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A small subset of lung adenocarcinomas harbour ROS1 gene arrangements and are amenable to tyrosine kinase inhibitor therapy. Current practice in Australia involves screening for ROS1 rearrangements in adenocarcinomas using ROS1 immunohistochemistry (IHC) followed by confirmatory molecular testing such as fluorescence in situ hybridisation (FISH), if other known genetic driver alterations are absent. The best threshold to determine ROS1 IHC positivity is not well defined, however, and this study aims to determine the optimal threshold for ROS1 IHC screening to identify ROS1-rearranged lung adenocarcinomas. A total of 177 lung adenocarcinomas tested for a ROS1 rearrangement by FISH at our institution between 2017 and 2020 due to presence of ROS1 IHC staining were included in the study. ROS1 IHC staining was assessed by scoring the staining intensity (0, 1, 2, or 3+) and multiplying by the percentage of positive cells to generate an H-score. IHC H-scores were compared with FISH. Of 177 cases, 32 (18%) were ROS1 FISH-positive and 145 (82%) were negative. FISH-positive cases had a median H-score of 300 (range 200-300; mean 290.3) and negative cases had a median H-score of 40 (range 0-300; mean 63). All FISH-positive cases showed strong and diffuse IHC positivity. Using a threshold H-score of 200, the sensitivity of identifying ROS1 rearrangements was 100% and the specificity was 95% amongst cases referred with ROS1 IHC positivity. Adenocarcinomas with a FISH-confirmed ROS1 rearrangement demonstrate diffuse, strong (2-3+) IHC staining. Cases with weak, patchy ROS1 IHC staining are not associated with ROS1 rearrangements and in these cases FISH testing is of little to no utility.

A 3.5-month-old boy presented with a changing medium-sized congenital melanocytic nevus on his leg. Due to atypical features on dermoscopy and reflectance confocal microscopy (RCM), an excision of the area of concern was performed. Histopathology showed many of the pathological features usually associated with a diagnosis of melanoma in situ in older patients, but due to the young age of the patient, absence of mitoses, and the degree of atypia, a diagnosis of a dysplastic compound nevus arising in a congenital compound (predominantly dermal) nevus was favored. In our case, RCM corresponded to histopathology helped target the area of concern and map the clinical and subclinical components to facilitate an optimal biopsy.

BACKGROUND The ocular vestibular evoked myogenic potential is otolith-dependent and has been suggested to be a manifestation of the linear vestibulo-ocular reflex (L-VOR). A characteristic feature of the translational LVOR (t-LVOR) is its dependence on the distance of a target. OBJECTIVE To assess if viewing distance affects amplitude and latency properties of the ocular vestibular evoked myogenic potential (oVEMPs). METHODS Bone- and air-conducted (BC and AC) stimuli were used to evoke oVEMPs in 10 healthy subjects. BC stimuli consisted of impulsive accelerations applied at the mastoids, AFz, Oz and Iz. AC stimuli consisted of 500 Hz tones delivered unilaterally to each ear. Target distances of 40 cm (near), 190 cm (intermediate) and 340 cm (far) were used for all stimuli. RESULTS The largest amplitude oVEMP was obtained from Iz and the latency for AFz was shorter than for BC stimulation at other sites. We found no significant effect of target distance on oVEMP amplitudes for any of the stimuli used. There was a small but significant effect on latency with the nearest target having a longer latency (overall 12.4 ms vs 12.0 ms for the 2 more distant sites). CONCLUSIONS Previously reported differences between latencies and stimulus sites for midline BC stimulation were confirmed. Target distance had no significant effect on oVEMP amplitude, which suggests it is not modified like other components of the t-LVOR.

Purpose Circulating tumor DNA (ctDNA) allows noninvasive disease monitoring across a range of malignancies. In metastatic melanoma, the extent to which ctDNA reflects changes in metabolic disease burden assessed by 18F-labeled fluorodeoxyglucose positron emission tomography (FDG-PET) is unknown. We assessed the role of ctDNA analysis in combination with FDG-PET to monitor tumor burden and genomic heterogeneity throughout treatment. Patients and Methods We performed a comprehensive analysis of serial ctDNA and FDG-PET in 52 patients who received systemic therapy for metastatic melanoma. Next-generation sequencing and digital polymerase chain reaction were used to analyze plasma samples from the cohort. Results ctDNA levels were monitored across patients with mutant BRAF, NRAS, and BRAF/NRAS wild type disease. Mutant BRAF and NRAS ctDNA levels correlated closely with changes in metabolic disease burden throughout treatment. TERT promoter mutant ctDNA levels also paralleled changes in tumor burden, which provide an alternative marker for disease monitoring. Of note, subcutaneous and cerebral disease sites were not well represented in plasma. Early changes in ctDNA and metabolic disease burden were important indicators of treatment response. Patients with an early decrease in ctDNA post-treatment had improved progression-free survival compared with patients in whom ctDNA levels remained unchanged or increased over time (hazard ratio, 2.6; P = .05). ctDNA analysis contributed key molecular information through the identification of putative resistance mechanisms to targeted therapy. A detailed comparison of the genomic architecture of plasma and multiregional tumor biopsy specimens at autopsy revealed the ability of ctDNA to comprehensively capture genomic heterogeneity across multiple disease sites. Conclusion The findings highlight the powerful role of ctDNA in metastatic melanoma as a complementary modality to functional imaging that allows real-time monitoring of both tumor burden and genomic changes throughout therapy.

In the original publication of the article, Fig. 3 is incorrect.

The accurate recognition of subtle melanomas and their distinction from benign mimics is an oft-recurring diagnostic problem, critical for patient management. Melanomas that bear resemblance to benign nevi (so-called nevoid melanomas, NMs) and benign mitotically active nevi in pregnancy (MANP) are 2 lesions particularly prone to error. Molecular data, including analysis of noncoding regions, in MANP and NM are very limited. This study sought to identify differences in clinical, pathologic, and molecular characteristics between MANP and NMs to facilitate correct diagnosis and reduce the risk of overtreatment or undertreatment. Clinicopathologic characteristics of NM (n=18) and MANP (n=30) were evaluated, and mutation data were analyzed using next-generation sequencing for available cases in each group (NM, n=8; MANP, n=12). All MANP showed innocent histopathologic characteristics apart from increased mitotic activity, frequently in both superficial and deep parts of the lesion (median dermal mitotic rate: 2/mm, range: 1 to 7/mm). All cases of NM demonstrated a characteristic nevoid silhouette, subtle atypical architectural and cytologic features, and variable mitoses (median mitotic rate: 3/mm, range: 1 to 5/mm). Median NM tumor thickness was 1.4 mm. Four of 10 NM patients with follow-up had metastatic disease, including 3 patients who developed widespread metastases, with 1 disease-related death. No other recurrences have been identified (follow-up period: 24 to 60 mo). None of the 15 MANP patients with available follow-up had a recurrence. Most NMs harbored hotspot mutations in NRAS (6/8, 75%). Noncoding mutations were significantly more common in NMs than in MANP (median: 4 vs. 0, P=0.0014). Copy number alterations were infrequent but, when present, were seen in NMs (3/8 NMs vs. 0/12 MANP). All NMs but only 1 of 12 MANP had >1 abnormality in the noncoding regions. Similar to conventional common acquired nevi, MANP mostly harbored driver BRAF mutations, while activating NRAS mutations, noncoding mutations, and copy number alterations were rare. NM and MANP have subtle but recognizable distinguishing histopathologic characteristics that are underpinned by molecular differences. Mutation analysis of targeted noncoding mutations may assist in the diagnosis of difficult lesions.

Vestibular evoked myogenic potentials (VEMPs) are now widely used for the noninvasive assessment of vestibular function and diagnosis in humans. This review focuses on the origin, properties, and mechanisms of cervical VEMPs and ocular VEMPs; how these reflexes relate to reports of vestibular projections to brain stem and cervical targets; and the physiological role of (otolithic) cervical and ocular reflexes. The evidence suggests that both VEMPs are likely to represent the effects of excitation of irregularly firing otolith afferents. While the air-conducted cervical VEMP appears to mainly arise from excitation of saccular receptors, the ocular VEMP evoked by bone-conducted stimulation, including impulsive bone-conducted stimuli, mainly arises from utricular afferents. The surface responses are generated by brief changes in motor unit firing. The effects that have been demonstrated are likely to represent otolith-dependent vestibulocollic and vestibulo-ocular reflexes, both linear and torsional. These observations add to previous reports of short latency otolith projections to the target muscles in the neck (sternocleidomastoid and splenius) and extraocular muscles (the inferior oblique). New insights have been provided by the investigation and application of these techniques.

The benign melanocytic nevus is the most common tumor in humans and rarely transforms into cutaneous melanoma. Elucidation of the nevus genome is required to better understand the molecular steps of progression to melanoma. We performed whole genome sequencing on a series of 14 benign melanocytic nevi consisting of both congenital and acquired types. All nevi had driver mutations in the MAPK signaling pathway, either BRAF V600E or NRAS Q61R/L. No additional definite driver mutations were identified. Somatic mutations in nevi with higher mutation loads showed a predominance of mutational signatures 7a and 7b, consistent with UVR exposure, whereas nevi with lower mutation loads (including all three congenital nevi) had a predominance of the ubiquitous signatures 1 and 5. Two nevi had mutations in promoter regions predicted to bind E26 transformation-specific family transcription factors, as well as subclonal mutations in the TERT promoter. This paper presents whole genome data from melanocytic nevi. We confirm that UVR is involved in the etiology of a subset of nevi. This study also establishes that TERT promoter mutations are present in morphologically benign skin nevi in subclonal populations, which has implications regarding the interpretation of this emerging biomarker in sensitive assays.

The aim of this project was to evaluate the current practice and implement best practice related to Enhanced Recovery After Surgery (ERAS) nutrition care protocols amongst elective colorectal surgery patients at Calvary North Adelaide Hospital. A second aim was to improve outcomes regarding length of hospital stay and rate of unplanned readmissions within 28-days in patients undergoing elective colorectal surgery.The rate of postoperative morbidity remains high after elective colorectal surgery. Enhanced Recovery After Surgery is an evidence-based program incorporating multimodal interventions (including nutrition interventions) in the perioperative period to reduce postoperative morbidity and expedite recovery.This evidence implementation project used the JBI Practical Application of Clinical Evidence System (JBI PACES) and Getting Research into Practice (GRiP) audit and feedback tool. This project was conducted across the preadmission clinic, intensive care unit and surgical wards of a 153-bed, private, acute care hospital in Australia, along with five private surgical clinics. The sample size included 20 patients undergoing elective colorectal surgery and five colorectal surgeons. Seven audit criteria based on the ERAS Society nutrition care protocols for elective colorectal surgery were used, and patient outcomes were length of stay and rate of unplanned readmission within 28 days. A pre-implementation audit was conducted, which informed the development of an implementation plan for ERAS nutrition care protocols using the GRiP analysis. A follow-up audit was conducted to measure change in practice and patient outcomes.Improvement in compliance was observed in four audit criteria: preoperative fasting is minimized (from 0% to 15%), early feeding is implemented postoperatively (from 10% to 65%), preoperative carbohydrate drinks are given (from 20% to 25%) and oral supplements are given postoperatively (from 0% to 20%). Compliance for one audit criterion remained constant: patients are screened for malnutrition risk in preadmission clinic (100% for both audits). Two audit criteria saw a drop in compliance: nutrition support is provided preoperatively to malnourished patients (from 60% to 15%) and nutrition education is provided preoperatively (from 60% to 20%). There was a 2.5-day reduction in length of stay (average 10.8 days length of stay pre-implementation versus 8.3 days post-implementation) and an increase from 0% to 20% in the rate of unplanned readmissions within 28 days post-implementation; however, these were not statistically significant (p = 0.7 and p = 0.11, respectively).Changes in patient outcomes could not be attributed to the implementation of ERAS nutrition care protocols, given the mixed compliance with audit criteria in the post-implementation audit. This project has, however, raised awareness of the importance of having operational definitions for audit criteria, systems to ensure adherence to protocols, and audits of calendar year data for reliability and validity of results. It has also increased knowledge of ERAS nutrition care protocols amongst those involved in the care of patients undergoing elective colorectal surgery and strengthened relationships within the multidisciplinary team. This project represents the first step toward the development of an effective ERAS nutrition care program for patients underoing elective colorectal surgery at Calvary North Adelaide Hospital and informs future audits and feedback cycles.

Melanoma is usually driven by mutations in BRAF or NRAS, which trigger hyperactivation of MAPK signaling. However, MAPK-targeted therapies are not sustainably effective in most patients. Accordingly, characterizing mechanisms that co-operatively drive melanoma progression is key to improving patient outcomes. One possible mechanism is the Hippo signaling pathway, which regulates cancer progression via its central oncoproteins YAP and TAZ, although is thought to be only rarely affected by direct mutation. As YAP hyperactivation occurs in uveal melanoma, we investigated this oncogene in cutaneous melanoma. YAP protein expression was elevated in most benign nevi and primary cutaneous melanomas but present at only very low levels in normal melanocytes. In patient-derived xenografts and melanoma cell lines, we observed variable reliance of cell viability on Hippo pathway signaling that was independent of TAZ activity and also of classical melanoma driver mutations such as BRAF and NRAS. Finally, in genotyping studies of melanoma, we observed the first ever hyperactivating YAP mutations in a human cancer, manifest as seven distinct missense point mutations that caused serine to alanine transpositions. Strikingly, these mutate four serine residues known to be targeted by the Hippo pathway and we show that they lead to hyperactivation of YAP. Implications: Our studies highlight the YAP oncoprotein as a potential therapeutic target in select subgroups of melanoma patients, although successful treatment with anti-YAP therapies will depend on identification of biomarkers additional to YAP protein expression.

The short-latency vestibulo-collic reflex in humans is well defined for only the sternocleidomastoid (SCM) neck muscle. However, other neck muscles also receive input from the balance organs and participate in neck stabilization. We therefore investigated the sound-evoked vestibular projection to the splenius capitis (SC) muscles by comparing surface and single motor unit responses in the SC and SCM muscles in 10 normal volunteers. We also recorded surface responses in patients with unilateral vestibular loss but preserved hearing and hearing loss but preserved vestibular function. The single motor unit responses were predominantly inhibitory, and the strongest responses were recorded in the contralateral SC and ipsilateral SCM. In both cases there was a significant decrease or gap in single motor unit activity, in SC at 11.7 ms for 46/66 units and in SCM at 12.7 ms for 51/58 motor units. There were fewer significant responses in the ipsilateral SC and contralateral SCM muscles, and they consisted primarily of weak increases in activity. Surface responses recorded over the contralateral SC were positive-negative during neck rotation, similar to the ipsilateral cervical vestibular evoked myogenic potential in SCM. Responses in SC were present in the patients with hearing loss and absent in the patient with vestibular loss, confirming their vestibular origin. The results describe a pattern of inhibition consistent with the synergistic relationship between these muscles for axial head rotation, with the crossed vestibular projection to the contralateral SC being weaker than the ipsilateral projection to the SCM. NEW & NOTEWORTHY We used acoustic vestibular stimulation to investigate the saccular projections to the splenius capitis (SC) and sternocleidomastoid (SCM) muscles in humans. Single motor unit recordings from within the muscles demonstrated strong inhibitory projections to the contralateral SC and ipsilateral SCM muscles and weak excitatory projections to the opposite muscle pair. This synergistic pattern of activation is consistent with a role for the reflex in axial rotation of the head.

We studied 12 patients with Parkinson's disease (PD): 6 with postural instability (Hoehn and Yahr Stage 3) and 6 without (Stage 2 or 2.5), using a quantitative test based on the clinical pull test. Their findings were compared with those for 12 healthy controls. The patients on their usual medications were pulled either forwards or backwards at the level of the shoulders and asked not to take a step in a series of five trials. Acceleration was monitored for the upper trunk, sacrum, and both tibias. EMG was measured in soleus and tibialis anterior (TA) muscles in all and for thigh and truncal muscles in a subgroup. A target of 0.2 g trunk acceleration was used, but smaller perturbations were used in very unstable patients. All the Stage 3 patients lost balance in at least one trial for the posterior perturbations but none for the anterior ones. None of the Stage 2 patients lost balance. There was increased tonic EMG and agonist activity but no difference in EMG onset or initial force production compared to healthy controls. For posterior perturbations, there were two related disorders that separated the PD patients from controls. There was a significantly higher ratio of sacral-to-applied acceleration and both PD groups showed reduced knee acceleration and shortened latency, more so for the Stage 3 group. The increased sacral-to-C7 acceleration ratio was correlated with the tonic level of activation of the hamstrings (HS), quadriceps, and lumbar paraspinal muscles (PS), while the tibial acceleration latency was also correlated with the level of tonic PS activation. We also found that the size of balance responses, 0-200 ms post-perturbation, correlated significantly with the level of tonic activation in nearly all the muscles studied. We confirmed that PD patients show greater instability posteriorly than anteriorly to applied perturbations. Our findings support increasing axial and limb rigidity as the cause of the impaired pull test rather than postural bradykinesia and suggest that tonic truncal and thigh muscle activation may be an important underlying cause.

In this review, we summarise the function and structure of telomerase reverse transcriptase (TERT) in humans, including its regulation. The dysregulation of telomerase through TERT promoter mutations across a range of cancers is discussed. The molecular mechanism activated by TERT promoter mutations is outlined. Finally, the timing of TERT promoter mutations during carcinogenesis is reviewed in the context of their potential utility as clinical biomarkers of malignant transformation.

Highlights • Vestibular evoked myogenic potentials (VEMPs) are used to test the otolith organs in patients with vertigo and imbalance. • This review discusses the optimal procedures for recording VEMPs and the pitfalls commonly encountered by clinicians. • Better understanding of VEMP methodology should lead to improved quality of recordings., Vestibular evoked myogenic potentials (VEMPs) are a useful and increasingly popular component of the neuro-otology test battery. These otolith-dependent reflexes are produced by stimulating the ears with air-conducted sound or skull vibration and recorded from surface electrodes placed over the neck (cervical VEMPs) and eye muscles (ocular VEMPs). VEMP abnormalities have been reported in various diseases of the ear and vestibular system, and VEMPs have a clear role in the diagnosis of superior semicircular canal dehiscence. However there is significant variability in the methods used to stimulate the otoliths and record the reflexes. This review discusses VEMP methodology and provides a detailed theoretical background for the techniques that are typically used. The review also outlines the common pitfalls in VEMP recording and the clinical applications of VEMPs.

Although melanoma is initiated by acquisition of point mutations and limited focal copy number alterations in melanocytes-of-origin, the nature of genetic changes that characterise lethal metastatic disease is poorly understood. Here, we analyze the evolution of human melanoma progressing from early to late disease in 13 patients by sampling their tumours at multiple sites and times. Whole exome and genome sequencing data from 88 tumour samples reveals only limited gain of point mutations generally, with net mutational loss in some metastases. In contrast, melanoma evolution is dominated by whole genome doubling and large-scale aneuploidy, in which widespread loss of heterozygosity sculpts the burden of point mutations, neoantigens and structural variants even in treatment-naïve and primary cutaneous melanomas in some patients. These results imply that dysregulation of genomic integrity is a key driver of selective clonal advantage during melanoma progression., The genetic changes that occur in late stage metastatic melanoma are not well delineated. Here, the authors use rapid autopsy samples from metastatic melanoma patients and show that the late stage in the disease is characterised by whole genome doubling and aneuploidy.

In this work we examine the possible neural basis for two brainstem-spinal reflexes using source analyses of brain activity recorded over the cortex and posterior fossa. In a sample of 5 healthy adult subjects, using axial and vestibular stimulation by means of applied impulsive forces, evoked potentials were recorded with 63 channels using a 10 % cerebellar extension montage. In parallel, EMG was recorded from soleus and tibialis anterior muscles and accelerometry from the lower leg. Recordings over the cerebellum (ECeG) confirmed the presence of short latency (SL) potentials and these were associated with changes in high-frequency power. The SL responses to the two stimulus modalities differed in that the axial stimulation produced an initial pause and then a burst in the high-frequency ECeG, followed by excitation/inhibition in soleus while vestibular stimulation produced an initial burst then a pause, followed by inhibition/excitation in soleus. These short latency responses were followed by longer latency N1/P2/N2 responses in the averaged EEG, which were maximal at FCz. Brain Electrical Source Analysis (BESA) demonstrated both cerebellar and cerebral cortical contributions to the short-latency responses and primarily frontal cortex contributions to the long-latency EPs. The latency and polarity of the SL EPs, in conjunction with changes in high-frequency spontaneous activity, are consistent with cerebellar involvement in the control of brainstem-spinal reflexes. The early involvement of frontal cortex and subsequent later activity may be an indicator of the activation of the cortical motor-related system for rapid responses which may follow the reflexive components. These findings provide evidence of the feasibility of non-invasive electrophysiology of the human cerebellum and have demonstrated cerebellar and frontal activations associated with postural-related stimuli.

Immunotherapy with checkpoint inhibitors is well established as an effective treatment for non-small cell lung cancer and melanoma. The list of approved indications for treatment with PD-1/PD-L1 checkpoint inhibitors is growing rapidly as clinical trials continue to show their efficacy in patients with a wide range of solid tumours. Clinical trials have used a variety of PD-L1 immunohistochemical assays to evaluate PD-L1 expression on tumour cells, immune cells or both as a potential biomarker to predict response to immunotherapy. Requests to pathologists for PD-L1 testing to guide choice of therapy are rapidly becoming commonplace. Thus, pathologists need to be aware of the different PD-L1 assays, methods of evaluation in different tumour types and the impact of the results on therapeutic decisions. This review discusses the key practical issues relating to the implementation of PD-L1 testing for solid tumours in a pathology laboratory, including evidence for PD-L1 testing, different assay types, the potential interchangeability of PD-L1 antibody clones and staining platforms, scoring criteria for PD-L1, validation, quality assurance, and pitfalls in PD-L1 assessment. This review also explores PD-L1 IHC in solid tumours including non-small cell lung carcinoma, head and neck carcinoma, triple negative breast carcinoma, melanoma, renal cell carcinoma, urothelial carcinoma, gastric and gastroesophageal carcinoma, colorectal carcinoma, hepatocellular carcinoma, and endometrial carcinoma. The review aims to provide pathologists with a practical guide to the implementation and interpretation of PD-L1 testing by immunohistochemistry.

Primary melanomas >1 mm thickness are potentially curable by resection, but can recur metastatically. We assessed the prognostic value of T cell fraction (TCFr) and repertoire T cell clonality, measured by high-throughput-sequencing of the T cell receptor beta chain (TRB) in T2-T4 primary melanomas (n=199). TCFr accurately predicted progression-free survival (PFS) and was independent of thickness, ulceration, mitotic rate, or age. TCFr was second only to tumor thickness in its predictive value, using a gradient boosted model. For accurate PFS prediction, adding TCFr to tumor thickness was superior to adding any other histopathological variable. Furthermore, a TCFr >20% was protective regardless of tumor ulceration status, mitotic rate or presence of nodal disease. TCFr is a quantitative molecular assessment that predicts metastatic recurrence in primary melanoma patients whose disease has been resected surgically. This study suggests that a successful T cell-mediated antitumor response can be present in primary melanomas.

Tumor mutation burden (TMB) has been proposed as a key determinant of immunogenicity in several cancers, including melanoma. The evidence presented thus far, however, is often contradictory and based mostly on RNA-sequencing data for the quantification of immune cell phenotypes. Few studies have investigated TMB across acral, mucosal, and cutaneous melanoma subtypes, which are known to have different TMB. It is also unknown whether chromosomal structural mutations [structural variant (SV) mutations] contribute to the immunogenicity in acral and mucosal melanomas where such aberrations are common. We stained 151 cutaneous and 35 acral and mucosal melanoma patient samples using quantitative IHC and correlated immune infiltrate phenotypes with TMB and other genomic profiles. TMB and SVs did not correlate with the densities of CD8+ lymphocytes, CD103+ tumor-resident T cells (Trm), CD45RO+ cells, and other innate and adaptive immune cell subsets in cutaneous and acral/mucosal melanoma tumors, respectively, including in analyses restricted to the site of disease and in a validation cohort. In 43 patients with stage III treatment-naïve cutaneous melanoma, we found that the density of immune cells, particularly Trm, was significantly associated with patient survival, but not with TMB. Overall, TMB and chromosomal structural aberrations are not associated with protective antitumor immunity in treatment-naïve melanoma.

Genetic testing strategies such as next-generation sequencing (NGS) panels and whole genome sequencing (WGS) can be applied to the hereditary cerebellar ataxias (HCAs), but their exact role in the diagnostic pathway is unclear. We aim to determine the yield from genetic testing strategies and the genetic and phenotypic spectrum of HCA in Australia by analysing real-world data. We performed a retrospective review on 87 HCA cases referred to the Neurogenetics Clinic at the Royal North Shore Hospital, Sydney, Australia. Probands underwent triplet repeat expansion testing; those that tested negative had NGS-targeted panels and WGS testing when available. In our sample, 58.6% were male (51/87), with an average age at onset of 37.1 years. Individuals with sequencing variants had a prolonged duration of illness compared to those with a triplet repeat expansion. The detection rate in probands for routine repeat expansion panels was 13.8% (11/80). NGS-targeted panels yielded a further 11 individuals (11/32, 34.4%), with WGS yielding 1 more diagnosis (1/3, 33.3%). NGS panels and WGS improved the overall diagnostic rate to 28.8% (23/80) in 14 known HCA loci. The genetic findings included novel variants in ANO10, CACNA1A, PRKCG and SPG7. Our findings highlight the genetic heterogeneity of HCAs and support the use of NGS approaches for individuals who were negative on repeat expansion testing. In comparison to repeat disorders, individuals with sequencing variants may have a prolonged duration of illness, consistent with slower progression of disease.

We studied the short-latency (SL) effects of postural perturbations produced by impulses applied over the spine of the C7 vertebra or the sternum ("axial impulses") in 12 healthy subjects. EMG recordings were made bilaterally from the triceps brachii, biceps brachii, soleus, and tibialis anterior muscles, and unilaterally from the deltoid, forearm flexors, forearm extensors, and first dorsal interosseous (FDI) muscles. Sternal impulses evoked short-latency responses in the biceps when subjects leaned posteriorly to support approximately 12% of their body weight with the arms, but these responses were only modestly larger than for isometric contraction of the arms (26.3 vs. 14.7%). In contrast, clear excitatory responses could be evoked in the deltoid, triceps, forearm muscles, and FDI when leaning anteriorly to support similar amounts of body weight. These responses were significantly larger than during isometric contraction. The deltoid (42.5%) and triceps (44.7%) had the largest responses in supported anterior lean and onset latencies increased distally in this condition (mean 31.8 ms in deltoid to 53.7 ms in FDI). There was a disproportionate delay between the forearm muscles and FDI. For both directions of lean, postural reflex responses normally present in the legs were severely attenuated. SL upper limb excitatory responses were bigger in proximal muscles as well as larger and more widespread for anterior axial perturbations compared to posterior axial perturbations when using the arms to support body weight. Our findings also provide further evidence of a role for reticulospinal pathways in mediating these rapid postural responses to accelerations of the trunk.

Our object was to investigate the effect of location and phase on the properties of oVEMPs and cVEMPs evoked by two bone conducted (BC) stimuli, 500 Hz and an impulsive stimulus for midline skull sites from Nz to Iz, in normal volunteers. Compressive and rarefactive onset phases were used and the induced linear and rotational accelerations measured. We confirmed our previous finding of marked changes in the polarity of oVEMPs with location. For cVEMPs using the 500Hz stimulus there were few changes with location or phase, but the impulsive stimulus showed clear phase-related changes at several locations, with the shortest latencies occurring with compressive stimuli at AFz and Fz and the largest amplitudes at Iz. For oVEMPs, both stimuli showed clear effects of phase, with the shortest latencies with compressive stimuli at AFz and Fz and with the largest negativity at Oz or Iz. Whereas the effectiveness at Iz is consistent with a role in the linear VOR, the inversion of polarity and shorter latency around AFz and Fz is not and could not be explained by changes in acceleration of the head. The latency for BC 500Hz oVEMPs for AFz was the same as that for air-conducted (AC) stimuli. We suggest that whereas BC stimuli at most sites work through displacement of the otolith membrane, BC oVEMPs evoked at AFz and Fz may work through a direct action on utricular hair cells. Our findings have implications for clinical testing of VEMPs using midline BC stimuli. NEW & NOTEWORTHY We investigated VEMPs evoked from multiple midline skull sites. Large oVEMP responses were obtained with compressive stimuli at Iz, consistent with a role in the linear VOR, but we also showed inversion of polarity and the shortest latency for stimuli given at AFz and Fz. We propose that BC stimuli given at AFz and Fz may have a direct effect on otolith hair cells, whereas at other sites they work through displacement of the otolith membrane.

We studied the response to axial taps (mini-perturbations) of a group of 13 healthy older subjects (mean age 63 ± 12 years, 7 females, 6 males), 12 of whom were also studied using larger applied (macro-) perturbations requiring active postural responses. The mini-perturbation consisted of a brief impulsive force produced by a mini-shaker applied to the trunk at the level of the shoulders and anteriorly at the upper sternum which was perceived as a tap. Acceleration, force platform, and EMG measurements were made. The average peak accelerations for the mini-perturbations were 108 mG (anterior) and - 78.9 mG (posterior). Responses overall were very similar to those previously reported for younger subjects: the perturbation evoked short latency responses in leg muscles, modulated by degree and direction of lean, and were largest for the muscle most relevant for the postural correction. The increases in the amplitude for the main agonist were greater than the increase in tonic activity. With both anterior and posterior lean, co-contraction responses were present. The size of the EMG response to the mini-perturbations correlated with the corresponding earliest EMG responses (0-100, 100-200 ms intervals) to the larger postural perturbations, timing which corresponds to balance responses. The balance responses evoked by the larger imposed postural perturbations may, therefore, receive a contribution through the reflex pathway mediating the axial tap responses, whose efferent limb appears to be the reticulospinal tract.

We studied nine normal volunteers with a classical conditioning paradigm using a mastoid tap, believed to activate otolith receptors, as an unconditional stimulus (US) and the consequent blink as the unconditioned response (UR). Both visual (alternation of stripes) and an auditory tone were used as conditional stimuli (CS). Recordings were made below the eyes at IO1 and IO2, from over the frontal eye fields (C3′ and C4′) and over the posterior fossa, the latter at sites we have previously reported that we were able to record an evoked climbing fibre response (CFR) at short latency. Behavioural analysis confirmed that weak conditioning did occur early, which subsequently showed extinction on repeated CS alone trials. Further, a UR was more likely to occur following a preceding CFR when preceded by a CS, supporting a correlation between the CFRs and behaviour. For further statistical analysis, the time period of interest was divided into a series of epochs, based around the events occurring at the time. Grand averages, plus analysis of variance, confirmed evidence of weak conditioning for the blink response following both modalities. The EMG associated with the eyeblink for the UR occurred at a similar time to the expected post-CFR pause in the spontaneous cerebellar activity, or electrocerebellogram (ECeG), while hypothesised conditioned pausing in the ECeG was also observed in CS alone trials. A correlation was found between the size of the CFR and the RMS amplitudes of the segments covering the ocular vestibular evoked myogenic potential oVEMP, (periocular) EMG and the EOG. The slope was greater for the non-oVEMP segments than for the oVEMP segment suggesting the correlation was not simply due to differing sizes of the vestibular volley. We suggest that these recorded events fit with the proposed role of the CFR in Purkinje neurons in classical conditioning, gating the excitability of the cerebellar nuclei, and thereby neurons in the reticular formation mediating the otolith blink reflex. This effect appears to apply to polysynaptic reflexes only as there was no evidence of changes to the oVEMP.

The vestibular system makes strong connections with the oculomotor nuclei, the neck, the cerebellum and also projects to the cortex. Over- or under-activity of vestibular afferents causes disturbances of posture, vision and perception. While methods have been available for some time for assessing some of the properties of the vestibular system, these have had limitations. These methods have been difficult to apply widely, either being indirect and not always well tolerated (rotating chairs, centrifuges and caloric testing) or poorly standardised, such as galvanic stimulation in standing subjects. Relatively simple methods of assessing short latency vestibular projections have become available. The best known of these require averaging of muscle activity thus are termed “vestibular evoked myogenic potentials” or VEMPs. Short latency potentials can be recorded from the sternocleidomastoid muscle in the neck (cervical VEMPs) or from the inferior oblique (ocular VEMPs). Both can be evoked by either air conducted sound (AC) or bone conducted sound (BC). The AC-evoked cVEMP mainly reflects saccular function and the oVEMP mainly utricular. Most recently it has been possible to record an evoked potential from the cerebellum (VsCEP). The VEMP techniques are well tolerated and have been widely applied in vestibular diagnosis. They have also been used in investigations of central disorders such as multiple sclerosis, Parkinson’s disease and progressive supranuclear palsy (PSP).

Objective:To systematically review the evidence and make recommendations with regard to diagnostic utility of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP, respectively). Four questions were asked: Does cVEMP accurately identify superior canal dehiscence syndrome (SCDS)? Does oVEMP accurately identify SCDS? For suspected vestibular symptoms, does cVEMP/oVEMP accurately identify vestibular dysfunction related to the saccule/utricle? For vestibular symptoms, does cVEMP/oVEMP accurately and substantively aid diagnosis of any specific vestibular disorder besides SCDS?Methods:The guideline panel identified and classified relevant published studies (January 1980–December 2016) according to the 2004 American Academy of Neurology process.Results and Recommendations:Level C positive: Clinicians may use cVEMP stimulus threshold values to distinguish SCDS from controls (2 Class III studies) (sensitivity 86%–91%, specificity 90%–96%). Corrected cVEMP amplitude may be used to distinguish SCDS from controls (2 Class III studies) (sensitivity 100%, specificity 93%). Clinicians may use oVEMP amplitude to distinguish SCDS from normal controls (3 Class III studies) (sensitivity 77%–100%, specificity 98%–100%). oVEMP threshold may be used to aid in distinguishing SCDS from controls (3 Class III studies) (sensitivity 70%–100%, specificity 77%–100%). Level U: Evidence is insufficient to determine whether cVEMP and oVEMP can accurately identify vestibular function specifically related to the saccule/utricle, or whether cVEMP or oVEMP is useful in diagnosing vestibular neuritis or Ménière disease. Level C negative: It has not been demonstrated that cVEMP substantively aids in diagnosing benign paroxysmal positional vertigo, or that cVEMP or oVEMP aids in diagnosing/managing vestibular migraine.

Hereditary endocrine neoplasias, including phaeochromocytoma/paraganglioma and medullary thyroid cancer, are caused by autosomal dominant mutations in several familial cancer genes. A common feature of these diseases is the presentation of multiple primary tumours, or multifocal disease representing independent tumour clones that have arisen from the same initiating genetic lesion, but have undergone independent clonal evolution. Such tumours provide an opportunity to discover common cooperative changes required for tumourigenesis, while controlling for the genetic background of the individual. We performed genomic analysis of synchronous and metachronous tumours from five patients bearing germline mutations in the genes SDHB, RET, and MAX. Using whole exome sequencing and high-density single-nucleotide polymorphism arrays, we analysed two to four primary tumours from each patient. We also applied multi-region sampling, to assess intratumoural heterogeneity and clonal evolution, in two cases involving paraganglioma and medullary thyroid cancer, respectively. Heterogeneous patterns of genomic change existed between synchronous or metachronous tumours, with evidence of branching evolution. We observed striking examples of evolutionary convergence involving the same rare somatic copy-number events in synchronous primary phaeochromocytoma/paraganglioma. Convergent events also occurred during clonal evolution of metastatic medullary thyroid cancer. These observations suggest that genetic or epigenetic changes acquired early within precursor cells, or pre-existing within the genetic background of the individual, create contingencies that determine the evolutionary trajectory of the tumour. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

We studied the short-latency (SL) postural effects of axial impulses in 11 subjects (22 ± 2 years old). Recordings were made bilaterally from soleus and tibialis anterior (TA) muscles. We confirmed that with leaning anteriorly and posteriorly, reflex EMG increases occurred in both muscle groups at short latency following brief perturbations applied over C7 or the sternum (soleus mean latencies 57.5 and 66.4 ms; TA mean 51.7 and 55.4 ms, respectively). While the size of the SL reflexes was affected by the direction of lean when standing we found that light touch did not affect the amplitudes or latencies significantly. We investigated the presence of SL responses in the upper limb muscle triceps brachii during an isometric contraction and when the arm muscles had a direct role in supporting approximately 40% of the body weight. Similar levels of tonic EMG activity occurred in triceps in both conditions but significantly larger SL reflexes occurred when used posturally compared to the isometric contraction (23.0 vs 3.3%) while the reverse occurred for SL responses in soleus and TA, which were significantly attenuated. The responses were present with the head in the neutral position but with head rotation were larger contralateral to the direction of rotation. Calculations based upon the relative latencies suggest that the pathway responsible is not the corticospinal tract. We conclude that axially evoked SL postural reflexes are unaffected by light tactile input but are present in upper limb muscles when used for postural support. We propose that the pathway mediating these responses is the reticulospinal tract.

We evaluated the differences in sonographic parameters in carpal tunnel syndrome (CTS) patients with normal and mildly abnormal nerve conduction studies (NCS). This was a prospective cross-sectional study. We assessed 169 wrists (101 patients) with a clinical diagnosis of carpal tunnel syndrome (CTS), as well as 20 healthy controls (40 wrists). 49 wrists were classified as mild NCS-positive and 38 as NCS-negative based on our laboratory NCS normal values. The cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet and mid-forearm were measured and the wrist-to-forearm ratio (WFR) was calculated. 26% of the NCS-negative group had abnormal CSA. The CSA and WFR also differed significantly between the two groups. There was significant correlation between the sonographic and electrophysiologic variables. Ultrasound was diagnostic for CTS in a third of the NCS-negative wrists. Ultrasound may be useful in clinical CTS patients with normal or borderline NCS.

Loud sounds were used to activate vestibular receptors in human volunteers and the effects of head and eye position studied for short-latency responses. A potential (p10/n17) recorded in the parieto-occipital leads showed behavior not expected for a response with a myogenic origin. Source modeling suggested a possible origin from the cerebellum. It may represent a new indicator of human vestibulocerebellar function., This study investigated the effect of eye gaze and head position on vestibular-evoked potentials (VsEPs). Head position would be expected to affect myogenic sources, and eye position is known to affect ocular myogenic responses (ocular vestibular-evoked myogenic potentials), whereas a neurogenic source should behave otherwise. Eleven healthy subjects were recruited, and VsEPs, using 72-channel EEG, were recorded at a fixed intensity above the vestibular threshold. Three eye gaze and three head positions were tested (−20°, 0°, and +20° to the horizontal). Short-latency potentials showed that in addition to the expected effect of gaze on infraocular (IO′) leads, where up-gaze gives a maximum response, significant changes in amplitude were also observed in electrodes remote from the eyes and in particular, from contralateral parietal-occipital (PO) and neck (CB′) leads. Short-latency potentials of similar latency were observed (p10/n17 and n10/p17, respectively). The pattern of change with gaze in the PO leads was distinct from that observed for the IO′ leads. For the PO leads, the maximum response was obtained with neutral gaze, and this was also distinct from that observed for CB′ electrodes, where a maximal response was observed with head flexion in the second wave but not the first. Evidence of modulation of N42 and N1 potentials with both eye and head position was also observed. Head- and eye-position manipulation thus suggests that the inion response consists of an early neurogenic component, as well as myogenic responses. The p10/n17 at PO, in particular, may be an indicator of vestibulocerebellar projections. NEW & NOTEWORTHY Loud sounds were used to activate vestibular receptors in human volunteers and the effects of head and eye position studied for short-latency responses. A potential (p10/n17) recorded in the parieto-occipital leads showed behavior not expected for a response with a myogenic origin. Source modeling suggested a possible origin from the cerebellum. It may represent a new indicator of human vestibulocerebellar function.

Objective To measure axially-evoked postural reflexes in 11 Parkinson’s disease (PD) subjects, both stable and unstable, and to compare these with 13 age-matched controls. Methods: We measured the short-latency electromyography (EMG) reflex effects of brief impulsive displacements applied to the upper sternum or C7 for tibialis anterior (TA) and soleus. Our subjects were studied standing normally and when leaning both forwards and backwards. Results The initial mechanical effects of the stimuli were similar but the reflex responses for the unstable PD group were increased, even after allowing for the increased levels of tonic activation. For TA, unstable PD subjects had significantly larger responses than the stable PD group whose responses were in turn significantly larger than controls. For soleus, unstable PD subjects had significantly greater responses than controls. Conclusions These findings are consistent with previous evidence that exaggerated postural responses are characteristic of unstable PD subjects. Significance Increased postural reflexes are characteristic of unstable PD subjects and may contribute to the instability seen for these patients in response to larger perturbations.

Vestibular cerebellar evoked potentials (VsCEPs) were recorded from over the occipital and cerebellar regions of the scalp using bone-conducted (BC) stimuli applied at the mastoids (impulsive accelerations and 500 Hz) and 500 Hz acoustic tones (AC). Ten healthy subjects were tested. Electrodes were positioned over the midline (Oz, Iz, CBz) and at 3, 6 and 9 cm intervals lateral to the midline electrodes bilaterally. Additional electrodes were also positioned over posterior neck muscles (SPL1 and SPL2). The largest evoked potentials on average were recorded from the electrodes 3 and 6 cm lateral to the Iz and CBz midline locations. BC stimuli produced short latency potentials on the side contralateral to the stimulated mastoid and were dependent on stimulus polarity. Positive polarity stimuli produced biphasic VsCEPs at approximately 12 and 17 ms (P12–N17) for BC impulses and 10 and 15 ms (P10–N15) for BC 500 Hz stimuli. Following the initial excitation, there was a period of suppression of background activity lasting an average of 16.8 ms for positive polarity BC impulses. Negative polarity stimuli produced later VsCEPs both for BC impulses (P20–N26) and BC 500 Hz (P13–N18). VsCEPs to AC 500 Hz stimuli lateralised to the contralateral side and were larger for right than left ear stimulation. Stimulus polarity (condensation and rarefaction) did not alter the timing of the VsCEPs to AC 500 Hz tones. No evoked response was recorded to somatosensory (median and radial nerve) stimulation. Four patients with cerebellar disease were tested and two showed abnormal VsCEPs with initial negativities. VsCEPs show distinct mapping over the posterior fossa and are likely to reflect climbing fibre responses via crossed otolith–cerebellar pathways.

We have recently shown that it is possible to record vestibular cerebellar evoked potentials (VsCEPs) in the form of a contralateral short-latency biphasic positive-negative wave with surface electrodes placed over the posterior fossa and, in parallel with this, the spontaneous electrocerebellogram (or ECeG). VsCEPs were further shown to exhibit considerable plasticity depending on visual context and in this article we show additionally that the ECeG power and cerebro-cerebellar coherence which accompanies the VsCEPs also changes systematically during vestibular and optokinetic stimuli. In a sample of nine healthy human subjects, half of whom had VsCEPs, we recorded in parallel the ECeG and for comparison the EEG from central scalp sites. The results showed that during vection with vestibular stimulation there is actually a reduction in the power of the ECeG accompanied by an increase in cerebro-cerebellar coherence, both of which correlate with the subjective sensation of vection. Only the VsCEPs present group showed the significant power reduction and increase in coherence, indicating a link between the VsCEP and plasticity in the ECeG. We suggest that these data are consistent with a human cerebro-cerebellar network associated with control of the VOR. The network exhibits the plasticity expected from the known inhibitory properties of Purkinje cells and the pausing of spontaneous Purkinje cell activity following a climbing-fibre evoked response with conjunctive inputs from the mossy-fibre system.

Background Following the withdrawal of the Liverpool Care Pathway concerns were expressed about staff confidence and competence to deliver end of life care. In response to locally identified needs and the recommendations for individualised care plans underpinned by the Five Priorities for Care of the Dying Person we have designed and implemented a Quality Improvement Project(QIP) within our NHS Foundation Trust. Method We have introduced two tools, a symptom observation chart and care plan guide modelled on the Five Priorities. The tools were piloted initially on an acute medical admissions ward and have now been cascaded across four elderly care wards. Implementation was tracked and supported using QI methodology to include Run charts and PDSA cycles. Our aim is that all patients on elderly care wards who were recognised as being in the last days of life have 60% of their nursing care plans completed in line with the Five Priorities and 5/7 of symptoms listed on the symptom observation chart recorded and managed appropriately every 4 hours. Results Over 22 weeks we identified 57 patients with End of Life Notifications. During this period 0%–70% of patients had 60% of their nursing care plans in line with the Five Priorities and 0%–100% of patients had 5/7 symptoms listed on the symptom observation chart recorded and managed appropriately every 4 hours. The variation in the use and completion of both tools may be explained to some extent by the small sample size and missing data (59% of charts in PDSA1 and 50% in PDSA2 were missing). Conclusion Staff on these wards require ongoing education and efforts to promote engagement and investment in the tools. Data collection to assess the adherence to standards with regards to the timing of bedside assessments and escalation of concerns to senior staff where applicable is currently ongoing.

Objectives To investigate the properties of lateral electrode locations compared to the conventional ones and to bipolar compared to chin-referenced montages for recording ocular vestibular evoked myogenic potentials (oVEMPs). Methods A total of 18 subjects were studied using 5 electrode locations around the eye, including the conventional location and more lateral ones (i.e. M, ML and L electrodes near the orbital margin, R 1 and R 2 electrodes below the two more medial ones). Unilateral air-conducted (AC) sound, bone-conducted (BC) impulses at the mastoid and BC vibration (500Hz) at the forehead were used. These were applied while the subjects looked in neutral gaze and with 4 levels of increasing elevation. A subset of 10 subjects were also studied when looking downwards at 4 levels. Five bipolar montages were created offline by subtraction. Results The M and ML electrodes had the largest responses but responses were seen for all 5 electrodes. The chin reference was associated with substantial pickup from the contralateral side (as judged using unilateral AC stimulation). The M-R 1 (conventional) montage showed a significantly non-linear response to gaze angle, unlike the ML montages. The ML-R 1 montage gave the largest responses. There was a clear change in latency for the conventional montage with downgaze for the AC and BC impulsive stimuli. Conclusions The ML active electrode has a more stable n1 latency, a larger and a more linear response to gaze angle than the conventional recording site, probably due to contamination by pickup of inferior rectus activity when using the conventional site. Significance The ML location is a better site for the active pickup for recording oVEMPs if the main object of study is the inferior oblique muscle and particularly if subjects have difficulty with upgaze.

A range of chlorophosphinocarbyne complexes [W(≡CPClR)(CO)2(Tp*)] (R = Cl, Cy, Ph; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) has been prepared by reaction of chlorophosphines with the lithiocarbyne complex [W{≡CLi(THF)n}(CO)2(Tp*)]. These complexes undergo nucleophilic substitution of chloride to enable the preparation of phosphinocarbynes bearing alkyl, aryl, alkynyl, aryloxy, and secondary phosphino substituents [W(≡CPRR′)(CO)2(Tp*)] (R = Ph, R′ = Me, Ph, C≡CPh, OPh, H; R = Cy, R′ = H).

Objectives To compare threshold and amplitude properties for air- (AC) and mastoid bone-conducted (BC) cervical (cVEMP) and ocular (oVEMP) vestibular evoked myogenic potentials in superior canal dehiscence (SCD). Methods Thirteen patients (53±14yrs) clinically diagnosed with SCD were tested using AC 500Hz sound and BC 500Hz transmastoid vibration. Baseline intensities of 135dBpSPL and 138dBpFL respectively were used and reduced until the response amplitudes were less than 2.5 standard deviations of the prestimulus baseline mean. SCD VEMP amplitudes, response gradients and threshold parameters for the initial peaks for the cVEMP (ipsilateral) and the oVEMP (contralateral) were compared with results for normal subjects over a range of intensities. Results Despite higher amplitudes, reflex gradients against intensity for AC and BC cVEMPs were significantly less in SCD than normals ( P ≪0.001) while AC and BC oVEMP gradients were not significantly different between the groups. Abnormally low thresholds for AC 500Hz were present for 85% of cVEMPs and 62% of oVEMPs. Abnormally low BC 500Hz thresholds were seen for 33% of cVEMPs and 83% of oVEMPs. Amplitudes for AC 500Hz were compared over the 135–105dBpSPL intensity range. The cVEMP showed more pathologically large amplitude responses with the lower stimulus intensities (135dBpSPL: 5%, 105dBpSPL: 100%) whereas the oVEMP demonstrated high rates of amplitude increases for all intensities (129–111dBpSPL: 92%). The pattern of pathologically large amplitudes evoked by BC 500Hz was similar for both reflexes such that both cVEMPs and oVEMPs showed maximum prevalence of abnormally large responses around 117dBpFL (cVEMP: 58%, oVEMP: 83%). Conclusions In SCD, both AC and BC evoked cVEMPs show evidence of saturation but this is not evident for oVEMPs. Both cVEMPs and oVEMPs show frequent abnormalities of amplitudes and thresholds in SCD compared to normal subjects but the sensitivities differed between measures. Significance Previous evidence of saturation of cVEMP responses in SCD was confirmed. For diagnosis, AC cVEMP amplitudes at 105dBpSPL or AC-evoked oVEMP amplitudes both have over 90% sensitivity in separating SCD from normal responses.

BRAF mutations at codons L597 and K601 occur uncommonly in melanoma. Clinical and pathological associations of these mutations were investigated in a cohort of 1119 patients with known BRAF mutation status. A BRAF mutation was identified in 435 patients; Mutations at L597 and the K601E mutation were seen in 3.4 and 3.2% of these, respectively. K601E melanomas tended to occur in male patients, a median age of 58 yr, were generally found on the trunk (64%) and uncommonly associated with chronically sun-damaged (CSD) skin. BRAF L597 melanomas occurred in older patients (median 66 yr), but were associated with CSD skin (extremities or head and neck location - 73.3%, P = 0.001). Twenty-three percent of patients with V600E- and 43% of patients with K601E-mutant melanomas presented with nodal disease at diagnosis compared to just 14% of patients with BRAF wild-type tumors (P = 0.001 and 0.006, respectively). Overall, these mutations represent a significant minority of BRAF mutations, but have distinct clinicopathological phenotypes and clinical behaviors.

Objective To define and compare the input–output properties of 500 Hz and 100 Hz bone-conducted (BC) transmastoid stimulation when evoking cVEMPs and oVEMPs. The findings for 500 Hz were compared with those previously reported for air-conducted (AC) 500 Hz stimulation. Methods Twelve healthy subjects (18–57 years old) participated in this study, with simultaneous recordings of cVEMPs and oVEMPs bilaterally. Initial intensities of 138 dB (FL) were used and then reduced in 3 or 6 dB increments to 105 dB. Results For BC 500 Hz, like AC 500 Hz, the relationship between the stimulus and reflex output fitted a power law for most peaks, but not the initial peak of the oVEMP. Some of the subjects did not have early crossed oVEMP responses for BC 500 Hz but all did for 100 Hz. For BC 100 Hz, while the initial waveforms were similar, many of the peaks showed a tendency to saturate at the higher intensities. For both BC 500 Hz and 100 Hz, the initial (contralateral) oVEMP peaks had a higher threshold than for the (ipsilateral) cVEMP responses although this difference was more marked for 500 Hz. Conclusions BC 500 Hz shows similar properties to AC 500 Hz, consistent with an overlapping spectrum of afferents being excited by both, with bilateral effects for the BC stimulus. BC 100 Hz evokes more non-vestibular peaks, presumably from muscle afferents, for the SCM recordings but is a more reliable method of evoking the early crossed potentials of the oVEMP. Significance BC 500 Hz is a useful adjunct to the AC 500 Hz stimulus and has similar properties. The BC 100 Hz stimulus may be a more reliable method of evoking the early crossed oVEMP responses.

Merkel cell carcinoma (MCC) is an uncommon, but highly malignant, cutaneous tumor. Merkel cell polyoma virus (MCV) has been implicated in a majority of MCC tumors; however, viral-negative tumors have been reported to be more prevalent in some geographic regions subject to high sun exposure. While the impact of MCV and viral T-antigens on MCC development has been extensively investigated, little is known about the etiology of viral-negative tumors. We performed targeted capture and massively parallel DNA sequencing of 619 cancer genes to compare the gene mutations and copy number alterations in MCV-positive (n = 13) and -negative (n = 21) MCC tumors and cell lines. We found that MCV-positive tumors displayed very low mutation rates, but MCV-negative tumors exhibited a high mutation burden associated with a UV-induced DNA damage signature. All viral-negative tumors harbored mutations in RB1, TP53, and a high frequency of mutations in NOTCH1 and FAT1. Additional mutated or amplified cancer genes of potential clinical importance included PI3K (PIK3CA, AKT1, PIK3CG) and MAPK (HRAS, NF1) pathway members and the receptor tyrosine kinase FGFR2. Furthermore, looking ahead to potential therapeutic strategies encompassing immune checkpoint inhibitors such as anti-PD-L1, we also assessed the status of T-cell–infiltrating lymphocytes (TIL) and PD-L1 in MCC tumors. A subset of viral-negative tumors exhibited high TILs and PD-L1 expression, corresponding with the higher mutation load within these cancers. Taken together, this study provides new insights into the underlying biology of viral-negative MCC and paves the road for further investigation into new treatment opportunities. Cancer Res; 75(24); 5228–34. ©2015 AACR.