Pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis: a case report.

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

Anemia to Median Nerve Palsy.

Mesenteric angina has a high mortality rate. Occlusion of the superior mesenteric artery is the most common cause. Increasingly, it is managed endovascularly instead of by open revascularization. Despite the lower risk of complications in minimally invasive procedures, it is important to be mindful of long-term sequelae of minor complications. Patient education regarding risks and complications is paramount for better clinical outcomes. The risks of transbrachial angiography procedures are low. Postprocedural vigilance for interventionists and written educational advice to patients are paramount in all minimally invasive endovascular procedures, especially because most of these patients with a complication require urgent operative correction.

Median nerve entrapments in the forearm - a case report of rare anterior interosseous nerve syndrome.

Nowadays, median nerve entrapment is a frequent issue. Many physicians are familiar with the most common median entrapment, which is the carpal tunnel syndrome (CTS). By contrast, less frequent entrapments, historically called "pronator syndrome" are still misdiagnosed as overuse syndrome, flexor tendinitis or other conditions. This article is meant to introduce proximal median nerve entrapments, followed by a case report of the rarest example - anterior interosseous nerve syndrome (AIN syndrome).

Proximal Median Nerve Compression: Pronator Syndrome.

Pronator syndrome (PS) is a compressive neuropathy of the median nerve in the proximal forearm, with symptoms that often overlap with carpal tunnel syndrome (CTS). Because electrodiagnostic studies are often negative in PS, making the correct diagnosis can be challenging. All patients should be initially managed with nonsurgical treatment, but surgical intervention has been shown to result in satisfactory outcomes. Several surgical techniques have been described, with most outcomes data based on retrospective case series. It is essential for clinicians to have a thorough understanding of median nerve anatomy, possible sites of compression, and characteristic clinical findings of PS to provide a reliable diagnosis and treat their patients.

Median Nerve Entrapment in the Ulna in a Both-Bone Pediatric Forearm Fracture: Case Report and Review of the Literature.

This case report presents entrapment with subsequent complete disruption of the median nerve in the distal ulna in a both-bone fracture of the forearm in a 9-year-old girl. Closed fractures of the radius and ulna commonly occur in pediatric populations. Postinjury nerve dysfunction is often seen. Severe nerve injury is rare. There are only 3 reports of the median nerve becoming entrapped in an ulnar fracture in a child, with no reports of entrapment in the distal forearm. Features seen on examination and the radiographs supported possible nerve entrapment. Although uncommon, nerve entrapment or transection should be considered in all forearm fractures with sensory or motor nerve dysfunction. If suspicions are high, an early diagnosis of nerve entrapment may be obtained with magnetic resonance imaging evaluation.

[Diagnostic ability of power measurement of different grip forms for distal median nerve lesion]. / Stellenwert der Kraftmessung verschiedener Greifformen zur Diagnostik der peripheren Medianusläsion.

BACKGROUND: Peripheral lesions of the median nerve cause characteristic changes of the grip function of the hand. For evaluating grip force changes, measurement by dynamometers (JAMAR dynamometer and pinch dynamometer) is of high relevance. In this study the ability of grip force measurements of different grip forms was evaluated to discriminate between a simulated median nerve lesion and healthy subjects. MATERIAL AND METHODS: In 21 healthy subjects, the grip force of power grip was measured by the JAMAR dynamometer at the second stage including measurement of force at the fingertips and the thenar by a sensor glove. With a pinch dynamometer the power of palmar abduction, precision grip, pincer grip and pinch grip was determined. Measurements were performed with and without median nerve block at the wrist. RESULTS: In power grip of the JAMAR dynamometer at the second stage a significant reduction of the grip force of 13.4% was found (p < 0.03). The power distribution between the fingers D2-D5 did not change with median nerve block. The most relevant reduction of grip force in median nerve block compared with the healthy control was measured in palmar abduction (72.1%, p < 0.0002), followed by precision grip 31.0% (p < 0.0001), pincer grip 23.6% (p < 0.0004) and pinch grip 18.8% (p < 0.0002). CONCLUSIONS: For the discrimination between healthy subjects and subjects with a median nerve block there was a limited relevance of the measurement of the power grip and force distribution at the fingers by the JAMAR dynamometer. However, the best distinction was observed by dynamometric measurement of other grips than power grip, such as palmar abduction, precision grip, pincer grip and pinch grip. The results could be relevant for the clinical diagnostics and rehabilitation of median nerve lesion, complementing the widespread measurement of the power grip by other grip forms.

Bilateral spontaneous anterior shoulder dislocation: A missed orthopedic injury mistaken as proximal neuropathy.

A number of orthopedic injuries can occur during epileptic seizures. Anterior shoulder dislocation is one such orthopedic injury that is quite rare. The shoulder dislocation may injure the brachial plexus. Besides seizures, the nerves can also be damaged by anticonvulsive therapy. Muscle wasting following a seizure can misguide a clinician to investigate only neural or muscular pathologies. We report here an individual with epilepsy who was referred to us for electrodiagnostic evaluation of proximal muscle wasting related to a suspected proximal neuropathy. He was found to have a normal electrodiagnostic evaluation and later on discovered to have had bilateral shoulder dislocation on X-rays. This report advocates a thorough clinical appraisal, radiographs, and electrodiagnostic evaluation in a case with muscle wasting following a seizure.

Median nerve penetration by a persistent median artery and vein mimicking carpal tunnel syndrome.

INTRODUCTION: Carpal tunnel syndrome (CTS) is a common clinical syndrome seen in the outpatient setting that is easily confirmed by electrodiagnostic testing. METHODS: We describe the case of a patient who presented with the classic symptoms and neurological examination for CTS, but had a normal nerve conduction study and electromyogram. RESULTS: Neuromuscular ultrasound of the median nerve on the symptomatic side revealed penetration of the nerve by a persistent median artery and vein in the mid-forearm, with a positive sonographic Tinel sign over this spot. This finding is an anatomical variation that has been described sparingly in the literature, mostly in cadavers. It has not been reported previously to be a mimic of CTS. CONCLUSIONS: This case demonstrates the diagnostic utility of neuromuscular ultrasound and the importance of considering an anatomical variation involving the median nerve in the differential diagnosis of CTS.

Mixed neuropathy presenting clinically as an anterior interosseous nerve palsy following shoulder arthroscopy: a report of four cases.

BACKGROUND: Anterior interosseous nerve (AIN) palsies can arise spontaneously or be attributed to one of many causes. We present 4 cases, the largest series to date, in which a mixed peripheral neuropathy presented primarily as an AIN palsy following ipsilateral shoulder arthroscopy. In this report, we detail the patient's presenting symptoms, describe our management of the complication, and provide hypotheses for the mechanism behind the complication. METHODS: Four different surgeons performed the initial arthroscopic surgeries, but the senior author in all cases managed follow-up and treatment of the neuropathy. All patients were informed and agreed to have their cases published. RESULTS: All four patients experienced significant recovery, although 2 of 4 required AIN decompression and exploration because of failure to improve with conservative management. CONCLUSION: Whereas variables such as position, index surgical procedure, and use of regional anesthesia varied among our patients, the one constant was the fluid extravasation from the arthroscopy itself, and for this reason we believe that if there is one singular cause to explain all of these neuropathies, it would be increased pressure in the upper arm and forearm from fluid extravasation in patients with at-risk anatomy. Outside of prevention, recognizing this complication and providing appropriate intervention or referral to a surgeon capable of appropriate intervention are important for any surgeon performing shoulder arthroscopies.

[Nerve injuries after elbow luxation fractures in childhood : Indication and timing for surgical revision]. / Nervenverletzungen nach Ellenbogenluxationsfraktur im Kindesalter : Indikation und Zeitpunkt zur operativen Revision.

BACKGROUND: Supracondylar humerus fractures are very common in pediatric populations. In cases of dislocated fractures, closed reduction and percutaneous K­wire fixation is recommended. Initially, 10-16 % of the patients also present lesion of the ulnar nerve as well as median nerve palsy in 6.4% and radial nerve palsy in 2.6 % of cases, respectively. METHOD: We present the case of a 10-year-old boy with a dislocation of the elbow and fracture of the medial epicondyle. After closed reduction and K­wire fixation from medial, he presents a median nerve palsy. That a lesion of the ulnar nerve is also present is only noticed 3½ years posttraumatically. A surgical decompression and neurolysis of the ulnar and median nerve is performed and the postoperative grip and key strength presented. DISCUSSION: With the help of the presented case we discuss the indication and the point of surgical revision. Clinical assessment and neurosonography are essential for an exact diagnosis.

Severe and extreme idiopathic median nerve lesions at the wrist: new insights into electrodiagnostic patterns and review of the literature.

INTRODUCTION: We evaluated the electrodiagnostic (EDX) pattern of severe and extreme median nerve lesions at the wrist (MNLW) in patients with idiopathic carpal tunnel syndrome. METHODS: EDX data were recorded in 229 patients with 314 severe and extreme MNLW and 447 patients with 777 non-severe MNLW. We recorded distal motor latency (DML) to abductor pollicis brevis (APB) and second lumbricalis (2L), sensory conduction (SC) from digits 2 and 3, and needle examination of APB. RESULTS: Preservation rate of DML to APB and 2L and of SC from digits 2 and 3 were 100%, 100%, 85%, and 76%, respectively, for severe MNLW, and 37%, 90%, 36%, and 26% for extreme MNLW. Active denervation, as demonstrated by fibrillation potentials, was found in 1% of non-severe NMLW, 7% of severe MNLW, and 56% of extreme MNLW cases. CONCLUSIONS: In idiopathic severe and extreme MNLW, the DML to the 2L and averaged SC from digit 2 can be present when other responses are absent.

Neurovascular compromise due to true brachial artery aneurysm at the site of a previously ligated arteriovenous fistula: Case report and review of literature.

True arterial aneurysms of the upper extremity are rare. The case described is that of a 48-year-old man presenting with median neuropathy and distal vascular compromise 4 years after ligation of a brachiocephalic arteriovenous fistula. We describe our approach and present a review of the relevant literature.

Asymptomatic Lambert-Eaton syndrome.

INTRODUCTION: All descriptions of the Lambert-Eaton syndrome are based on symptomatic patients. We incidentally encountered electromyographic evidence of this syndrome in a patient being studied for another reason. The patient had controlled hypothyroidism and smoked for 9 pack-years but never had symptoms of weakness or had evidence of cancer. METHODS: Detailed electrophysiological and serological evaluations were undertaken in this study. RESULTS: Neuromuscular transmission tests were consistent with a presynaptic disorder. Autoantibodies specific for P/Q-type voltage-gated calcium channels (VGCC) were detected in the serum and persisted throughout 7 years of follow-up. Multiple IgG markers of thyrogastric autoimmunity also were detected. CONCLUSIONS: This demonstration of asymptomatic Lambert-Eaton syndrome persisting for 8 years provided novel insight into the natural history of the disorder. It is plausible that patients with a subclinical syndrome would have abrupt neuromuscular decompensation when challenged with medications that compromise the safety factor for synaptic transmission.

Tortuous axillary artery aneurysm causing median nerve compression.

Axillary artery aneurysms are rare entities that warrant surgical intervention. Reported complications include thrombosis, distal embolization, and debilitating neurologic symptoms caused by median nerve compression. Common etiologies include trauma or repetition injuries. Less recognized associations include atherosclerotic, connective tissue, or mycotic processes. We report a case of a rare tortuous axillary artery aneurysm causing neurologic symptoms in a woman with an unused arteriovenous fistula.

Median nerve neuropraxia by a large false brachial artery aneurysm.

Peripheral nerve compression is a rare complication of an iatrogenic false brachial artery aneurysm. We present a 72-year-old patient with median nerve compression due to a false brachial artery aneurysm after removal of an arterial catheter. Surgical exclusion of the false aneurysm was performed in order to release traction of the median nerve. At 3-month assessment, moderate hand recovery in function and sensibility was noted. In the case of neuropraxia of the upper extremity, following a history of hospital stay and arterial lining or catheterization, compression due to pseudoaneurysm should be considered a probable cause directly at presentation. Early recognition and treatment is essential to avoid permanent neurological deficit.

[A rare tumor of the median nerve in a young child: Intraneural perineurioma. About one clinical case]. / Une tumeur rare du nerf médian chez le jeune enfant : le périneuriome intraneural. À propos d'un cas clinique.

Intraneural perineurioma is a rare benign peripheral sheath tumor, which is most prevalent in adolescents and young adults. It is characterized by focal perineural cell proliferation infiltrating the endoneurium leading to the macroscopic aspect of hypertrophic nerve. It typically presents a loss of motor function in the involved nerve. We report the case of a 3-year-old boy presented with painless, subcutaneous mass on the palmar aspect of his right hand without loss of motor function. Imaging studies showed a large mass within the median nerve suggesting schwannoma. Surgical exploration was undertaken. The tumor could not be removed without leading to motor and sensitive loss. Neurolysis of the hypertrophic fascicles was performed. Microbiopsies ruled out malignant tumor and could make the diagnosis of intraneural perineurioma of the median nerve. An annual clinical follow-up has been decided in order to detect any functional trouble such as loss of motor function.

Other median neuropathies.

Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of the median nerve and many known anatomical variants can lead to misdiagnosis and unexpected surgical complications if their presence is not correctly identified. A number of inherited and acquired disorders can affect the median nerve proximal to the wrist, alone or accompanied by other affected peripheral nerves. Recognizing other disorders that can masquerade as median mononeuropathies can avoid misdiagnosis and misguided management. This chapter explores median nerve anatomical variants, disorders, and lesions, emphasizing the need for careful examination and electrodiagnostic study in the localization of median neuropathy.

Chronic bilateral T1 denervation in women with macromastia.

INTRODUCTION: The objective of this study was to identify the pattern of neurological deficits and document electrophysiological changes in women with macromastia. METHODS: Patients with macromastia and neurological complaints underwent clinical evaluation and electrodiagnostic (EDx) studies of the upper limbs. RESULTS: Findings include low-amplitude medial antebrachial cutaneous (MACN) sensory nerve action potentials (SNAPs) and median compound muscle action potentials (CMAPs) and chronic denervation changes in the bilateral abductor pollicis brevis (APB) muscles on needle electrode examination (NEE), indicating axonal loss in the bilateral T1 distribution. CONCLUSIONS: The EDx data are in keeping with lesions involving bilateral T1 anterior primary rami (APR). Potential sites of compromise of the T1 APR are discussed. Further study of the effect of treatment for macromastia on the clinical and EDx findings is proposed.

Prevalence of bifid median nerves and persistent median arteries and their association with carpal tunnel syndrome in a sample of Latino poultry processors and other manual workers.

INTRODUCTION: The prevalence of bifid median nerves and persistent median arteries, their co-occurrence, and their relationship to carpal tunnel syndrome (CTS) are only understood partially. METHODS: We screened 1026 wrists of 513 Latino manual laborers in North Carolina for bifid median nerves and persistent median arteries using electrodiagnosis and ultrasound. RESULTS: A total of 8.6% of wrists had a bifid median nerve, and 3.7% of wrists had a persistent median artery independent of subgroup ethnicity, age, gender, or type of work. An association with definite carpal tunnel syndrome was not found. The presence of either anatomic variant was associated with a high likelihood of co-occurrence of another variant in the same or the contralateral wrist. CONCLUSIONS: The occurrence of median anatomic variants can be determined in field studies using ultrasound. Persistent median arteries and bifid median nerves tend to co-occur but do not put manual laborers at additional risk of developing CTS.

Computer protocol for the electrodiagnostic evaluation of patients with suspected median neuropathy at the wrist.

Patients with median entrapment neuropathy at the wrist (MEW) present a large burden to electrodiagnostic (EDx) services. We report here our experience with a computer protocol for EDx standardized evaluation of these patients. The computer program guiding the examiners through the history, focused clinical examination and nerve conduction studies (NCSs), and automatically generating the report was employed in patients with suspected MEW referred to our unit in year 2010. Included were 1,935 patients (3,870 hands) with suspected MEW. Median motor study had to be performed in 100 %, a ring finger sensory comparison study in 99 %, a thumb study in 23 %, wrist study in 3 % and a middle finger study in 19 % of hands with cumulative sensitivities of 45, 68, 73, 74, and 82 %, respectively. In conclusion, our computer program helped to relieve some burden, standardized NCSs and provided data needed to further develop evidence-based protocol for the NCSs in patients with suspected MEW.