Electrophysiological course of uraemic neuropathy in haemodialysis patients.
(1/19)
The objective of this study was to confirm electrophysiologically both the presence and course of uraemic neuropathy in haemodialysis patients. Nerve conduction studies of the lower extremities were done in 70 haemodialysis patients and 20 normal volunteers. Compared with that in normal volunteers, the distal motor latency in the tibial nerve of patients was prolonged significantly (p<0.05), and the minimal F wave latency in the tibial nerve was also prolonged significantly (p<0.05). Motor conduction velocity in the tibial nerve was reduced significantly (p<0.05), and sensory nerve conduction velocity in the medial plantar nerve also was reduced significantly (p<0.05). These results suggest the presence of uraemic neuropathy in haemodialysis patients. Twenty patients were investigated by a follow up study five years later. Parameters from F wave conduction studies, which were thought to be the most useful in the evaluation of neuropathy, showed no significant differences between the initial and follow up trials. These observations suggest that uraemic neuropathy does not progress during haemodialysis. These results also suggest that most haemodialysis patients showed electrophysiological evidence of uraemic neuropathy, but no remarkable electrophysiological change in uraemic neuropathy during haemodialysis was recognised. (+info)
An unusual case of haemorrhagic median neuropathy.
(2/19)
The authors describe a rare case of carpal tunnel syndrome secondary to intraneural haemorrhage of the median nerve. (+info)
Shoulder posture and median nerve sliding.
(3/19)
BACKGROUND: Patients with upper limb pain often have a slumped sitting position and poor shoulder posture. Pain could be due to poor posture causing mechanical changes (stretch; local pressure) that in turn affect the function of major limb nerves (e.g. median nerve). This study examines (1) whether the individual components of slumped sitting (forward head position, trunk flexion and shoulder protraction) cause median nerve stretch and (2) whether shoulder protraction restricts normal nerve movements. METHODS: Longitudinal nerve movement was measured using frame-by-frame cross-correlation analysis from high frequency ultrasound images during individual components of slumped sitting. The effects of protraction on nerve movement through the shoulder region were investigated by examining nerve movement in the arm in response to contralateral neck side flexion. RESULTS: Neither moving the head forward or trunk flexion caused significant movement of the median nerve. In contrast, 4.3 mm of movement, adding 0.7% strain, occurred in the forearm during shoulder protraction. A delay in movement at the start of protraction and straightening of the nerve trunk provided evidence of unloading with the shoulder flexed and elbow extended and the scapulothoracic joint in neutral. There was a 60% reduction in nerve movement in the arm during contralateral neck side flexion when the shoulder was protracted compared to scapulothoracic neutral. CONCLUSION: Slumped sitting is unlikely to increase nerve strain sufficient to cause changes to nerve function. However, shoulder protraction may place the median nerve at risk of injury, since nerve movement is reduced through the shoulder region when the shoulder is protracted and other joints are moved. Both altered nerve dynamics in response to moving other joints and local changes to blood supply may adversely affect nerve function and increase the risk of developing upper quadrant pain. (+info)
Complications of treating distal radius fractures with external fixation: a community experience.
(4/19)
OBJECTIVE: To analyze the immediate postoperative complications associated with treating distal radius fractures with external fixation. DESIGN: A retrospective chart review of data obtained from 24 consecutive patients who were treated with small AO external fixators in 1997. SETTING: Two community medical centers. INTERVENTION: Preoperative and postoperative radiograph measurements were taken of radial inclination, radial tilt, and radial length, and fractures were classified according to the AO system. Patient charts were reviewed to document demographics, type of fixator used, open or percutaneous technique for pin placement, use of augmentation, additional operations, and complications. MAIN OUTCOME MEASUREMENTS: Complications associated with treating distal radius fractures with one type of external fixator. RESULTS: Sixteen of the 24 patients had complications: 5 with neuropathies of the median or superficial radial nerve, 9 with pin track infections, 2 with pin loosening, one with a nonunion, 2 with malunion, and 4 patients each with radial shortening, loss of radial tilt, collapse of ulnar border or volar intercalated segment instability (VISI) of the lunate and rotatory subluxation of the scaphoid. CONCLUSIONS: Postoperative complications following distal radius fractures treated with external fixation are common. Their effect, however, on long term functional results and patient satisfaction is negligible, with the exception of those patients with complications intrinsic to the fracture itself, i.e., nonunion, malunion or carpal malalignment. (+info)
Lipofibromatous hamartoma of the median nerve with long-term follow-up.
(5/19)
Lipofibromatous hamartoma is a rare, benign tumor that most often involves the median nerve. A 16-year-old male with lipofibromatous hamartoma of the median nerve at the wrist level is described. This patient was a child when the mass was first noted. Although there were no symptoms or signs of carpal tunnel compression, the growth of the tumor was progressing. In addition to the release of the carpal tunnel, microsurgical intraneural dissection was done to preserve the thenar motor branch. Then segmental excision of the residual sensory component with sural nerve grafting was performed. Subjectively the patient did not notice the minor motor deficit, however, the patient did experience numbness of fingertips after surgery. There were no scars or trophic ulcers on fingertips at 3 years of follow-up regardless of the inadequate sensory return. Treatment of this benign tumor is still controversial. The relevant reports in the literature are reviewed. (+info)
Nerve conduction studies and current perception thresholds in workers assessed for hand-arm vibration syndrome.
(6/19)
BACKGROUND: Workers exposed to hand-arm vibration are at risk of developing the neurological abnormalities of hand-arm vibration syndrome (HAVS). The Stockholm classification of the neurological component of HAVS is based on history and physical examination. There is a need to determine the association between neurological tests and the Stockholm scale. AIMS: The main objective of this study was to compare the Stockholm neurological scale and the results of current perception threshold (CPT) tests and nerve conduction studies (NCS). METHODS: Detailed physical examinations were done on 162 subjects referred for HAVS assessment at a specialist occupational health clinic. All subjects had NCS and measurement of CPT. The Stockholm neurological classification was carried out blinded to the results of these neurological tests and compared to the test results. RESULTS: The nerve conduction results indicated that median and ulnar neuropathies proximal to the hand are common in workers being assessed for HAVS. Digital sensory neuropathy was found in only one worker. Neither the nerve conduction results nor the current perception results had a strong association with the Stockholm neurological scale. Exposure to vibration in total hours was the main variable associated with the Stockholm neurological scale [right hand: OR 1.30, 95% CI (1.10-1.54); left hand: OR 1.18, 95% CI (1.0-1.39)]. CONCLUSION: Workers being assessed for HAVS should have nerve conduction testing to detect neuropathies proximal to the hand. Quantitative sensory tests such as current perception measurement are insufficient for diagnostic purposes but may have a role in screening workers exposed to vibration. (+info)
A fluid-immersed multi-body contact finite element formulation for median nerve stress in the carpal tunnel.
(7/19)
Carpal tunnel syndrome (CTS) is among the most important of the family of musculoskeletal disorders caused by chronic peripheral nerve compression. Despite the large body of research in many disciplinary areas aimed at reducing CTS incidence and/or severity, means for objective characterization of the biomechanical insult directly responsible for the disorder have received little attention. In this research, anatomical image-based human carpal tunnel finite element (FE) models were constructed to enable study of median nerve mechanical insult. The formulation included large-deformation multi-body contact between the nerve, the nine digital flexor tendons, and the carpal tunnel boundary. These contact engagements were addressed simultaneously with nerve and tendon fluid-structural interaction (FSI) with the synovial fluid within the carpal tunnel. The effects of pertinent physical parameters on median nerve stress were explored. The results suggest that median nerve stresses due to direct structural contact are typically far higher than those from fluid pressure. (+info)
Hereditary neuropathy with liability to pressure palsies in a Turkish patient (HNPP): a rare cause of entrapment neuropathies in young adults.
(8/19)
Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant nerve disease usually caused by 1,5 Mb deletion on chromosome 17p11.2.2-p12, the region where the PMP-22 gene is located. The patients with HNPP usually have relapsing and remitting entrapment neuropathies due to compression. We present a 14-year-old male who had acute onset, right-sided ulnar nerve entrapment at the elbow. He had electrophysiological findings of bilateral ulnar nerve entrapments (more severe at the right side) at the elbow and bilateral median nerve entrapment at the wrist. Genetic tests of the patient demonstrated deletions in the 17p11.2 region. The patient underwent decompressive surgery for ulnar nerve entrapment at the elbow and completely recovered two months after the event. Although HNPP is extremely rare, it should be taken into consideration in young adults with entrapment neuropathies. (+info)