Supinator to Posterior Interosseous Nerve Transfer for Recovery of Hand Opening in the Tetraplegic Patient: A Case Series

BACKGROUND AND OBJECTIVES

Cervical spinal cord injury results in devastating loss of function. Nerve transfers can restore functional use of the hand, the highest priority function in this population to gain independence. Transfer of radial nerve branches innervating the supinator to the posterior interosseous nerve (SUP-PIN) has become a primary intervention for the recovery of hand opening, but few outcome reports exist to date. We report single-surgeon outcomes for this procedure.

METHODS

The SUP-PIN transfer was performed on adults with traumatic spinal cord injury resulting in hand paralysis. Outcome measures include Medical Research Council strength grade for extension of each digit, and angles representing critical apertures: the first web space opening of the thumb, and metacarpophalangeal angle of the remaining fingers. Factors affecting these measurements, including preserved tone and spasticity of related muscles, were also assessed.

RESULTS

Twenty-three adult patients with a C5-7 motor level underwent SUP-PIN transfers on 36 limbs (median age 31 years, interquartile range [21.5, 41]). The median interval from injury to surgery was 10.5 (8.2, 6.5) months, with 9 (7.5, 11) months for the acute injuries and 50 (32, 66) months for the chronic (>18 months) injuries. Outcomes were observed at a mean follow-up of 22 (14, 32.5) months. 30 (83.3%) hands recovered at least antigravity extension of the thumb and 34 (94.4%) demonstrated successful antigravity strength for the finger extensors, providing adequate opening for a functional grasp. Chronic patients (>18 months after injury) showed similar outcomes to those who had earlier surgery. Supination remained strong (at least M4) in all but a single patient and no complications were observed.

CONCLUSION

SUP-PIN is a reliable procedure for recovery of finger extension. Chronic patients remain good candidates, provided innervation of target muscles is preserved. Higher C5 injuries were more likely to have poor outcomes.

Selective Tibial Neurotomy for Spastic Equinovarus Foot: Operative Technique

BACKGROUND AND OBJECTIVES

Spastic equinovarus foot (SEF) is a common complication of stroke and other upper motor neuron injuries. It is characterized by a plantigrade and inverted foot, often with toe curling, causing significant disability from pain, gait, and balance difficulties. Management includes physical therapy, antispasticity drugs, orthoses, chemical neurolysis, or botulinum toxin, all of which may be insufficient, sedating, or transient. Selective tibial neurotomy (STN) provides a surgical option that is effective and long-lasting. Our goal is to provide a concise description of our technique for performing the STN for treatment of SEF. We discuss the standard posterior approach with surgical variations used by other groups and a medial approach, should the posterior approach be insufficient.

METHODS

A posterior leg approach allows access to the tibial nerve and its branches to the bilateral gastrocnemius muscles, soleus, posterior tibialis, and extrinsic toe flexors. A medial approach is used if the toe flexors cannot be accessed sufficiently from the posterior approach. Nerve branch targets identified by preoperative functional assessment are carefully exposed and fully neurolysed distally to identify all terminal branches to each muscle of interest before neurotomy.

RESULTS

The STN is a powerful tool for treating SEF, with an immediate and lasting effect. Approximately 80% of the target muscle should be denervated to ensure long-term efficacy while maintaining adequate function of the muscle through collateral innervation.

CONCLUSION

The STN is a safe and effective outpatient procedure that can be performed by an experienced nerve surgeon to improve balance and ambulation and reduce pain for patients with SEF. Large clinical trials are necessary to further establish this underutilized procedure in the United States.

Current and Expected Advances in Deep Brain Stimulation for Movement Disorders

Deep brain stimulation (DBS) has become an established treatment for medically refractory movement disorders including Parkinson's disease, essential tremor, and dystonia. The field of DBS continues to evolve with advances in patient selection, target identification, electrode and pulse generator technology, and the development of more effective stimulation paradigms such as closed-loop stimulation. Furthermore, as the safety and efficacy of DBS improves through better hardware design and deeper understanding of its mechanisms of action, the indications for DBS will continue to expand to cover a wider range of disorders. Finally, the recent approval of MR-guided focused ultrasound for the treatment of essential tremor and potentially other movement disorders heralds a resurgence in lesion creation as a viable alternative to DBS for selected patients.

Intra-arterial and intravenous administration of prostaglandin E1 cause different changes to skin microcirculation in patients with peripheral arterial occlusive disease

BACKGROUND

Disturbed skin microcirculation in patients with peripheral arterial occlusive disease (PAOD) might be affected by prostaglandin E1 (PGE1). The purpose of this study was to investigate local skin perfusion at the forefoot and toe of PAOD patients during different modes of administration of PGE1.

PATIENTS AND METHODS

In 17 patients with severe PAOD local intradermal haemoglobin oxygen saturation (SHB) and dermal vascular reserve capacity, transcutaneous oxygen pressure (tcPO2) and laser Doppler flux (LDF) were determined during intra-arterial (1.5 ng/kg body weight/min) and intravenous (6 ng/kg body weight/min) infusion of PGE1.

RESULTS

SHB significantly increased at both locations during intravenous PGE1; intra-arterial administration significantly increased SHB in the skin of the forefoot only. Reserve capacity increased during intravenous administration and was markedly reduced during intra-arterial infusion. No significant changes were found regarding tcPO2 and LDF.

CONCLUSIONS

These data suggest different therapeutic mechanisms for intra-arterial and intravenous administered of PGE1.

Changes of dermal haemoglobin oxygenation and concentration in healthy subjects and in patients with peripheral arterial occlusive disease during and after acute ischemia

BACKGROUND

Oxygen saturation (SHB) and concentration (CHB) of dermal haemoglobin play an important role in the nutrition of the skin. In patients with severe peripheral arterial occlusive disease (PAOD) they are reduced at the forefoot. We investigated the changes of the named parameters during an acute ischemia and during reactive hyperemia using an occlusion test.

PATIENTS AND METHODS

Dermal reflection spectra were conducted from the forefoot of 11 healthy subjects and 39 patients with peripheral arterial occlusive disease of various stages at rest, during, and after an arterial occlusion at the thigh. Using a multicomponent analysis SHB and CHB were calculated iteratively. The halftime of the post-occlusive increase of SHB (post-occlusive recovery halftime PORHT) and the relation of post- to pre-occlusive CHB (post-occlusive reactive hyperemia PORH) were calculated to estimate the dynamic of the post-occlusive inflow of blood. TcPO2 (37 degrees C) was additionally determined at the forefoot.

RESULTS

In patients from stage III and IV all resting values were lower compared to controls. TcPO2 decreased in all persons to 0 mm Hg during the occlusion, SHB was between 0 and 10%, while CHB remained unchanged. In healthy subjects and in patients with claudication the post-occlusive values exceeded the preocclusive ones, while in some patients with higher stages of the disease this could not be found. There was a marked, on the stage of the disease depending difference in the post-occlusive course between controls and patients: in healthy subjects it took only 5.5 +/- 4.8 s until SHB reached half of the maximum value, in patients from the stage IIa group 26.8 +/- 16.9 s (p < 0.001) was measured while in stage III and IV the value was 132 +/- 75 s (p < 0.001).

CONCLUSIONS

During ischemia a decrease of the haemoglobin oxygen saturation (SHB) and tcPO2 was found. Haemoglobin concentration (CHB) remained constant, hence a significant shift of blood from skin to muscle did not take place. PORHT was selectively dependent on the stage of the disease. The occlusion manoeuvre enhances the significance of reflection photometry in PAOD.

Nailfold capillaroscopy and laser Doppler fluxmetry for evaluation of Raynaud's phenomenon: how valid is the local cooling test?

BACKGROUND

Since there is a need for an objective parameter of microcirculation in follow-up of patients with Raynaud's syndrome we evaluated the reproducibility of the reaction to a cold exposure test with nailfold capillaroscopy and laser Doppler fluxmetry during a winter period.

PATIENTS AND METHODS

10 healthy subjects and 16 patients with primary Raynaud's syndrome were evaluated with nailfold capillaroscopy and laser Doppler fluxmetry of the finger tips during and after a standardized cold exposure stress test. The measurements were repeated in the controls within 2 weeks, in the patient population twice within 24 weeks.

RESULTS

In the healthy controls the percentage of capillaries with flow stop was stable (r = 0.785) and the duration of flow stop was reproducible (r = 0.993). Both parameters were significantly lower in controls than in the patients. The flow stop durations in patients varied intra-individually to a great extent between the different weeks without any significant correlation. For all calculated laser Doppler perfusion and time parameters we did not find any significant differences between controls and patients nor any consistent correlations in the intra-individual comparison within the different weeks for both, controls and patients.

CONCLUSION

Nailfold capillaroscopy during cold exposure is able to discriminate between healthy persons and patients with primary Raynaud's syndrome, but seems to be of minor value for follow-up evaluation of patients because of intraindividual variations. Laser Doppler fluxmetry is invalid for both purposes when using the applied cold exposure test.

Non-invasive determination of dermal hemoglobin oxygenation and concentration in patients with peripheral arterial occlusive disease

BACKGROUND

Oxygen saturation (SHB) and concentration (CHB) of dermal hemoglobin are important parameters for the supply of the skin. They may be non-invasively assessed by means of reflection photometry as hemoglobin is predominantly contributing to the skin reflection spectrum.

METHODS AND RESULTS

Dermal reflection spectra from the middle of the forefoot and from the tip of the toe of 20 healthy subjects and 61 patients suffering from peripheral arterial occlusive disease (PAOD) were recorded and compared to transcutaneous oxygen pressure (tcPO2). SHB, and tcPO2 were significantly higher in controls: compared to patients (ankle pressure (AP) > 50 mmHg) SHB in the skin of the forefoot was 63.8 vs. 54.5% (p < 0.05), CHB was 0.89 vs. 0.62 aU (p < 0.01). In the great toe SHB was 92.9 vs. 59.9% (p < 0.001), CHB was 2.21 vs. 0.92 aU (p < 0.001). Heating the skin of the forefoot to 44 degrees C yields local dermal vascular reserve capacity: SHB and CHB increased in all healthy subjects (96.4%; 1.44 aU, respectively). SHB decreased at the forefoot in 14 and at the toe in 18 of 21 patients with AP < 50 mmHg. At the toe decrease was found in 50 of 61 patients (sensitivity 82%, specificity 100%).

CONCLUSIONS

Local vascular reserve capacity of dermal perfusion is reduced in patients with PAOD, depending on AP. It should be determined preferably in patients with severe PAOD.

A new method for the assessment of tissue hemoglobin oxygenation in patients with chronic venous insufficiency

Venous incompetence often leads to ulceration of the skin of the lower limb due to a disturbance of skin microcirculation. We investigated 10 healthy subjects and 18 patients with chronic venous insufficiency by means of a fast scanning reflection photometer and determined noninvasively the hemoglobin oxygen saturation (S(HB)) and the relative concentration of hemoglobin (C(HB)) in the skin of the forefoot and at the calf, 10 cm proximal of the inner malleolus during positional changes. In supine position no significant differences were found. During sitting and standing S(HB) dropped and was significantly lower in patients at both locations (calf, standing, patients 22.2 +/- 10.6% vs controls 48.2 +/- 13.5%, P < 0.001). C(HB) increased in patients during standing from 0.71 to 2.13 +/- 0.33 aU (in controls from 0.69 to 1.49 +/- 0.28 aU, P < 0.001). Activation of the muscle pump decreased C(HB) and increased S(HB) in patients and in controls. After the movements were stopped, S(HB) decreased again and fell to the initial low values eight times faster in patients (7.4 +/- 5.3 vs 57.5 +/- 19.6 sec, P < 0.001). C(HB) increased four times faster in patients (7.2 +/- 6.1 vs 29.9 +/- 13.6 sec). In sitting and standing positions hemoglobin oxygenation in the skin of the lower limb was markedly reduced in patients, but normal perfusion conditions were restored in supine position, indicating reversibility of the changes. Reflection oxymetry seems a valuable tool for the assessment of chronic venous insufficiency. The substantially reduced oxygenation of dermal hemoglobin in standing patients may contribute to the development of venous ulcers.

Quantitative reflection spectrophotometry: spatial and temporal variation of Hb oxygenation in human skin

Applying a fast scanning reflection spectrophotometer and multicomponent spectra analysis, oxygen saturation (SHb) and relative concentration (CHb) of hemoglobin in the skin were determined at eight skin sites in 11 healthy persons. SHb was significantly higher at the tip of the index finger and big toe (90 +/- 3.9 and 92 +/- 4.2%, respectively) compared with the forehead, volar forearm, back of hand, abdomen, calf and forefoot where mean values varied between 52 and 67% (p < 0.001). CHb also was higher at acral sites (big toe: 2.04 +/- 0.14 arbitrary units (AU); index finger: 2.13 +/- 0.19 AU) than at the other locations (p < 0.0001) where it was between 0.56 +/- 0.12 AU (abdomen) and 0.95 +/- 0.28 AU (forefoot). In the course of time, rhythmical oscillations of both parameters at a frequency of 3-5/min were seen in 68% of the measurements, predominantly at the six proximal sites. Heating the measuring site to 44 degrees C caused a biphasic increase of CHb and SHb which was significant at the proximal sites (p < 0.0001). SHb values came into the range of arterial blood. Temporal and spatial variation of both parameters decreased. Reflection spectrophotometry gives the possibility to directly assess dermal hemoglobin saturation, its physiological variability and reactions to provocation stimuli. Concentration and saturation of hemoglobin in dermal vessels appear definitely different at acral compared with proximal sites.

Skin oxygen pressure histograms in patients with peripheral arterial occlusive disease during intraarterial and intravenous prostaglandin E1 infusions of different dosages and their prognostic value

Skin surface oxygen pressure fields (tcPO2 [37 degrees C]) reproducibly characterize skin microcirculation in patients with peripheral arterial occlusive disease. These appear suited for investigation of short- and long-term effects of vasoactive drug treatment. The authors studied whether skin surface oxygen pressure histograms change depending on dosage and route of administration of prostaglandin E1 (PGE1), whether they are of predictive value for patients' clinical outcome, and whether they normalize after therapy with PGE1. The authors investigated 15 patients with various degrees of disease and measured forefoot oxygen histograms consisting of at least 80 single tcPO2 (37 degrees C) values before and during intraarterial infusion (1.5, 3, or 6 ng/kg/minute) and intravenous infusion (4.5, or 9 ng/kg/minute). The measurements were repeated two and six hours after the end of intraarterial application of 1.5 ng/kg/minute. Furthermore, the orthostatic vasoconstrictor response was tested. Skin oxygen pressure histograms were controlled after a period of twenty-two (mean) days of intraarterial PGE1 therapy. Resting histograms were left shifted with median tcPO2 (37 degrees C) between 1 and 7 mm Hg. During intraarterial application, histograms were shifted to lower tcPO2 (37 degrees C) values in most patients. Only in 3 diabetic subjects with proximal or acral obliterations was a marked increase observed. The alterations were detectable at least two hours after the end of the infusion. During intravenous infusion, histograms did not change in most cases. After long-term therapy, histograms were substantially unchanged. A pathologic vasoconstrictor response, which was present in 10 patients, could not be restored. Despite a marked deterioration of the histograms the clinical outcome was favorable in 7 patients. Patients with a high resting tcPO2 (37 degrees C) (median 4 mm Hg and more) and those with a vasoconstriction on orthostasis are likely to respond to PGE1 therapy.

Decline in CD4+ cell numbers in cats with naturally acquired feline immunodeficiency virus infection

T-cell subsets were studied by fluorescence-activated cell sorter analysis in 57 feline immunodeficiency virus (FIV)-seropositive cats with naturally acquired FIV infection to see whether CD4(+)-CD8+ alterations were comparable to those observed in human immunodeficiency virus-infected patients. CD4+ values were decreased and CD8+ values were increased. The CD4+/CD8+ ratio was reduced to 1.6, compared with 3.3 in 33 FIV-seronegative control cats. Variance analysis of data showed a significant influence of FIV seropositivity, sex, and spaying of female cats on CD4+ values. CD8+ values were significantly influenced by FIV seropositivity, age, and breed. These findings indicate a similarity between FIV and human immunodeficiency virus infections, as far as alterations of T-cell subsets are concerned.

Anaemia and reduced exercise capacity in patients on chronic haemodialysis

1. In order to evaluate the influence of varying degrees of anaemia on exercise capacity and haemodynamic parameters, 13 patients on chronic intermittent haemodialysis with haemoglobin levels between 5.1 and 12.2 g/100 ml were subjected to an exhaustive exercise test. Measurements during bicycle ergometry consisted of O2 uptake at the anaerobic threshold and of maximum O2 uptake. Resting haemodynamic parameters such as cardiac index, heart rate, stroke volume index and blood pressure were assessed non-invasively in the 13 patients undergoing exercise and in an additional three patients. 2. O2 uptake at the anaerobic threshold as well as maximum peripheral O2 uptake were severely impaired and were positively correlated with haemoglobin concentration. The strongest correlation was found between the impairment of O2 uptake at maximum workload, as assessed by maximum O2 uptake/predicted maximum O2 uptake, and haemoglobin concentration. Haemodynamic alterations in the resting state consisted of a cardiac index in the upper normal range and did not correlate with the haemoglobin concentration. 3. We conclude from our study that exercise capacity in patients on chronic intermittent haemodialysis is severely impaired and that the impairment of aerobic and anaerobic capacity is significantly correlated with the severity of renal anaemia.

[Aerobic and anaerobic capacity of chronic hemodialysis patients under continuous therapy with recombinant human erythropoietin]

In earlier studies we have shown that partial correction of anemia by recombinant human erythropoietin (r-HuEPO) already after 12 weeks results in a significant increase of exercise capacity in patients on chronic hemodialysis. As causative effect increased oxygen availability with improved oxygen delivery to the tissues was assumed. To elucidate the long-term effects of a partial correction of anemia with r-HuEPO on exercise capacity, oxygen uptake at maximum exercise and at the anaerobic threshold was measured by repetitive spiroergometry. Measurements were done before, 3 months and 6 months after initiation of r-HuEPO therapy. The results are summarized below: (table; see text) Our results show that a long-term improvement of peripheral oxygen availability leads to a further increase of anaerobic threshold in patients on chronic hemodialysis even without a further increase of hemoglobin levels and without exercise training. It appears that elimination of the chronic hypoxic condition results in a restoration of previously diminished mitochondrial enzymes in muscle, particularly for aerobic glycolysis. Besides acute improvement of aerobic and anaerobic exercise capacity, the long-term administration of r-HuEPO with its increased anaerobic threshold enhances the patients' everyday life working capacity.

Working capacity is increased following recombinant human erythropoietin treatment

To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on aerobic and anaerobic working capacity, eight patients underwent a bicycle spiro-ergometry before and after treatment with recombinant human erythropoietin (r-HuEPO). the initial mean (+/- SD) hemoglobin value was 5.9 mg/dl +/- 0.61 and increased during treatment to 10.9 +/- 0.59 mg/dl, P less than 0.0001). This partial correction of anemia resulted in a significant increase of both oxygen uptake at the anaerobic threshold and peak peripheral oxygen uptake at subjective exhaustion (P less than 0.01 and P less than 0.0002, respectively). The increase in oxygen uptake corresponded to significant increases in Watts, both at the anaerobic threshold and at maximum workload (P less than 0.02 and P less than 0.0004). These data show that partial correction of renal anemia results in a significant increase of both exercise capacity and maximum work.

Beta-2-microglobulin in hemodialysis patients. Effects of different dialyzers and different dialysis procedures

beta 2-Microglobulin (beta 2m) has been identified as the major constituent of dialysis-related amyloid. Although there is no clear correlation between absolute beta 2m levels and amyloidosis-related symptoms, elevated serum levels are thought to be the basis for tissue deposition of beta 2m. Besides diminished renal excretion and insufficient removal during hemodialysis, a dialysis-related induction of beta 2m production is discussed as the major cause of elevated serum beta 2m levels. In order to evaluate the influence of hemodialysis membranes and the hemodialysis procedure on beta 2m levels we determined serum beta 2m levels in patients on chronic intermittent hemodialysis. Polymethylmethacrylate 2.0 m2, cuprophane and cellulose acetate dialyzers led to increasing beta 2m levels during dialysis, which was in excess of what could be accounted for by hemoconcentration. The polymethylmethacrylate 1.6 m2 dialyzer did not result in a significant rise of beta 2m levels during dialysis. This indicates that production of beta 2m is not only dependent on the membrane material but also on the surface area of the dialyzer. The use of polysulfone and hemophane low-flux dialyzers did not induce an increase in beta 2m levels during dialysis but a significant clearance of beta 2m was not demonstrable either. Volume-controlled dialysis with high-flux membranes (polysulfone 0.65 m2 and polysulfone 1.25 m2) lowered beta 2m; clearance values, however, were significantly higher when these dialyzers were used in a hemodiafiltration procedure. We conclude from our study that some dialysis membranes appear to induce beta 2m production, whereas others do not.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effectiveness of recombinant human erythropoietin in the treatment of transfusion-dependent anemia in patients on chronic dialysis]

Recombinant human erythropoietin (r-HuEPO) has recently become available for clinical trial and has been used for the first time in Austria for the treatment of transfusion dependent patients on chronic haemodialysis. Inclusion criteria into the study were baseline haemoglobin levels of less than or equal to 6 g/dl and transfusion requirements of greater than or equal to 1 unit of blood per month. r-HuEPO (CILAG/AMGEN/ORTHO) was administered intravenously 3 times weekly at the end of dialysis. The initial dose was 100 U/kg body weight at each administration and was increased by 25 U/kg if Hb levels failed to increase by greater than 5% of baseline at intervals of 3 weeks. All 9 patients studied showed an increase in Hb values to the desired value at least greater than or equal to 10 g/dl within 6 to 16 weeks and none of the patients required further blood transfusions. All patients reported subjective improvement of life quality and markedly increased working ability. Apart from minor episodes of bone pain and subfebrile temperatures after r-HuEPO administration no major side effects were noted. These preliminary results show that r-HuEPO (CILAG/AMGEN/ORTHO) is a safe and effective form of therapy for renal anaemia and one which opens new horizons in the management of patients on chronic haemodialysis.