to only 7.5% with isolated cubital tunnel syndrome.

CONCLUSION

A high prevalence should prompt clinicians towards more routine assessment for double crush syndrome to avoid misdiagnosis, inadequate treatment, recurrence, and revision surgeries.

Compression Neuropathies: Revisions and Managing Expectations

Most compression neuropathies can be reliably treated with surgical decompression; however, in approximately 25% of the cases, this release fails, requiring revision surgery. Defining the correct diagnosis after a failed nerve decompression (ie, persistent, recurrent, or new symptoms) is of the utmost importance and guides toward the optimal treatment. This article describes the clinical categorization of secondary carpal tunnel syndrome and cubital tunnel syndrome, intraoperative principles of revision surgery and treatment options that are currently available.

Clinical Presentation of Foramen Magnum Meningioma Masqueraded by Carpal Tunnel Syndrome: A Report of 2 Cases

CASE

Meningioma is the second most common intracranial tumor. We present 2 cases of foramen magnum meningioma (FMM) that was first operated on with the diagnosis of carpal tunnel syndrome (CTS).

CONCLUSION

During the diagnostic assessment of CTS and recalcitrant CTS, a more proximal etiology of nerve compression should be considered, including FMM. If a more proximal cause of nerve dysfunction is suspected, cervical spine magnetic resonance imaging may be beneficial to evaluate a patient for spinal etiology.

Interventional treatment for neuropathic pain due to combined cervical radiculopathy and carpal tunnel syndrome: a case report

The coexistence of median and cervical nerve root damage might hide a complex pathophysiology. Here, we describe and discuss the case of a patient suffering from numbness and painful tingling of the hand, whose symptoms were effectively treated with pulsed radiofrequency and epidural administration of bupivacaine and morphine.

The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

INTRODUCTION

Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS.

AIM

To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading.

MATERIALS AND METHODS

Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson's classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated.

RESULTS

In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel's and Phalen's sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had mild CTS, 25 (50%) had moderate CTS and 9 (18%) had severe CTS clinically. Prolongation of motor latency, latency difference between median and ulnar amplitudes, motor and sensory nerve conduction velocities, sensory latency between median and ulnar nerves, sensory nerve conduction velocities showed significant changes in comparison with controls. Among them sensory latency difference between median and ulnar nerves and sensory nerve conduction velocities are the most sensitive and specific for diagnosing CTS.

CONCLUSION

In this study, there was a graded deterioration of electrophysiological parameters along with the clinical severity grades, thus reiterating the fact that NCS provide additional, independent objective evidence in the diagnosis and severity assessment of CTS. The sensory conductions were more sensitive than motor conductions in assessing CTS.

Pathophysiology of carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common median nerve neuropathy, accounting for 90% of all neuropathies. Carpal tunnel syndrome presents in 3.8% of the general population, with a higher prevalence among women. There are several risk factors associated with CTS, including both medical and non medical factors. The pathophysiologic mechanisms involved in the median nerve compression and traction are thought to be complex, and as yet are not fully understood. The present review aimed to provide an overview of the pathophysiology of median nerve neuropathy in the carpal tunnel, and subsequent development of CTS.

Multiple locations of nerve compression: an unusual cause of persistent lower limb paresthesia

A paucity of appreciation exists that the "double crush" phenomenon can account for persistent leg symptoms even after spinal neural decompression surgery. We present an unusual case of multiple locations of nerve compression causing persistent lower limb paresthesia in a 40-year old male patient. The patient's lower limb paresthesia was persistent after an initial spinal surgery to treat spinal lateral recess stenosis thought to be responsible for the symptoms. It was later discovered that he had peroneal muscle herniations that had caused superficial peroneal nerve entrapments at 2 separate locations. The patient obtained much symptomatic relief after decompression of the peripheral nerve. The "double crush" phenomenon and multiple levels of nerve compression should be considered when evaluating lower limb neurogenic symptoms, especially after spinal nerve root surgery.

Women with carpal tunnel syndrome show restricted cervical range of motion

STUDY DESIGN

A case control, blinded study.

OBJECTIVES

To compare the amount of cervical range of motion in women with minimal, mild/moderate, and severe carpal tunnel syndrome (CTS) to that of healthy control participants. We also assessed the relationships between cervical range of motion and clinical variables related to the intensity and temporal profile of pain within each CTS group.

BACKGROUND

It is plausible that the cervical spine may be involved in individuals with CTS. No study has investigated the relationship between cervical range of motion and symptoms associated with CTS severity.

METHODS

Cervical range of motion was assessed in 71 women with CTS (18 with minimal, 18 with mild/moderate, and 35 with severe signs and symptoms) and in 20 similar, healthy women. Those with CTS were aged 35 to 59 years (mean ± SD, 45 ± 8 years) and those in the healthy group were aged 31 to 60 years (45 ± 8 years). An experienced therapist, blinded to the participants' conditions, used a cervical range-of-motion (CROM) device to assess cervical range of motion. Mixed-model analyses of variance (ANOVAs) were conducted to evaluate the differences in cervical range of motion among the 3 groups of patients with CTS and healthy controls. A corrected P value of less than .025 was used as threshold for significance (Bonferroni correction).

RESULTS

The mixed-model ANOVAs revealed that the individuals with CTS exhibited restricted cervical range of motion compared to healthy controls (P<.001), with no significant differences among the groups with minimal, mild/moderate, or severe CTS (P>.356). A significant negative correlation between pain intensity and cervical spine lateral flexion away from the affected side was identified: the greater the mean pain intensity, the lesser the cervical lateral flexion away from the affected side.

CONCLUSIONS

Women with minimal, mild/moderate, or severe CTS exhibited less cervical range of motion compared to women of a similar age, suggesting that restricted cervical range of motion may be a common feature in individuals with CTS, independent of severity subgroups, as defined by electrodiagnosis. Future research should investigate cervical range of motion as a possible consequence or causative factor of CTS and related symptoms.

Central sensitization does not identify patients with carpal tunnel syndrome who are likely to achieve short-term success with physical therapy

The aim of the current study was to identify whether hyperexcitability of the central nervous system is a prognostic factor for individuals with carpal tunnel syndrome (CTS) likely to experience rapid and clinical self-reported improvement following a physical therapy program including soft tissue mobilization and nerve slider neurodynamic interventions. Women presenting with clinical and electrophysiological findings of CTS were involved in a prospective single-arm trial. Participants underwent a standardized examination and then a physical therapy session. The physical therapy sessions included both soft tissue mobilization directed at the anatomical sites of potential median nerve entrapment and a passive nerve slider neurodynamic technique targeted to the median nerve. Pressure pain thresholds (PPT) over the median, radial and ulnar nerves, C5-C6 zygapophyseal joint, carpal tunnel and tibialis anterior muscle were assessed bilaterally. Additionally, thermal detection and pain thresholds were measured over the carpal tunnel and thenar eminence bilaterally to evaluate central nervous system excitability. Subjects were classified as responders (having achieved a successful outcome) or non-responders based on self-perceived recovery. Variables were entered into a stepwise logistic regression model to determine the most accurate variables for determining prognosis. Data from 72 women were included in the analysis, of which 35 experienced a successful outcome (48.6%). Three variables including PPT over the C5-C6 joint affected side <137 kPa, HPT carpal tunnel affected side <39.6º and general health >66 points were identified. If 2 out of 3 variables were present (LR + 14.8), the likelihood of success increased from 48.6 to 93.3%. We identified 3 factors that may be associated with a rapid clinical response to both soft tissue mobilization and nerve slider neurodynamic techniques targeted to the median nerve in women presenting with CTS. Our results support that widespread central sensitization may not be present in women with CTS who are likely to achieve a successful outcome with physical therapy. Future studies are now necessary to validate these findings.

Chiropractic manipulation for carpal tunnel syndrome: a systematic review

Background

Although chiropractic is most commonly used for spinal problems, many chiropractors use manipulations for the treatment of non-spinal conditions. Carpal tunnel syndrome (CTS) has been identified as one such condition. This systematic review evaluates the evidence for or against the effectiveness of chiropractic as a treatment for CTS.

Methods

Eight electronic databases were searched from inception until November 2008. Reference lists of retrieved articles were hand-searched. Chiropractic associations were contacted in order to identify further non-published studies. No language restrictions were applied.

Results

Of 26 potentially relevant studies, only one trial of chiropractic for CTS met all the inclusion criteria. The trial was of poor quality and reported no significant differences between the groups on any outcome measure. However, our re-analyses indicated a significant difference in favour of the control treatment (non-steroidal anti-inflammatory drugs [NSAIDs] use). Adverse effects were noted in both groups.

Conclusions

There is insufficient evidence to suggest that chiropractic is effective for the treatment of CTS. Therapy should continue to focus on the use of NSAIDs, corticosteroid injection, splinting and surgical release of the median nerve. Further research into the utility of chiropractic for CTS is required.

Increased forward head posture and restricted cervical range of motion in patients with carpal tunnel syndrome

STUDY DESIGN

Case control study.

OBJECTIVES

To compare the amount of forward head posture (FHP) and cervical range of motion between patients with moderate carpal tunnel syndrome (CTS) and healthy controls. We also sought to assess the relationships among FHP, cervical range of motion, and clinical variables related to the intensity and temporal profile of pain due to CTS.

BACKGROUND

It is plausible that the cervical spine may be involved in patients with CTS. No studies have investigated the possible associations among FHP, cervical range of motion, and symptoms related to CTS.

METHODS

FHP and cervical range of motion were assessed in 25 women with CTS and 25 matched healthy women. Side-view pictures were taken in both relaxed-sitting and standing positions to measure the craniovertebral angle. A CROM device was used to assess cervical range of motion. Posture and mobility measurements were performed by an experienced therapist blinded to the subjects' condition. Differences in cervical range of motion were examined using the nonparametric Mann-Whitney U test. A 2-way mixed-model analysis of variance (ANOVA) was used to evaluate differences in FHP between groups and positions.

RESULTS

The ANOVA revealed significant differences between groups (F = 30.4; P<.001) and between positions (F = 6.5; P<.01) for FHP assessment. Patients with CTS had a smaller craniovertebral angle (greater FHP) than controls (P<.001) in both standing and sitting. Additionally, patients with CTS showed decreased cervical range of motion in all directions when compared to controls (P<.001). Only cervical flexion (rs = -0.43; P = .02) and lateral flexion contralateral to the side of the CTS (rs = -0.51; P = .01) were associated with the reported lowest pain experienced in the preceding week. A positive association between FHP and cervical range of motion was identified in both groups: the smaller the craniovertebral angle (reflective of a greater FHP), the smaller the range of motion (r values between 0.27 and 0.45; P<.05). Finally, cervical range of motion and FHP were negatively associated with age in the control group but not in the group with CTS.

CONCLUSIONS

Patients with mild/moderate CTS exhibited a greater FHP and less cervical range of motion, as compared to healthy controls. Additionally, a greater FHP was associated with a reduction in cervical range of motion. However, a cause-and-effect relationship cannot be inferred from this study. Future research should investigate if FHP and restricted cervical range of motion is a consequence or a causative factor of CTS and related symptoms (eg, pain).