A Comparative Study of the Percutaneous versus Intraoral Technique for Mental Nerve Block

Objective: Mental nerve block is frequently used to aid repair of facial lacerations; both percutaneous and intraoral approaches to blocking this nerve are used, but have never been compared. The authors compared the two techniques for pain of administration and effectiveness of anesthesia. Methods: A prospective, randomized, single-blind, crossover study was conducted using ten healthy volunteers aged 22 to 33 years. Patients having prior experience with mental nerve blocks, lidocaine allergy, active oral/facial infection, or previous facial fractures were excluded. Bilateral mental nerve blocks were done using intraoral technique on one side and percutaneous technique on the other. Both techniques were used by the same investigator and were carried out with 27-gauge needles and 2.5 mL of 2% buffered lidocaine at room temperature injected over 20 seconds. The oral mucosa was topically anesthetized with viscous lidocaine for 1 minute prior to intraoral injection. The orders of the blocks and sides of the face anesthetized were randomized. Subjective and objective pain (visual-analog scale), efficacy (anesthesia of lower lip), time to onset, and duration of anesthesia were evaluated. Results: The intraoral technique was subjectively less painful than the percutaneous approach in nine of ten subjects (p = 0.02). Scores on the visual-analog pain scale were significantly lower for the intraoral technique (p = 0.03). Intraoral injection produced lower-lip anesthesia in 10/10 subjects versus 7/10 for percutaneous (p = 0.25). Times to onset (approximately 1–2 minutes) and durations of anesthesia (approximately one hour) were similar for the two techniques. Conclusion: The intraoral approach to the mental nerve block with adjunctive topical anesthesia was subjectively and objectively less painful than the percutaneous approach without adjunctive anesthesia. While the intraoral approach had a greater efficacy of lower-lip anesthesia and a longer duration of action, these differences were not statistically significant.     

Anesthetic considerations of an infant with Beckwith-Wiedemann syndrome

The case of a 3-day-old infant with Beckwith-Wiedemann syndrome who required anesthetic care during closure of an abdominal wall defect is presented. Beckwith-Wiedemann syndrome comprises a constellation of clinical features, including macroglossia, macrosomia, omphalocele, visceromegaly, mild microcephaly, facial nevus flammeus, horizontal earlobe creases, and renal medullary dysplasia. Due to the high rate of omphalocele in this syndrome, anesthetic care is frequently required during the neonatal period. Many of these infants (greater than 50%) are born prematurely. Therefore, their anesthetic care may be further complicated by associated diseases of prematurity, such as hyaline membrane disease. Additional anesthetic implications of this syndrome relate to the occurrence and management of hypoglycemia and polycythemia. Careful intraoperative management of glucose homeostasis is particularly important, since eventual neurologic outcome and intelligence will be normal provided prolonged neonatal hypoglycemia is avoided. Preoperative evaluation of the cardiac and genitourinary system, including echocardiography and renal ultrasound, are recommended because of the frequent occurrence of associated anomalies with omphalocele.     

Metastatic colon carcinoma to oral soft tissues

Metastatic tumors to the oral cavity are uncommon. Most of these cases involve the mandible or the maxilla. Rarely, metastasis occurs to the oral soft tissues from a distant primary tumor. The lung and breast are the most common primary sites. It is extremely rare to have an oral soft-tissue metastasis from a carcinoma of the colon. A case of primary adenocarcinoma of the colon with metastasis to the soft tissues of the mouth is described. Three similar case reports are reviewed. A metastatic lesion to the oral cavity could be the first indication of the presence of a primary tumor.     

Levodopa improves physical fatigue in Parkinson's disease: a double-blind, placebo-controlled, crossover study.

We quantitatively investigated the effect of carbidopa/levodopa (25/100) on physical fatigue during finger tapping and force generation in a double-blind, placebo-controlled crossover study. Parkinson's disease (PD) subjects were randomly assigned to carbidopa/levodopa or placebo for Visit 1 or 2 and participated in the following two studies: (1) Finger tapping. Twenty-five PD patients used their index fingers to strike two keys 20 cm apart on a musical instrument digital interface (MIDI) keyboard. The slopes of the regression line of dwell time and movement time were used to assess the rate of fatigue development. (2) Force generation. Twelve PD patients contracted the wrist extensors maximally to obtain a baseline maximum voluntary contraction (BMVC) force. Then they repetitively contracted the wrist extensors at 50% of the BMVC for 7 seconds and rested for 3 seconds. An interval maximum voluntary contraction (IMVC) was measured every three repetitions. Fatigue was defined as an IMVC of less than 60% of the BMVC. The slope of the regression line of IMVC was used to assess the rate of force decline. These two studies were repeated 1 hour after carbidopa/levodopa (25/100) or placebo. Subjects filled out the Multidimensional Fatigue Inventory (MFI) at the beginning of the first visit. Results showed that the slope of dwell time decreased with levodopa but not with placebo (P = 0.004). The rate of force decline also decreased with levodopa but not with placebo (P = 0.01). The subscores in the dimension of physical fatigue in the MFI did not correlate with the rate changes in dwell time or the rate changes in force decline. We concluded that (1) levodopa improves physical fatigue in finger tapping and force generation, (2) physical fatigue in Parkinson's disease is at least partially related to dopamine deficiency, and (3) the MFI measures different aspects of physical fatigue compared with those measured by finger tapping and force generation.     

MR-Guided percutaneous ethanol ablation of liver tissue in a .2-T open MR system: Preliminary study in porcine model

The purpose of this study was to test the feasibility of MR-guided percutaneous ethanol ablation of liver tissue on a .2-T open MR scanner. Needles were placed by MR guidance first into an ex vivo sheep liver and then into livers of three anesthetized pigs, and injection of 10 ml of 96% alcohol was performed. T1 fast low-angle shot (FLASH), T2 turbo spin echo (TSE), and T1 spin echo (SE) images were obtained after incremental volumes of injection. In one pig, simultaneous injection of saline into normal liver was also performed with subsequent pathological correlation. Ethanol-infiltrated liver was hypointense to liver on all sequences, whereas saline caused no tissue signal changes on T1 SE and either isointense or hyperintense changes on T2 TSE images. Pathological examination confirmed ethanol-induced acute liver changes as compared with the control. MR guidance of needle placement and monitoring of ethanol effects on liver tissue is feasible. This may have implications for potential MR-guided hepatic tumor ablation.     

Initial evaluation of123|-5-|-R91150, a selective 5-HT2A ligand for single-photon emission tomography, in healthy human subjects

The mapping of 5-HT₂ receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands. Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (¹²³I-5-I-R91150 or¹²³I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT_2A receptors. This study reports on preliminary¹²³I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately 2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free from 5HT_2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately 100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100 min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic data on the distribution of 5-HT_2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that¹²³I-5-I-R91150 may be used for the imaging of 5-HT_2A receptors in the living human brain with SPET.     

Body composition in the elderly: Total body water and anthropometry

Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied.