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  • Catastrophic hyperkalaemia following administration of suxamethonium chloride to a patient with undiagnosed amyotrophic lateral sclerosis.

    24 October 2018

    The depolarising neuromuscular blocking agent suxamethonium chloride, frequently used during endotracheal intubation, is contraindicated in patients with chronic denervation in whom it can cause a life-threatening hyperkalaemic reaction, thought to be mediated through upregulation of nicotinic alpha7 acetylcholine receptors. An underlying neuromuscular disorder should be considered in all patients with acute respiratory insufficiency, and an alternative neuromuscular blocking drug must be used if there is any possibility of widespread denervation.

  • LRRK2 is a component of granular alpha-synuclein pathology in the brainstem of Parkinson's disease.

    24 October 2018

    Classical Parkinson's disease (PD) is characterized by the appearance of Lewy bodies (LBs) in affected brain regions, showing mostly compact alpha-synuclein deposition, in contrast with punctate or granular deposition, hypothesized to represent early stages of aggregation. Leucine-rich repeat kinase 2 (LRRK2) is the commonest mutated gene in inherited and idiopathic PD. LRRK2 mutation carriers display a diverse neuropathology, including alpha-synuclein and tau inclusions, suggesting an upstream role for LRRK2 in protein aggregation. We studied LRRK2 expression throughout the normal human brain with three different antibodies. We also examined the pattern of LRRK2 expression in relation to alpha-synuclein aggregation and LB formation in the brainstem of sporadic LB disease. Physiological LRRK2 expression was not restricted to regions preferentially affected in PD and LRRK2 often localized to the nuclear envelope in addition to the known cytoplasmic expression. In PD, we were able to consistently detect LRRK2 in the halo of a minority (approximately 10%) of nigral LBs using three different antibodies. Only one antibody detected LRRK2 in the core of approximately 80% of classic LBs. In the lower brainstem, most notably in the dorsal motor nucleus of the vagus, we found previously unrecognized LRRK2 labelling of complex globular lesions, filled with LB-like matter showing a punctate or granular staining for alpha-synuclein. This was often accompanied by strong LRRK2 expression within dystrophic neurites. Our findings confirm widespread physiological LRRK2 expression in the human brain and suggest an association of LRRK2 with possible early-stage alpha-synuclein pathology in the brainstem of PD.

  • Cerebral primitive neuroectodermal tumor in an adult with a heterozygous MSH2 mutation.

    24 October 2018

    BACKGROUND: A 37-year-old woman presented with a supratentorial cerebral mass, which was diagnosed histologically as a primitive neuroectodermal tumor. She had been treated for rectal adenocarcinoma 7 years previously. A family history revealed a young-onset colorectal carcinoma in the patient's father. INVESTIGATIONS: Immunohistochemical analysis for DNA mismatch repair proteins, germline mutation analysis of MSH2. DIAGNOSIS: Lynch syndrome with a heterozygous germline mutation in MSH2. MANAGEMENT: Debulking of the cerebral tumor, craniospinal axis radiotherapy, and genetic counseling of family.

  • Expression of vascular Notch ligands Delta-like 4 and Jagged-1 in glioblastoma.

    24 October 2018

    AIMS: The coordinated expression of the Notch ligands Delta-like 4 (Dll4) and Jagged (Jag)1 is believed to define appropriate endothelial sensitivity to vascular endothelial growth factor (VEGF). Preclinical data suggest that Dll4-Notch signalling may confer resistance to anti-VEGF therapy with bevacizumab, and Jag1 may antagonize Dll4-Notch. The aims of this study were to characterize the expression of Dll4 and Jag1 in primary glioblastomas. METHODS AND RESULTS: Immunohistochemistry was performed on 40 glioblastomas and normal brain using validated antibodies against Dll4 and Jag1. In-situ hybridization for Dll4 was performed on serial sections and compared with protein expression. Dll4 expression was localized to the cytoplasm and membrane of endothelial cells in all glioblastomas; it was weak or absent in normal brain. Jag1 expression was observed in the cytoplasm and membrane of glomeruloid and non-glomeruloid endothelial cells from 76% and 67% of glioblastomas, respectively. However, endothelial Jag1 expression was less intense and less prevalent than Dll4. There was no association between Dll4 and Jag1 expression. CONCLUSIONS: In summary, Dll4 and Jag1 are expressed in glioblastoma vasculature. These data may define subsets of glioblastoma that might be sensitive (Dll4(+) /Jag1(+) ) or resistant (Dll4(+) /Jag1(-) ) to bevacizumab. Our data also suggest that anti-Dll4 therapy should be evaluated experimentally in glioblastoma.

  • Craniopharyngiomas in children and adults: systematic analysis of 121 cases with long-term follow-up.

    24 October 2018

    BACKGROUND: Craniopharyngiomas account for 2-5% of all primary intracranial tumours. Despite their benign histological appearance, they are often associated with an unfavourable prognosis and their optimal treatment remains controversial. AIM: To analyse the natural history and treatment outcome of children and adults presenting to the Departments of Paediatrics and Endocrinology with craniopharyngioma between 1964 and 2003. PATIENTS AND METHODS: The records of 121 patients (age range 2.5-83 years, 42 aged < 16 and 79 aged > or = 16) were identified. The mean follow-up period since presentation was 103 months (8.6 years) (range 0.3-468 months). Sixteen patients underwent gross total removal (A), 3 gross total removal + radiotherapy (B), 51 partial removal (C), 33 partial removal + radiotherapy (D), 6 cyst evacuation alone (E) and 3 cyst evacuation + radiotherapy (F). The clinical, imaging and endocrinological data at presentation and during follow-up were analysed. RESULTS: Headache and visual field defects were the most common presenting clinical features (64% and 55%, respectively). Ninety-four per cent of the tumours had an extrasellar component and 23% of them were associated with hydrocephalus. There was a significant difference in the recurrence-free survival rates between groups A-D [at 10 years: 100% (A), 100% (B), 38% (C) and 77% (D), P < 0.01], which persisted even when analysing patients operated after 1980. The median time of first recurrence was 2.5 years (range 0.5-36). The peri-operative mortality of the patients who had any type of neurosurgical intervention due to recurrence was higher than that observed after primary surgery (24%vs. 1.8%) (P < 0.01). The rate of re-accumulation of the cyst fluid was 58% during the first year in patients of group E, whereas none of the subjects of group F experienced such an event during their follow-up period. There was no reversal of pre-existing pituitary hormone deficits after any surgical intervention. The probabilities of GH, FSH/LH, ACTH, TSH deficiency and diabetes insipidus at the 10-year follow-up were 88%, 90%, 86%, 80% and 65%, respectively. After excluding the non-tumour-related deaths, the 10-year survival rate following presentation was 90%. Patients with recurrence had a significantly lower probability for survival compared with those without it (at 10 years: 70%vs. 99%, P < 0.01). At the 10-year follow-up the probability of the presence of major visual field defects was 48%, hyperphagia/obesity 39%, epilepsy 12% and hemi-/monoparesis 11%. In this large series no substantial differences in the outcome of tumours diagnosed during childhood or adult life were found. CONCLUSIONS: Craniopharyngiomas remain tumours associated with significant morbidity. Gross total removal provides favourable results in terms of recurrences. If this cannot be achieved safely, adjuvant radiotherapy is beneficial in preventing tumour re-growth. Childhood- and adult-onset lesions generally behave similarly.

  • Neuronal intranuclear inclusions in SCA2: a genetic, morphological and immunohistochemical study of two cases.

    24 October 2018

    Spinocerebellar ataxia 2 (SCA2) belongs to the family of autosomal dominant cerebellar ataxias (ADCA), a genetically heterogeneous group of neurodegenerative diseases. The SCA2 gene maps to chromosome 12q24 and the causative mutation involves the expansion of a CAG repeat within the coding region of the gene. Pathologically, SCA2 presents as olivo-ponto-cerebellar atrophy (OPCA). We present the cases of a 41-year-old man and a 54-year-old woman who died after a long illness characterized by severe cerebellar ataxia. Diagnosis of SCA2 was confirmed by genetic analysis. The brains were moderately to severely atrophic and atrophy was particularly obvious in the cerebellum and brainstem. Histological examination revealed extreme loss of pontine and olivary nuclei and Purkinje cells, with preservation of the dentate nuclei, and of the pigmented cells in the substantia nigra. The whole spinal cord was also severely affected, with shrinkage of the dorsal columns and reduction in the number of neurones in the motor pool and Clarke's nuclei. Immunohistochemistry with 1C2 antibody showed granular neuronal cytoplasmic deposits in all the areas examined and widespread intranuclear inclusions, which were particularly numerous in the residual pontine nuclei. Intranuclear inclusions were not considered a feature in SCA2. Our results support the view that intranuclear inclusions are an integral part of the pathology of this mutation.

  • Rathke's cleft cysts.

    24 October 2018

    Rathke's cleft cysts (RCCs) are benign, sellar and/or suprasellar lesions originating from the remnants of Rathke's pouch. Although a common finding in routine autopsies (12-33% of normal pituitary glands), symptomatic cases are rare and comprise 5-15% of all surgically resected sellar lesions. Small, asymptomatic RCC do not require surgical intervention, and their natural history is not clear. In series of nonoperated presumed RCCs, 26-94% did not progress during follow-up periods up to 9 years. In symptomatic ones, surgery is indicated, aiming to drain the cyst content and safely remove as much of the capsule as possible. Following surgical intervention, headaches and visual field defects improve or resolve in a significant number of patients (40-100% and 33-100%, respectively) and partial hypopituitarism recovers in 14-50%. Data on relapse rates published in the last 15 years are based on variable follow-up periods and show wide variation (between 0% and 33%). The lowest relapse rates have been described in reports with relatively short mean observation periods (<3 years), whereas in those with longer follow-up the relapse rates increase. Most of the relapses occur within 5-6 years, suggesting that follow-up is required for at least 5 years after surgery. Risk factors for relapse include the presence of squamous metaplasia in the cyst wall, cyst size and the presence of inflammation. Long-term sufficiently powered studies aiming to clarify the natural history of asymptomatic RCCs and of those relapsing postoperatively are required.

  • What are the markers of aggressiveness in prolactinomas? Changes in cell biology, extracellular matrix components, angiogenesis and genetics.

    24 October 2018

    Prolactinoma is the most common pituitary tumour in adults. Macroprolactinomas, particularly in men, may occasionally exhibit a very aggressive clinical course as evidenced by progressive growth, invasion through bone into the sphenoid sinus, cavernous sinus, suprasellar region or the nasopharynx. Some may even progress to pituitary carcinoma with craniospinal or systemic metastases. Aggressive tumours have low cure rates despite appropriate medical and surgical treatment. The mechanisms underlying this aggressive biological behaviour have not yet been fully clarified. Recent immunohistochemical, molecular and genetic studies have provided some insight in this respect. Invasive prolactinomas may be associated with a high Ki-67/MIB-1 labelling index indicating increased cell proliferation, although this is not a universal finding. The AA polymorphism in the cyclin adenine (A)/guanine (G) gene is more frequently detected in invasive prolactinomas. Increased expression of the polysialylated neural cell adhesion molecule (NCAM) and reduced expression of the E-cadherin/catenin complex implies a contribution of altered cell-to-cell adhesion and cellular migration. Extracellular matrix components (ECM), matrix metalloproteinases (MMPs) and their inhibitors play important roles in the context of angiogenesis and invasion. The induction of fibroblast growth factor and vascular endothelial growth factor via oestrogen-induced overexpression of novel genes (PTTG, hst and Edpm5) enhance cell growth, proliferation and angiogenesis contributing to invasiveness in prolactinomas. Although mutations in proto-oncogenes like Ras are uncommon, loss of tumour suppressor genes at loci 11q13, 13q12-14, 10q and 1p seem to be associated with invasiveness. Of the described mechanisms, only reduced E-cadherin/catenin expression and overexpression of hst gene seem to be relatively specific markers for prolactinoma invasiveness compared with other pituitary adenomas. Further research is needed to clarify the molecular mechanisms behind the aggressive course of some prolactinomas to predict those with a potentially poor clinical outcome, and to devise treatments that will eventually enable the cure of these challenging tumours.

  • Amyloid in neurosurgical and neurological practice.

    24 October 2018

    The amyloidoses are a diverse group of diseases characterized by the deposition of specific proteins with distinct affinity to the dye Congo red, collectively called amyloid. The amyloidogenic proteins have acquired an abnormal, highly ordered, beta-pleated sheet configuration with a propensity to self-aggregate. The amyloid may be distributed in different organs with a remarkable diversity. Two broad categories of amyloidoses are recognised: The systemic (consisting of the primary or light chain form, the secondary or reactive form and the familial or hereditary form) and the localised that target specific organs. A tropism of amyloid proteins to the neural tissue produces certain patterns of central nervous system diseases: cerebral amyloid angiopathy, a substrate of spontaneous intracerebral haemorrhage; mature neuritic plaques found in Alzheimer disease and a subset of prion diseases; a topographically restricted accumulation of extracellular proteins giving rise to tumour-mimicking masses, the amyloidomas; and finally, spinal extradural amyloid collections that occasionally are found in the context of rheumatoid arthritis. In this review article we present original illustrative cases of amyloid diseases of the central nervous system that may be encountered in neurosurgical and neurological practice. Molecular aspects and clinical management problems are discussed.