Effect of Deep Margin Elevation on CAD/CAM-Fabricated Ceramic Inlays

CLINICAL RELEVANCE

Using the deep margin elevation technique in preparations extending beyond the cemento-enamel junction appears to be beneficial in maintaining structural integrity of CAD/CAM-fabricated feldspathic ceramic inlays.

SUMMARY

Objective: To evaluate the effect of deep margin elevation on structural and marginal integrity of ceramic inlays.Methods and Materials: Forty extracted human third molars were collected and randomly separated into four groups (n=10/group). In group 1 (enamel margin group), the gingival margin was placed 1 mm supragingival to the cemento-enamel junction (CEJ). In group 2 (cementum margin group), the gingival margin was placed 2 mm below the CEJ. In group 3 (glass ionomer [GI] margin group), the gingival margin was placed 2 mm below the CEJ, and then the margin elevated with GI to the CEJ. In group 4 (resin-modified glass ionomer [RMGI] margin group), the gingival margin was placed 2 mm below the CEJ, and then the margin elevated with RMGI to the CEJ. Standardized ceramic class II inlays were fabricated with computer-aided design/computer-aided manufacturing and bonded to all teeth, and ceramic proximal box heights were measured. All teeth were subjected to 10,000 cycles of thermocycling (5°C/55°C) and then underwent 1,200,000 cycles of vertical chewing simulation at 50 N of force. Ceramic restorations and marginal integrity were assessed with a Hirox digital microscope. The Fisher exact test (two-tailed) with adjusted p-values (α=0.05) and logistic regression were used for statistical analysis.Results: The cementum margin group had a significantly higher ceramic fracture rate (90%) compared to other groups (10% in enamel margin and GI margin groups, p=0.007; 0% in RMGI group, p<0.001). Logistic regression showed that with increased ceramic proximal box heights, the probability of ceramic fracture increased dramatically.Conclusion: Deep marginal elevation resulted in decreased ceramic fracture when preparation margins were located below the CEJ. There was no difference found between margin elevation with GI or RMGI. Increased heights of ceramic proximal box may lead to an increased probability of ceramic fracture.

FP1-7 Neurology – the european specialty

Objectives

The case records at Queen Square afford a unique opportunity to understand the evolution of neurological diagnosis between 1870 and 1920. This period witnessed a shift from the descriptive and observational to a sophisticated and detailed understanding of discrete disease patterns.

Results

By 1870, the introduction of microscopic pathological analysis of the nervous system had led to the recognition of disease processes including tumour, haemorrhage, infarction, meningitis and sclerosis. However, the most frequent diagnoses remained symptomatic (epilepsy, movement and functional disorders, visual loss and paralysis). Syphilis, paralysis agitans, and poliomyelitis were amongst the few specific diagnoses. The final decade of the 19th century saw the description of disease patterns, particularly in France, Germany and the US. These included disseminated and amyotrophic lateral sclerosis, myasthenia gravis and latterly eponymous disorders and signs attributed to Dejerine, Duchenne, Sanger Brown, Huntington, Marie, Romberg, Wernicke, Babinski and Charcot as well as Bright, Jackson, Gowers and Wilson in the UK.

Conclusions

The case record diagnoses, as well as the writings of Gowers and others, show how rapidly neurological thought evolved over 50 years. Queen Square was able to systematise neurological disease but was also remarkably responsive in understanding, accepting and adopting the neurological advances made across Europe.

FM2-5 Shell shock or neurasthenia? The queen square experience in the first world war

Objectives

The neurological response to psychological trauma during the Great War changed between the initial engagements, the final offensive and the later reflections of the Southborough enquiry.

Design

At Queen Square, neurasthenia was a recorded diagnosis from 1890 and, for the next 30 years, between 4%–8% of all admissions were so described. The term ‘shell shock’ was first used in 1914 but the diagnosis burgeoned until, by 1918, it amounted to 25% of all admissions.

Subjects

Early in the war, affected soldiers were rapidly evacuated to the UK, but attitudes changed after the Somme, because of the need to expedite return to the frontline. The use of ‘Electrical Therapy’ at Queen Square was an example of this imperative (Linden 2013).

Results

Review of the case records suggests that ‘Shell Shock’ became an increasingly pejorative term as the condition was seen as a ‘contagious psychological response of the weak.’ The records show it was largely restricted to the lower ranks whilst officers were generally considered to have neurasthenia requiring a more gentle psychotherapeutic approach, occasionally involving transfer to specialist facilities.

Conclusions

Ultimately, at Queen Square, the diagnosis and management of acute traumatic neurosis was driven by the needs of war but also by popular prejudice.

The benefit of inpatient neurorehabilitation in multiple sclerosis

The role of an inpatient neurorehabilitation unit in the management of multiple sclerosis (MS) remains unclear. A necessary first step is the demonstration of benefit in those who are admitted. In order to address this question, 79 patients with MS admitted over a 16-month period for multidisciplinary rehabilitation were studied using assessment scales as measures of disability and handicap. Fourteen patients were recovering from a recent relapse and the remaining 65 were in the progressive phase of the disease. The patients were clinically assessed and rated on admission and discharge using Kurtzke's Disability Status Scale (DSS), the Barthel Index (BI) and the Environmental Status Scale (ESS). A statistically significant functional improvement was seen in 65% of patients as determined by the Barthel Index and 44% improved on the ESS. Improvement was most marked in those in whom a reduction in impairment had occurred during recovery from relapse but also occurred in 63% of those who had not changed neurologically. These results suggest a beneficial effect from admission to a neurorehabilitation unit for patients with MS, including those in the progressive phase of the disease, although its role in the long-term management of MS remains to be defined.

Neurofilament heavy chain as a marker of neuroaxonal pathology and prognosis in acute encephalitis

BACKGROUND AND PURPOSE

The neurological outcome of acute encephalitis can be devastating and early prognosis remains difficult. Biomarkers that quantify the extent of early brain injury are needed to improve the prognostic accuracy and aid patient management. Our objective was to assess whether cerebrospinal fluid (CSF) protein biomarkers of neuroaxonal and glial cell injury are elevated in distinct forms of acute encephalitis and predictive of poor outcome.

METHODS

This was a prospective study of patients presenting with acute encephalitis to three teaching hospitals in London, UK. Levels of neurofilament heavy chain (NfH, SMI35) and S100B were quantified in CSF using enzyme-linked immunosorbent assay. The outcome was assessed by the Glasgow Outcome Scale (GOS).

RESULTS

Fifty-six patients with acute encephalitis were recruited and classified into the following diagnostic categories: infectious (n = 20), inflammatory (n = 14) and unknown etiology (n = 22). Pathological levels of NfH and S100B were observed in 24/56 (43%) and 54/56 (96%), respectively. Patients with infectious encephalitis had significantly higher NfH levels compared with the other two groups (P < 0.05). A poor outcome (GOS < 5) was associated with significantly higher CSF NfH levels within samples taken 2 weeks after symptom onset.

CONCLUSIONS

This study suggests that longitudinal CSF NfH levels are of superior prognostic value compared with CSF S100B levels. Prolonged release of NfH, a marker of neuroaxonal damage, was associated with poor outcome. Potentially there is a window of opportunity for future neuroprotective treatment strategies in encephalitis.

Thymectomy: role in the treatment of myasthenia gravis

Thymectomy is a frequently used treatment for myasthenia gravis (MG) and is virtually always indicated in MG patients who have a thymoma. However, the evidence for thymectomy in non-thymomatous MG remains less certain-no randomised controlled trials have been published to date, although one is currently underway. We reviewed the management and clinical outcome of patients with MG who underwent thymectomy over a 12 year period. Eighty-nine patients who underwent transsternal thymectomy were identified. A thymoma was identified on histology in 24 %, whereas 48, 9 and 19 % had hyperplastic, atrophic and normal thymic histology, respectively. One patient developed post operative myasthenic crisis but generally the procedure was well tolerated. Outcome was favourable for the majority of patients, with 34 % achieving complete stable remission (CSR) and an additional 33 % achieving pharmacological remission. Moreover, steroid requirements fell progressively during follow-up. Patients with a hyperplastic gland had a significantly greater chance of achieving CSR compared to other histological subtypes and the incidence of CSR increased with a longer duration of follow-up. Thymectomy for MG is generally safe and well tolerated and is associated with a sustained improvement of symptoms in the majority of patients.

Myasthenia gravis and neuromyelitis opica: A causal link

Neuromyelitis Optica (NMO) and Myasthenia Gravis (MG) are rare antibody mediated disorders of the central nervous system (CNS) and neuromuscular junction (NMJ) respectively. Both diseases are predominantly mediated by IgG1 antibodies that activate complement. There have been increasing reports of patients who develop both disorders. Given the rarity of both diseases it would seem that these occurrences are not purely coincidental. There is heterogeneity between the cases described in the literature but common trends are observed in patients who develop both disorders. Most patients described are female. Typically the MG precedes the NMO and the majority of patients have undergone thymectomy. Generally, the symptoms of MG are mild but the NMO tends to follow a more aggressive clinical course. The pathogenesis of NMO in combination with MG is unknown, but thymectomy has been implicated in a subset of patients. We present the case of a female patient who developed NMO on a background of sero-positive MG and discuss the relevant literature.

Hypoxic-ischaemic brain injury: imaging and neurophysiology abnormalities related to outcome

BACKGROUND

The outcome for patients with hypoxic-ischaemic brain injury (HIBI) is often poor. It is important to establish an accurate prognosis as soon as possible after the insult to guide management. Clinical assessment is not reliable and ancillary investigations, particularly imaging and EEG, are needed to understand the severity of brain injury and the likely outcome.

METHODS

We undertook a retrospective study of 39 patients on an intensive therapy unit (ITU) with HIBI who were referred for MRI. The patients were seen consecutively >57 months. HIBI was due to a variety of insults causing cardiac arrest, hypoperfusion or isolated hypoxia.

RESULTS

The outcome was poor, 29 patients died, 7 were left severely disabled and only 3 made a good recovery. Characteristic imaging changes were seen on MRI. These included extensive changes in the cortex and the deep grey matter present on diffusion-weighted imaging (DWI) and T2-weighted imaging within 6 days of the insult. In other patients, different patterns of involvement of the cortex and basal ganglia occurred. There was no significant difference in the outcome or imaging appearances according to aetiology. A poor prognosis was consistently associated with a non- or poorly responsive EEG rhythm and the presence of periodic generalized phenomena with a very low-voltage background activity.

CONCLUSION

In this retrospective study of patients with HIBI, MRI and EEG provided valuable information concerning prognosis.

Carotid cavernous fistula associated with persistent trigeminal artery: endovascular treatment using coil embolization

Carotid-cavernous fistula (CCF) associated with persistent trigeminal artery (PTA) is a rare but important clinical entity. We present a case treated by microcoil embolization with preservation of internal carotid, PTA, and hasilar artery flow following embolization. A 62-year-old female developed pulsatile tinnitus followed by left eye proptosis and diplopia. Examination revealed a cranial nerve VI palsy and an objective bruit over the left orbit. Angiographic evaluation revealed a carotid cavernous fistula originating from a persistent trigeminal artery. Placement of a detachable balloon across the fistula site while preserving the PTA proved impossible, and the fistula was treated with microcoils following placement of a microcatheter across the fistula into the cavernous sinus. Complete closure of the fistula was followed by resolution of the patient's symptoms. Preservation of all major vessels including the PTA was accomplished through the use of coil embolization. Careful evaluation of the angiogram is necessary to identify PTA associated with a CCF. Previous reports have described treatment of CCF with PTA by surgical or balloon ocolusion, some involving sacrifice of the PTA. Examination of the relevant embryology and anatomy reveals, however, that occlusion of the PTA must be approached with caution due to potential supply to the posterior circulation.

Weakness on the intensive care unit

Patients who are recovering from critical illness may be weak and difficult to wean from ventilatory support as a complication of their underlying disorder, intercurrent events or treatment given during prolonged intensive care. These patients are difficult to assess because of the severity of their weakness and any accompanying encephalopathy. It is essential to undertake a meticulous review, including assessment of any septic, hypoxic or metabolic derangements and a detailed look at the dosage and duration of medication including antibiotics, neuromuscular junction blocking agents and sedation. If a primary underlying neurological cause or an intercurrent event have been excluded, the likeliest cause of weakness is one of the neuromuscular complications of critical care such as: critical care polyneuropathy, an acute axonal neuropathy which develops in patients with preceding sepsis or multi-organ failure; the use of neuromuscular junction blocking agents or steroids; and critical illness myopathy, which is the most common cause of critical care related weakness.

The role of the thalamus in amnesia: a tractography, high-resolution MRI and neuropsychological study

Although it is well established that thalamic lesions may lead to profound amnesia, the precise contribution of thalamic sub-regions to memory remains unclear. In an influential article Aggleton and Brown proposed that recognition memory depends on two processes supported by distinct thalamic and cortical structures. Familiarity is mediated by the mediodorsal (MD) thalamic nucleus and the entorhinal/perirhinal cortex. Recollection is mediated by the anterior thalamic nucleus (AN), the mamillothalamic tract (MTT) and the hippocampus. The authors also suggested that the lateral dorsal nucleus (LD) may contribute to the thalamic/hippocampus system, thereby implying that the LD may play a role in recollection. Given the finding that material specific amnesia can occur following thalamic lesions, we tested an extension of the Aggleton and Brown model. We predicted that patients with bilateral lesions with a bias to the left or right MD or AN/MTT/LD may exhibit impaired familiarity or recollection on verbal or non-verbal memoranda. We report two patients with highly focal thalamic lesions and profound memory impairments affecting verbal and non-verbal memoranda. For the first time, diffusion-weighted imaging was employed to perform tractography of the MTT along with high-resolution anatomical MRI and detailed assessments of verbal and non-verbal memory. Our data support only some aspects of the Aggleton and Brown model. Both patients had left MD nucleus and AN/MTT lesions and performed poorly on familiarity and recall for verbal memoranda, just as predicted by the model. However, both patients' performance for non-verbal memoranda (human faces and topography) is more difficult to reconcile with the model. Patient 1 had damage to the right AN/MTT/LD with sparing of the MD: familiarity should therefore have been preserved but was not. Patient 2 had damage to the right MD with sparing of AN/MTT: recollection should have been preserved but was not. This finding raises the possibility that fractionation of familiarity and recollection to separate thalamic nuclei may not fully capture the role of thalamic sub-regions in memory function.

The impact of race on outcome of autologous transplantation in patients with multiple myeloma

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Background: Multiple myeloma (MM) is the most common hematologic malignancy in African-Americans (AA), with historically double the mortality of Caucasians (C). Monoclonal gammopathy of undetermined significance (MGUS) is also three times more frequent in AA than C. There has been limited data exploring racial differences in survival during the era of high dose chemotherapy with autologous stem cell transplantation (ASCT). Methods: We retrospectively analyzed the records of all C (n=55) and AA (n=36) MM patients who underwent ASCT over 10 years. Presenting demographic, clinical features and response to therapy by the Bladé criteria were obtained from medical records. Progression-free survival (PFS) and overall survival (OS) were analyzed by Kaplan-Meier method, and compared using the log-rank test. Results: The median age at diagnosis for AA was 52 years (30–75 years), compared to C at 56 years (39–79 years), p=0.006. There was no statistical difference in presenting ISS stage (AA: I- 50%, II- 28.1%, III- 21.9%; C: I- 51.2%, II- 20.9%, III- 27.9%), or values for presenting hemoglobin, calcium, and creatinine. There was a trend for increased skeletal involvement at diagnosis in the C group (82% vs. 69%, p=0.08). AA presented with an increased CRP (1.2 mg/dl vs. 0.25mg/dl, p=0.05). The most commonly used induction and conditioning regimen was VAD (78% AA vs. 70% C), and Mel 200 (72% AA vs. 65% C), respectively. Response to induction: CR: AA- 6%, C- 5%, p=1.00; PR: AA- 64%, C- 56%, p=0.519. Response to ASCT: CR: AA- 17%, C- 26%, p=0.438; PR: AA- 56%, C- 46%, p=0.519. At a median follow-up of 46.7 months, PFS was 60.5 months and 43.7 months (p=0.490), for AA and C, respectively; OS was 95.2 months and 68.5 months (p=0.421), for AA and C, respectively. Conclusion: In this series, AA with MM present at a younger age, with an increased CRP and a trend for less skeletal involvement than C at diagnosis. Despite a trend for less CR rates in AA, there was a trend for increased PFS and OS compared to C. This suggests there are biologic differences in MM between the races that may result in different therapeutic outcomes. One possible explanation would be the known higher frequency of MGUS in AA resulting in a reversion to a stable, indolent MGUS-like state after ASCT. These findings should be confirmed in larger studies.

No significant financial relationships to disclose.

Nerve excitability changes in critical illness polyneuropathy

Patients in intensive care units frequently suffer muscle weakness and atrophy due to critical illness polyneuropathy (CIP), an axonal neuropathy associated with systemic inflammatory response syndrome and multiple organ failure. CIP is a frequent and serious complication of intensive care that delays weaning from mechanical ventilation and increases mortality. The pathogenesis of CIP is not well understood and no specific therapy is available. The aim of this project was to use nerve excitability testing to investigate the changes in axonal membrane properties occurring in CIP. Ten patients (aged 37-76 years; 7 males, 3 females) were studied with electrophysiologically proven CIP. The median nerve was stimulated at the wrist and compound action potentials were recorded from abductor pollicis brevis muscle. Strength-duration time constant, threshold electrotonus, current-threshold relationship and recovery cycle (refractoriness, superexcitability and late subexcitability) were recorded using a recently described protocol. In eight patients a follow-up investigation was performed. All patients underwent clinical examination and laboratory investigations. Compared with age-matched normal controls (20 subjects; aged 38-79 years; 7 males, 13 females), CIP patients exhibited reduced superexcitability at 7 ms, from -22.3 +/- 1.6% to -7.6 +/- 3.1% (mean +/- SE, P approximately 0.0001) and increased accommodation to depolarizing (P < 0.01) and hyperpolarizing currents (P < 0.01), indicating membrane depolarization. Superexcitability was reduced both in patients with renal failure and without renal failure. In the former, superexcitability correlated with serum potassium (R = 0.88), and late subexcitability was also reduced (as also occurs owing to hyperkalaemia in patients with chronic renal failure). In patients without renal failure, late subexcitability was normal, and the signs of membrane depolarization correlated with raised serum bicarbonate and base excess, indicating compensated respiratory acidosis. It is inferred that motor axons in these CIP patients are depolarized, in part because of raised extracellular potassium, and in part because of hypoperfusion. The chronic membrane depolarization may contribute to the development of neuropathy.

Serine proteases purified from sera of patients with amyotrophic lateral sclerosis (ALS) induce contrasting cytopathology in murine motoneurones to IgG

Affinity purified IgG from sera of patients with amyotrophic lateral sclerosis (ALS) is claimed to enhance transmitter release, induce apoptotic death of cultured motoneurones, and elicit a distinctive cytopathology with raised Ca(2+) in mouse motoneurones. An alternative hypothesis attributes these events to serine proteases in ALS sera. To test this, motoneurones in BALB/c mice injected intraperitoneally with plasminogen affinity purified from sera of ALS patients and healthy controls were analysed using immunochemical and ultrastructural morphometric methods. The responses were validated in motoneurones of mice injected with commercially purified plasminogen, tissue plasminogen activator (tPA), or plasmin. Motoneurones in non-injected mice had normal morphology and ultrastructure without evidence of electron-dense degeneration. Purified plasminogen from both ALS patients and healthy controls, evoked electron-dense motoneurone degeneration, as did commercially purified plasminogen and tPA. The common cytopathology comprised disruption and distension of Nissl body rough endoplasmic reticulum, cytoplasmic polyribosomal proliferation, and significant Ca(2+) enhancement in mitochondria. By contrast, using affinity purified serum immunoglobulins, ALS-IgG but not IgG from healthy or disease controls, elicited necrosis, with 30% of ALS-IgGs tested evoking electron-dense degeneration in 40% of motoneurones. The primary cytopathology was extensive swelling of Golgi endoplasmic reticulum and mitochondria, with enhancement of Ca(2+) in Golgi endoplasmic reticulum and presynaptic boutons. We conclude that serine proteases purified from sera of ALS patients elicits a distinctive cytopathology and pattern of Ca(2+) enhancement in motoneurones different from that found on passive transfer of affinity purified ALS-IgG.

Infection-associated encephalopathies: their investigation, diagnosis, and treatment

Reduced level of consciousness is a common clinical finding in acutely sick patients. In the majority of cases a cause for the encephalopathy is readily identifiable,whilst in a minority the aetiology is more difficult to ascertain. Frequently the onset of encephalopathy is associated with, or follows, infection. The mechanisms through which infection leads to encephalopathy are diverse. They range from direct microbial invasion of the brain or its supporting structures, to remote, infection-triggered mechanisms such as acute disseminated encephalomyelitis. Most common however, is the encephalopathy caused through a remote effect of systemic sepsis-septic encephalopathy. This article discusses the clinical presentation and underlying pathogeneses of the acute encephalopathies associated with infection, aiming to aid both their recognition and treatment.

Probabilistic diffusion tractography: a potential tool to assess the rate of disease progression in amyotrophic lateral sclerosis

The goal of probabilistic tractography is to obtain a connectivity index along a white matter pathway that reflects fibre organization and is sensitive to pathological abnormalities contributing to disability. Here, we present the development of voxel-based connectivity measures along the tractography-derived corticospinal tract (CST). We investigated whether these connectivity measures are different in patients with amyotrophic lateral sclerosis (ALS) and correlate with the rate of disease progression. We also investigated whether fractional anisotropy (FA), which reflects directional coherence of fibre tracts, is reduced in the CST of ALS patients and relates to disease progression rate. Thirteen patients with probable or definite ALS and 19 healthy subjects were studied. The probabilistic tractography algorithm segmented the bilateral CST, along which FA and connectivity values were obtained. To take into account the asymmetric distribution of connectivity values, two summary statistic measures that focused on voxels with higher connectivity values were selected and then used in the analysis, together with the mean connectivity and the mean FA. To complete the analysis, the same summary measures for FA were included. Differences in all these indices between patients with moderate or rapid disease progression rate and controls were investigated using linear regression, adjusted for age and white matter fraction. The association between FA or connectivity in the CST and the disease progression rate was assessed using linear regression. Patients with a rapid disease progression rate had significantly lower summary connectivity measures than controls in the left CST, but there was only a borderline statistical difference in mean connectivity. Patients with rapid progression had a significantly lower mean FA, and any other FA measure, in both CSTs than controls. When only patients were considered, strong associations between the rate of disease progression and all the connectivity measures in the left CST were found (P-values between P < 0.001 and P = 0.002, partial correlation coefficients between -0.90 and -0.82). However, there was no evidence of an association between disease progression rate and any of the FA measures in the bilateral CST. Our findings suggest that FA and connectivity provide complementary information, since FA is sensitive to the detection of all the group differences, whereas the summary connectivity measures correlate with disease progression rate. The development of such connectivity measures raises their potential as markers of disease progression in ALS, and provides guidance for their use in other neurological diseases.

Analysis of an adult Duchenne muscular dystrophy population

BACKGROUND

Advances in management have led to increasing numbers of patients with Duchenne muscular dystrophy (DMD) reaching adulthood. Older patients with DMD are necessarily severely disabled, and their management presents particular practical issues.

AIM

To review the management of a late adolescent and adult DMD population, and to identify areas in which the present service provisions may be inadequate to their needs.

DESIGN

Retrospective review.

METHODS

We studied 25 patients with DMD referred to an adult neuromuscular clinic over a 7-year period. Clinical details were obtained retrospectively, from case notes or direct observations.

RESULTS

There were 24 males and one symptomatic female carrier. Nine patients died during the observation period. There was no significant correlation between age of wheelchair confinement and age of death. Sixteen patients received non-invasive positive pressure support. Twelve attended mainstream schools and 12, residential special schools. All the patients lived at home for some or all of the time, when their main carers were either one or both of the parents. The most striking difficulties were with the provision of practical aids, including appropriate hoists and belts, feeding and toileting aids, and the conversion of accommodation. Patients rarely wished to discuss the later stages of their disease, and death was often more precipitate than expected. Death usually occurred outside hospital and the final cause was often difficult to establish.

DISCUSSION

Adult patients with DMD develop progressive impairment, due to respiratory, orthopaedic and general medical factors. However, the particular areas of difficulty in this study often reflected inadequate and poorly directed social and medical support, illustrating the need for improvements in the structure, co-ordination and breadth of rehabilitation services for adult patients with DMD.

Factors influencing PCR detection of viruses in cerebrospinal fluid of patients with suspected CNS infections

BACKGROUND

Polymerase chain reaction (PCR) is used to detect viruses in the cerebrospinal fluid (CSF) of patients with neurological disease. However, data to assist its use or interpretation are limited.

OBJECTIVE

We investigated factors possibly influencing viral detection in CSF by PCR, which will also help clinicians interpret positive and negative results.

METHODS

CSF from patients with was tested for human herpesviruses types 1-6, JC virus, enteroviruses, and Toxoplasma gondii. The likelihood of central nervous system (CNS) infection was classified as likely, possible, or unlikely. PCR findings in these categories were compared using single variable and logistic regression analysis.

RESULTS

Of 787 samples tested, 97 (12%) were PCR positive for one or more viruses. Of episodes likely to be CNS viral infections, 30% were PCR positive compared to 5% categorised as unlikely. The most frequent positive findings were Epstein Barr virus (EBV), enteroviruses, and herpes simplex virus (HSV). Enteroviruses and HSV were found predominantly in the likely CNS viral infection group, whereas EBV was found mainly in the unlikely group. Positive PCR results were more likely when there were 3-14 days between symptom onset and lumbar puncture, and when CSF white cell count was abnormal, although a normal CSF did not exclude a viral infection.

CONCLUSIONS

The diagnostic yield of PCR can be maximised by using sensitive assays to detect a range of pathogens in appropriately timed CSF samples. PCR results, in particular EBV, should be interpreted cautiously when symptoms cannot readily be attributed to the virus detected.

Frontotemporal lobar degeneration with ubiquitin-only-immunoreactive neuronal changes: broadening the clinical picture to include progressive supranuclear palsy

The frontotemporal lobar degenerations (FTLDs) are a group of disorders in which the clinical picture is not necessarily predictive of the underlying neuropathology. The FTLD with ubiquitin-only-immunoreactive neuronal changes (FTLD-U) subtype is pathologically characterized by ubiquitin-positive, tau and alpha-synuclein-negative neuronal cytoplasmic inclusions in the frontotemporal cortex and hippocampal dentate fascia. When similar pathological changes are accompanied by histological features of motor neuron disease (MND), the term FTLD-MND is used. The latter pathological changes may be found in patients with or without clinical evidence of MND. We retrospectively reviewed the clinical details of three patients with a rapidly progressive, levodopa-unresponsive bradykinetic-rigid syndrome and frontal cognitive impairment. A diagnosis of progressive supranuclear palsy (PSP) had been considered in all three cases at initial presentation. Two of the cases fulfilled clinical diagnostic criteria for PSP, which was the final clinical diagnosis during life. Pathological analysis showed typical histological appearances of FTLD-MND in two cases and of FTLD-U in one case. Semi-quantitative analysis of pathological load seemed to correlate with the clinical phenotype. FTLD-U or FTLD-MND should be considered in the differential diagnosis of progressive frontal dementia with an akinetic rigid syndrome and supranuclear gaze palsy or Steele-Richardson-Olszewski disease.

Herpes simplex encephalitis: an audit of the use of laboratory diagnostic tests

BACKGROUND

The combination of both PCR and intrathecal antibody studies is recommended to confirm or refute the diagnosis of herpes simplex encephalitis (HSE).

AIM

To investigate the pattern of use of laboratory tests in the diagnosis of suspected cases of HSE, and to determine the final diagnosis in cases proven not to be HSE.

DESIGN

Structured audit.

METHODS

We reviewed the case-notes of all patients who, over a five-year time period, presented with suspected encephalitis; and/or were prescribed aciclovir. Clinical and laboratory criteria were used to categorize the likelihood of HSE.

RESULTS

We identified 222 patients: 10 (5%) had definite HSE, 24 (10%) possible HSE, and 144 (65%) a definite alternative diagnosis. In 44 (20%), no final diagnosis was made, but the diagnosis of HSE was excluded. PCR was performed in 68 (31%), intrathecal antibody studies in 24 (11%), and brain biopsy in 17 (8%). A wide range of diseases mimicked HSE, but most common were inflammatory diseases and other infections of the central nervous system.

DISCUSSION

Laboratory tests, particularly intrathecal antibody assays, are under-used in the diagnosis of HSE. Although early empirical treatment of suspected HSE is essential, confirmation or exclusion of the diagnosis is equally important to avoid overlooking alternative diagnoses. Identification of the aetiology of encephalitis is of particular importance, given the current concerns of emerging infections and bioterrorism.

Passive transfer of purified IgG from patients with amyotrophic lateral sclerosis to mice results in degeneration of motor neurons accompanied by Ca2+ enhancement

It has been reported that immunoglobulins (IgG) in sera of patients with amyotrophic lateral sclerosis (ALS) kill cultured motoneurones (MN), but whether they also cause MN degeneration in vivo is unclear. To test this, protein-A affinity purified and dialysed IgGs were prepared from sera of 44 ALS patients without paraproteinemias, 20 healthy controls and 15 disease controls. Control and ALS-IgGs were injected intraperitoneally into groups of mice for 5 consecutive days and examined at day 8. IgG was localised immunocytochemically and spinal MN were characterised histologically and ultrastructurally and by comparative counts of Ca(2+) containing organelles revealed with oxylate-pyroantimonate histochemistry. ELISA revealed no differences in IgG concentration between ALS patients and control subjects. Immunocytochemistry showed IgG was present in MN of mice injected with control or ALS-IgG, but densitometry showed immunostaining in MN was stronger in mice injected with ALS-IgG. Compared to MN of non-injected mice, control-IgG-treated mice showed near normal MN morphology and numbers of Ca(2+)-containing organelles. Disease control IgGs evoked negligible or minor morphological changes according to disease, but normal numbers of Ca(2+) containing organelles. Ultrastructurally, about 70% of ALS-derived IgGs induced a population of MN with electron lucent cytoplasm, distended Golgi, disrupted Nissl and mitochondria (i.e., necrosis). However 30% of ALS-IgGs additionally induced electron-dense degeneration in 40% of the MN. These MN exhibited shrinkage, condensed nuclear chromatin and ill-defined nuclear membranes and resembled preliminary stages of apoptosis. We conclude that passive transfer of ALS-derived, but not control IgGs, does result in MN degeneration in the recipient mice. This appears to be associated with abnormal calcium homeostasis, but the exact target of ALS-IgG remains conjectural, and the possibilities are discussed.

Opposites attract? Mate choice for parasite evasion and the evolutionary stability of sex

If sex is naturally selected as a way to combat parasites, then sexual selection for disease resistance might increase the overall strength of selection for outcrossing. In the present study, we compared how two forms of mate choice affect the evolutionary stability of outcrossing in simultaneous hermaphrodites. In the first form, individuals preferred to mate with uninfected individuals (condition-dependent choice). In the second form, individuals preferred to mate with individuals that shared the least number of alleles in common at disease-resistance loci. The comparisons were made using individual-based computer simulations in which we varied parasite virulence, parasite transmission rate, and the rate of deleterious mutation at 500 viability loci. We found that alleles controlling both forms of mate choice spread when rare, but their effects on the evolutionary stability of sex were markedly different. Surprisingly, condition-dependent choice for uninfected mates had little effect on the evolutionary stability of sexual reproduction. In contrast, active choice for mates having different alleles at disease-resistance loci had a pronounced positive effect, especially under low rates of deleterious mutation. Based on these results, we suggest that mate choice that increases the genetic diversity of offspring can spread when rare in a randomly mating population, and, as an indirect consequence, increase the range of conditions under which sexual reproduction is evolutionarily stable.

Mutation accumulation in growing asexual lineages

The stochastic loss of entire classes of individuals bearing the fewest number of mutations-a process known as Muller's ratchet-is studied in asexual populations growing unconstrained from a single founder. In the neutral regime, where mutations have zero effect on fitness, we derive a recursion equation for the probability distribution of the minimum number of mutations carried by individuals in the least-loaded class, and obtain an explicit condition for the halting of the ratchet. Next, we consider the case of deleterious mutations, and show that weak selection can actually accelerate the ratchet beyond that achieved for the neutral regime. This effect is transitory, however, as our results suggest that even weak purifying selection will eventually lead to the complete cessation of the ratchet. These results may have important implications for problems in biology and the medical sciences.

Brain stem encephalitis caused by primary herpes simplex 2 infection in a young woman

A 27 year old woman developed a vesicular genital rash and cerebellar dysfunction with progressive neurological deterioration suggesting brain stem encephalitis. Respiratory support was required. Magnetic resonance imaging (MRI) of the brain on day 7 showed signal hyperintensity in the central medulla and ventral pons, typical of acute inflammation. The course was severe and relapse occurred. MRI on day 33 showed a haemorrhagic area in the medulla. Treatment with aciclovir/valaciclovir eventually led to gradual recovery. Herpes simplex virus 2 (HSV-2) DNA was detected in CSF on days 11 and 14. HSV-2 was also detected in vesicle fluid from the genital rash. Serum was initially negative for HSV-1 and HSV-2 antibodies, but convalescent samples showed seroconversion to HSV-2, indicating primary infection. Intrathecal synthesis of oligoclonal IgG bands specific for HSV was identified in the CSF. It is important to differentiate HSV-2 from HSV-1, and primary from initial or reactivated infection, so that prolonged aciclovir treatment followed by prophylaxis is instituted to prevent the high likelihood of symptomatic relapse in primary HSV-2 infection.

Diffusion tensor imaging detects corticospinal tract involvement at multiple levels in amyotrophic lateral sclerosis

BACKGROUND

Histopathological studies of amyotrophic lateral sclerosis (ALS) are of end stage disease. Diffusion tensor imaging (DTI) provides the opportunity to investigate indirectly corticospinal tract pathology of ALS in vivo.

METHODS

DTI was used to study the water diffusion characteristics of the corticospinal tracts in 21 patients with ALS and 14 normal controls. The authors measured the fractional anisotropy (FA) and mean diffusivity (MD) along the pyramidal tracts from the internal capsules down to the pyramids. A mixed model regression analysis was used to compare FA and MD between the ALS and control groups.

RESULTS

FA showed a downward linear trend from the cerebral peduncles to the pyramids and was lower in the ALS group than controls at multiple levels of the corticospinal tract. At the internal capsules, FA was higher on the right. MD showed an upward trend, progressing caudally from the internal capsules to the pyramids. MD was higher at the level of the internal capsule in the ALS group, but caudally this difference was not maintained. No correlations were found between clinical markers of disability and water diffusion indices.

CONCLUSIONS

These findings provide insights into the pathological processes of ALS. Differences in diffusion characteristics at different anatomical levels may relate to underlying tract architecture or the distribution of pathological damage in ALS. Further development may permit monitoring of progression and treatment of disease.

Androgen deprivation in men with prostate cancer is associated with an increased rate of bone loss

The objective of this work was to determine the effect of androgen deprivation therapy (ADT) on rates of bone mineral density (BMD) loss in men with prostate cancer. It was a prospective study comparing men receiving ADT to age matched controls for 2 y. Subjects received a history, physical exam, bone mineral density measurement, and laboratory evaluation every 6 months. Thirty-nine subjects receiving continuous ADT for prostate cancer (subjects) were compared to 39 age-matched controls not receiving ADT (controls). Twenty-three subjects and 30 controls completed the study through 24 months. Men in the ADT group demonstrated greater rates of bone mineral density loss than men in the control group at every site except the lumbar spine. Twenty-four month per cent of bone mineral density loss is presented as mean+/-standard error (s.e.). At the distal forearm, the ADT group value was -9.4%+/-1.0% and -4.4%+/-0.3% for controls (P<0.0005). The ADT group femoral neck values were -1.9%+/-0.7% and 0.6%+/-0.5% in the control group (P=0.0016). The ADT group total hip value was -1.5%+/-1.0% and 0.8%+/-0.5% in the control group (P=0.0018). The ADT group trochanter value was -2.0%+/-1.3% and -0.1%+/-0.5% in the control group (P=0.0019). The ADT group lumbar spine value was -0.2%+/-0.8 % and 1.1%+/-0.6% in the control group (P=0.079). Our data demonstrate greater rates of bone mineral density loss in men receiving androgen deprivation therapy for prostate cancer.

Hypocretin (orexin) deficiency in narcolepsy and primary hypersomnia

The discovery that hypocretins are involved in narcolepsy, a disorder associated with excessive daytime sleepiness, cataplexy, and unusually rapid transitions to rapid eye movement sleep, opens a new field of investigation in the area of disorders of sleep and activation. Hypocretin-1 (hcrt-1) and hypocretin-2 (hcrt-2) (also called orexin-A and orexin-B) are newly discovered neuropeptides processed from a common precursor. Hypocretin containing cells are located exclusively in the lateral hypothalamus, with widespread projections within the central nervous system. The role of the hypocretin system in other disorders causing excessive daytime sleepiness is more uncertain. This study reports the findings of a prospective study measuring cerebrospinal fluid concentrations of hypocretin-1 and hypocretin-2 in HLA DQB1*0602 positive narcolepsy with cataplexy, monosymptomatic narcolepsy, and primary hypersomnia. The results confirmed the previous observations, that hcrt-1 is deficient in narcolepsy and for the first time report very low levels of hcrt-1 in primary hypersomnia. It is also reported for the first time that there is a generalised defect in hcrt-2 transmission in all three of these clinical entities compared with controls.

Management of motor neurone disease

Motor neurone disease is a progressive neurodegenerative disorder leading to severe disability and death. It is clinically characterised by mixed upper and lower motor neurone involvement affecting bulbar, limb, and respiratory musculature. Recent guidelines have established diagnostic criteria and defined management of the condition. In a proportion of familial amyotrophic lateral sclerosis there is a mutation in the gene encoding the enzyme copper/zinc superoxide dismutase 1; this has allowed mutation screening and generated considerable laboratory based research. The diagnosis must be given with care and consideration and close follow up is essential. Management involves a multidisciplinary team based in the hospital and the community. Riluzole is the only drug shown to have a disease modifying effect and has been approved by the National Institute for Clinical Excellence. The essence of care is good symptomatic management, including nutritional support with percutaneous endoscopic gastrostomy and ventilatory care with non-invasive ventilation. Palliative care should be introduced before the terminal stages after careful discussion with the patient and carers. Knowledge of this condition has grown dramatically recently with a parallel improvement in treatment and ability to deal with the most troublesome problems.

Outcome of ventilatory support for acute respiratory failure in motor neurone disease

OBJECTIVES

To review the outcome of acute ventilatory support in patients presenting acutely with respiratory failure, either with an established diagnosis of motor neurone disease (MND) or with a clinical event where the diagnosis of MND has not yet been established.

METHODS

Outcome was reviewed in 24 patients with respiratory failure due to MND who received endotracheal intubation and intermittent positive pressure ventilation either at presentation or as a result of the unexpected development of respiratory failure. Patients presenting to local hospitals with acute respiratory insufficiency and requiring tracheal intubation, ventilatory support, and admission to an intensive therapy unit (ITU) before transfer to a regional respiratory care unit were selected. Clinical features of presentation, management, and outcome were studied.

RESULTS

24 patients with MND were identified, all being intubated and ventilated acutely within hours of presentation. 17 patients (71%) were admitted in respiratory failure before the diagnosis of MND had been made; the remaining seven patients (29%) were already known to have MND but deteriorated rapidly such that intubation and ventilation were initiated acutely. Seven patients (29%) died on ITU (between seven and 54 days after admission). 17 patients (71%) were discharged from ITU. 16 patients (67%) received long term respiratory support and one patient required no respiratory support following tracheal extubation. The daily duration of support that was required increased gradually with time.

CONCLUSION

When a patient with MND is ventilated acutely, with or without an established diagnosis, independence from the ventilator is rarely achieved. Almost all of these patients need long term ventilatory support and the degree of respiratory support increases with time as the disease progresses. The aim of management should be weaning the patient to the minimum support compatible with symptomatic relief and comfort. Respiratory failure should be anticipated in patients with MND when the diagnosis has been established.

Brain excitatory amino acid concentrations are lower in the neonatal pig: a buffer against excitotoxicity?

Hypoglycemic brain damage has been associated with high levels of the excitatory amino acids (EAA) aspartate and glutamate in the newborn and adult. We hypothesized that newborn piglet EAA would be different from those of older pigs when stressed with severe insulin-induced hypoglycemia (<30 mg/dl). Brain EAA were measured in piglets and adolescent pigs via microdialysis. Eleven of 12 newborn normoglycemic piglets had no detectable baseline levels (<0.5 microM) of EAA, while pigs had aspartate and glutamate concentrations of 1.78 +/- 0.44 and 3.43 +/- 1.14 microM (mean +/- SEM), respectively. Piglet aspartate and glutamate concentrations reached but did not significantly exceed normoglycemic pig levels after 2 h with plasma glucose values < or =20 mg/ml. Elevations in EAA were only detected in piglets whose EEG activity ceased. Aspartate and glutamate concentrations did not increase in insulin-treated pigs nor in control animals. We speculate that newborns with blood glucose less than clinically acceptable values (35 mg/dl) may be protected from EAA-associated neuronal damage during acute hypoglycemia. Lower normoglycemic and hypoglycemic levels of EAA in newborns when compared to older pigs provide this protection.

Measurement of isolated subtalar range of motion: a cadaver study

Fifteen fresh-frozen cadaveric lower extremities were studied to evaluate the reliability of measuring subtalar motion using a bubble inclinometer. There was high intra-observer reliability for manual inversion and eversion of the subtalar joint with the tibiotalar joint locked and unlocked. Poor correlation of radiographic and clinical measurements questioned the validity of bubble inclinometer measurements. The contribution of the tibiotalar joint to apparent subtalar motion, as measured clinically and radiographically, was found to be one-third of the arc of motion, as compared to motion measured clinically and radiographically with the tibiotalar joint locked.

Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity

PURPOSE

Rituximab has been reported to have little activity in small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and to be associated with significant infusion-related toxicity. This study sought to decrease the initial toxicity and optimize the pharmacokinetics with an alternative treatment schedule.

PATIENTS AND METHODS

Thirty three patients with SLL/CLL received dose 1 of rituximab (100 mg) over 4 hours. In cohort I (n = 3; 250 mg/m(2)) and cohort II (n = 7; 375 mg/m(2)) rituximab was administered on day 3 and thereafter three times weekly for 4 weeks using a standard administration schedule. Cohort III (n = 23; 375 mg/m(2)) administered rituximab similar to cohort II for the first two treatments and then over 1 hour thereafter.

RESULTS

A total of 33 CLL/SLL patients were enrolled; only one patient discontinued therapy because of infusion-related toxicity. Thirteen patients developed transient hypoxemia, hypotension, or dyspnea that were associated with significant changes in baseline interleukin-6, interleukin-8, tumor necrosis factor alpha, and interferon gamma compared with those not experiencing such reactions. Infusion-related toxicity occurred more commonly in older (median age 73 v 62 years; P =.02) patients with no other pretreatment clinical or laboratory features predicting occurrence of these events. The overall response rate was 45% (3% CR, 42% PR; 95% CI 28% to 64%). Median response duration for these 15 patients was 10 months (95% CI, 6.8-13.2; range, 3 to 17+).

CONCLUSION

Rituximab administered thrice weekly for 4 weeks demonstrates clinical efficacy and acceptable toxicity. Initial infusion-related events seem to be cytokine mediated and resolve by the third infusion making rapid administration possible. Future combination studies of rituximab with other therapies in CLL seem warranted.

Outcome of sulcus fixation of dislocated posterior chamber intraocular lenses using temporary externalization of the haptics

OBJECTIVE

This study evaluated the visual outcome and complications of repositioning and sulcus fixation of a dislocated posterior chamber intraocular lens (PC IOL) using a technique in which the haptics of the IOL are temporarily externalized for suture placement.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Seventy-eight patients with a dislocated PC IOL.

INTERVENTION

All patients underwent surgery to fixate the PC IOL using this technique.

MAIN OUTCOME MEASURES

Patients were evaluated for visual acuity, refractive error, and surgical complications associated with the procedure.

RESULTS

The average visual acuity before surgery was 20/205 (range, 20/20 to light perception), with a median refractive error of -1.00 diopters (D; range, -7.25-+15.00 D). After surgery, the average visual acuity improved to 20/72 (range, 20/20 to no light perception), with a median refractive error of -0.75 D (range, -5.50-+3.50 D). Patients were observed for a median of 15.5 months (range, 6-57 months). Twenty patients had postoperative cystoid macular edema (26%), 7 patients had an epiretinal membrane (ERM) (9%), and 5 patients had a retinal detachment (6%). Eight patients (10%) experienced iris capture of the sutured IOL, and in three patients (4%) the PC IOL dislocated again after surgery.

CONCLUSIONS

This technique is an effective method for securing a dislocated PC IOL.