Measurement of carpal canal and median nerve pressure in patients with carpal tunnel syndrome

Carpal tunnel syndrome is a compression neuropathy wherein the median nerve is compressed inside of the carpal canal. Its diagnosis is made clinically, electrophysiologically, and sometimes by carpal canal pressure measurement. The objective of surgical management of this condition is the decompression of the median nerve. We usually measure carpal canal pressure preoperatively and postoperatively using a continuous infusion technique for diagnoses as well as for postoperative evaluation of decompression following our Universal Subcutaneous Endoscope system procedure. To evaluate whether our procedure effectively decompressed the median nerve, we measured intraneural pressure preoperatively and postoperatively in the resting position, with active power grip, and in the Okutsu test position. Correlation between the carpal canal pressure and intraneural median nerve pressure was statistically analyzed using the Kendall rank correlation coefficient (n = 157 hands). A significant correlation was present preoperatively in resting position and postoperatively with active power grip and in the Okutsu test position. Because of this correlation, we conclude that our endoscopic operative procedure effectively decompresses the median nerve and that simple carpal canal pressure measurement is sufficient to confirm diagnoses and to evaluate the status of postoperative decompression.     

Giant median nerve in bilateral carpal tunnel syndrome

We introduce a middle age healthy man with sequential bilateral carpal tunnel syndrome. At the surgery, we encountered a wide median nerve in both wrists. Although enlargement of median nerve in carpal tunnel has been well documented, 25 mm width of the nerve is a rare scene, underscoring that leaving the nerve under the unyielding pressure would lead to a fibrous atrophic median nerve.KEY WORDS: Blood-nerve barrier, carpal tunnel syndrome, compressive neuropathy, median nerve, neural edema     

Intraoperative electroneurography during median nerve decompression in carpal tunnel syndrome

Summary In 17 patients with the diagnosis of carpal tunnel syndrome, orthodromic sensory nerve conduction measurements during ligament division and internal neurolysis were performed without the use of a pneumatic tourniquet. While ligament division led to an increase in conduction velocity (p < 0.05; median increase 0.7 m/s), it did not result in a significant change of the amplitude. During internal neurolysis, an increase of the sensory nerve potential (p<0.01; median increase 0.9 V) and no significant change in conduction velocity were observed. We conclude that internal neurolysis does not cause a disruption of nerve function during the operation.     

超声引导下正中神经阻滞对腕管综合征治疗效果的影响

目的观察超声引导下正中神经阻滞治疗腕管综合征的临床效果。方法选择40例(69个患腕)腕管综合征患者,性别不限,年龄33~61岁,ASAⅠ或Ⅱ级。随机分为超声组(U组)和对照组(C组),每组20例。U组采用超声引导下正中神经阻滞,C组采用解剖标志定位正中神经阻滞,两组每次阻滞药物均为布比卡因4.5mg、曲安奈德5mg、维生素B12 100μg混合液3ml。通过Boston腕管问卷调查表(BCTQ)评估患者治疗前后手症状和功能;记录治疗前后正中神经电生理参数;记录二次治疗及不良反应情况。结果与治疗前比较,治疗后1个月两组BCTQ评分中的症状严重程度评分(SSS)和功能状态评分(FSS)明显降低(P0.05),且U组SSS明显低于C组(P0.05),两组FSS差异无统计学意义。与治疗前比较,治疗后1个月两组运动潜伏期(MDL)、感觉潜伏期(SDL3)明显缩短(P0.05),感觉神经传导速度(SNCV)明显增快(P0.05),而运动神经传导速度(MNCV)差异无统计学意义。治疗后1个月,U组SNCV明显快于C组(P0.05),其余神经电生理参数两组差异无统计学意义。U组二次治疗及不良反应明显少于C组(P0.05)。结论采用超声引导下神经阻滞治疗腕管综合征能显著改善患者的手部症状,减少并发症。     

Giant cell arteritis of the median nerve simulating carpal tunnel syndrome

We present a distinctly rare case of giant cell arteritis involving the small artery of the median nerve with symptoms that may be confused with carpal tunnel syndrome. The excision of the involved arterial segment cures the patient of the local symptoms, but the administration of corticosteroids as soon as the diagnosis is established is very important for these patients with multiple arterial involvement.     

Longitudinal sliding of the median nerve in patients with carpal tunnel syndrome

In nerve compression syndromes restricted nerve sliding may lead to increased strain, possibly contributing to symptoms. Ultrasound was used to examine longitudinal median nerve sliding in 17 carpal tunnel syndrome patients and 19 controls during metacarpophalangeal joint movement. Longitudinal movement in the forearm averaged 2.62 mm in controls and was not significantly reduced in carpal tunnel syndrome (CTS) patients (mean=2.20 mm). In contrast, CTS patients had a 40% reduction in transverse nerve movement at the wrist on the most, compared to least, affected side and nerve areas were enlarged by 34%. Normal longitudinal sliding in the patients indicates that nerve strain is not increased and will not contribute to symptoms.     

Carpal tunnel pressure alters median nerve function in a dose-dependent manner: a rabbit model for carpal tunnel syndrome.

BACKGROUND: An in vivo animal model for carpal tunnel syndrome (CTS) is presented which allows for graded application of pressure to the median nerve within the carpal canal. We hypothesized that such pressure would cause electrophysiologic changes in the median nerve in a dose-related manner, with NCS/EMG changes consistent with CTS in humans. METHODS: In 40 New Zealand white rabbits, ranging from 2 to 2.5 kg, angioplasty catheters were placed in the carpal tunnel in the forepaws and pressures ranging from 50 to 80 mmHg applied to one side while the contralateral side served as the control and remained uninflated. Pressure was applied until a 15% increase in distal motor latency was obtained for 2 consecutive weeks by nerve conduction studies. RESULTS: All the experimental limbs exhibited a 15% increase in distal motor latency. None of the control limbs showed a significant increase in distal motor latency. In the experimental animals the 15% delay was achieved in approximately 4-5 weeks in the 50-70 mmHg groups and in approximately 1 week in the 80 mmHg group. CONCLUSION: This new animal model for CTS demonstrates a direct cause and effect relationship between carpal tunnel pressure and median nerve dysfunction. We anticipate that this in vivo model with clinically relevant outcomes will facilitate identification of injury mechanisms, and will serve as a basis for future development of novel interventions and treatments.     

Acute carpal tunnel syndrome due to a hemangioma of the median nerve

Hemangioma of the median nerve presenting as acute carpal tunnel syndrome is unusual A-18- year old male presented with severe incapacitating pain of sudden onset of left forearm and hand after manual field work. There was swelling on volar aspect of forearm, with hyperalgesia in the median nerve distribution. The fingers and wrist were inmarked flexion and the patient did not allow wrist and finger extension. X-rays were within normal limits. An emergency volar carpal ligament release revealed, haematoma about 100 ml with numerous vessels encircling the median nerve. Histopathology of lesion turned out to be a cavernous hemangioma. Post operatively patient had full recovery.     

Location of impaired sensory conduction of the median nerve in carpal tunnel syndrome

Sensory conduction of the median nerve at the carpal tunnel for eight consecutive 1 cm segments of the nerve was evaluated in 217 hands of 153 of our patients with carpal tunnel syndrome. Impairment was found to be highly focal and often confined to a single 1 cm segment of the nerve. The section of the nerve at or just distal to the distal margin of the carpal tunnel was affected most frequently, the section within the tunnel was affected less often, and the section proximal to the tunnel at the level of the mid-carpal and radio-carpal joints was affected least. The greatest contrast between frequencies of slowing at adjacent segments occurred at the proximal and distal margins of the carpal tunnel. The distribution of the nerve impairment was similar between the sexes; however, among the men the segment affected most frequently was located 1 cm distal to the segment affected most frequently among the women. The general pattern of slowing which we found does not substantiate some commonly-held opinions about the aetiology of carpal tunnel syndrome.     

Surgical release of the median nerve under local anaesthesia for carpal tunnel syndrome

Carpal tunnel release was performed under local anaesthesia in 124 wrists of 108 patients. The local anesthetic was injected into the carpal tunnel and into the subcutaneous tissue under the line of the skin incision. A tourniquet was used in all cases. Analgesia was complete in all but six patients. Only one patient had real difficulty in tolerating the tourniquet. In 18 cases the median nerve, when exposed at operation, showed evidence of some damage caused by the needle or by injection of local anaesthetic but, at follow-up, no symptoms or signs related to this damage were found.     

Evolving concepts of median nerve decompression in the carpal tunnel

Carpal tunnel syndrome is the most common and best known of the compression neuropathies in the upper extremity. The authors review their clinical experiences in the diagnosis and management of this entity and survey the extensive literature on the subject. An operative approach for decompression of the median nerve in the carpal canal is described that has proved to be most efficacious and safe.     

Hyperostotic macrodactyly and lipofibromatous hamartoma of the median nerve associated with carpal tunnel syndrome

A new case with 14-year follow-up of an extremely rare variety of congenital hand macrodactyly is presented. The disease characteristically presents a diffuse proliferation of fibrofatty tissue, but in this special type, osteocartilaginous deposits around the joints can also be found. The case presented included the troublesome feature of a lipofibromatous hamartoma in the median nerve at the wrist and its branches producing carpal tunnel syndrome. The patient obtained benefit from carpal tunnel release and epineurolysis. The hyperostotic development was managed with conservative resection of the periarticular osteochondromas. The literature reviewed suggests that the hyperostotic cases of macrodactyly do not differ from general cases of this congenital condition, except for the osteochondral deposits. These tumours develop during adulthood or after previous trauma, before epiphyseal closure.