[Ocular complications of local anaesthesia in dentistry]. / Oculaire bijwerkingen van lokale anesthesie in de tandheelkunde.

An estimated 1 in 1,000 local anaesthetic injections in the maxilla or the mandible lead to unwanted effects on the ipsilateral eye. We have seen a case with diplopia and lateral rectus palsy following bimaxillary anaesthesia. A systematic literature review of reports on this type of complication resulted in a total of 144 documented cases published between 1936 and 2016. The most frequently reported symptoms included diplopia (72%), partial or full ophthalmoplegia (26%), ptosis (22%), mydriasis (18%), amaurosis (13%) and orbital pain (12%). This type of complication is best understood by pathophysiological hypotheses that include intra-arterial injection, intravenous injection, autonomic dysregulation, or deep injection and diffusion. If ocular symptoms appear after local intraoral anaesthesia, the patient should be reassured. In the case of diplopia, the eye should be covered with a gauze dressing, and the patient should be instructed about associated safety risks. If symptoms persist or when vision deteriorates, referral to an ophthalmologist is advisable.

Limited regression of central giant cell granuloma by interferon alpha after failed calcitonin therapy: a report of 2 cases.

Central giant cell granuloma (CGCG) is a benign lesion of the jaws with a sometimes locally aggressive behaviour. The most common therapy is surgical curettage which has a high recurrence rate, especially in lesions with aggressive signs and symptoms (i.e. pain, paresthesia, root-resorption and rapid growth). Alternative therapies such as interferon alpha (INFalpha) or calcitonin are described in the literature. In this study 2 patients with an aggressive CGCG are presented who were treated with INF mono-therapy. INF mono-therapy was capable of terminating the rapid growth of the lesion in both patients and induced a partial reduction. Total resolution, however, was not obtained and alternative treatment is still necessary.

Continuous brachial plexus block as treatment for the Pancoast syndrome.

BACKGROUND: Six patients with severe neuropathic pain caused by a Pancoast tumor were treated with the continuous administration of local anesthetics. These patients had not responded to any other treatment, including nonsteroidal anti-inflammatory drugs, opioids, dexamethasone, tricyclic antidepressants, anticonvulsants, ketamine, and transcutaneous electric nerve stimulation. INTERVENTIONS: An axillary catheter was placed in the brachial plexus using a posterior approach that has not been described previously. A continuous infusion system of local anesthetics was delivered via a catheter. In two patients, the main purpose was to evaluate the technical possibilities and implications of this new approach. In all patients, the visual analogue scale score was evaluated until the patient died. In four additional patients, the quality of life and performance skills were recorded. RESULTS: In all patients, there was a significant reduction in the visual analog scale score, and there was an increase in performance skills and quality of life in four patients. No side effects occurred from this technique or from the continuous administration of local anesthetics. CONCLUSIONS: We conclude that neuropathic pain may be treated by local anesthetics administered through an axillary catheter placed in the brachial plexus. This technique is reversible and is preferable to destructive procedures such as cordotomy.

[Neuroanatomy and anaesthesiology]. / Neuro-anatomie en anesthesiologie.

The pathways of nociception, concerning dentogenic pain, are followed from the peripheral nociceptors to the cortex. The branches of the trigeminal nerve supply the semilunar ganglion. From this ganglion the trigeminal nuclei are reached, extending from the bottom of the third ventricle to the upper cervical segments. The thalamus and subsequently the cortex are receiving nociceptive information from trigeminal nuclei. Either ascendent or descendent pathways are involved concerning nociception.

The rate of percutaneous permeation of xylene, measured using the "perfused pig ear" model, is dependent on the effective protein concentration in the perfusing medium.

In order to study the dermal permeation of compounds through the skin, an in vitro model was developed which utilized pig ears perfused with autologous pig blood (de Lange, J., van Eck, P., Elliott, G. R., de Kort, W. L. A. M., and Wolthuis, O. L. (1992). J. Pharmacol. Toxicol. Methods 27, 71-77). In the present article we investigated to what extent the rate of permeation of xylene through pig ear skin is dependent on the perfusion medium used. Pig ears were exposed to xylene (10 cm2 area) for a 4-hr period (30 degrees C, relative humidity of 40-60%) and the perfusate was analyzed for xylene using gas chromatography. The rates of permeation of xylene for whole blood, blood depleted of white blood cells, and a buffer containing 4.5% albumin were similar (+/- 300 ng/min/cm2). The rate of penetration was fivefold higher when pig plasma was used and ninefold lower when albumin was excluded from the buffer. Using the buffer, we found that the rate of permeation of xylene was proportional to flow (constant protein concentration) and protein concentration (constant flow). Our data demonstrate that the measured permeation rate for xylene is, to a large degree, dependent on the effective protein concentration (mg/min) passing through the ear. Differences in this parameter could explain the variations in rates of permeation found using the different perfusion media. To avoid problems associated with the choice of receptor fluid for permeation experiments, we suggest that full blood remains the vehicle of choice, although the practical perfusion period is limited to about 6 hr. If longer perfusion periods are required, then it should be possible to reproduce results obtained with whole blood by choosing an appropriate buffer.