Azzam Ismail

[18F]flutemetamol amyloid positron emission tomography in preclinical and symptomatic Alzheimer's disease: Specific detection of advanced phases of amyloid-β pathology

Amyloid positron emission tomography (PET) has become an important tool to identify amyloid‐β (Aβ) pathology in Alzheimers disease (AD) patients. Here, we determined the diagnostic value of the amyloid PET tracer [18F]flutemetamol in relation to Aβ pathology at autopsy.

A RYR1 mutation associated with recessive congenital myopathy and dominant malignant hyperthermia in Asian families

In this study we present 3 families with malignant hyperthermia (MH), all of Indian subcontinent descent. One individual from each of these families was fully sequenced for RYR1 and presented with the non‐synonymous change c.11315G>A/p.R3772Q. When present in the homozygous state c.11315*A is associated with myopathic symptoms. Muscle Nerve, 2009

Characteristic Features of Stem Cells in Glioblastomas: From Cellular Biology to Genetics

Glioblastoma is the most common type of primary brain tumor in adults and is among the most lethal and least successfully treated solid tumors. Recently, research into the area of stem cells in brain tumors has gained momentum. However, due to the relatively new and novel hypothesis that a subpopulation of cancer cells in each malignancy has the potential for tumor initiation and repopulation, the data in this area of research are still in its infancy. This review article is aimed at attempting to bring together research carried out so far in order to build an understanding of glioblastoma stem cells (GSCs). Initially, we consider GSCs at a morphological and cellular level, and then discuss important cell markers, signaling pathways and genetics. Furthermore, we highlight the difficulties associated with what some of the evidence indicates and what collectively the studies contribute to further defining the interpretation of GSCs.

Post-mortem histopathology underlying β-amyloid PET imaging following flutemetamol F 18 injection

In vivo imaging of fibrillar β-amyloid deposits may assist clinical diagnosis of Alzheimer’s disease (AD), aid treatment selection for patients, assist clinical trials of therapeutic drugs through subject selection, and be used as an outcome measure. A recent phase III trial of [18F]flutemetamol positron emission tomography (PET) imaging in 106 end-of-life subjects demonstrated the ability to identify fibrillar β-amyloid by comparing in vivo PET to post-mortem histopathology. Post-mortem analyses demonstrated a broad and continuous spectrum of β-amyloid pathology in AD and other dementing and non-dementing disease groups. The GE067-026 trial demonstrated 91% sensitivity and 90% specificity of [18F]flutemetamol PET by majority read for the presence of moderate or frequent plaques. The probability of an abnormal [18F]flutemetamol scan increased with neocortical plaque density and AD diagnosis. All dementia cases with non-AD neurodegenerative diseases and those without histopathological features of β-amyloid deposits were [18F]flutemetamol negative. Majority PET assessments accurately reflected the amyloid plaque burden in 90% of cases. However, ten cases demonstrated a mismatch between PET image interpretations and post-mortem findings. Although tracer retention was best associated with amyloid in neuritic plaques, amyloid in diffuse plaques and cerebral amyloid angiopathy best explain three [18F]flutemetamol positive cases with mismatched (sparse) neuritic plaque burden. Advanced cortical atrophy was associated with the seven false negative [18F]flutemetamol images. The interpretation of images from pathologically equivocal cases was associated with low reader confidence and inter-reader agreement. Our results support that amyloid in neuritic plaque burden is the primary form of β-amyloid pathology detectable with [18F]flutemetamol PET imaging. ClinicalTrials.gov NCT01165554. Registered June 21, 2010; NCT02090855. Registered March 11, 2014.

Multiple cranial neuropathy as the initial presentation of metastatic prostate adenocarcinoma: case report and review of literature

The skull base is an atypical metastatic site for prostate carcinoma. It is usually encountered late in the disease process in patients with known advanced disease. However, skull base involvement causing cranial nerve palsies may rarely be the presenting sign of prostate carcinoma. Such patients may present to a number of specialties including neurosurgery and can pose a diagnostic challenge in the absence of lower urinary tract symptoms. Here, we describe an unusual case of prostate adenocarcinoma presenting as a central skull base tumour with multiple cranial neuropathy.

Glioblastoma multiforme fades on CT imaging after dexamethasone therapy

We describe a patient in whom an enhancing lesion seen on CT scan faded following dexamethasone therapy. Subsequent biopsy revealed a glioblastoma multiforme. Various intrinsic cerebral lesions have been noted to disappear on CT imaging after the administration of corticosteroids, but it is less common for gliomas to exhibit this property.

Paediatric intramedullary spinal cord cavernous malformations: case report and review of the literature.

Cavernous malformations are vascular lesions which can occur throughout the entire neuraxis. This term is synonymous to cavernous angioma, cavernous haemangioma, and cavernoma. They comprise of closely packed, capillary-like vascular channels, without intervening neural tissue. MR imaging is currently the study of choice for the diagnosis of cavernous malformations as they are considered angiographically occult lesions. Intramedullary location represents only 3-5% of all central nervous system cavernous malformations, with the majority of them being supratentorial. Only 10% of the intramedullary cavernous malformations present in the paediatric population. As the natural history of these lesions is not well known, the debate on the optimal management of them is still ongoing. Here we describe the case of a 14-year-old male with progression of symptoms over an 18 months period, which necessitated microsurgical removal of a T9 intramedullary cavernous malformation.

Methylation-specific multiplex ligation-dependent probe amplification identifies promoter methylation events associated with survival in glioblastoma

DNA methylation plays an important role in cancer biology and methylation events are important prognostic and predictive markers in many tumor types. We have used methylation-specific multiplex ligation-dependent probe amplification to survey the methylation status of MGMT and 25 tumor suppressor genes in 73 glioblastoma cases. The data obtained was correlated with overall survival and response to treatment. The study revealed that methylation of promoter regions in TP73 (seven patients), THBS1 (eight patients) and PYCARD (nine patients) was associated with improved outcome, whereas GATA5 (21 patients) and WT1 (24 patients) promoter methylation were associated with poor outcome. In patients treated with temozolomide and radiation MGMT and PYCARD promoter methylation events remained associated with improved survival whereas GATA5 was associated with a poor outcome. The identification of GATA5 promoter methylation in glioblastoma has not previously been reported. Furthermore, a cumulative methylation score separated patients into survival groups better than any single methylation event. In conclusion, we have identified specific methylation events associated with patient outcome and treatment response in glioblastoma, and these may be of functional and predictive/prognostic significance. This study therefore provides novel candidates and approaches for future prospective validation.

A parkinsonian movement disorder with brain iron deposition and a haemochromatosis mutation.

A 60-year-old, right-handed, Caucasian woman presented to the outpatient department with a three-month history of clumsiness and resting tremor in her right hand, associated with micrographia. She had no significant past medical history. Her family history included a brother who died at the age of 50 after a gastrointestinal bleed, attributed to alcoholic liver disease. Examination showed hypomimia, right hand resting tremor, and right arm and leg rigidity with bradykinesia. There was reduced arm swing during gait, and retropulsion on pull testing. The provisional diagnosis was idiopathic Parkinson’s disease. She was started on dopamine agonists and later on levodopa. However, the symptoms progressed rapidly, with worsening slowness and stiffness, development of postural hypotension and incomplete bladder emptying. She also reported daytime somnolence and snoring at night. As such, the diagnosis was revised to a Parkinson’s-plus syndrome: multiple system atrophy. Investigations revealed mildly raised serum alanine aminotransferase (63 IU/L), but the other liver function tests, full blood count, and copper studies (including serum ceruloplasmin) were all normal. No iron studies were performed. A 24-h cardiac monitor showed no arrhythmias. MRI-head (T1, T2, FLAIR and Gradient echo) at the time of presentation was normal. The patient did not attend for planned autonomic and respiratory function tests. Thirteen months after the first clinic appointment she died in her sleep. A post-mortem examination showed extraand intra-cellular deposition of iron in the globus pallidus, putamen, substantia nigra, locus coeruleus, red nuclei and dentate nuclei. This iron was visualised by Perl’s stain (Figs. 1 and 2), and was in fine granules, in moderate amounts. In addition, there was marked and diffuse neuronal loss from the substantia nigra and locus coeruleus with pale bodies within their neurons. However, no Lewy bodies were seen (alpha-synuclein negative). Axonal spheroids were present, dispersed through brain white matter tracts, consistent with secondary axonal damage. The liver was strongly positive for iron throughout (Perl’s stain). A DNA sample from post-mortem tissue was homozygous for the C282Y Hereditary Haemochromatosis mutation. This is the first case reported of a patient with a movement disorder and a haemochromatosis mutation, in which clear iron deposition in relevant parts of the brain has been seen at postmortem. Several idiopathic neurological conditions (including Parkinson’s disease) are associated with increased brain iron [1], but this is at the level of percentage changes in overall concentration, rather than the gross iron deposition seen in the case reported here. Very high brain iron does occur in conjunction with extrapyramidal disorders in neurodegeneration with brain iron accumulation (NBIA), a group of inherited diseases [2]. Our patient’s age, family history, liver iron, and C282Y mutation all go against this diagnosis. Hereditary haemochromatosis (HH) involves pathological iron deposition in a variety of organs [3]. However, central nervous system disorders are not traditionally listed among the sequelae of the disease. Previous postmortem studies in HH patients have shown excess iron in choroid plexus and pituitary, but not elsewhere in the brain [4], suggesting the blood brain barrier is protective. S. Williams (&) M. R. Vinjam A. Ismail A. Hassan Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, UK e-mail: stefanwilliams@doctors.org.uk

Diffuse hemispheric dysembryoplastic neuroepithelial tumor: a new radiological variant associated with early-onset severe epilepsy

The authors describe the clinical and radiological features in 3 children with a diffuse hemispheric dysembryoplastic neuroepithelial tumor (DNET) presenting with severe epilepsy and a previously unreported and characteristic MR imaging appearance. The DNET is a well-recognized cause of focal epilepsy, usually with a very good response to resection. These tumors are usually intracortical, and most commonly arise in the temporal lobe or frontal lobes. Radiologically they are usually sharply demarcated, and show little contrast enhancement. Three children (2 boys and 1 girl) presented at 14, 17, and 22 months of age with epileptic seizures. The seizures were focal motor or complex focal. One patient had epileptic spasms. The response to antiepileptic drug therapy was poor. Motor and cognitive development was delayed in all patients. One patient developed a severe epileptic encephalopathy, with regression of motor and cognitive skills. Her electroencephalogram obtained at that time showed hypsarhythmia. Admission MR imaging showed a diffuse unilateral abnormality involving frontal, temporal, and parietal lobes with little or no mass effect. There was involvement of both gray and white matter, with a striking sparing of the internal capsule in spite of apparent tumor throughout the basal ganglia and thalamus. In 2 patients there was prominent expansion of cortical gyri by tumor. In 1 child the initial radiological diagnosis was a middle cerebral artery infarct. On subsequent review the radiological diagnosis was thought to be low-grade glioma in all patients. The first patient underwent 2 limited resections involving the temporal lobe. He has continued to have poorly controlled seizures and severe behavioral and cognitive problems. The other patients had subtotal resection to the level of the internal capsule. One patient is currently seizure free 24 months postsurgery, but remains cognitively impaired. The patient in Case 3 is having some seizures 3.5 years postsurgery and remains hemiplegic, but the regression has reversed and she is making steady developmental progress. The pathological specimens showed the typical features of a DNET in all cases. This striking radiological pattern has not previously been described as a feature of a DNET. Recognition of this radiological pattern in young children with epilepsy will allow early consideration for resection, which may lead to improved long-term cognitive outcome.