Out of hours magnetic resonance imaging for suspected cauda equina syndrome: lessons from a comparative study across two centres.

BACKGROUND: Cauda equina syndrome, a rare but disabling spinal surgical emergency, requires prompt investigation, ideally using magnetic resonance imaging as patients may require decompressive surgery. Out of hours access to magnetic resonance imaging is only routinely available in major trauma centres and neurosurgical units. Patients in regional hospitals with suspected cauda equina syndrome may require transfer for diagnostic imaging. We retrospectively studied the proportion of patients referred with suspected cauda equina syndrome who required out of hours transfer for magnetic resonance imaging and decompressive surgery. MATERIALS ANDS METHODS: Retrospective cohort study of patients referred using online referral platforms with suspected acute cauda equina syndrome and transferred out of hours between 6pm to 8am on weekdays and all day on weekends to two of the largest neurosurgical units in the UK in Birmingham and Cambridge. RESULTS: A total of 441 patients were referred across both sites with a suspicion of acute cauda equina syndrome; 339 patients were transferred for diagnostic scans and only 16 of them (4.7%) were positive for cauda equina compression, necessitating prompt decompressive surgery. Of the patients with negative magnetic resonance scans, 50% had their discharge or transfer back to referring hospitals delayed by more than 24 hours. CONCLUSIONS: Over 95% of patients who were transferred for imaging did not undergo emergency decompression. The authors propose a greater role for the provision of out of hours magnetic resonance imaging in all hospitals admitting emergency patients to streamline management.

Outcomes of CSF spectrophotometry in cases of suspected subarachnoid haemorrhage with negative CT: two years retrospective review in a Birmingham hospital.

AIM: The aim of this study was to evaluate the adherence to current guidelines for the investigation of suspected subarachnoid haemorrhage and the prevalence and outcome of computed tomography (CT)-negative aneurysmal subarachnoid haemorrhage. DESIGN: A retrospective review in a single large tertiary referral centre. SUBJECTS: A total of 796 patients, aged 16-90 years, who underwent lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) following a negative or equivocal CT scan between January 2012 and November 2013 (23 months). METHODS: Xanthochromia reports were obtained using the hospital's department of biochemistry database and clinical data for these patients were reviewed using patient notes. RESULTS: Of 796 CSF reports reviewed, 728 (91%) were negative for xanthochromia, 31 (4%) were positive and 37 (5%) were equivocal. Only 2 out of the 31 patients with positive spectrophotometry results were subsequently found to have an underlying aneurysm on CT angiography. A further 9 out of these 31 patients underwent digital subtraction angiography, with no cerebral aneurysms being detected. Amongst the 37 patients with equivocal xanthochromia reports, 13 underwent CT angiography and only 1 cerebral aneurysm was detected. CONCLUSIONS: In patients with clinically suspected SAH but who have negative or questionable CT findings, CSF analysis is likely to be negative in the vast majority of cases, which was 91% in our series. In patients yielding positive or equivocal CSF results the likelihood of an aneurysm being detected is low, amounting to three out of 68 or approximately one in 23 (approximately 4%). Overall in suspected SAH cases where CT scan has been negative, the rate for the detection of cerebral aneurysm is three out of 796 cases (0.4%).

Impact of tropomyosin isoform composition on fast skeletal muscle thin filament regulation and force development.

Tropomyosin (Tm) plays a central role in the regulation of muscle contraction and is present in three main isoforms in skeletal and cardiac muscles. In the present work we studied the functional role of α- and ßTm on force development by modifying the isoform composition of rabbit psoas skeletal muscle myofibrils and of regulated thin filaments for in vitro motility measurements. Skeletal myofibril regulatory proteins were extracted (78%) and replaced (98%) with Tm isoforms as homogenous ααTm or ßßTm dimers and the functional effects were measured. Maximal Ca(2+) activated force was the same in ααTm versus ßßTm myofibrils, but ßßTm myofibrils showed a marked slowing of relaxation and an impairment of regulation under resting conditions compared to ααTm and controls. ßßTm myofibrils also showed a significantly shorter slack sarcomere length and a marked increase in resting tension. Both these mechanical features were almost completely abolished by 10 mM 2,3-butanedione 2-monoxime, suggesting the presence of a significant degree of Ca(2+)-independent cross-bridge formation in ßßTm myofibrils. Finally, in motility assay experiments in the absence of Ca(2+) (pCa 9.0), complete regulation of thin filaments required greater ßßTm versus ααTm concentrations, while at full activation (pCa 5.0) no effect was observed on maximal thin filament motility speed. We infer from these observations that high contents of ßßTm in skeletal muscle result in partial Ca(2+)-independent activation of thin filaments at rest, and longer-lasting and less complete tension relaxation following Ca(2+) removal.

Endoscopic biopsy of cystic intracerebral tumours.

This technical note describes the application of neuroendoscopy for decompressing and obtaining tissue samples from cystic intracerebral tumours. The method provides for visualisation of the solid tumour component prior to biopsy and retains the advantages of being a burr hole procedure.

Virchow-Robin spaces in idiopathic normal pressure hydrocephalus: a surrogate imaging marker for coexisting microvascular disease?

BACKGROUND: Virchow-Robin spaces (VRSs) surround perforating cerebral arteries and are reported to be found with increasing frequency with advancing age. In addition, some studies indicate an association between VRSs and vascular dementias. The present study examined the incidence of VRSs in patients with idiopathic normal pressure hydrocephalus (INPH) and considered their use as a potential surrogate imaging marker of coexisting microvascular disease in patients with this condition. METHODS: The MRI incidence of VRS in the centrum semiovale (CS), basal ganglia (BG), mesencephalon (MES), and the subinsular (SI) region was measured in 12 patients with INPH and in 12 control subjects, using the scoring system proposed by Patankar et al. (Am J Neuroradiology 26:1512, 2005). Historical control data were also used for further comparison. RESULTS: All 12 INPH patients had clearly visible VRSs, distributed in the CS (all 12), basal ganglia (11/12), SI region (9/12), and MES region (6/12). The mean Patankar scores of the INPH group were BG 2.25, CS 1.66, SI 0.91, and ME 0.5. The respective scores for our control group were 1.41, 1.5, 1.16, and 0.16, and for historical controls were 1.46, 0.51, 0.96, and 0.51. There were, however, no statistically significant differences between the INPH patients and either of the control groups. No correlation was found between age and the overall incidence of VRS. CONCLUSION: This preliminary study suggests that there may be a higher incidence of VRSs in patients with INPH, when compared with normal patients of similar age, but our small numbers prevent us from demonstrating statistical significance, and larger studies are clearly required.

Surgical treatment of post-traumatic syringomyelia.

STUDY DESIGN: A retrospective study. OBJECTIVES: To review the outcome of 40 patients with post-traumatic syringomyelia treated with laminectomy and reconstitution of the spinal subarachnoid channels. SETTING: Birmingham, United Kingdom. METHOD: A retrospective study of patients undergoing surgery between 1996 and 2007 was carried out. All 40 patients underwent a laminectomy with the creation of a cerebrospinal fluid (CSF) conduit. RESULTS: A total of 18 (1 in 2) patients had long-term stabilization of symptoms after laminectomy and creation of a CSF conduit alone. Later, 17 patients underwent supplementary procedures. Overall, surgical treatment resulted in 27(2 in 3) patients with continued stabilization of symptoms and 13 (1 in 3) experiencing worsening of symptoms in the long term (mean follow-up was 64 months). Radiological review at 6 months revealed a reduction in the size of the syrinx in 21 out of 33 (2 in 3) patients. CONCLUSIONS: Laminectomy for syringomyelia, with reconstruction of the spinal CSF channels alone, resulted in a reduction of syrinx size by 6 months, with half of all patients experiencing stabilization of symptoms in the long term. When additional techniques are taken into account, two in three of patients achieved long-term stabilization of symptoms.

Hindbrain hernia masquerading as postpartum subarachnoid haemorrhage.

A 29-year-old postpartum lady presented with a headache suggestive of subarachnoid haemorrhage. Investigations were negative for sources of haemorrhage, but revealed a hindbrain hernia. Hindbrain hernia should be considered as a cause of headache postpartum, as repeated Valsalva manoeuvres performed during vaginal delivery may further aggravate tonsillar decent.

Ring fracture of the skull base: case report and review of the literature.

Ring fractures of the skull base are rare and have hitherto been regarded as invariably fatal injuries. They are difficult to diagnose, as routine radiographs of the head and spine are usually normal. Increasing use of computerized tomography in the evaluation of head and neck injuries may, however, lead to an increased frequency of diagnosis of this injury. We present a case of such a fracture where the patient survived with a generally good neurological recovery.

Can homeopaths detect homeopathic medicines by dowsing? A randomized, double-blind, placebo-controlled trial.

Dowsing is a method of problem-solving that uses a motor automatism, amplified through a pendulum or similar device. In a homeopathic context, it is used as an aid to prescribing and as a tool to identify miasm or toxin load. A randomized double-blind trial was conducted to determine whether six dowsing homeopaths were able to distinguish between Bryonia in a 12c potency and placebo by use of dowsing alone. The homeopathic medicine Bryonia was correctly identified in 48.1% of bottle pairs (n=156; 95% confidence interval 40.2%, 56.0%; P=0.689). These results, wholly negative, add to doubts whether dowsing in this context can yield objective information.

A metallurgical approach to metal contact dermatitis.

It is well-known that some metals/alloys are sensitizing on skin contact, but it is not so well appreciated that sensitization is dependent on the reaction of the metal/alloy with sweat. The first step in skin sensitization by metals/alloys is a corrosion process and the formation of soluble metal ions. The nature of this process has implications with respect to occurrence of metal contact dermatitis, to testing techniques and to classification of metals/alloys as skin sensitizers.

Purity of food cooked in stainless steel utensils.

An extensive programme of cooking operations, using household recipes, has shown that, apart from aberrant values associated with new pans on first use, the contribution made by 19% Cr/9% Ni stainless steel cooking utensils to chromium and nickel in the diet is negligible. New pans, if first used with acid fruits, showed a greater pick-up of chromium and nickel, ranging from approximately 1/20 to 1/3 and 1/20 to 1/2 of the normal daily intake of chromium and nickel respectively. This situation did not recur in subsequent usage, even after the pan had been cleaned by abrasion. A higher rate of chromium and nickel release in new pans on first use was observed on products from four manufactures and appears to be related to surface finish, since treatment of the surface of a new pan was partly, and in the case of electropolishing, wholly effective in eliminating their initial high release.

Imaging of childhood torticollis due to atlanto-axial rotatory fixation.

Atlanto-axial rotatory fixation is a rare cause of childhood torticollis. It may occur spontaneously or may be associated with trauma, upper respiratory tract infection or congenital abnormality of the cervical spine. Presentation is usually with persistent torticollis and "cock robin" deformity of the neck. In this paper the radiological experience in three patients is presented. Investigations included plain radiographs, plain anteroposterior tomography, CT and MRI. Displacement of the lateral mass of the atlas and the eccentric position of the odontoid peg can be seen in the plain films. CT scan can exclude fractures and confirm atlanto-axial rotation. The superimposition of CT images is demonstrated as a way of diagnosing subluxation. MRI offers better soft tissue differentiation and allows assessment of the integrity of the transverse ligament. This has an important bearing on the prognosis and may influence surgical treatment. It is important to recognise the plain film features of this uncommon condition and confirm the diagnosis with CT or MRI. The treatment options are discussed with particular reference to long term outcome.

Systemic nickel: the contribution made by stainless-steel cooking utensils.

An extensive programme of cooking operations, using household recipes, has shown that, apart from aberrant values associated with new pans on first use, the contribution made by 19 Cr/9 Ni stainless-steel cooking utensils to nickel in the diet is negligible. The amount of nickel (0 to 8 micrograms) derived from the utensils in standard portions of various "aggressive" foodstuffs tested was less than that to be found occurring in 1 square of a bitter-sweet chocolate bar. New pans, if first used with acid fruits, can show a greater pick-up of nickel, which, in the worst case observed, amounted to approximately 1/5 of the normal daily intake for the average person (ca. 200 micrograms). This situation does not recur in subsequent usage, even after the pan has been cleaned by abrasion. A higher rate of nickel release was observed in new pans on first use from 4 manufacturers located in different countries and appears to be a general phenomenon. This could provide a possible explanation for the high pick-up of nickel by acid fruits reported in 1 instance in the literature.