Distribution patterns of transforaminal injections in the cervical spine evaluated by multi-slice computed tomography

Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.     

Clinical safety of enamel matrix derivative (EMDOGAIN®) in the treatment of periodontal defects

Abstract The aim of the present clinical trial was to test tolerability during 2 treatments with EMDOGAIN® in a large number of patients. An open, controlled study design in 10 Swedish specialist clinics was chosen, with a test group of 107 patients treated with EMDOGAIN® in connection with periodontal surgery at 2 surgical test sites per patient. The procedures were performed 2 to 6 weeks apart on one-rooted teeth with at least 4 mm deep intraosseous lesions. A control group of 33 patients underwent flap surgery without EMDOGAIN® at I comparable site. In total 214 test and 33 control surgeries were performed. Serum samples were obtained from test patients for analysis of total and specific antibody levels. 10 of the patients had samples taken before and after the first surgery. 56 other samples were taken after one treatment with EMDOGAIN®, and 63 after 2 treatments. None of the samples, not even from allergy-prone patients after 2 treatments, indicated deviations from established baseline ranges. This indicates that the immunogenic potential of EMDOGAIN® is extremely low when applied in conjunction with periodontal surgery. Comparison between the test and control groups demonstrated the same type and frequency of post-surgical experiences, i.e., reactions caused by the surgical procedure itself. Clinical probing and radiographic evaluation was performed at baseline and 8 months postsurgery. About half of the patients (44 test and 21 control) were also evaluated after 3 years. There was a significant difference between the test and control results at 8 months post surgery. and this difference had increased further at the 3 year follow-up. The 2.5–3 mm increase in attachment and bone level after treatment with EMDOGAIN® was of the same magnitude as seen in the studies with split-mouth design aiming for lest of effectiveness of EMDOGAIN®.     

Reconstructive microsurgery —a review

We present some important current applications of reconstructive microsurgery. This field is expanding rapidly and the techniques are finding application in many branches of surgery. There is a pressing need for educational programs and training in microsurgery, as well as for continued research.

Many of the procedures reviewed here have already been shown to substantially reduce costs, shorten hospitalization, and lessen patient disability; and as a result, several conventional procedures have been out-dated. We have stressed the concept that this is team surgery. To cover the needs of replantation and emergency free flaps around the clock, several micro-surgeons must work together in established centers, and the team must possess expertise from all the involved surgical specialities. This may imply revision of many organizational aspects of patient care. Replantation centers would provide the necessary educational bases and give an impetus to the development of microsurgery.     

Wear of the Christiansen hip prosthesis

The wear was examined in 39 Christiansen total hip prostheses, which were removed because of mechanical loosening after being used 5 (3-11) years. In the polyacetal acetabular cups, the head had made an eccentric defect, the mean volume of which was 680 (180-3310) mm³. The mean penetration of the head into the wall of the cup was 0.8 (0.1-3.2) mm. In two additional cups the head had penetrated right through the wall of the cup. In three prostheses the polyacetal sleeve of the trunnion was so worn that the head bore directly on the stem. There was a positive correlation between wear and the time the prostheses had been used before symptoms of loosening presented.     

A clinical comparison of the Laryngeal Tube™ and the Laryngeal Mask™ in spontaneously breathing anesthetized patients

Abstract: Background: The laryngeal mask airway (LMA) can be used in general anaesthesia without neuromuscular block. The laryngeal tube (LT) is a new airway device with similar airway features as LMA. LT is provided with a distal cuff to prevent regurgitation. In this study we compared the LMA and LT concerning patient and user aspects. Methods: Sixty patients with ASA (American Society of Anestesiologists) score 1–2 scheduled for minor surgery were randomized to be ventilated either through LMA or LT. After insertion, the number of insertion attempts, and “positioning” and “airway-assessment” was evaluated. The patients reported on “sore throat” after 30 and 60 minutes and the day after anaesthesia. Results: Gender and mean age were equal in both groups. The first insertion attempt was successful in 25 of 28 patients randomised to LMA and in 23 of 27 patients randomised to LT. LMA was evaluated to be easier in “positioning” whereas no difference in “sore throat” was reported. Conclusion: We found no difference between the LMA and the LT in terms user and patient friendliness and safety.     

Receptor binding of N-(methyl-11C) clozapine in the brain of rhesus monkey studied by positron emission tomography (PET)

By means of positron emission tomography the uptake and kinetics of N-(methyl-¹¹C)clozapine in different brain regions have been studied in Rhesus monkeys. ¹¹C-clozapine rapidly entered the brain and maximum radioactive uptake was seen 5–12 min after administration. Highest uptake was measured in the striatum. Other regions with an uptake higher than in the cerebellum were thalamus and mesencephalon. The radioactivity from different brain regions decreased with an elimination half-life of about 5 h and parallelled the plasma kinetics of unlabelled clozapine. The striatum/cerebellum ratio of ¹¹C-clozapine-derived radioactivity remained constant during the period studied and did not change after pretreatment with atropine. In contrast, the striatum/cerebellum ratio was somewhat lower after pretreatment with N-methylspiperone (NMSP), indicating competition for the same binding sites in the striatum. After pretreatment with increasing doses of clozapine, a dose-dependent protection of binding sites in the striatum for ¹¹C-NMSP was seen. It is concluded that clozapine is more loosely bound to dopamine receptors in the striatum than N-methylspiperone and that the kinetics of clozapine in the brain parallel that in the plasma. The binding properties of clozapine within the brain may explain some of the clinical properties of the drug.     

Spigelian hernia

The diagnosis of spigelian hernia presents greater difficulties than its treatment. The clinical presentation varies, depending on the contents of the hernial sac and the degree and type of herniation. The pain, which is the most common symptom, varies and there is no typical pain of spigelian hernia. Findings to facilitate diagnosis are palpable hernia and a palpable hernial orifice. Large, easily palpable spigelian hernias are not a diagnostic problem. It is small hernias and hernial orifices that are overlooked because they are masked by the subcutaneous fat and an intact external aponeurosis. In the absence of a palpable orifice or sac, persistent point tenderness in the spigelian aponeurosis with a tensed abdominal wall most strongly suggests the diagnosis. Spigelian hernia can be ruled out in patients without palpable tenderness. Ultrasonic scanning can be recommended for verification of the diagnosis in both palpable and nonpalpable spigelian hernia. The hernial orifice and sac can also be demonstrated by computed tomography, which gives more detailed information on the contents of the sac than does ultrasonic scanning. The treatment of spigelian hernia is surgical, and the risk of recurrence is small. A gridiron incision is excellent for operations for palpable hernias. If the hernia cannot be palpated preoperatively, preperitoneal dissection through a vertical incision is recommended. This gives good exposure, facilitates hernioplasty, and permits preperitoneal exploration and treatment of other abdominal wall hernias. The incision is also suitable for exploratory laparotomy, which should be performed on patients with abnormal ultrasonographic or computed tomographic findings in whom no palpable hernia can be detected preoperatively.

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Resumen El diagnóstico de la hernia spigeliana presenta mayores dificultades que su tratamiento. La presentación clínica varía según el contenido del saco herniario y el grado y tipo de herniación. El dolor, que es el síntoma más común, es variable y no existe un dolor que sea típico de la hernia spigeliana. Los signos físicos que facilitan el diagnóstico son la hernia palpable y un orificio herniano palpable. Las hernias spigelianas grandes y fácilmente palpables no constituyen un problema diagnóstico. Son más bien las hernias pequeñas y los orificios mínimos los que pueden pasar desapercibidos al ser enmascarados por la grasa subcutánea y por una aponeurosis intacta. En ausencia de un orificio o de un saco palpable, el dolor a la presión sobre la aponeurosis spigeliana, manteniendo tensa la pared abdominal, sugiere fuertemente este diagnóstico; la hernia spigeliana puede ser excluída como posibilidad diagnóstica en pacientes que no exhiban tal dolor a la palpación. La ultrasonografía puede ser recomendada para verificación del diagnóstico, tanto en las hernias spigelianas palpables como en las no palpables. El orificio y el saco herniarios también pueden ser demostrados mediante tomografía computadorizada, estudio que provee información más detallada que la ultrasonografía sobre el contenido del saco.El tratamiento es quirúrgico y el riesgo de recurrencia es bajo. Una incisíon oblicua o transversa resulta excelente para la operación en hernias palpables; si la hernia no es palpable en el examen preoperatorio, se recomienda realizar disección preperitoneal a través de una incisión vertical. Esto da buena exposición, facilita la hernioplastia, y permite la exploración preperitoneal y el tratamiento de otras hernias de la pared abdominal. La incisión también es adecuada para la laparotomía exploratoria, la cual debe ser realizada en pacientes con hallazgos anormales en la ultrasonografía o en la tomografía computadorizada y en quienes no haya sido posible detectar una hernia palpable preoperatoriamente.

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Résumé Le diagnostic d'une hernie de Spiegel est plus difficile que son traitement. Les signes de découverte varient, dépendant du contenu du sac herniaire, d l'importance, et du type de la hernie. La douleur, symptôme le plus fréquent, n'est pas typique. Les signes qui aident au diagnostic sont la palpation de la hernie et de l'orifice herniaire. Lorsque l'orifice est large et palpable, le diagnostic de hernie de Spiegel ne pose pas de problème. Ce sont les hernies de petite taille, à orifice réduit, qui sont souvent masquées par la graisse sous-cutanée et l'aponévrose oblique externe. En l'absence d'orifice ou de hernie palpable, la persistance de la douleur à la palpation au niveau de l'aponévrose, alors que la paroi abdominale est sous tension, est significative. En l'absence de cette douleur provoquée, on peut pratiquement éliminer ce diagnostic. On conseille de vérifier le diagnostic par une échographie, que cette douleur existe ou pas. L'orifice et le sac herniaire se voient bien également par la tomodensitométrie plus performante que l'échographie en ce qui concerne le contenu herniaire.Le traitement de la hernie est chirurgical; le risque de récidive est réduit. Une incision centrée sur la hernie, sans section musculaire, est excellente. Si la hernie ne peut être palpée, on conseille une incision verticale avec un abord extrapéritonéal. L'exposition est excellente, la cure est aisée et l'exploration prépéritonéale ainsi facilitée, permet en outre la cure d'autres hernies pariétales associées. La même incision convient également pour une laparotomie exploratrice, au cas où l'échographie ou la tomodensitométrie ne montrent rien de spécifique et où il n'existe pas de hernie détectée préopérativement.

     

The Excitatory Action of Acetylcholine on Intradental Sensory Units

In order to test the hypothesis that ACh mediates the transmission of pain stimuli from dentin to sensory intradental nerve endings the following experiments were performed. Intradental nerve impulses were recorded by means of low impedance electrodes inserted in dentinal cavities in the tooth of the cat. An air blast proved to be an efficient physical stimulus to excite the intradental nerves. Local application of acetylcholine caused a similar response. This response to acetylcholine was followed by a transient blockage to repeated application. The response to acetylcholine could be blocked by d-tubocurarine, atropine, succinylcholine and hexamethonium administered locally. In contrast, the response to physical stimuli (air blasts) could not be blocked by these drugs. Moreover, during the period of depression following acetylcholine the preparation responded to physical stimuli. These findings suggest that acetylcholine is not a mediator in the intradental pain transmission provoked by physical stimuli.