Bilateral median nerve compression at the level of Struthers' ligament. Case report

Struthers' ligament syndrome is a rare cause of median nerve entrapment. Bilateral compression of the median nerve is even more rare. It presents with pain, sensory disturbance, and/or motor function loss at the median nerve's dermatomal area. The authors present the case of a 21-year-old woman with bilateral median nerve compression caused by Struthers' ligament. She underwent surgical decompression of the nerve on both sides. To the authors' knowledge, this case is the first reported bilateral compression of the median nerve caused by Struthers' ligament. The presentation and symptomatology of Struthers' ligament syndrome must be differentiated from median nerve compression arising from other causes.     

Isolated volar fracture-dislocation of the scaphoid with acute carpal tunnel syndrome: a case report

Dislocations and fracture-dislocations of the scaphoid are rare injuries. When they occur in a volar direction, they may be complicated by median nerve compression. While volar dislocations and fracture-dislocations of the scaphoid presenting late with median nerve compression have been reported, such injuries presenting with acute median nerve compression have not been reported. We describe a case of volar fracture-dislocation of the proximal half of the scaphoid causing median nerve compression and presenting with acute carpal tunnel syndrome. Urgent open reduction and internal fixation of the scaphoid along with decompression of the median nerve achieved prompt relief of the neurological symptoms.     

Median nerve compression in the palm of the hand by an anomalously enlarged ulnar artery

Median nerve compression in the carpal tunnel by a thrombosed persistent median artery and a large aberrant artery substituting for the radial artery has been described but there have been no reports of median nerve compression in the palm of the hand by an anomalously enlarged ulnar artery. A 46 year old man is described who presented with clinical and electrophysiological features consistent with a median neuropathy at the wrist but surgical exploration revealed median nerve compression in the palm of the hand by an anomalously enlarged palmar branch of the ulnar artery. This case highlights another treatable cause of median nerve compression and illustrates that symptoms suggestive of carpal tunnel syndrome may be produced by median nerve compression in the palm of the hand.     

Increased median nerve latency at the carpal tunnel of patients with "trigger finger": Comparison of 62 patients and 13 controls

An association between symptomatic compression neuropathy of the median nerve at the carpal tunnel and "trigger finger" has been reported in endocrine and metabolic disorders. We assessed the incidence of increased median nerve latency in subjects with "trigger finger". 62 consecutive patients with "trigger finger" and no signs or symptoms of median nerve compression underwent nerve conduction studies of the median nerve. 13 healthy adults served as controls. 39/62 patients had increased distal motor latency in the median nerve. Only 1 of 13 subjects in the control group had a borderline value of distal motor latency.     

Increased median nerve latency at the carpal tunnel of patients with "trigger finger": comparison of 62 patients and 13 controls

An association between symptomatic compression neuropathy of the median nerve at the carpal tunnel and "trigger finger" has been reported in endocrine and metabolic disorders. We assessed the incidence of increased median nerve latency in subjects with "trigger finger". 62 consecutive patients with "trigger finger" and no signs or symptoms of median nerve compression underwent nerve conduction studies of the median nerve. 13 healthy adults served as controls. 39/62 patients had increased distal motor latency in the median nerve. Only 1 of 13 subjects in the control group had a borderline value of distal motor latency.     

Increased median nerve latency at the carpal tunnel of patients with "trigger finger": Comparison of 62 patients and 13 controls

An association between symptomatic compression neuropathy of the median nerve at the carpal tunnel and "trigger finger" has been reported in endocrine and metabolic disorders. We assessed the incidence of increased median nerve latency in subjects with "trigger finger".

62 consecutive patients with "trigger finger" and no signs or symptoms of median nerve compression underwent nerve conduction studies of the median nerve. 13 healthy adults served as controls. 39/62 patients had increased distal motor latency in the median nerve. Only 1 of 13 subjects in the control group had a borderline value of distal motor latency.     

Evaluation of microsurgical internal neurolysis in a primate median nerve model of chronic nerve compression

This study evaluates the effect of internal neurolysis on a chronically compressed primate median nerve as compared with a simple decompression procedure. In 11 adult, cynomologous monkeys, the median nerve in the carpal tunnel was banded with a silicone tube. After 6 months of nerve compression (mild to moderate compression in our model) in eight monkeys, a microneurosurgical internal neurolysis was carried out on the median nerve of one hand and a simple decompression (removal of band) was carried out on the median nerve of the other hand. Histologic, morphologic, and electrophysiologic evaluation was carried out 6 months later. Six control animals were similarly evaluated after 0, 6, and 12 months of nerve compression. The degree of compression produced was not severe in that it did not cause Wallerian degeneration. Histologic and electrophysiologic improvement was produced in both treatment groups over the two chronically compressed groups (6 and 12 months of compression). While internal neurolysis did not cause intraneural scarring or nerve fiber damage as compared with simple decompression alone, there was no difference noted between the effects of these two treatment methods on the chronically compressed nerve.     

Compression neuropathy of the median nerve caused by a loose body in the elbow

We present a case of median nerve compression at the elbow associated with an intra-capsular loose body cured by arthroscopic removal of the loose body. This is a rare but eminently treatable cause of median nerve compression.     

Median nerve compression associated with displaced Salter-Harris type II distal radial epiphyseal fracture

Three children with grossly displaced Salter-Harris Type II fractures of the distal radial epiphysis underwent immediate manipulation under anaesthetic (MUA) because of rapidly developing median nerve compression. In each case nerve function was quickly restored with no late neurological sequelae. We believe that in children who sustain this injury with signs of median nerve compression, immediate MUA without carpal tunnel release is acceptable initial management. Late exploration of the median nerve can be considered should a neurological deficit persist.     

Late compression neuropathies after Colles' fractures

Conservative management of 166 Colles' fractures was associated with a 12% rate of late compression neuropathies (mean follow-up period, 28 months). Compression of the median nerve (8%) was twice as common as ulnar nerve compression (4%). Eighty-five percent of the patients with median nerve compression had malunion with radial collapse with or without other deformities (dorsal angulation/radial displacement). Patients with ulnar nerve compression had either malunion with radial collapse or volar subluxation of the ulnar head in those fractures that healed with dorsal angulation. Patients without nerve complications showed a significantly lower rate of malunions. These results demonstrate that anatomic derangements play a role in the development of late compression neuropathies following Colles' fractures.     

Postoperative edema after vascular access causing nerve compression secondary to the presence of a perineuronal lipoma: case report

OBJECTIVE AND IMPORTANCE: Median nerve neuropathy can be clinically devastating to a patient. It can be caused by compression of the median nerve anywhere along its course. We present the case of delayed median nerve neuropathy after the placement of a vascular graft in the arm. CLINICAL PRESENTATION: An arm shunt was placed in the nondominant upper extremity in a 60-year-old man with end-stage renal disease. Twelve hours postoperatively, the patient developed neurapraxia in the median nerve distribution in the hand. INTERVENTION: Exploration of the arm revealed a lipoma coursing along and deep to the median nerve. Resection of the lipoma decompressed the nerve. CONCLUSION: In this patient, median nerve neuropathy was caused by a lipoma and postoperative swelling from placement of the vascular graft. The swelling that occurred after the shunt placement unmasked subclinical compression of the nerve by a lipoma deep to the median nerve. To our knowledge, this report is unique in documenting damage to the median nerve after vascular graft placement as a result of an occult mass.     

正中神经返支的解剖及临床研究

目的　研究正中神经返支的解剖特点 ,提高腕管综合征的手术疗效。方法　通过应用解剖观察正中神经返支在走行过程中存在的易卡因素。 2 0 0 2 -2 0 0 4年 ,对 2 3例 3 4侧腕管综合征 ,在作正中神经松解时 ,同时探查及松解正中神经返支 ,并切除对返支形成卡压的拇短屈肌尺侧缘腱纤维束和致密的纤维弓。结果　 3 4侧术中均发现正中神经返支存在易卡压解剖因素 ,其中 8侧受到纤维弓及腱纤维束的明显卡压。全部病例获得 2个月～ 1年随访。功能评定 :优 17侧 ,良 7侧 ,可 10侧 ,优良率为 70 .6%。结论　中、重度腕管综合征在松解正中神经时 ,应同时行返支松解术。     

Median nerve compression within the humeral head of pronator teres

We describe a case of the pronator syndrome caused by compression of the median nerve by a fibrous band as the nerve passed through the humeral head of origin of pronator teres. This rare anatomical arrangement resulted in displacement of the median nerve to the anterior aspect of the medial humeral epicondyle and, as far as we are aware, has not previously been described as a site of compression neuropathy.     

Median nerve compression by a radially inserted palmaris longus tendon after release of the antebrachial fascia: A complication of carpal tunnel release

We describe a case that had recurrent median nerve compression after release of the antebrachial fascia in carpal tunnel release. The nerve was compressed by a palmaris longus tendon that was inserted radially into the thenar fascia. After decompression (detachment of the tendon) the patient had symptom relief. Release of the antebrachial fascia in the presence of this tendon variant carries a risk of median nerve compression by the tendon.     

Carpal tunnel syndrome: Neurographical parameters in different stages of median nerve compression

In a series of 47 cases and 55 hands operated upon for carpal tunnel syndrome, the pre-operative electrodiagnostic findings have been compared retrospectively with the morphological findings within the carpal tunnel during operation. As a main result there was no significant correlation between the degree of electrophysiological changes and the degree of median nerve compression. Only the lack of any motor or sensory response seems to indicate a more severe median nerve compression. In about 20% of cases with operatively proven marked median nerve compression, both distal motor latency and motor nerve conduction velocity were well within normal limits and would not have led to the diagnosis of a carpal tunnel syndrome in these cases. The diagnosis, therefore, cannot be made on the basis of electrodiagnostic pathological values only of distal motor latency and motor nerve conduction velocity, but has to take into account as well the sensory nerve conduction velocity as well as the clinical picture and neurological findings.     

Persistent median artery as a cause of pronator syndrome

Pronator syndrome may be caused by a persistent median artery that passes completely through the proximal median nerve and then gives origin to a vascular leash to the flexor muscles that compresses the nerve. A "double crush" compression of the median nerve caused by persistent median artery producing first a carpal tunnel syndrome and then a pronator syndrome is described.     

Infraclavicular median nerve compression caused by a lipoma

The most common site of median nerve compression is in the carpal tunnel, the most common of all entrapment neuropathies. Less frequent entrapment neuropathies of the median nerve include the anterior interosseous and pronator syndromes in the proximal forearm. Even less commonly seen is entrapment at the infraclavicular segment of the brachial plexus. Median nerve compression at the level of the axilla has been reported as being caused by anomalous axillary arch muscles, anomalous vascular perforations of the nerve or its roots, the pectoralis minor muscle, and a thickening of the deltopectoral fascia. To the authors' knowledge, this is the first report of compression at that level by a benign tumor.     

A primate model for chronic nerve compression

Peripheral compression neuropathy is a common clinical entity but little human nerve material has been available for study. It has been difficult to develop an experimental model of chronic nerve compression which is reliable and reproducible, making it difficult to assess the various treatment modalities currently in use to manage this problem. In a recent study using a rat model, connective tissue and nerve fiber changes associated with chronic nerve compression were described by the authors. The present study expands this same model of chronic nerve compression to the multifascicular median nerve of the cynomolgus monkey, using this model to test whether or not current surgical treatment modalities for nerve entrapment will alter the course of chronic nerve compression. Using histologic and morphometric parameters, there did not appear to be a difference between nerves treated by decompression alone or by decompression and internal neurolysis. Total number of nerve fibers remained constant, as did axon size, but a demyelinating process was demonstrated which is a significant component of chronic nerve compression. Although the small number of experimental animals (7) makes precise evaluation of the clinical modalities impossible, the authors expect that further study of the multifascicular median nerve of the cynomolgus monkey will prove to be a useful source of future experimental evidence and will help to interpret the diverse therapeutic and operative techniques currently in use.     

Hemangioma of the median nerve: a report of two cases

Two cases of intraneural hemangiomas are described. Both lesions produced compression of the median nerve and required multiple excisions. In one case, interfascicular nerve dissection failed to produce a cure, while the other patient remains free of recurrence after excision of the involved median nerve and sural nerve grafting.