OBJECTIVE: To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared. RESULTS: The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ²=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody. CONCLUSION The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.
Humans ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/pathology* ; Median Nerve/pathology* ; Ulnar Nerve/pathology* ; Brachial Plexus/pathology* ; Magnetic Resonance Imaging/methods*

OBJECTIVE: This study aimed to clarify the morphology of the Martin-Gruber anastomosis (MGA) in Chinese. METHODS: One hundred and five Chinese upper limbs (36 males and 20 femalese) were dissected to find the connections between medial nerve and ulnar nerve. The MGA was classified as previously described by Lee. RESULTS: MGA was found in 24 cases (22.9%), in 11 of the 36 male and 5 of the 20 female. There was no obvious difference in the frequency of MGA in both upper limbs. Most MGA ulnar position was located at the medial and distal segment of the forearm. CONCLUSION MGA anatomy could play important role in forensic diagnosis of ulnar nerve injury in Chinese population.
Cadaver ; China/epidemiology* ; Expert Testimony/legislation & jurisprudence* ; Female ; Humans ; Male ; Median Nerve/pathology* ; Muscle, Skeletal/innervation* ; Nervous System Malformations/physiopathology* ; Ulnar Nerve/pathology* ; Upper Extremity/innervation*

BACKGROUND: The aim of this study was to evaluate the contribution of the proximal nerve stump, in end-to-side nerve repair, to functional recovery, by modifying the classic end-to-side neurorrhaphy and suturing the proximal nerve stump to a donor nerve in a rat model of a severed median nerve. METHODS: Three experimental groups were studied: a modified end-to-side neurorrhaphy with suturing of the proximal nerve stump (double end-to-side neurorrhaphy, Group I), a classic end-to-side neurorrhaphy (Group II) and a control group without neurorrhaphy (Group III). Twenty weeks after surgery, grasping testing, muscle contractility testing, and histological studies were performed. RESULTS: The grasping strength, muscle contraction force and nerve fiber count were significantly higher in group I than in group II, and there was no evidence of nerve recovery in group III. CONCLUSIONS: The contribution from the proximal nerve stump in double end-to-side nerve repair might improve axonal sprouting from the donor nerve and help achieve a better functional recovery in an end-to-side coaptation model.
Anastomosis, Surgical/methods ; Animals ; Axons/pathology ; Forelimb ; Hand Strength ; Male ; Median Nerve/pathology/*surgery ; Muscle Contraction ; Muscle, Skeletal/physiopathology ; Nerve Regeneration ; Nerve Transfer/*methods ; Rats ; Rats, Sprague-Dawley ; Recovery of Function ; Ulnar Nerve/pathology/*surgery

OBJECTIVE: To study the morphological changes of the rat claw inner skeletal muscle after ulnar nerve injury at different sections and different recovery times. METHODS: Forty-two adult male Sprague-Dawley rats were selected and placed randomly in seven groups. After establishing model of injury and repair of claw inner skeletal muscle by cutting off the ulnar nerve, the muscle wet weight, cross section area of myocytes, and collagen fibers were measured. RESULTS: Claw inner skeletal muscle atrophy was significantly less in experiment groups compared with the control groups after ulnar nerve injuries. The functional recovery was better in the early repair groups than the late repair group. Collagen fibers increased slowly in earlier stage, but more significantly in late stage. The muscle atrophy was similar in wrist and elbow after ulnar nerve injury during the same recovery period. CONCLUSION The function can recover completely or partly in early repair groups, but not quite effective in late stage. The increase of collagen fiber is one of the reasons to undermine the recovery effect of damaged ulnar nerve. There is no obvious difference of effect on the morphological changes of the rat claw inner skeletal muscle no matter the ulnar nerve is injured at wrist or elbow.
Animals ; Male ; Muscle, Skeletal/pathology* ; Muscular Atrophy/prevention & control* ; Nerve Regeneration/physiology* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Plastic Surgery Procedures ; Ulnar Nerve/surgery*

Leprosy, one of the oldest diseases known to humans, still affects almost 10-15 million people throughout the world. Neuropathy affects 15-20% of infected individuals. Therefore leprous neuropathy is still one of the most common neuropathy in the world. It is due to infection with Mycobacterium leprae and occurs primarily in Asia and Africa. The cardinal symptom of leprosy is sensory loss caused by superficial neuropathy. Anesthetic depigmented skin lesions are an important finding and should be sought. Nerve involvement is a hallmark of leprosy. Nerve involvement is rare in other diseases, so the finding of skin lesions with enlarged nerves should raise the possibility of leprosy. Nerve involvement tends to occur with skin lesions, and the pattern of nerve involvement parrellels the skin disease. In the tuberculoid form, mononeuropathy multiplex is typical pattern, whereas asymmetrical or symmetrical polyneuropathy is most common in the lepromatous form. Motor involvement occurs in a predictable sequence as a result of nerve trunk damage to those nerves that course close to the skin surface and hence are locally cool. Nerve involved include the ulnar nerve at the elbow, the deep peroneal branch at the ankle, superficial branches of the facial nerve, and the median nerve at the wrist, and especially the greater auricular nerve. Nerve involvement without skin lesions, called pure neural leprosy, can occur. Other characteristic findings are thickened nerve, trophic ulcers, mutilated digits, and Charcot joint. In clinically affected nerves, the motor nerve conduction velocities are minimally slow. The terminal latency is often prolonged and the compound muscle action potentials are temporally dispersed and decreased in amplitude. Sensory and mixed compound nerve action potentials are often difficult to obtain or else a reduced amplitude. The facial nerve is commonly involved in leprosy. Improvement in motor nerve conduction was reported in leprosy patients under sulfone treatment. Nerve biopsy reveals subperineurial edema and various amounts of loss of myelinated and unmyelinated fibers. Teased fiber studies reveal paranodal demyelination affecting successive internodes. Therefore segmental demyelination is the main pathology in leprous neuropathy.
Action Potentials ; Africa ; Ankle ; Arthropathy, Neurogenic ; Asia ; Biopsy ; Demyelinating Diseases ; Edema ; Elbow ; Facial Nerve ; Humans ; Leprosy ; Leprosy, Tuberculoid ; Median Nerve ; Mononeuropathies ; Mycobacterium leprae ; Myelin Sheath ; Neural Conduction ; Pathology ; Polyneuropathies ; Skin ; Skin Diseases ; Ulcer ; Ulnar Nerve ; Wrist