Finger Nerve Research Articles

Proper digital nerves of the first and little fingers repaired with transfer of dorsal digital nerves of the same fingers

目的 探讨拇小指指背神经移位修复指固有神经的疗效.方法 2002年8月至2008年2月治疗58例拇小指指固有神经撕脱离断伤患者,男39例,女19例;年龄15～64岁,平均38岁.采用同指指背神经移位,修复指固有神经,恢复指腹感觉.结果 56例患者获4个月至1年8个月(平均1年2个月)随访,2例失访.所修复指固有神经侧指腹感觉均恢复良好.两点分辨距离为6～9 mm,平均约7.7 mm.按照感觉功能评定标准为S4:佳.结论 拇小指指背神经移位修复同指指固有神经,方法较简单,指腹感觉恢复良好,疗效满意。

Autologous nerve implantation into denervated monkey skin promotes regeneration of Meissner’s corpuscle

SummaryBackgroundThe aim of this study was to observe the effects of autologous nerve implantation into the denervated finger flap on the regression and regeneration of sensory nerve endings and Meissner’s corpuscles.Material/MethodsBilateral nerves of fingers were separated: one was removed and the other was implanted into the denervated finger in the implantation group. In the non-implantation group, both nerves were removed. The ventral skin of fingers was collected for immunohistochemistry and electron microscopy 3, 6, 9 and 12 months after surgery.ResultsThe nerve endings in the Meissner’s corpuscles began to degenerate 3 months after denervation. The elementary structure of Meissner’s corpuscles was not significantly altered. Nerve fibers were present around the Meissner’s corpuscles, accompanied by growing into its inward. The axons in the denervated nerve disappeared and the Meissner’s corpuscles began to atrophy at month 6. More regenerated nerve fibers were observed after nerve implantation, including intensive and thick fibers, accompanied by reinnervation of Meissner’s corpuscles. More nerve fibers and a higher proportion of myelinated nerve fibers were noted at month 9 in the implantation group, and the reinnervation was present in the majority of Meissner’s corpuscles. Naive myelinated nerve fibers appeared at the caudal end of Meissner’s corpuscles. The nerve fibers in the Meissner’s corpuscles increased to the normal level at 12 months after nerve implantation.ConclusionsThe implanted nerve regenerated a large amount of free nerve endings, which helped to regenerate simple Meissner’s corpuscles via governing previously degenerated corpuscles.

Microscopic anatomy of nevers and blood vessels of the finger distal phanlanx and its clinical significance

Objective To provide anatomical evidence for the repair of wounds of finger distal phalanx,espe-cially for the recovery of feeling. Methods 10 samples of fresh adult hand were dissected under microscope. The course,branches,distribution and external diameter of nerves and blood vessels in finger distal phalanx and morpho-logical relationship between nerves and vessels were measured. Results Proper palmar digital nerves mostly step over digital arteries at section starts of distal finger arterial arcades and go to finger pulps and latero-backs. Their thinks di-vide into 2 branches. Transverse diameters of interior and exterior branches are 0.8 ～ 1.2 mm and 0.9 ～ 1.4 mm re-spectively at liner semilunaris levels. Distributionsof left and right branches are reciprocal chiasmas. Conclusion Finger nerve mostly ramifies to finger pulp,finger tip and finger back at the level of phalangette bottom. Its branches are lower and thinner than concomitant arteries. The suitable anatomy region for anastomosis of nerves and blood ves-sels is the middle1/3 section from the distal interphalangeal joint to the nail during replanation of amputated finger pa-ratelum. Key words: Fingers; Microdissection

Is intraoperative luxation of the ulnar nerve a criterion for transposition?

The relevance of subcutaneous transposition of the ulnar nerve in the therapy of cubital tunnel syndrome is still under debate. The aim of this study was to compare the results after decompression to additional transposition in cases of intraoperative luxation. A total of 54 cases after surgery of cubital tunnel syndrome between 2000 and 2006 were analyzed. Nerve transposition was performed in cases of intraoperatively apparent nerve luxation. Of the patients 12 were treated by decompression alone and 42 by additional subcutaneous transposition. There was no significant difference concerning symptom amelioration, usage properties of the hand, sensation impairment and duration of disability. Force measurements of grip strength and pinch strength revealed no significant differences between either hand in both groups. The 2-point discrimination ability of the 8th to 10th finger nerves was not significantly different between the groups either. Nerve transposition revealed no benefits in the treatment of cubital tunnel syndrome when performed in cases of intraoperative nerve luxation.

Symmetric Lipofibromatous Hamartoma Affecting Digital Nerves

Lipofibromatous hamartoma of the nerve is a benign tumor, which affects the major nerves and their branches in the human body. It is often found in the median nerve of the hand and is commonly associated with macrodactyly, but it is rarely found in the digital nerves at the peripheral level. This tumor is often found in young adults and may go through a self-limiting course. However, operation is indicated when the tumor size is large or when the associated nerve compressive symptoms are present. We have experienced a rare case of lipofibromatous hamartoma that symmetrically involved the volar digital nerves of both index fingers on the ulnar side. With the aid of a microscope, we dissected and removed the tumor as much as possible without sacrificing the nerve. No sensory change occurred in both fingers and no sign of recurrence was observed upon follow-up.

FMRI shows multiple somatotopic digit representations in human primary somatosensory cortex

Using electrical finger nerve stimulation in normal human subjects, fMRI detected separate representations for all 5 fingers in the primary somatosensory cortex. Responses were located in the posterior wall of the deep central sulcus (most likely corresponding to Brodmann Area (BA) 3b), and the anterior (BA 1) or posterior crown of the postcentral gyrus (BA 2) with rare activations in BA 3a and 4. In BA 3b we found a regular somatotopic mediolateral digit arrangement for fingers 5 to 1 with a mean Euclidean distance of 16 mm between fingers 1 and 5. In contrast BA 1/2 showed a greater number of adjacent activation foci with significantly more overlap and partly even reversed ordering of neighbouring fingers.

Selective temporal shift in the somatosensory evoked potential produced by chronic stimulation of the human index finger.

The present study determined whether the cortical potential from the human index finger changed with chronic nerve stimulation. Cerebral potentials were repeatedly recorded to stimulation of the ulnar nerve and the digital nerves of thumb, index and middle fingers, before and during a 7-day period in which the index was electrically stimulated (80 Hz) for 8-10 h daily. Cerebral potentials were recorded at three scalp sites over the contralateral "hand" area. Chronic stimulation produced no significant changes in the amplitudes or distribution of the cerebral potentials from the individual digits or the ulnar nerve. However, for the stimulated index finger there was a significant, progressive increase in latency of N20 and P25 without a detectable change in conduction velocity of distal peripheral axons. Timing in human central somatosensory pathways may be altered by the previous pattern of peripheral nerve inputs.

Vasomotor oscillation in vibration-induced white finger.

Vasomotor oscillation at different ambient temperatures, with and without anesthesia of the finger nerves, was studied in six persons with vibration-induced white finger (VWF) and in 10 referents. The power spectral density (PSD) of the Fourier transform of the laser-Doppler flowmeter signal from the finger pad vessels was analyzed. In both groups, the PSD of the vasomotor oscillation in the frequency range of 0.05-0.25 Hz was more pronounced in a cold than in a hot environment. Without finger nerve anesthesia, the oscillations of the referents were significantly greater (p less than 0.01) than those of the VWF subjects (PSD -34.4 dB and -41.6 dB, respectively). With anesthesia of the finger vasomotor nerves, the PSD was reduced in both groups. In the anesthetized finger there was no statistically significant group difference. Thus the myogenic component of the vasomotor activity was the same in the referents as in the VWF subjects. The results show that the autonomic neural influence on vasomotor oscillation in skin of the finger pad is weaker in persons with VWF. This weakness may be a sign of peripheral neuropathy, which may lead to a denervation syndrome causing hypersensitivity of the adrenoceptors to cold.

Somatosensory evoked potentials after removal of somatosensory cortex in man

Somatosensory evoked potentials (SEPs) to median nerve, ulnar nerve, thumb, middle finger, and posterior tibial nerve stimulation were recorded in a patient with a discrete resection of part of the postcentral somatosensory cortex as a treatment for focal epilepsy. Comparison of the different stimulation sites confirmed electrophysiologically the restricted locus of the lesion. The results strongly suggest that the early negative component (N20) and subsequent components recorded postcentrally are of cortical origin and depend upon postcentral gyrus cytoarchitectonic areas 3, 2, and 1. Moreover, these postcentral SEPs are distinct from precentrally recorded activity.

Epidurally recorded cervical somatosensory evoked potential in humans

Three slow wave components, P10 , N13 and P18 , can be seen in the cervical somatosensory evoked potential (CSEP) in response to median nerve stimulation recorded by an electrode in the epidural space at the dorsal aspect of the cervical spinal cord referenced to an electrode at the suprasternal notch. In the region of high CSEP amplitude, which extends over several cervical segments, the peak-to-peak amplitude is more than 10 μV, permitting observation of the CSEP slow waves in single, unaveraged records. The CSEP to finger nerve stimulation had a similar wave form and the same latencies (referred to the Erb's potential) as the CSEP to median nerve stimulation. The P10 activity is of presynaptic origin; it is generated in the brachial plexus, spinal roots and terminal branches of the primary sensory fibers. The N13 slow wave is of postsynaptic origin; however, the small wave on the ascending phase of this main postsynaptic component represemts superimposed presynaptic activity. In bipolar epidural recordings, 3–5 fast wave are superimposed on the slow CSEP waves, which are of lower amplitude than the slow waves in unipolar recordings. The fast waves show a slight but progressive delay at the more rostral recording sites and are present even with high frequency stimulation, presumably reflecting activity in long ascending tracts. The surface recorded CSEP to median nerve stimulation is 4–7 times lower in amplitude than the CSEP in unipolar epidural recordings. The small wave on the ascending phase of N13 and the N13 peak of the unipolar epidural recordings had the same latencies as the surface N11 and N13 peaks.

Hand injuries in children

The differences in management, of hand injuries in children and adults are highlighted. Topics covered include skin and subcutaneous tissues, finger nail and finger nail matrix injuries, amputations, tendon injuries, and nerve injuries.

The effects of cold exposure and exercise upon peripheral function.

To assess effects of cold exposure and exercise on peripheral function, 14 volunteers engaged in a ten-day snowshoe march at a mean temperature of -52.5 F. Peripheral function was evaluated by finger nerve conduction velocity measurements, finger skin temperatures, a knot-lying test, and a block-stringing test. Data were evaluated on a beforehand-after basis, and men were divided into groups of those who sustained greatest exposure to cold and exercise (group A) vs those less frequently exposed (group B). Results showed that group B improved in every test parameter after the exercise, while those in group A remained the same, or decreased in their test scores. Since tests of maximum oxygen uptake showed that group A had the greatest postexercise Improvement in physical condition, results seemed to indicate that beneficial effects of exercise on peripheral function may be modified by extensive, sewere cαld exposure.

TENSILE STRENGTH OF HUMAN NERVES

GRAFTS of peripheral nerves across long gaps, except for the facial and the short finger nerves, were a dismal failure in the recent war, as they had been before. This was true of fresh homologous grafts (Spurling and associates1) and of our own attempts with dehydrated frozen grafts (Nulsen, Lewey and Van Wagenen). This sad experience, together with the urgent need of some kind of nerve repair, focused attention on the possibility of end to end sutures after extensive mobilization and transposition of the corresponding nerves in conjunction with maximal flexion of the extremities. Encouraging results with this procedure were reported by Naffziger,3Platt,4Platt and Bristow,5Babcock,6Forrester-Brown7and, lately, Highet and Holmes.8The last two authors followed the course of 42 patients operated on during this war at the Oxford Nerve Center for gaps of 1.5 to 11 cm. in practically