Thumb Finger Research Articles

Reconstruction of many fingers with bilateral multiple toe transplantation

Objective To evaluate the treatment effect of hand reconstruction with bilateral multiple toe transplantation. Methods There are four schedules as follow applied in 102 cases: (1) bilateral second toes to thumb and index finger transplantation in 86 cases; (2) wrap-around flap to thumb and second toe on opposite side to index or middle finger transplantation in 11 cases; (3) wrap-around flap to thumb and bilateral second toes to index and middle fingers transplantation in 8 cases; (4) bilateral wrap-around flap to bilateral thumb and second toe to index finger transplantation in 1 case. Results All reconstructed finger survived in 102 cases except for partial wrap-around flap necrosis in one case and second toe in two cases. Sixty-two patients got more than one-year following up. Two points discrimination in reconstructed finger was between 8 to 14 mm in all cases. The reconstructed finger grew synchronously with toe among children. Thumb opposition function recovered in all cases except for one case. Donor site: no limp or hallux eversion observed in all cases. Conclusion There is less damage on foot and most hand function recovery using bilateral multiple toe transplantation to repair hand or multiple fingers defect. Key words: Finger; Reconstruction; Toe; Transplantation; Microsurgery

Emergent reconstruction and repair of thumb and finger defect by toes and combined toes transplantation

Objective To explore the method and effect of thumb and finger reconstruction and repair by emergent primary toes transplantation. Methods Three hundred and fourteen fingers of 282 cases including finger thumb defect and complex injury with hyperthena palm radid soft tissue of forearm were reconstructed and repaired by the second toes, wrap-around flap and the second third toes wrap-around flap combined with distal flap of leg or other complex tissue flap transplantation. Results Three hundred and eight reconstructed fingers survived, the survival rate was 98%. After a follow up to 6 months to 6 years, the reconstructed thumbs and fingers have accepted nip, grasp, opponent function. The result was graded as excellent in 214 fingers, good in 63, fair in 26, poor in 5. The excellent and good rate was 88%according to the upper limb functional evaluation criteria issued by the Hand Surgery Society of the Chinese Medical Association. Conclusion Different type of toes and combined toes transplantation can obtain preferable clinical effect on emergent primary thumb and finger defect. Key words: Thumb; Finger; Microsurgical operation; Emergency; Reconstruction

Clinical analysis of 73 cases of macrodactyly

To analyze the clinical characteristics of 73 cases of macrodactyly. Review the incidence, distribution, characteristic, X-rays, pathogenesis and treatment of involved digits on the base of the clinical documents of 73 macrodactyly which were treated from 1965 to 2006. Twenty-eight cases had been followed-up. Unilateral involved 71 cases, bilateral involved 2 cases. In upper deformities, the most involved digit was the index finger, followed by thumb and middle finger enlargement. In lower deformities, the second toes were affected more. There were 12 cases of static macrodactyly, which were all presented at or soon after birth. Sixty-one cases were progressive macrodactyly: 39 cases presented at birth; 17 cases occurred at about 2 years old; 5 cases were found after age 2. Thirty-seven cases of progressive type presented digital deviation; 3 cases associated with syndactyly; 16 cases complicated with thenar eminence hypertrophy; 8 cases of multiple-digit involved combined with palm and forearm hyperplasia. Macrodactyly in hand has a preference for the median nerve territory, mainly involving index, thumb and middle finger. Pedal macrodactyly prefers medial plantar nerve territory, the second toe is the most commonly affected. The progressive macrodactyly is more common than static. It may present at birth and combine with syndactyly, digital deviation, thenar eminence hypertrophy, palm and forearm hyperplasia.

Discrimination of Finger Area of Somatosensory Cortex by NIRS

We carried out a near-infrared spectroscopy (NIRS) study to observe the hemodynamic responses associated with cortical activation in the primary somatosensory cortex (SI) by finger electrical stimulation. We examined whether NIRS can assist in investigating the somatotopic arrangement of fingers on the SI hand area. We found that although relatively low in spatial resolution, NIRS can to some extent help to discriminate the representations of thumb and ring finger on the SI hand area.

Machines for Life

This article provides details of various smart prosthetics that have been developed in last few years. Behind smart prosthetics are many technologies powering consumer products-faster microprocessors, more powerful batteries, wireless technology and new control systems that use the body’s nerves and muscles. A new bionic hand enables users to move the thumb and index finger independently of the remaining three fingers, a significant advance in dexterity over prior claw-like mechanisms. The bionic ear transmits sound and power wirelessly to electrodes implanted deep in the ear, allowing the deaf to hear. The Rheo Knee uses force and position sensors that monitor speed and load more than 1000 times per second. This information goes to an artificial intelligence program that emulates the feedback a natural knee would receive from the body’s central nervous system. However, researchers believe that despite outstanding progress, the future holds more challenges; a second looming issue involves sensory input. At Brown University, neuroscience professor John Donaghue has teamed with Peckham to develop ways to activate nerves from within the brain itself. Their goal is to develop within five years a brain-controlled system that will let a tetraplegic take a glass of water, lift it, and bring it to his or her mouth.

Reticulate keloidal purpura associated with transient antiphospholipid antibodies and hyperhomocysteinaemia

A 66-year-old woman presented with a reticulate pattern of purpuric, keloidal scarring affecting her lower legs and necrosis of her left thumb and little finger as sequelae of an episode of staphylococcal septicaemia. Her premorbid past history includes three miscarriages, three episodes of pulmonary embolism and an internal iliac vein thrombosis. Skin biopsy specimens showed keloidal scar tissue in the dermis but no evidence of thrombosis or vasculitis. Blood tests demonstrated moderate hyperhomocysteinaemia. Elevated levels of anticardiolipin antibodies were found on one occasion but this was not detected on initial or repeat testing.

Isometric Finger Device for Assessment and Training of Force Coordination Using Virtual Reality

Grasping of stroke patients is often affected by improper coactivation of muscles controlling the fingers. The restoration of hand function therefore represents an important goal in rehabilitation. Quantitative data on coordination between fingers can be helpful for the assessment of therapy effectiveness. We have designed a novel isometric finger device to assess three-dimensional forces applied by the thumb, index, and middle finger. The device was used in connection with a simple virtual reality task where the patient had to open a safe by sequentially rotating a knob using the isometric finger input. The presented virtual reality application was evaluated in a group of healthy subjects and a chronic stroke patient to obtain preliminary performance results. We analyzed the coordination of fingertip forces between the thumb and opposing fingers. Pearson correlation coefficient was determined to assess the coordination of force in each direction. In healthy subjects, the analysis of the fingertip forces showed precise coordination of force between the fingers to control a virtual object. The performance of the stroke patient was considerably lower due to reduced muscle control and presence of strong spasticity. The results showed use of excessive force in both hands and lower coordination of force between the fingers as compared to the healthy subjects. The proposed virtual reality system is considered as a complementary method to the existing methods used in physical and occupational therapy. Specific virtual reality tasks could be designed to train coordination of force between the affected fingers.

P66 Trp24 and Phe61 Are Essential for Accurate Association of HIV-1 Reverse Transcriptase with Primer/Template

Preventing dimerization of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) constitutes an alternative strategy to abolish virus proliferation. We have previously demonstrated that a short peptide derived from the Trp cluster of the connection domain disrupts the RT dimer by interacting with Trp24 and Phe61 in a cleft located between the fingers and the connection domains of p51. Both Trp24 and Phe61 of p51 are essential for the stability of the RT dimer. Here, in order to understand the requirement of Trp24 and Phe61 in the p66 subunit, we have investigated their implication in the formation of RT–primer/template (p/t) complexes and in RT processivity by combining pre-steady-state and steady-state kinetics with site-directed mutagenesis. We demonstrate that both residues are essential for proper binding of the p/t and control conformational changes required for RT ordered mechanism. Trp24 and Phe61 act on p/t binding and remodeling of the catalytic site. Phe61G mutation increases the binding “on” rate of both p/t and mismatched p/t, yielding an unfavorable RT–p/t for polymerase catalysis, unable to pursue mispair extension. Considering the structure of unliganded RT, Phe61 seems to be involved in the dynamics of p66 thumb–finger interactions and in stabilization of the p/t in the catalytic site. In contrast, the p66 Trp24G mutation alters the overall kinetics of p/t binding and is essentially involved in stabilizing the RT–p/t complex by contacting the 5′ overhang of the template strand. Mutation of both Trp24 and Phe61 alters mispair extension efficiency, suggesting that disruption of the tight contacts between the fingers domain and the 5′ overhang of the template strand increases RT fidelity and reduces RT processivity. Taken together, these studies infer that mutations altering the aromatic nature of Phe61 or Trp24 that may occur to counteract peptide inhibitors targeting this region will generate an unstable RT exhibiting low polymerase activity and higher fidelity. As such, our work suggests that the combined application of peptide-based RT dimerization inhibitors is likely to be highly efficient.

Comparative Source Localization of Electrically and Pressure-Stimulated Multichannel Somatosensory Evoked Potentials

The purpose of the study was to determine if there is a difference in the determination of the cortical hand area by dipole source estimation after artificial and natural stimuli. In principle, there are advantages of both methods: pressure stimulation is less invasive and compatible to fMRI, whereas electrical stimulation can be applied with higher stimulus rates and elicits sharper waveforms. Electrical and pressure stimulation was performed simultaneously on the thumb and fifth finger on eight healthy volunteers. The somatosensory evoked potentials after electrical stimulation showed sharper peaks and higher amplitudes than the pressure stimulated potentials. For the two stimulus qualities, cortical source positions of thumb and fifth finger separated significantly in the vertical z-axis. Both methods deliver reliable stimulation and therefore allow separate source localization of thumb and fifth finger. For cortical plasticity studies, peripheral somatosensory stimulation is of great importance. According to these findings, the choice of method, electrical or mechanical stimulation, may depend on practical criteria.

Discrimination of multiple sources in the somatosensory area of human finger based on 3-D SEF measurement

Abstract To discriminate multiple sources of human hand somatosensory cortex we recorded somatosensory evoked field after stimulation of three fingers (the thumb, fourth finger, and little finger), respectively. Time-frequency analysis (wavelet transforms, WT) was applied to the SEF data to examine the frequency component of each SEF data. Dominant power spectrum to the thumb (median nerve) stimulation appeared at higher frequency range than that of the little finger (ulnar nerve) stimulation (thumb: 15–20 Hz, little finger: 10–15 Hz). The frequency of dominant power spectrum to the fourth finger stimulation existed between that of the thumb and little finger stimulation. From the result of the coherence by the SEF data between the fourth finger and the other finger, band-pass filtering for the fourth finger was done with different frequency ranges (13–15 Hz: little finger and 16–18 Hz: the thumb). Source localization was done with these SEF data. It was confirmed that the proposed method, combining time-frequency analysis with the inverse problem of MEG (magnetoencephalogram), is useful for discriminating multiple sources of the SEF elicited by two nerve activities in the fourth finger overlapping in time.

‘Just a sharp scratch’: permanent radial, median and ulnar neuropathy following diagnostic venepuncture

An 82-year-old woman was admitted to hospital with acute left ventricular failure following a recent myocardial infarction for which she had been commenced on clopidogrel. An uneventful venepuncture in her left antecubital fossa yielded a normal full blood count and coagulation profile. Diuretics were commenced to which she responded well. Five days later she described pain, swelling and bruising of her left forearm with numbness over her thumb, index and middle fingers. Prophylactic low molecular weight heparin was discontinued and the arm elevated. Nine days later she was unable to move her left hand. Bruising extended from the shoulder to the hand with swelling distal to the antecubital fossa (Figures 1 and 2). Woody subcutaneous oedema was present around the antecubital fossa with forearm tenderness. The radial pulse was present with good capillary circulation in all fingers. Neurological examination revealed complete wrist drop, minimal finger flexion and no small muscle function of the hand. The dorsal aspect of the forearm and hand were hypersensitive, with numbness over the volar aspect of the thumb, index and middle fingers. These findings were consistent with an ischaemic neuropathy of the median, radial and ulnar nerves as a result of compartment syndrome, secondary to a compressive haematoma at the antecubital fossa following venepuncture. Surgery to relieve compartment pressures at this stage was thought to provide little chance of recovery, with the additional risk of supervening infection. Initial treatment was therefore conservative consisting of physiotherapy, vitamin B and gabapentine. An ultrasound scan confirmed the presence of a haematoma occupying the entire flexor compartment of the forearm. Nerve conduction studies revealed completely absent sensory potentials, with motor potentials 1%, 30% and 60% of normal in the radial, median and ulnar nerves respectively. This confirmed a severe subtotal axonotmesis of the radial nerve with partial axonal injury to the median and ulnar nerves. The prognosis was one of permanent major neurological deficit and despite intensive hand physiotherapy there was little functional recovery 1 year later.

Finger shape expansion and recognition by wavelet transform

This study uses the object extracting technique to extract thumb, index, middle, ring, and small fingers. The developed algorithm can locate the precise locations of fingertips and finger-to-finger-valleys. The extracted fingers contain many useful geometry features. One can use these features to identify different fingers. The geometry descriptor is used to transfer fingers to another straight positions. Finger is scaled and the reverse wavelet transform is performed to cause the finger to possess more salient feature. Image subtraction is used to examine the difference of the two fingers. This study uses fingers and palm to recognize different persons.

Rapid Screening and Diagnosis of Various Cancers From Human Voice Using Bi-Digital O-Ring Test Resonance Phenomenon Between 2 Identical Substances i.e. Between Microscope Slide of Specific Cancer Tissue & Cancer Information in the Sound of Human Voice, and Detection of Myocardial Damage & Infection from Human Voice

Since 1982, the author has been successfully using Bi-Digital O-Ring Test (BDORT) electro-magnetic resonance phenomenon between 2 identical substances; i.e. between specific cancer (in vivo) of a patient and a microscope slide of identical cancer tissue to detect cancers at a very early stage. Since 2000, the author has found that when BDORT is performed while an individual with a malignant tumor is talking, BDORT became (-1 approximately -10) in 94% of 200 cases and the number of openings (-) is approximately proportional to the degree of abnormality up to -10. Thus, cancer can be screened from voice within 1 min., without any instruments. Also, when cancer-free persons hold slides of cancer tissue or 10ng or higher Oncogene C-fos Ab2 or Integrin alpha5beta1 while talking over a short or long distance, BDORT always opens. To identify the type of the patient's malignancy, if BDORT is performed by an examiner holding a microscope slide of cancer tissue identical to the patient's cancer, characteristic strong BDORT resonance phenomenon appears with opening of all O-Rings formed between thumb and other fingers. When patients with myocardial infarct or various infections speak, no O-Rings open without holding identical pathological substances. Thus, it is possible to detect any type of malignancy from the voice, as long as a set of about 35 different tumor tissue slides is available. Based on these new findings, the author concluded that the voice of an individual with a malignancy carries information about the amount and structure of molecules present in malignant tissue.

Afferent Contributions to Digit Force Coupling and Force Level Variation During Performance of Non-lift Pinch

Afferent contributions to the coordination of thumb and index finger forces during non-lift pinch were studied using an anesthetization case study design. Two subjects, one performing with and without digital anesthetization and one with intact sensation, produced dynamic pinch forces against a stable object, with and without visual feedback. Error corrections were less frequent post-anesthetization, and the cross correlation between digit forces was lower when sensation was removed. However, this decrease in cross correlation between digit forces seemed to reflect a loss in the magnitude of tightly coupled error corrections when sensation was removed, rather than more frequent deviations of force magnitude between the digit forces. Force-time output without visual feedback lacked these error corrections, and the correlation between digit forces remained high, irrespective of sensory status. Additionally, with vision occluded, the time rate of force change did not vary in a gradual manner as would be expected from a neural representation of a sinusoidal target, but was instead marked by sudden abrupt reversals of force rate of change, invariant of somatosensory status. The coupling of digit forces and rates of force change during non-lift pinch appear to be controlled primarily with feedforward mechanisms, where the lack of proprioceptive feedback does not seem to disrupt this coupling.

Anterior Interosseous Neuropathy in Instrumental Musicians

The anterior interosseous nerve is a pure motor branch of the median nerve supplying the flexor pollicis longus, flexor digitorum profundus of the index and middle fingers, and pronator quadratus. Anterior interosseous neuropathy is rare and typically causes weakness of flexion of the tips of the thumb and index finger. Four instrumentalists, 3 violinists and 1 pianist (3 males, 1 female), seen from 1986 to 2002 at our clinic, are the subjects of this report. Age at onset ranged from 16 to 76 yrs. A possible precipitating factor was identified in each. One violinist could not hold the bow; two others noted inability to stabilize the distal left first (index) finger. The pianist noted impaired dexterity of the right hand. Examination showed weakness of flexion of the distal phalanx of the index finger and thumb and variable weakness of forearm pronation. Electrodiagnostic testing confirmed the diagnosis in all four patients. All improved over time. One symphony violinist continued to play for over 15 yrs, despite some persisting difficulty with the left index finger. Another violinist recovered function almost completely but suffered a stroke affecting the opposite hand 2.5 years later. The third violinist retired from the symphony on disability because his recovery was delayed for >1 yr. The young pianist is playing 4 to 5 hrs/day. It is likely that at least three of the four had a localized form of neuralgic amyotrophy.

Flexor Pollicis Brevis Adductorplasty

Loss of pinch power associated with loss of coordinated movement of thumb and index fingers is the major disability in patients with ulnar nerve paralysis. Several tendon transfer methods utilizing different donor muscles have been used to restore adductor pollicis muscle function in ulnar nerve paralysis. In this paper, we discuss the transfer of flexor digitorum brevis muscle to the tendon of adductor pollicis muscle as an alternative method to restore key pinch in ulnar nerve paralysis. The technique was applied to 4 patients with ulnar nerve paralysis. Before clinical application, an anatomic study was carried out in 6 cadaver hands. In cadavers, radial and ulnar arteries were injected with latex and arterial pedicles of flexor pollicis brevis muscle were dissected under 4x magnification. Also, motor branches from the median nerve were shown at the entrance point to the muscle. In surgical practice, the superficial head of the muscle is detached from its insertion and the minor pedicle of the muscle is cut. Muscle is dissected proximally up to two thirds of its length. The dominant pedicle of the muscle originating from superficial palmar arcus is preserved, and the muscle is sutured to the tendon of the adductor pollicis muscle close to its insertion. Patients were evaluated in terms of key pinch strength preoperatively and at the postoperative sixth month using a pinch meter (Chattanooga Group, Inc). Key pinch strengths were recorded and expressed as percentage of the strength of the contralateral uninvolved hand. Mean key pinch strength of our patients was 29.7%. In conclusion, we believe in that flexor pollicis brevis adductorplasty may be an alternative method for restoration of adductor pollicis muscle function in ulnar nerve paralysis.

Effects of paired pulse TMS of primary somatosensory cortex on perception of a peripheral electrical stimulus

Paired pulse transcranial magnetic stimulation (paired TMS) was introduced to study local inhibitory or facilitatory intracortical circuits of the primary motor cortex. However, similar interactions can be shown in other areas of cortex. The current study tests the effects of paired pulse TMS of the right primary somatosensory cortex (S1) on the sensory perception of electrical stimuli applied on the contralateral thumb finger. In the main experiment a subthreshold conditioning stimulus (CS) preceded a suprathreshold test stimulus (TS) at different inter-stimulus intervals. We found that perception of a peripheral electrical stimulus was markedly attenuated by paired TMS in comparison to single pulse TMS when the ISIs was 10 or 15 ms, while there was no effect at shorter ISIs. There was no additional effect of the CS pulse if the intensity of the TS was subthreshold. In control experiments we observed that the effect vanished when the delay between the peripheral stimulus and the TS was 10 or 30 ms rather than 20 ms or if the pairs of pulses were applied over the vertex rather than the hand area. Furthermore, there was no change at longer ISIs when paired TMS was applied over the posterior parietal cortex of the same hemisphere. These results demonstrate that paired pulse TMS is able to probe intracortical circuits in S1 and that the intrinsic properties of these circuits differ even between closely adjacent areas of the cortex.

Effects of motor activity on the organization of primary somatosensory cortex

Recent studies have shown that adaptation of representational maps within the primary somatosensory cortex can be induced by task-related motor activity. Here, we explore the relationship between the complexity of the motor task and the extent of task-specific adaptation within the primary somatosensory cortex. We hypothesized that the extent of adaptation increases with the complexity of the motor task. Using neuromagnetic source imaging based on electrical stimulation of the thumb and ring finger, we demonstrate that cortical finger representations are more distant during performance of the pinch finger grip than in a rest condition. Our data suggest that somatosensory cortical maps undergo rapid modulation depending on the task-specific involvement of somatosensory feedback in movements.

Dexterity and versatility in the pinching motion of robot fingers with multi-degrees of freedom

This paper focuses on dexterity and versatility in pinching a rectangular object by a pair of robot fingers based on sensory feedback. In the pinching motion of humans, it is possible to execute concurrent pinching and orientation control quickly and precisely by using only the thumb and index finger. However, it is not easy for robot fingers to perform such imposed tasks agilely and simultaneously. In the case of robotic grasping, to perform concurrently such plural tasks retards the convergence speed in the execution of the overall task. This means that in order to increase versatility by imposing additional tasks, dexterity in the execution of each task may deteriorate. In this paper it is shown that both dexterity and versatility in the execution of such imposed tasks can be enhanced remarkably, without any deterioration in dexterity in the execution of each task, by using a sensory feedback method based on the idea of role-sharing joint control which comes from observation of the functional role of each human finger joint.

Distribution of grip force in three different functional prehension patterns

Normative data of the grip force distribution necessary to complete functional tasks are limited. Small force sensors have been specially designed for accurate measurement of the dynamic handgrip force distribution by attaching them to the palmar surface of the hand. Seventeen healthy participants performed three different tasks, each requiring a different functional prehension pattern. When cylindrical objects were manipulated, the highest average grip forces were found at the fingertips and the thumb, followed by the middle finger. In a spherical grasp pattern, the contributions by the thumb, ring and small fingers always exceeded 71% of the total grip force. The highest local forces of 9.9 N were measured when a zip was closed with a tip pinch. Individual finger forces were found to differ by gender, but not by hand dimension and age. The results are useful for biomechanical modelling of the hand, for designing ergonomic tool grips, and for evaluating hand function.