Gamma oscillations in the somatosensory thalamus of a patient with a phantom limb: case report.

The amputation of an extremity is commonly followed by phantom sensations that are perceived to originate from the missing limb. The mechanism underlying the generation of these sensations is still not clear although the development of abnormal oscillatory bursting in thalamic neurons may be involved. The theory of thalamocortical dysrhythmia implicates gamma oscillations in phantom pathophysiology although this rhythm has not been previously observed in the phantom limb thalamus. In this study, the authors report the novel observation of widespread 38-Hz gamma oscillatory activity in spike and local field potential recordings obtained from the ventral caudal somatosensory nucleus of the thalamus (Vc) of a phantom limb patient undergoing deep brain stimulation (DBS) surgery. Interestingly, microstimulation near tonically firing cells in the Vc resulted in high-frequency, gamma oscillatory discharges coincident with phantom sensations reported by the patient. Recordings from the somatosensory thalamus of comparator groups (essential tremor and pain) did not reveal the presence of gamma oscillatory activity.

Effects of Adding Neuromuscular Electrical Stimulation to Traditional Military Amputee Rehabilitation.

BACKGROUND: Traumatic transtibial amputations lead to an early decline in the use and weight bearing of the residual limb. These changes result in progressive quadriceps muscle atrophy with strength loss that affects standing and walking. Neuromuscular electrical stimulation (NMES) may be useful as an adjunct to amputee prosthetic rehabilitation to maintain quadriceps muscle strength and mass. The objective of this pilot study was to compare the effects of a home-based NMES rehabilitation program plus the traditional military amputee rehabilitation program (TMARP) to the effects of TMARP alone on quadriceps muscle strength, functional mobility, and pain in military service members after a combat-related lower extremity amputation. METHODS: In total, 44 participants, aged 19 to 46 years, with a unilateral transtibial amputation were randomly assigned to the TMARP plus NMES (n = 23) or to TMARP alone (n = 21). Both groups received 12 weeks of the traditional amputee rehabilitation, including pre- and postprosthetic training. Those in the NMES group also received 12 weeks of NMES, 15 to 20 minutes/day, 5 days a week. Participants were tested at 3-week intervals during the study (baseline, 3, 6, 9, and 12 weeks) for muscle strength and pain. For functional measures, they were tested after receiving their prosthesis and at study completion (weeks 6 and 12). RESULTS: In both groups, residual limb quadriceps muscle strength and pain severity improved from baseline to 12 weeks. The NMES plus TMARP group showed greater strength than the TMARP alone group at 3 weeks, before receiving the prosthesis. However, 6 weeks after receiving their prosthesis, there was no group difference in the residual limb strength. Functional mobility improved in both groups between weeks 6 and 12 with no difference between the two treatment groups. DISCUSSION: A home-based NMES intervention with TMARP worked at improving residual limb strength, pain, and mobility. NMES seemed most effective in minimizing strength loss in the amputated leg before receiving the prosthesis. Further research on amputation rehabilitation is warranted as NMES may accelerate recovery post amputation.

Exudado en «arcilla blanca» en gota tofácea crónica / White clay drainage in chronic tophaceous gout

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Disordered conditioned pain modulation system in patients with posttraumatic cold intolerance.

BACKGROUND: Conditioned pain modulation (CPM) is a phenomenon of 'pain inhibiting pain' that is important for understanding idiopathic pain syndromes. Because the pathophysiology of posttraumatic cold intolerance is still unknown but it could involve similar mechanisms as idiopathic pain syndromes, we evaluated the functioning of the CPM system in patients with posttraumatic cold intolerance compared to healthy controls. METHODS: Fourteen healthy controls and 24 patients diagnosed with cold intolerance using the Cold Intolerance Symptom Severity questionnaire were included in the study. Of the 24 patients with cold intolerance, 11 had a nerve lesion and 13 an amputation of one or more digits. To quantify the CPM, pain threshold for mechanical pressure was measured at the affected region as a baseline measure. Then, the contralateral hand received a cold stimulus of ice water to evoke the noxious conditioning. After the cold stimulus, the pain threshold for mechanical pressure was determined again. RESULTS: The absolute and relative changes in algometer pressure (CPM effect) between pre- and post-conditioning were significantly smaller in the cold intolerance group compared to the control group (absolute p = 0.019, relative p = 0.004). The CPM effect was significantly different between the control group and the subgroups of nerve lesion (p = 0.003) and amputation patients (p = 0.011). CONCLUSIONS: In this study, we found a CPM effect after a cold stimulus in both controls and patients. A significant weaker CPM effect compared to the controls was found, as in other chronic pain conditions. The CPM system within patients with cold intolerance is altered.

Long-term trans-synaptic glial responses in the human thalamus after peripheral nerve injury.

Limb denervation leads to reorganization of the representational zones of the somatosensory cortex. Using [11C](R)-PK11195, a sensitive in vivo marker of glial cell activation, and PET, we provide first evidence that limb denervation induces a trans-synaptic increase in [11C](R)-PK11195 binding in the human thalamus but not somatosensory cortex: these brain structures appeared morphologically normal on magnetic resonance imaging (MRI). The increased thalamic signal was detectable many years after nerve injury, indicating persistent reorganization of the thalamus. This glial activation, beyond the first-order projection area of the injured neurons, may reflect continually altered afferent activity. Our findings support the view that long-term rearrangement of cortical representational maps is significantly determined within the thalamus.

Use of a mechanical leech in a reverse-flow radial forearm flap: case report.

The reverse-flow radial forearm flap provides excellent coverage for distal upper-limb defects. It is simply raised and does not require microsurgical skills. However, since its vascular pedicle is reversed, its venous outflow can be significantly diminished because of the venous valves. The authors present the case of a 16-year-old patient with a sagittal amputation of the radial aspect of the right thumb, who manifested at the time of surgery marked venous engorgement of a reverse-flow radial forearm flap. This was successfully relieved by the placement of a mechanical leech consisting of a Silastic rubber catheter--of the kind used to gain central vascular access in newborns--introduced in the lumen of the reversed vein at the extremity of the flap. This permitted intermittent evacuation of blood from the flap postoperatively, contributing to the success of this procedure. The technique used is detailed and pertinent literature is reviewed.

Leech therapy in digital replantation.

This article presents a protocol for the perioperative care of patients undergoing digital replantation, which is the most common microsurgical procedure performed today. Venous congestion, a common complication of digital replantation, often has been treated through surgical exploration and creation of arteriovenous anastomosis. Leech therapy, however, is experiencing a resurgence among surgeons as an alternative method for treating venous congestion. This article discusses the anatomical, physiological, and clinical indications and methods of leech therapy in digital replantation.

Bioenergetic comparison of a new energy-storing foot and SACH foot in traumatic below-knee vascular amputations.

In this study, the metabolic performances of a new energy-storing foot (Proteor) and of the solid-ankle cushion heel (SACH) are compared. Twelve patients with traumatic below-knee amputations (mean age: 50.0 +/- 19.9 years) and 12 patients with vascular below-knee amputations (mean age: 73 +/- 7 years) were studied. Oxygen uptake (VO2) was measured in all the subjects on a walkway at a self-selected velocity; only the subjects with traumatic amputation were tested on a level treadmill (progressive speed: 2.4-4 and 6 km/h), and then in two randomized trials: incline (+5%) and decline walking treadmill test at 4 km/h. Vascular explorations were done in the vascular patients: distal pressure measurements, pulse plethysmography, transcutaneous oxygen tension. Free walking was improved in subjects with traumatic amputation using the energy-storing foot (+6%), with a better bioenergetic efficiency (0.24 +/- 0.4mL/kg.m vs 0.22 +/- 0.04mL/kg.m). However, in subjects with vascular amputation, this foot did not produce an increased free velocity nor an improved energy cost. During the level treadmill test, the traumatic amputee subjects showed a decrease of energy expenditure with the new prosthetic foot, more significant at sufficient speed (4 km/h): 17.00 +/- 3.42 vs 14.67 +/- 2.05 mL/kg/min (p < .05). The same effect is shown during the incline (19.31 +/- 2.80 vs 16.79 +/- 2.32 mL/kg/min-p < .02) and decline walking tests (14.13 +/- 3.64 vs 11.81 +/- 1.54mL/kg/min-p < .02). There is no significant difference in cardiocirculatory effects between the two types of prosthetic foot. Despite a lower velocity, the subjects with vascular amputation exceed 70% of the maximal heart rate, with the cardiocirculatory factor being the main cause of walking restriction. The energy-storing foot should be reserved for active and fast walkers, whereas the SACH foot seems more suitable for elderly patients with amputation with a slow walk.

[Amputation in the growth period]. / Amputationen im Wachstumsalter.

Amputations during childhood and juvenile age differ from those in adults: Osseous over-growth can be expected especially in trans-humeral and trans-tibial stumps,--to be prevented by stump-capping. After loss of a growth-plate transosseous stumps will reduce growth; therefore it is crucial to preserve the distal femoral growth-plate and a weight-bearing knee-disarticulation stump with respect to future prosthetic function and appearance. Besides predominantly traumatic origin of acquired amputations in the growth-period longitudinal deficiencies present at birth have to attract utmost attention when decision-making for surgical conversion--e.g. of a missing tibia to a knee-disarticulation stump or severe fibular deficiency to a weightbearing Symeor modified Pirogoff-/Boyd-stump. The multiple limb-deficient child and adolescent depends on a holistic approach towards therapy provided by specialised centers.

[Hyperbaric oxygenation in the prevention of wound infection in open injury to the locomotor apparatus]. / Giperbaricheskaia oksigenatsiia v profilaktike ranevoi infektsii pri otkrytoi travme oporno-dvigatel'nogo apparata.

Hyberbaric oxygenation in altitude chambers OKA-MT was used in the complex of prophylactic measures against wound infection in 91 patients with open traumas of the extremities (fractures, amputations, etc.). The effect of hyperbaric oxygenation on the external respiration was studied by the method of spirography. Tetrapolar rheography was used to follow the central hemodynamics. A number of immune parameteres were also studied. Hyperbaric oxygenation was established to abolish hyperventilation and myocardium hyperdynamia, to accelerate the recovery of the neutrophil phagocytic activity and immunoglobulin level, to contribute to the quicker diminishing of edema in the wound area and healing of the stump and open fracture without suppuration, early formation of dry necrosis with a distinct line of demarcation.