Fatal cerebral air embolism from atrio-oesophageal fistula following cardiac ablation.

A young woman with Rogers syndrome (thiamine-responsive megaloblastic anaemia, diabetes mellitus and sensorineural deafness) presented with headache, recurrent supraventricular tachycardia and features of an upper gastrointestinal bleed, 1 month after radiofrequency cardiac ablation for supraventricular tachycardia. She deteriorated rapidly after endoscopy and subsequently died. Brain imaging during the acute deterioration showed diffuse intracranial air embolism and hypoxic-ischaemic injury. Postmortem examination showed an atrio-oesophageal fistula, a rare complication of cardiac ablation. Clinicians should suspect this condition in patients with acute neurological deterioration after cardiac ablation who have diffuse air embolism on imaging.

Meningioangiomatosis: an uncommon cause of focal epilepsy with characteristic neuroimaging and neuropathology.

A 3-year-old boy presented with acute onset of prolonged right sided focal seizures with secondary generalisation. The investigation findings were suggestive of a neoplastic process more than an inflammatory process. Decision to perform brain biopsy from the lesion to establish the precise nature of lesion was undertaken.

Spinal cord compression from hypertrophic nerve roots in chronic inflammatory demyelinating polyradiculoneuropathy - A case report.

BACKGROUND: Spinal cord compression secondary to nerve root hypertrophy is often attributed to hereditary neuropathies. However, to avoid misdiagnosis, rare immune-mediated neuropathy such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) should not be overlooked. This report presents a case of multilevel nerve root hypertrophy leading to significant cord compression from CIDP. CASE DESCRIPTION: We report a 56-year-old gentleman with type two diabetes mellitus who presented with subacute cervical cord syndrome following a fall. Mixed upper and lower motor neuron features were noted on examination. Magnetic resonance imaging showed significant pan-spinal proximal nerve root hypertrophy, compressing the cervical spinal cord. Initial radiological opinion raised the possibility of neurofibromatosis type 1 (NF-1), but neurophysiology revealed both axonal and demyelinating changes that were etiologically non-specific. C6 root and sural nerve biopsies taken at cervical decompression displayed striking features suggestive for CIDP. Although NF-1 is the most observed condition associated with root hypertrophy, other important and potentially treatable differentials need to be entertained. CONCLUSION: While rare, CIDP can cause significant spinal cord compression. Furthermore, clinical manifestations of CIDP can mimic those of inherited peripheral neuropathies. Neurologists and neurosurgeons should be aware of this condition to optimize subsequent therapeutic decision-making.

The importance of genetic counseling and screening for people with pathogenic SMARCE1 variants: A family study.

Clear cell meningioma (CCM) is a rare variant of meningioma. In recent years, an association between cranial and spinal CCMs and germline loss of function mutations in the SMARCE1 gene (SWI/SNF chromatin remodeling complex subunit gene) has been discovered. We report a family with an incidental large spinal clear cell meningioma in a young adult following reflex screening for a germline loss of function pathogenic variant (PV) in the SMARCE1 gene. The index patient's mother and maternal grandfather were both also tested positive presymptomatically for SMARCE1. His mother developed intracranial and spinal meningiomas and his maternal grandfather developed a spinal CCM 4 years following a clear spinal MRI scan which required surgical excision. In this report we particularly emphasize the importance of genetic counseling and screening in siblings, parents and offspring of patients who are diagnosed with intracranial or spinal CCM in the context of SMARCE1 PVs. We recommend brain and spine Imaging screening of asymptomatic SMARCE1 PV carriers at least every 3 years, even if the baseline scan did not show any tumors.

Fibrous myopathy induced by intramuscular injections of cyclizine.

A 63-year-old woman was referred to neurology with bilateral severe progressive pain and stiffness in her thighs. The patient had a 3-year history of injecting intramuscular cyclizine into the anterior thigh to treat nausea associated with a longstanding pan-enteric dysmotility syndrome. MRI of the thighs demonstrated fibrotic appearances. A biopsy of the left vastus lateralis and surrounding fascia identified pathology consistent with a fibrous myopathy. The patient was advised to stop intramuscular injections of cyclizine and undergo physiotherapy but she still remained in considerable pain. Although fibrous myopathy occurring as a consequence of recurrent intramuscular drug injections, particularly heroin, has been previously described, this is the first report of fibrous myopathy associated with the use of intramuscular cyclizine. We highlight this rare association and suggest that the long-term use of intramuscular cyclizine be avoided.

A Comparative Study of Pathological Outcomes in The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age and Brains for Dementia Research Cohorts.

In the present study, we have characterized and compared individuals whose brains were donated as part of The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age (UoM) with those donated through the Manchester arm of the UK Brains for Dementia Research (BDR) program. The aim of this study was to investigate how differences in study recruitment may affect final pathological composition of cohort studies. The UoM cohort was established as a longitudinal study of aging and cognition whereas the BDR program was established, prima facie, to collect brains from both demented and non-demented individuals for the purpose of building a tissue research resource. Consequently, the differences in recruitment patterns generated differences in demographic, clinical, and neuropathological characteristics. There was a higher proportion of recruits with dementia [mostly Alzheimer's disease (AD)] within the BDR cohort than in the UoM cohort. In pathological terms, the BDR cohort was more 'polarized', being more composed of demented cases with high Braak pathology scores and non-demented cases with low Braak scores, and fewer non-AD pathology cases, than the UoM cohort. In both cohorts, cerebral amyloid angiopathy tended to be greater in demented than non-demented individuals. Such observations partly reflect the recruitment of demented and non-demented individuals into the BDR cohort, and also that insufficient study time may have elapsed for disease onset and development in non-demented individuals to take place. Conversely, in the UoM cohort, where there had been nearly 30 years of study time, a broader spread of AD-type pathological changes had 'naturally' evolved in the brains of both demented and non-demented participants.

Autoimmune fasciitis triggered by the anti-programmed cell death-1 monoclonal antibody nivolumab.

A 43-year-old woman with a history of recently diagnosed metastatic melanoma was commenced on systemic therapy with nivolumab, an anti-programmed cell death-1 monoclonal antibody and one of an increasing group of the so-called 'immune checkpoint inhibitors'. She experienced a dramatic complete response within 6 months of initiation. However, in addition to developing incident autoimmune hypothyroidism, she also developed progressive fatigue, proximal weakness, myalgia and dysphagia. Initial investigations with blood tests, electrophysiology and a muscle biopsy were non-specific or normal. Subsequent examination revealed 'woody' thickening of the subcutaneous tissues of the forearms, thighs and calves consistent with fasciitis. MRI and a full-thickness skin-muscle biopsy were ultimately diagnostic of a likely iatrogenic autoimmune myofasciitis. The clinical manifestations only responded partly to prednisolone 30 mg orally and treatment was escalated to include intravenous immunoglobulin. At 3 months, this has only resulted in a modest incremental improvement.

Assessing Inflammation in Acute Intracerebral Hemorrhage with PK11195 PET and Dynamic Contrast-Enhanced MRI.

BACKGROUND AND PURPOSE: Studies in animal models suggest that inflammation is a major contributor to secondary injury after intracerebral hemorrhage (ICH). Direct, noninvasive monitoring of inflammation in the human brain after ICH will facilitate early-phase development of anti-inflammatory treatments. We sought to investigate the feasibility of multimodality brain imaging in subacute ICH. METHODS: Acute ICH patients were recruited to undergo multiparametric MRI (including dynamic contrast-enhanced measurement of blood-brain barrier transfer constant (Ktrans ) and PET with [11 C]-(R)-PK11195). [11 C]-(R)-PK11195 binds to the translocator protein 18 kDa (TSPO), which is rapidly upregulated in activated microglia. Circulating inflammatory markers were measured at the time of PET. RESULTS: Five patients were recruited to this feasibility study with imaging between 5 and 16 days after onset. Etiologies included hypertension-related small vessel disease, cerebral amyloid angiopathy (CAA), cavernoma, and arteriovenous malformation (AVM). [11 C]-(R)-PK11195 binding was low in all hematomas and 2 (patient 2 [probable CAA] and 4 [AVM]) cases showed widespread increase in binding in the perihematomal region versus contralateral. All had increased Ktrans in the perihematomal region (mean difference = 2.2 × 10-3 minute-1 ; SD = 1.6 × 10-3 minute-1 ) versus contralateral. Two cases (patients 1 [cavernoma] and 4 [AVM]) had delayed surgery (3 and 12 months post-onset, respectively) with biopsies showing intense microglial activation in perilesional tissue. CONCLUSIONS: Our study demonstrates for the first time the feasibility of performing complex multimodality brain imaging for noninvasive monitoring of neuroinflammation for this severe stroke subtype.

In-frame seven amino-acid duplication in AIP arose over the last 3000 years, disrupts protein interaction and stability and is associated with gigantism.

OBJECTIVE: Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are associated with pituitary adenoma, acromegaly and gigantism. Identical alleles in unrelated pedigrees could be inherited from a common ancestor or result from recurrent mutation events. DESIGN AND METHODS: Observational, inferential and experimental study, including: AIP mutation testing; reconstruction of 14 AIP-region (8.3 Mbp) haplotypes; coalescent-based approximate Bayesian estimation of the time to most recent common ancestor (tMRCA) of the derived allele; forward population simulations to estimate current number of allele carriers; proposal of mutation mechanism; protein structure predictions; co-immunoprecipitation and cycloheximide chase experiments. RESULTS: Nine European-origin, unrelated c.805_825dup-positive pedigrees (four familial, five sporadic from the UK, USA and France) included 16 affected (nine gigantism/four acromegaly/two non-functioning pituitary adenoma patients and one prospectively diagnosed acromegaly patient) and nine unaffected carriers. All pedigrees shared a 2.79 Mbp haploblock around AIP with additional haploblocks privately shared between subsets of the pedigrees, indicating the existence of an evolutionarily recent common ancestor, the 'English founder', with an estimated median tMRCA of 47 generations (corresponding to 1175 years) with a confidence interval (9-113 generations, equivalent to 225-2825 years). The mutation occurred in a small tandem repeat region predisposed to slipped strand mispairing. The resulting seven amino-acid duplication disrupts interaction with HSP90 and leads to a marked reduction in protein stability. CONCLUSIONS: The c.805_825dup allele, originating from a common ancestor, associates with a severe clinical phenotype and a high frequency of gigantism. The mutation is likely to be the result of slipped strand mispairing and affects protein-protein interactions and AIP protein stability.

Genetic regulation of gene expression in the epileptic human hippocampus.

Epilepsy is a serious and common neurological disorder. Expression quantitative loci (eQTL) analysis is a vital aid for the identification and interpretation of disease-risk loci. Many eQTLs operate in a tissue- and condition-specific manner. We have performed the first genome-wide cis-eQTL analysis of human hippocampal tissue to include not only normal (n = 22) but also epileptic (n = 22) samples. We demonstrate that disease-associated variants from an epilepsy GWAS meta-analysis and a febrile seizures (FS) GWAS are significantly more enriched with epilepsy-eQTLs than with normal hippocampal eQTLs from two larger independent published studies. In contrast, GWAS meta-analyses of two other brain diseases associated with hippocampal pathology (Alzheimer's disease and schizophrenia) are more enriched with normal hippocampal eQTLs than with epilepsy-eQTLs. These observations suggest that an eQTL analysis that includes disease-affected brain tissue is advantageous for detecting additional risk SNPs for the afflicting and closely related disorders, but not for distinct diseases affecting the same brain regions. We also show that epilepsy eQTLs are enriched within epilepsy-causing genes: an epilepsy cis-gene is significantly more likely to be a causal gene for a Mendelian epilepsy syndrome than to be a causal gene for another Mendelian disorder. Epilepsy cis-genes, compared to normal hippocampal cis-genes, are more enriched within epilepsy-causing genes. Hence, we utilize the epilepsy eQTL data for the functional interpretation of epilepsy disease-risk variants and, thereby, highlight novel potential causal genes for sporadic epilepsy. In conclusion, an epilepsy-eQTL analysis is superior to normal hippocampal tissue eQTL analyses for identifying the variants and genes underlying epilepsy.

An integrative in silico system for predicting dysregulated genes in the human epileptic focus: Application to SLC transporters.

OBJECTIVE: Many different gene families are currently being investigated for their potential role in epilepsy and in the response to antiepileptic drugs. A common research challenge is identifying the members of a gene family that are most significantly dysregulated within the human epileptic focus, before taking them forward for resource-intensive functional studies. Published data about transcriptomic changes within the human epileptic focus remains incomplete. A need exists for an accurate in silico system for the prediction of dysregulated genes within the epileptic focus. We present such a bioinformatic system. We demonstrate the validity of our approach by applying it to the solute carrier (SLC) gene family. There are >400 known SLCs. SLCs have never been systematically studied in epilepsy. METHODS: Using our in silico system, we predicted the SLCs likely to be dysregulated in the epileptic focus. We validated our in silico predictions by identifying ex vivo the SLCs dysregulated in epileptic foci, and determining the overlap between our in silico and ex vivo results. For the ex vivo analysis, we used a custom oligonucleotide microarray containing exon probes for all known SLCs to analyze 24 hippocampal samples obtained from surgery for pharmacoresistant mesial temporal lobe epilepsy and 24 hippocampal samples from normal postmortem controls. RESULTS: There was a highly significant (p < 9.99 × 10(-7) ) overlap between the genes identified by our in silico and ex vivo strategies. The SLCs identified were either metal ion exchangers or neurotransmitter transporters, which are likely to play a part in epilepsy by influencing neuronal excitability. SIGNIFICANCE: The identified SLCs are most likely to mediate pharmacoresistance in epilepsy by enhancing the intrinsic severity of epilepsy, but further functional work will be needed to fully evaluate their role. Our successful in silico strategy can be adapted in order to prioritize genes relevant to epilepsy from other gene families.

Co-Occurrence of Language and Behavioural Change in Frontotemporal Lobar Degeneration.

BACKGROUND/OBJECTIVES: We aimed to evaluate the co-occurrence of language and behavioural impairment in patients with frontotemporal lobar degeneration (FTLD) spectrum pathology. METHODS: Eighty-one dementia patients with pathological confirmation of FTLD were identified. Anonymized clinical records from patients' first assessment were rated for language and behavioural features from frontotemporal dementia consensus criteria, primary progressive aphasia (PPA) criteria and 1998 FTLD criteria. RESULTS: Over 90% of patients with FTLD pathology exhibited a combination of at least one behavioural and one language feature. Changes in language, in particular, were commonly accompanied by behavioural change. Notably, the majority of patients who displayed language features characteristic of semantic variant PPA exhibited 'early perseverative, stereotyped or compulsive/ritualistic behaviour'. Moreover, 'executive/generation deficits with relative sparing of memory and visuospatial functions' occurred in most patients with core features of non-fluent variant PPA. CONCLUSION: Behavioural and language symptoms frequently co-occur in patients with FTLD pathology. Current classifications, which separate behavioural and language syndromes, do not reflect this co-occurrence.

Calcifying pseudoneoplasm of the neuraxis (CaPNoN): an unusual cause of third nerve palsy in a teenager.

An 18-year-old part-time teacher presented with headache and diplopia. Physical examination showed partial left oculomotor palsy. Neurology examination was otherwise unremarkable. Cross-sectional imaging was arranged for investigation of third nerve palsy. On CT scan, the lesion was calcified, and on MRI, hypointense on T 1 and T 2 weightedimages with thin rim enhancement, resembling an atypical meningioma. CT angiogram showed no vascular connection. Following worsening diplopia and a slight increase in lesion size on follow-up MRI, the patient was re-reviewed in our regional skull base multidisciplinary team meeting, where a decision for excision was made. Pre-operatively, the absence of a vascular connection was confirmed on catheter angiogram. Histopathological examination demonstrated features typical of calcified pseudoneoplasm of the neuraxis, with extensive metaplastic calcification with stroma containing variable fibrovascular tissue and focal inflammatory cell infiltrates, spindle and epithelioid cells, and psammoma bodies at the rim of the lesion. Following surgery, the patient had persisting diplopia. He remains under clinical review. As surgical resection is considered curative, no further imaging follow-up is planned.

Identifying the biological pathways underlying human focal epilepsy: from complexity to coherence to centrality.

Numerous diverse biological pathways are dysregulated in the epileptic focus. Which of these pathways are most critical in producing the biological abnormalities that lead to epilepsy? Answering this question is key to identifying the primary causes of epilepsy and for discovering new therapeutic strategies with greater efficacy than currently available antiepileptics (AEDs). We have performed the largest genome-wide transcriptomic analysis to date comparing epileptic with normal human hippocampi. We have identified 118 differentially expressed and, for the first time, differentially connected pathways in the epileptic focus. Using network mapping techniques, we have shown that these dysregulated pathways, though seemingly disparate, form a coherent interconnected central network. Using closeness centrality analysis, we have identified that the most influential hub pathways in this network are signalling through G protein-coupled receptors, in particular opioid receptors, and their downstream effectors PKA/CREB and DAG/IP3. Next, we have objectively demonstrated that genetic association of gene sets in independent genome-wide association studies (GWASs) can be used to identify causally relevant gene sets: we show that proven causal epilepsy genes, which cause familial Mendelian epilepsy syndromes, are associated in published sporadic epilepsy GWAS results. Using the same technique, we have shown that central pathways identified (opioid receptor and PKA/CREB and DAG/IP3 signalling pathways) are genetically associated with focal epilepsy and, hence, likely causal. Published functional studies in animal models provide evidence of a role for these pathways in epilepsy. Our work shows that these pathways play a central role in human focal epilepsy and that they are important currently unexploited antiepileptic drug targets.

The 18-kDa mitochondrial translocator protein in human gliomas: an 11C-(R)PK11195 PET imaging and neuropathology study.

UNLABELLED: The 18-kDa mitochondrial translocator protein (TSPO) is upregulated in high-grade astrocytomas and can be imaged by PET using the selective radiotracer (11)C-(R)PK11195. We investigated (11)C-(R)PK11195 binding in human gliomas and its relationship with TSPO expression in tumor tissue and glioma-associated microglia/macrophages (GAMs) within the tumors. METHODS: Twenty-two glioma patients underwent dynamic (11)C-(R)PK11195 PET scans and perfusion MR imaging acquisition. Parametric maps of (11)C-(R)PK11195 binding potential (BPND) were generated. Coregistered MR/PET images were used to guide tumor biopsy. The tumor tissue was quantitatively assessed for TSPO expression and infiltration of GAMs using immunohistochemistry and double immunofluorescence. The imaging and histopathologic parameters were compared among different histotypes and grades and correlated with each other. RESULTS: BPND of (11)C-(R)PK11195 in high-grade gliomas was significantly higher than in low-grade astrocytomas and low-grade oligodendrogliomas. TSPO in gliomas was expressed predominantly by neoplastic cells, and its expression correlated positively with BPND in the tumors. GAMs only partially contributed to the overall TSPO expression within the tumors, and TSPO expression in GAMs did not correlate with tumor BPND. CONCLUSION: PET with (11)C-(R)PK11195 in human gliomas predominantly reflects TSPO expression in tumor cells. It therefore has the potential to effectively stratify patients who are suitable for TSPO-targeted treatment.

Mutations in LZTR1 add to the complex heterogeneity of schwannomatosis.

OBJECTIVES: We aimed to determine the proportion of individuals in our schwannomatosis cohort whose disease is associated with an LZTR1 mutation. METHODS: We used exome sequencing, Sanger sequencing, and copy number analysis to screen 65 unrelated individuals with schwannomatosis who were negative for a germline NF2 or SMARCB1 mutation. We also screened samples from 39 patients with a unilateral vestibular schwannoma (UVS), plus at least one other schwannoma, but who did not have an identifiable germline or mosaic NF2 mutation. RESULTS: We identified germline LZTR1 mutations in 6 of 16 patients (37.5%) with schwannomatosis who had at least one affected relative, 11 of 49 (22%) sporadic patients, and 2 of 39 patients with UVS in our cohort. Three germline mutation-positive patients in total had developed a UVS. Mosaicism was excluded in 3 patients without germline mutation in NF2, SMARCB1, or LZTR1 by mutation screening in 2 tumors from each. CONCLUSIONS: Our data confirm the relationship between mutations in LZTR1 and schwannomatosis. They indicate that germline mutations in LZTR1 confer an increased risk of vestibular schwannoma, providing further overlap with NF2, and that further causative genes for schwannomatosis remain to be identified.

Intracranial desmoplastic small round cell tumor presenting as a suprasellar mass.

Desmoplastic small round cell tumors (DSRCTs) are rare, aggressive neoplasms that typically arise from abdominal and pelvic peritoneum in young adults. Other primary sites are uncommon, and an intracranial origin is exceptionally rare. Here the authors report the first case of a DSRCT presenting as a primary suprasellar tumor causing panhypopituitarism and severe bitemporal hemianopia in a young man. Macroscopic debulking of the tumor was undertaken, and histology revealed features of DSRCT. Reverse transcription polymerase chain reaction confirmed the presence of Ewing's sarcoma-Wilms tumor 1 (EWS-WT1) gene rearrangement specific to DSRCT. Postoperative whole-body imaging showed no primary malignancy elsewhere. The tumor recurred 4 months after surgery, and this was followed by cervical and mediastinal lymph node metastases. The patient died 20 months after initial presentation of rapidly progressive disease. DSRCTs should be included in the differential diagnosis of an unusual suprasellar mass in young adults. Early diagnosis is essential, and once the tumor is identified histologically, gross-total resection and radical postoperative treatment involving radiotherapy, chemotherapy, and close surveillance are required because of the lesion's potential for rapidly progressive malignancy.

Do NIA-AA criteria distinguish Alzheimer's disease from frontotemporal dementia?

BACKGROUND: Clinical criteria are important for improving diagnostic accuracy and ensuring comparability of patient cohorts in research studies. OBJECTIVE: The aim was to assess the National Institute on Aging and Alzheimer's Association (NIA-AA) criteria for Alzheimer's disease (AD) dementia in AD and frontotemporal lobar degeneration (FTLD). METHODS: Two hundred twelve consecutive patients with pathologically confirmed AD or FTLD who were clinically assessed in a specialist cognitive unit were identified. Fifty-five patients were excluded predominantly because of insufficient clinical information. Anonymized clinical data were rated against the NIA-AA criteria by raters who were blinded to clinical and pathologic diagnosis. RESULTS: The NIA-AA AD dementia criteria had a sensitivity of 65.6% for probable and 79.5% for possible AD and a specificity of 95.2% and 94.0% for probable and possible, respectively. CONCLUSION: In patients with FTLD and predominantly early-onset AD, the NIA-AA AD dementia criteria have high specificity but lower sensitivity. The high specificity is due to the broad exclusion criteria.