Multimodal quantitative examination of nerve function in colorectal cancer patients prior to chemotherapy

Introduction: Given recent findings of subclinical sensory deficits in colorectal cancer patients before oxaliplatin treatment, in the current study we aimed to identify evidence of subclinical peripheral neuropathy on multimodal testing before chemotherapy commencement. Methods: Clinical, functional, and neurophysiological assessments were undertaken in 93 colorectal cancer patients before chemotherapy. Results: There was no neurophysiological evidence of neuropathy, with 92 of 93 sural sensory values within normative reference values for age and no significant abnormalities detected in nerve conduction or nerve excitability studies. Clinical neurological assessment revealed 75.9% of patients with no signs or symptoms, 10.3% with reduction in distal vibration or pinprick sensitivity, and 6.9% with reduction in ankle reflexes only. There was no difference in manual dexterity (using the 9‐hole peg‐board test) compared with normative data. Discussion: The present study has established a low likelihood of significant distal symmetrical polyneuropathy in colorectal cancer patients before initiation of chemotherapy. Muscle Nerve 57 : 615–621, 2018     

Is There Material Loss at the Conical Junctions of Modular Components for Total Knee Arthroplasty?

BackgroundClinical concern exists regarding fretting corrosion and material loss from taper junctions in orthopedic devices, with previous research focusing on the modular components from total hip arthroplasty. Comparatively little has been published regarding the fretting corrosion and material loss in modular knee devices. The purpose of this study is to evaluate fretting corrosion damage and quantify material loss for conical total knee arthroplasty taper interfaces.MethodsStem tapers of 166 retrieved modular knee devices were evaluated for fretting corrosion using a semiquantitative scoring method. High precision profilometry was then used to determine volumetric material loss and maximum wear depth for a subset of 37 components (implanted for 0.25-18.76 years). Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to characterize the observed damage.ResultsMild to severe fretting corrosion was observed on the majority of tapers, with 23% receiving a maximum visually determined damage score of 4. The median rate of volumetric material loss was 0.11 mm³/y (range 0.00-0.76) for femoral components (both cone and bore taper surfaces combined) and 0.01 mm³ (range 0.00-8.10) for tibial components. Greater rates of material loss were associated with mixed metal pairings. There was a strong correlation between visual fretting corrosion score and calculated material loss (ρ = 0.68, P < .001). Scanning electron microscopy revealed varying degrees of scratching, wear, fretting corrosion, and instances of cracking with morphology not consistent with fretting corrosion, wear, or fatigue.ConclusionAlthough visual evidence of fretting corrosion damage was prevalent and correlated with taper material loss, the measured volumetric material loss was low compared with prior reports from total hip arthroplasty.     

Discontinuing antiepileptic drugs in long-standing idiopathic generalised epilepsy

Journal of Neurology - Once adults with long-standing idiopathic generalised epilepsy have achieved stable seizure remission, patients or physicians may attempt to discontinue their antiepileptic...     

Human BDNF rs6265 polymorphism as a mediator for the generalization of contextual anxiety

The Met allele of the human brain-derived neurotrophic factor (BDNF) gene might be a risk factor for anxiety disorders and is associated with reduced hippocampal volume. Notably, hippocampus plays a crucial role in contextual learning and generalization. The role of the BDNF gene variation in human context-conditioning and generalization is still unknown. We investigated 33 carriers of the Met allele (18 females) and 32 homozygous carriers of the Val allele (15 females) with a virtual-reality context-conditioning paradigm. Electric stimulations (unconditioned stimulus, US) were unpredictably delivered in one virtual office (CTX+), but never in another virtual office (CTX-). During generalization, participants revisited CTX+ and CTX- and a generalization office (G-CTX), which was a mix of the other two. Rating data indicated successful conditioning (more negative valence, higher arousal, anxiety and contingency ratings for CTX+ than CTX-), and generalization of conditioned anxiety by comparable ratings for G-CTX and CTX+. The startle data indicated discriminative learning for Met allele carriers, but not for Val homozygotes. Moreover, a trend effect suggests that startle responses of only the Met carriers were slightly potentiated in G-CTX versus CTX-. In sum, the BDNF polymorphism did not affect contextual learning and its generalization on a verbal level. However, the physiological data suggest that Met carriers are characterized by fast discriminative contextual learning and a tendency to generalize anxiety responses to ambiguous contexts. We propose that such learning may be related to reduced hippocampal functionality and the basis for the risk of Met carriers to develop anxiety disorders.