Reflex sympathetic dystrophy of the left hand and motor impairments of the unaffected right hand: impaired central motor processing?

OBJECTIVE: To test whether central motor processing can be impaired in chronic reflex sympathetic dystrophy (RSD). DESIGN: Experimental 2-group analysis. SETTING: Tertiary care center in the Netherlands. PARTICIPANTS: Five patients with stage 3 RSD of the left forearm, free of symptoms and complaints in the right forearm; and 10 healthy control subjects. INTERVENTION: On a digitizer, RSD patients and controls had to draw 3 sequences of graphemes of different complexity with their (unaffected) dominant right hand. The drawing tracks were segmented in time periods between points of velocity minima of the pen tip. MAIN OUTCOME MEASURES: Mean velocity, coefficients of variation of both length and movement time per segment, and mean intersegmental pausing time were calculated for each sequence. RESULTS: A repeated-measures analysis of variance by using the multivariate method yielded a 35% lower mean velocity (F(1,13) = 5.83, P =.031), a 110% larger segment length variability (F(1,13) = 9.72, P =.008) and a 60% larger variability of movement time per segment (F(1,13) = 5.78, P =.032) in RSD patients. No group difference was found for intersegmental pausing time or any interaction effect with the type of task. CONCLUSION: Patients with chronic RSD have a normal ability to preprogram sequential movements of their unaffected hand; but with impaired temporospatial coding and movement execution. We concluded that cortical mechanisms may be involved in motor impairments in patients with chronic RSD.     

Bell's palsy associated with IFN-alpha and ribavirin therapy for hepatitis C virus infection.

First-line therapy for hepatitis C virus (HCV) infection comprises interferon-alpha (IFN-alpha) and ribavirin for 6 or 12 months. Mild complications of therapy are common, but more serious complications are rare. Three patients with chronic HCV infection, acquired through injecting drug use, developed idiopathic facial paralysis (Bell's palsy) during therapy, with spontaneous resolution after withdrawal of treatment. Large-scale cohort studies reveal that IFNs are associated rarely with neurologic complications, and only one previous report has linked IFN-alpha therapy and Bell's palsy. We postulate that IFN-alpha therapy led to a breakdown of peripheral tolerance to myelin sheath antigens, leading to neuropathy, just as IFN-alpha therapy can cause autoimmune thyroiditis through breakdown of tolerance to native thyroid antigens.     

Acute Osteomyelitis of the Pubic Bone Following Pelvic Surgery

Primary osteomyelitis of the pubic bone has not been recorded previously. The authors present a case of this unusual entity.     

A measure of independence. Teaching home blood pressure monitoring

Encouraging hypertensive pregnant women to take their own blood pressure produces reliable and consistent results. It has proved popular among women, enabling them to assess the fluctuations of their blood pressure at first hand and to maintain a sense of control.     

Racial identification in the context of prehistoric-historic biological continua: examples from South Asia.

The practice of 'racial palaeontology' disappeared 50 years ago with the fall of the biological race concept in systematics and population genetics. However, certain ethnic minorities claim close biological affinities with extinct (sometimes Pleistocene) populations. Forensic anthropologists may be involved in this issue through analyses of prehistoric and modern populations in circumstances where a biological continuum may exist. Skeletal evidence from South Asia is discussed.     

Effect of compressive follower preload on the flexion-extension response of the human lumbar spine.

Traditional experimental methods are unable to study the kinematics of whole lumbar spine specimens under physiologic compressive preloads because the spine without active musculature buckles under just 120 N of vertical load. However, the lumbar spine can support a compressive load of physiologic magnitude (up to 1200 N) without collapsing if the load is applied along a follower load path. This study tested the hypothesis that the load-displacement response of the lumbar spine in flexion-extension is affected by the magnitude of the follower preload and the follower preload path. Twenty-one fresh human cadaveric lumbar spines were tested in flexion-extension under increasing compressive follower preload applied along two distinctly different optimized preload paths. The first (neutral) preload path was considered optimum if the specimen underwent the least angular change in its lordosis when the full range of preload (0-1200 N) was applied in its neutral posture. The second (flexed) preload path was optimized for an intermediate specimen posture between neutral and full flexion. A twofold increase in flexion stiffness occurred around the neutral posture as the preload was increased from 0 to 1200 N. The preload magnitude (400 N and larger) significantly affected the range of motion (ROM), with a 25% decrease at 1200 N preload applied along the neutral path. When the preload was applied along a path optimized for an intermediate forward-flexed posture, only a 15% decrease in ROM occurred at 1200 N. The results demonstrate that whole lumbar spine specimens can be subjected to compressive follower preloads of in vivo magnitudes while allowing physiologic mobility under flexion-extension moments. The optimized follower preload provides a method to simulate the resultant vector of the muscles that allow the spine to support physiologic compressive loads induced during flexion-extension activities.     

Paraneoplastic movement disorder in a patient with non-Hodgkin's lymphoma and CRMP-5 autoantibody.

The paraneoplastic autoantibody, collapsin response-mediator protein (CRMP)-5 immunoglobulin G (IgG), is specific for neuronal cytoplasmic CRMP-5, and is usually associated with small-cell lung carcinoma or thymoma. We report on details of a movement disorder that followed anti-B-cell therapy in a patient with lymphoma, and was accompanied by CRMP-5 IgG.     

New insights on P2X purinoceptors

Significant advances in understanding of P_2X purinoceptor pharmacology have been made in the last few years. The limitations of nucleotide agonists as drug tools have now been amply demonstrated. Fortunately, inhibitors of the degrading ecto-ATPase enzymes are becoming available and it has become apparent that the complete removal of all divalent cations can be used experimentally in some systems to prevent nucleotide breakdown. Despite these issues, convincing evidence for P_2X receptor heterogeneity, from data with agonists, has recently been reported.A number of new antagonists at P_2X purinoceptors have also recently been described which to some degree appear to be more specific and useful than earlier antagonists like suramin. It is now apparent that suramin is a poor antagonist of ATP in many tissues because it potently inhibits ATPase activity at similar concentrations to those at which it blocks the P_2X purinoceptor.Advances in the use of radiolabelled nucleotides as radioligands for binding studies has allowed the demonstration of P_2X purinoceptors in a variety of tissues throughout the body including the brain. These studies have also provided evidence for receptor heterogeneity. Excitingly, two P_2X purinoceptor genes have been cloned but operational studies suggest that more than two types exist. The cloning studies have also demonstrated a unique structure for the P_2X purinoceptor which differentiates it from all other ligand-gated ion channel receptors. Further studies on P_2X purinoceptor operation and structure are needed to help resolve controversies alluded to regarding the characterization and classification of nucleotide receptors. Hopefully such studies will also lead to a better understanding of the physiological and pathological importance of ATP and its activation of P_2X purinoceptors. This will require the identification of better drug tools, in particular antagonists which may also provide the basis for novel therapeutic agents.