Effect of body mass index on ulnar nerve conduction velocity, ulnar neuropathy at the elbow, and carpal tunnel syndrome

Both high and low body mass index (BMI) have been reported as risk factors for ulnar neuropathy at the elbow (UNE), and a high BMI as a risk factor for carpal tunnel syndrome (CTS). To determine whether the extremes of BMI are risk factors for UNE or CTS, and whether BMI affects calculation of median and ulnar motor nerve conduction velocity (NCV), we retrospectively analyzed the electrodiagnostic records of control patients, UNE patients, and CTS patients. The BMI was calculated for 50 patients with a sole diagnosis of UNE and compared to the BMI of 50 patients with CTS and 50 control subjects. The mean BMIs were 25.9 +/- 4.4, 30.1 +/- 5.5, and 28.3 +/- 5.6 for the UNE, CTS, and controls, respectively. By one-way analysis of variance, the difference in BMI between the UNE patients and the normal patients was significant (P < 0.01). In the control groups, increasing BMI directly correlated with increasing ulnar motor NCV across the elbow but not with forearm NCV. Across-elbow (AE) ulnar motor NCV may be falsely increased in patients with a high BMI, probably due to distance measurement factors. Not only do relatively slender individuals have comparatively slower AE ulnar NCVs, they are also at increased risk for developing UNE. Patients with a high BMI are at increased risk for CTS.     

Cold elbow syndrome: spurious slowing of ulnar nerve conduction velocity

Low temperature decreases nerve conduction velocity (NCV). The across-elbow segment of the ulnar nerve is superficial and may be particularly susceptible to decreased temperature. We evaluated patients without clinical ulnar neuropathy at the elbow (UNE) but with isolated slowing of the across-elbow ulnar NCV (normal group), and patients with clinical and electrodiagnostic findings of UNE (UNE group). All subjects had ulnar motor nerve studies completed before and after warming. The mean across-elbow NCV was 43.4 m/s and 48.6 m/s (P < 0.0001) in the normal group, and 37.4 m/s and 37.7 m/s (P = 0.90) in the UNE group, before and after warming, respectively. There was no change in the forearm segment NCV in either group. Seventeen of 32 subjects in the normal group had completely normal studies after warming. No patients with UNE developed normal across-elbow NCV with warming. Low temperature slows across-elbow ulnar NCV in normal subjects without impact on the forearm segment. Warming of the elbow improves across-elbow ulnar NCV in normals, but does not reverse the abnormalities in patients with UNE. Elbow warming should become a routine part of ulnar nerve conduction studies, especially when there is isolated conduction slowing in the across-elbow segment.     

Atypical midface tumor complicating nevus of ota

In the differential diagnosis of midface masses, the nevus of Ota (also called oculodermal melanocytosis) is a rare entity. We present a case of a young white man, who lost his left eye function by progression of a melanocytotic lesion involving the ophthalmic (VI) and maxillary (VII) divisions of the trigeminal nerve. The time course, distribution along the trigeminal nerve, and characteristic MR signal intensities of the lesion, in correlation with the clinical, ophthalmological, and dermatological findings, point to the correct diagnosis.     

Pain on injection: a double-blind comparison of propofol with lidocaine pretreatment versus propofol formulated with long- and medium-chain triglycerides

The incidence of pain on injection of propofol has been reported to be 70%. A new propofol formulation with a 10% emulsion of long- and medium-chain triglycerides (LCT/MCT) is associated with less pain on injection. Our goal was to compare the effect of propofol-LCT/MCT on the incidence of pain versus propofol with lidocaine 40 mg IV pretreatment injected as a Bier's block. Two hundred healthy women scheduled for ambulatory gynecological procedures were allocated to 1 of 2 groups in a randomized double-blind fashion. Group LIDO received lidocaine 2% 2 mL injected with a tourniquet 1 min before propofol 1% 2 mg/kg IV; group LCT/MCT received NaCl 0.9% 2 mL with tourniquet 1 min before propofol-LCT/MCT 1% 2 mg/kg IV. Spontaneous verbal expressions of pain, movement of hand, frowning, and moaning during the injection were recorded. The incidence and severity of pain were assessed 30 min and 6 h after surgery. Recall of pain was considered with a visual analog scale (VAS) score >1, and pain was graded as VAS 0-10. More women reported spontaneous verbal expression of pain with propofol-LCT/MCT (47% versus 24%; P = 0.0014; relative risk 1.61 [95% confidence interval, 1.22-2.13]). Among women with a painful injection, there was no difference after surgery regarding the intensity of pain or recall of pain. In contrast to previous reports, we found that propofol-LCT/MCT resulted in a more frequent incidence of pain than propofol 1% with IV lidocaine pretreatment. This may be due to the diversity of pain definitions used in studies or to the lack of premedication in our study.     

Blast injury

Blindness can be the consequence of trauma, which until now had only been described in cases involving direct facial or cranial trauma. In our case a 53-year-old street worker became irreversibly blind after a thoracoabdominal compression trauma. The investigations performed were inconclusive regarding the cause of blindness. We postulate a massive increase in venous blood pressure with capillary stasis and consequent optic nerve damage. Fat emboli syndrome or posterior ischemic optic neuropathy could be causes, but unrealistic for this case. It still comes into question why such a mechanism has not been seen in other blast injury cases. In the end, the additional factor that resulted here in complete irreversible blindness remains unclear.     

Beta2-adrenoceptor Thr164Ile polymorphism is associated with markedly decreased vasodilator and increased vasoconstrictor sensitivity in vivo

BACKGROUND: The uncommon Thr164Ile polymorphism of the beta2-adrenoceptor is associated with profoundly altered responses to agonist in vitro; however its effects on vascular responses in vivo are not known. Altered adrenergic vascular sensitivity may contribute to the decreased survival observed in patients with congestive heart failure carrying the Ile164 allele. METHODS AND RESULTS: We used the linear variable differential transformer dorsal hand vein technique to compare vasodilation in response to the beta-adrenergic receptor agonist, isoproterenol, and vasoconstriction in response to the alpha-adrenergic receptor agonist, phenylephrine, in healthy homozygous (Thr164/Thr164) (n = 21) and heterozygous Thr164/Ile164 (n = 5) women. The dose of isoproterenol required to achieve 50% venodilation (geometric mean; 95% CI) was significantly higher in women with the Ile164 allele (82.5 ng/min; 17.3-394 ng/min) than those without (15.8 ng/min; 11-25 ng/min; P = 0.004). The maximum response to isoproterenol was not different (102 +/- 1% and 102 +/- 3%, respectively, P = 0.9). The dose of phenylephrine needed to induce 50% venoconstriction was significantly lower in women with the Ile164 allele (151 ng/min; 42-543 ng/min) than those without (540 ng/min; 350-835 ng/min; P = 0.02). CONCLUSIONS: The Thr164Ile polymorphism of the beta2-adrenergic receptor is associated with a five-fold reduction in sensitivity to beta2 receptor agonist-mediated vasodilation; vasoconstrictor sensitivity is increased. The overall effect of the Thr164Ile polymorphism is to shift the balance of adrenergic vascular tone toward vasoconstriction. This suggests a mechanistic explanation for the clinical observation of decreased survival in patients with congestive heart failure heterozygous for the Thr164Ile polymorphism.     

异基因造血干细胞移植后嵌合体检测的研究

目的 利用微卫星(STR)位点多态性，建立移植后嵌合体检测方法，为造血干细胞移植疗效观察提供依据。方法 选择5个STR位点，提取10例白血病异基因造血干细胞移植供受者的骨髓或外周血DNA，PCR扩增后经银染分析其多态性，图像分析软件进行嵌合体定量分析。结果 5个STFI位点具有高度多态性，在移植供受者间鉴别率高，适合进行嵌合体检测研究，银染法敏感度在90％左右。结论 STR-PCR是异基因造血干细胞移植后嵌合体的灵敏、准确度高的检测方法，但银染法灵敏度欠佳，应采用更为灵敏的方法。