Facial muscle contraction in response to mechanical stretch after severe facial nerve injury: Clapham's sign.

INTRODUCTION: Following the onset of facial palsy, physiotherapists routinely inspect the inside of the patient's mouth and cheek for complications such as ulceration or trauma. In several patients with complete facial nerve palsy, it was noticed that when the cheek was stretched there was subsequent spasm of the muscles of facial expression. This also occurred in patients whose facial nerve had been transected. CASE REPORTS: We present four patients in whom this response was demonstrated. We consider the mechanism of this response and its relevance in the management of patients with facial paralysis. CONCLUSION: Following severe or complete denervation, contraction of the facial muscles following mechanical stretch provides evidence of preservation of activity in the facial muscle's excitation-contraction apparatus. Further research will investigate the clinical significance of this sign and whether it can be used as an early predicator of the development of synkinesis, as well as its relevance to facial nerve grafting and repair.

Facial motor function monitored by hand held calipers versus computer-assisted photography.

BACKGROUND: It is essential to have easy to use, reliable tools to assess and compare facial function for clinical records, audit and research purposes. In this study, two different techniques were examined, Hand held calipers (HHC, as described by Burres), and computerised analysis of digital photographs (CAOP) using Adobe Photoshop 7. The aim of this study was to determine the level of agreement between two operators (physiotherapist) using HHC to measure the distance between facial landmarks, and the level of agreement between two operators (photographers) using CAOP to measure the same distance between facial landmarks and explore whether these two techniques can be used interchangeably. METHOD: The distance between facial landmarks was measured, with the face at rest and following four standard facial expressions. All measurements were repeated one week later to permit inter/intra-rater reliability over time to be assessed. Nine female volunteers with normal facial function were included in the study. RESULTS: The intra- and inter-rater agreement using CAOP was high whereas the agreement was low when using HHC. CONCLUSION: Hand held calipers proved to be an unreliable technique for monitoring facial function. However digital photography when combined with Adobe Photoshop 7 provides a highly reliable objective measurement tool. It was simple to use, low cost and suitable for use in a clinical environment.

Psycho-socio-economic outcomes in acoustic neuroma patients and their carers related to tumour size.

The objective was to explore psycho-socio-economic outcomes of a 2-year cohort of patients having surgery for an acoustic neuroma, and carers and their relationship to tumour size after surgery. The Wessex Patient Carer Questionnaire was designed in conjunction with Patients and Carers, to determine psycho-socio-economic outcomes. The results were juxtaposed against clinical profiles. The House-Brackman (HB) scale was used to assess facial function at 6 and 12 months after operation. The cohort contained 102 patients. There were 87% effective responders. Half were aged below 54 years and 30% had school-aged children. The majority (93%) of patients were operated via the translabyrinthine approach. Patients with large tumours, i.e. greater than 3 cm (28%), had most post-treatment physical problems, including hearing and balance difficulties, and 42% reported difficulty eating in public. Thirty-four per cent felt 'stressed' and 18%'depressed'. After 6 months, facial function was recorded as HB scale 5/6 in 21% of patients but by 1 year only 8% of patients were HB 5/6. Patients and carers were generally very satisfied with their in-patient neurosurgical care, but significantly dissatisfied with post-discharge care - particularly the shortcoming of the community services. The majority of families felt 'unsupported' and only 20% of patients had confidence in their General Practitioner's knowledge. Families faced severe socio-economic disruption and patients"time-off-work' was estimated to cost pound 954,000. Carers carried considerable post-discharge psychological burdens and costs to the public purse were calculated to be pound 52,000.

Outcome-directed clinical practice in lumbar spine surgery.

Outcome audits describe the current level of clinical performance and direct change in clinical practice. The outcome measures used should be not only relevant and easily understood but also available to all interested parties, e.g. patients, clinicians and commissioners of health. The results of audits can be used to set the standard from which clinical practice can be monitored and improved. An expectation of likely outcome also gives the patient the opportunity of being able to make a fully informed choice. This audit using prospective data examines and compares the outcome of surgery for degenerative lumbar spine disease over a two-year period. The results allow more accurate information to be given to patients, areas of service development to be identified and changes in clinical practice to be made.

Preventing foot problems in patients with diabetes.

Patients with diabetes are vulnerable to damage to their feet, and minor problems can deteriorate rapidly. A diabetes clinical nurse, winner of the diabetes category in the Professional Nurse Awards 1997, introduced a scheme to raise awareness in this area.

A multidisciplinary audit of manual hyperinflation technique (sigh breath) in a neurosurgical intensive care unit.

Manual hyperinflation of the lungs (sigh breath) is a technique which is used to deliver a large volume of gas to the lungs. The purpose of this technique is to either maintain or improve the respiratory status of the patient. However, the volume of gas delivered is rarely measured, and therefore there is little evidence that hyperinflation occurs. Through the process of audit staff were able to examine the technique critically and improve it. With the addition of measurement tools a defined standard was developed against which performance was measured. To explore the effects of a particular technique it is essential that the delivery of that technique is standardised. This audit has enabled staff to achieve a standard technique and create a position from which research into its effects can now take place.

In vitro inhibition of struvite crystal growth by acetohydroxamic acid.

Struvite (MgNH4PO46H2O) crystals were produced by Proteus mirabilis growth in artificial urine, in the presence and absence of the urease inhibitor, acetohydroxamic acid (AHA). In the absence of AHA, struvite crystals assumed an "X-shaped" or dendritic crystal habit due to rapid growth along their 100 axis. When AHA was present, crystal growth, as monitored by phase contrast light microscopy, was greatly slowed, and the crystals assumed an octahedral crystal habit. Scanning electron microscopy revealed that crystals grown in the presence of AHA were pitted on their surface. This pitting was absent in control samples. While most of this inhibition by AHA was due to lowered urease activity, some crystal growth inhibition occurred in struvite produced in the absence of urease activity through NH4OH titration of artificial urine. We conclude that while AHA is primarily a urease inhibitor, it may also disrupt struvite growth and formation directly through interference with the molecular growth processes on crystal surfaces.

Pyrophosphate inhibition of Proteus mirabilis-induced struvite crystallization in vitro.

Struvite (MgNH4PO4.6H2O) crystals, the major mineral component of infectious urinary calculi, were produced in vitro by growth of a clinical isolate of Proteus mirabilis in artificial urine. P. mirabilis growth and urease-induced struvite production were monitored by phase contrast light microscopy and measurements of urease activity, pH, ammonia concentrations, turbidity, and culture viability. In the absence of pyrophosphate, struvite crystals appeared within 3-5 h due to the urease-induced elevation of pH and initially assumed a planar or 'X-shaped' crystal habit (morphology) characteristic of rapid growth. When pyrophosphate was present, initial precipitation and crystal appearance were significantly impaired and precipitates were largely amorphous. When crystals did appear (usually after 7 or 8 h) they were misshapen or octahedral in shape indicative of very slow growth. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) identified all crystals as struvite. Trace contaminates of carbonate-apatite (Ca10(PO4)6CO3) or newberyite (MgHPO4.H2O) were produced only in the absence of pyrophosphate. P. mirabilis viability and culture pH elevation were unaffected by the addition of pyrophosphate, whereas urease activity and ammonia concentrations were marginally reduced. Struvite could also be produced chemically by titration of the artificial urine with NH4OH. If pyrophosphate was present during titration, the same inhibitory effect on crystal growth occurred, so it is unlikely that urease inhibition is important. Lowering of pyrophosphate concentration from 13-0.45 mumol/l did not reduce its inhibitory activity so it is unlikely to act by chelating free Mg2+. We propose that pyrophosphate inhibits struvite growth principally through direct interference with the chemical mechanisms involved in crystal nucleation and growth, because of its effectiveness at very low concentrations.

Metal-Binding Characteristics of the Gamma-Glutamyl Capsular Polymer of Bacillus licheniformis ATCC 9945.

The metal-binding affinity of the anionic poly-gamma-d-glutamyl capsule of Bacillus licheniformis was investigated by using Na, Mg, Al, Ca, Cr, Mn, Fe, Ni, and Cu. Purified capsule was suspended in various concentrations of the chloride salts of the various metals, and after dialysis the bound metals were analyzed either by graphite furnace atomic absorption spectroscopy or by inductively coupled plasma-mass spectrometry. Exposure of purified capsule to excess concentrations of Na revealed it to contain 8.2 mumol of anionic sites per mg on the basis of Na binding. This was confirmed by titration of the capsule with HCl and NaOH. Other metal ions were then added in ionic concentrations equivalent to 25, 50, 75, 100, 200, and 400% of the available anionic sites. The binding characteristics varied with the metal being investigated. Addition of Cu, Al, Cr, or Fe induced flocculation. These metal ions showed the greatest affinity for B. licheniformis capsule in competitive-binding experiments. Flocculation was not seen with the addition of other metal ions. With the exception of Ni and Fe all capsule-metal-binding sites readily saturated. Ni had low affinity for the polymer, and its binding was increased at high metal concentrations. Fe binding resulted in the development of rust-colored ferrihydrite which itself could bind additional metal. Metal-binding characteristics of B. licheniformis capsule appear to be influenced by the chemical and physical properties of both the capsule and the metal ions.

Influence of chondroitin sulfate, heparin sulfate, and citrate on Proteus mirabilis-induced struvite crystallization in vitro.

Struvite crystals were produced by Proteus mirabilis growth in artificial urine, in the presence of a number of naturally occurring crystallization inhibitors. The use of phase contrast light microscopy enabled the effects of added chondroitin sulfate A, chondroitin sulfate C, heparin sulfate, or sodium citrate, on struvite crystal growth rates to be rapidly monitored as changes in crystal habit. Struvite crystals formed as a consequence of the urease activity of P. mirabilis under all chemical conditions. In the absence of inhibitor, early crystal development was marked by large quantities of amorphous precipitate, followed immediately by the appearance of rapidly growing X-shaped or planar crystals. Addition of the glycosaminoglycans, chondroitin sulfate A, chondroitin sulfate C, or heparin sulfate to the artificial urine mixture had no effect on the rate of crystal growth or appearance. When sodium citrate was present in elevated concentrations, crystal appearance was generally slowed, and the crystals assumed an octahedral, slow growing appearance. None of the added compounds had any influence on bacterial viability, pH, or urease activity. It is therefore likely that the inhibitory activity displayed by sodium citrate might be related to its ability to complex magnesium or to interfere with the crystal structure during struvite formation. From these experiments it would appear that citrate may be a factor in the natural resistance of whole urine to struvite crystallization.

A simple technique for studying struvite crystal growth in vitro.

Struvite urolithiasis forms as a consequence of a urinary tract infection by urease-producing species of bacteria such as Proteus mirabilis. Ammonia, produced by the enzymatic hydrolysis of urea, elevates urine pH causing a supersaturation and precipitation of Mg++ as struvite (NH4MgPO4). Calcium often precipitates as well, forming the mineral carbonate-apatite (Ca10(PO4)6CO3). We have developed a procedure based on direct observation by light microscopy whereby struvite crystal growth can be quickly monitored in response to chemical changes in urine. As struvite crystals assume a characteristic shape or crystal habit based on their growth rate, the effect of urine chemistry and the action of various crystallization or urease inhibitors on struvite formation can be quickly shown. In addition preliminary effects of alkaline pH, or the presence of toxic compounds on bacteria can also be shown through their loss of motility.