Evaluation of cerebrospinal fluid alpha-synuclein seed amplification assay in PSP and CBS.

Background: Seed amplification assay (SAA) testing has become an important biomarker in the diagnosis of alpha-synuclein related neurodegenerative disorders. Objectives: To assess the rate of alpha-synuclein SAA positivity in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), and analyse the clinical and pathological features of SAA positive and negative cases. Methods: 106 CSF samples from clinically diagnosed PSP (n=59), CBS (n=37) and indeterminate parkinsonism cases (n=10) were analysed using alpha-synuclein SAA. Results: Three cases (1 PSP, 2 CBS) were Multiple System Atrophy (MSA)-type SAA positive. 5/59 (8.5%) PSP cases were Parkinson's disease (PD)-type SAA positive, and these cases were older and had a shorter disease duration compared with SAA negative cases. In contrast, 9/35 (25.7%) CBS cases were PD-type SAA positive. Conclusions: Our results suggest that PD-type seeds can be detected in PSP and CBS using a CSF alpha-synuclein SAA, and in PSP this may impact on clinical course.

A standardised diagnostic approach to pituitary neuroendocrine tumours (PitNETs): a European Pituitary Pathology Group (EPPG) proposal.

The 2017 World Health Organization (WHO) classification proposes to type and subtype primary adenohypophyseal tumours according to their cell lineages with the aim to establish more uniform tumour groups. The definition of atypical adenoma was removed in favour of high-risk adenoma, and the assessment of proliferative activity and invasion was recommended to diagnose aggressive tumours. Recently, the International Pituitary Pathology Club proposed to replace adenoma with the term of pituitary neuroendocrine tumour (PitNET) to better reflect the similarities between adenohypophyseal and neuroendocrine tumours of other organs. The European Pituitary Pathology Group (EPPG) endorses this terminology and develops practical recommendations for standardised reports of PitNETs that are addressed to histo- and neuropathologists. This brief report presents the results of EPPG's consensus for the reporting of PitNETs and proposes a diagnostic algorithm.

White matter changes in the perforant path area in patients with amyotrophic lateral sclerosis.

OBJECTIVE: The aim of this study was to test the hypothesis that white matter degeneration of the perforant path - as part of the Papez circuit - is a key feature of amyotrophic lateral sclerosis (ALS), even in the absence of frontotemporal dementia (FTD) or deposition of pTDP-43 inclusions in hippocampal granule cells. METHODS: We used diffusion Magnetic Resonance Imaging (dMRI), polarized light imaging (PLI) and immunohistochemical analysis of post mortem hippocampus specimens from controls (n = 5) and ALS patients (n = 14) to study white matter degeneration in the perforant path. RESULTS: diffusion Magnetic Resonance Imaging demonstrated a decrease in fractional anisotropy (P = 0.01) and an increase in mean diffusivity (P = 0.01) in the perforant path in ALS compared to controls. PLI-myelin density was lower in ALS (P = 0.05) and correlated with fractional anisotropy (r = 0.52, P = 0.03). These results were confirmed by immunohistochemistry; both myelin (proteolipid protein, P = 0.03) and neurofilaments (SMI-312, P = 0.02) were lower in ALS. Two out of the fourteen ALS cases showed pTDP-43 pathology in the dentate gyrus, but with comparable myelination levels in the perforant path to other ALS cases. CONCLUSION: We conclude that degeneration of the perforant path occurs in ALS patients and that this may occur before, or independent of, pTDP-43 aggregation in the dentate gyrus of the hippocampus. Future research should focus on correlating the degree of cognitive decline to the amount of white matter atrophy in the perforant path.

Changes in cortical thickness in the frontal lobes in schizophrenia are a result of thinning of pyramidal cell layers.

Decreased cortical thickness and reduced activity as measured by fMRI in the grey matter of the subgenual cingulate cortex have been reported in schizophrenia and bipolar disorder, and cortical grey matter loss has been reliably reported in the frontal and temporal lobes in schizophrenia. The aim of this study was to examine the thickness of each of the six cortical layers in the subgenual cingulate cortex, five frontal lobe and four temporal lobe gyri. We examined two separate cohorts. Cohort 1 examines the subgenual cingulate cortex (SCC) in schizophrenia (n = 10), bipolar disorder (n = 15) and major depressive disorder (n = 20) against control subjects (n = 19). Cohort two examines frontal and temporal gyri in schizophrenia (n = 16), major depressive disorder (n = 6) against matched controls (n = 32). The cohorts were selected with identical clinical criteria, but underwent different tissue processing to contrast the effect of chemical treatment on tissue shrinkage. Measurements of layer I-VI thickness were taken from cresyl-violet- and haematoxylin-stained sections in cohort one and from cresyl-violet- and H&E-stained sections in cohort two. SCC cortical thickness decreased in male subjects with bipolar disorder (p = 0.048), and male schizophrenia cases showed a specific decrease in the absolute thickness of layer V (p = 0.003). Compared to controls, the relative thickness of layer V in the crown of the SCC decreased in schizophrenia (p < 0.001). A significant decrease in total cortical thickness was observed across the frontal lobe in schizophrenia (p < 0.0001), with specific pyramidal layer thinning in layers III (p = 0.0001) and V (p = 0.005). There was no effect of lateralization. No changes were noted in temporal lobe cortical thickness. This study demonstrates diminished pyramidal layer thickness resulting in decreased frontal lobe thickness in schizophrenia.

Neuropathology of the hippocampus in FTLD-Tau with Pick bodies: a study of the BrainNet Europe Consortium.

AIMS: Frontotemporal lobar degeneration with Pick bodies (Pick's disease) is characterized by the presence of tau immunoreactive spherical structures in the cytoplasm of neurones. In view of confusion about the molecular pathology of Pick's disease, we aimed to evaluate the spectrum of tau pathology and concomitant neurodegeneration-associated protein depositions in the characteristically affected hippocampus. METHODS: We evaluated immunoreactivity (IR) for tau (AT8, 3R, 4R), α-synuclein, TDP43, p62, and ubiquitin in the hippocampus, entorhinal and temporal cortex in 66 archival cases diagnosed neuropathologically as Pick's disease. RESULTS: Mean age at death was 68.2 years (range 49-96). Fifty-two (79%) brains showed 3R immunoreactive spherical inclusions in the granule cells of the dentate gyrus. These typical cases presented mainly with the behavioural variant of frontotemporal dementia, followed by progressive aphasia, mixed syndromes or early memory disturbance. α-Synuclein IR was seen only in occasional spherical tau-positive inclusions, TDP-43 IR was absent, and 4R IR was present only as neurofibrillary tangles in pyramidal neurones. Aß IR was observed in 16 cases; however, the overall level of Alzheimer's disease-related alterations was mainly low or intermediate (n = 3). Furthermore, we identified six cases with unclassifiable tauopathy. CONCLUSIONS: (i) Pick's disease may occur also in elderly patients and is characterized by a relatively uniform pathology with 3R tau inclusions particularly in the granule cells of dentate gyrus; (ii) even minor deviation from these morphological criteria suggests a different disorder; and (iii) immunohistological revision of archival cases expands the spectrum of tauopathies that require further classification.

Neuropathological changes in the nucleus basalis in schizophrenia.

The nucleus basalis has not been examined in detail in severe mental illness. Several studies have demonstrated decreases in glia and glial markers in the cerebral cortex in schizophrenia, familial bipolar disorder and recurrent depression. Changes in neocortical neuron size and shape have also been reported. The nucleus basalis is a collection of large cholinergic neurons in the basal forebrain receiving information from the midbrain and limbic system, projecting to the cortex and involved with attention, learning and memory, and receives regulation from serotonergic inputs. Forty-one cases aged 41-60 years with schizophrenia or major depressive disorder with age-matched controls were collected. Formalin-fixed paraffin-embedded coronal nucleus basalis sections were histologically stained for oligodendrocyte identification with cresyl-haematoxylin counterstain, for neuroarchitecture with differentiated cresyl violet stain and astrocytes were detected by glial fibrillary acid protein immunohistochemistry. Cell density and neuroarchitecture were measured using Image Pro Plus. There were larger NB oval neuron soma in the combined schizophrenia and major depression disorder groups (p = 0.038), with no significant change between controls and schizophrenia and major depression disorder separately. There is a significant reduction in oligodendrocyte density (p = 0.038) in the nucleus basalis in schizophrenia. The ratio of gemistocytic to fibrillary astrocytes showed a greater proportion of the former in schizophrenia (18.1 %) and major depressive disorder (39.9 %) than in controls (7.9 %). These results suggest glial cell abnormalities in the nucleus basalis in schizophrenia possibly leading to cortical-limbic disturbance and subcortical dysfunction.

Recurrent mutations in DNAJC5 cause autosomal dominant Kufs disease.

We sought to identify the molecular basis of the autosomal dominant form of Kufs disease, an adult onset form of neuronal ceroid lipofuscinosis. We used a combination of classic linkage analysis and Next Generation Sequencing to map and identify mutations in DNAJC5 in a total of three families. We analyzed the clinical manifestations in 20 individuals with mutation in DNAJC5. We report here the mapping and the identification of a p.L116del mutation in DNAJC5 segregating with the disease in two distinct American families, as well as a p.L115R mutation in an additional family. The age of onset and clinical manifestations were very homogeneous among mutation positive individuals, including generalized tonic-clonic seizures, myoclonus, ataxia, speech deterioration, dementia, and premature death. A few individuals also exhibited parkinsonism. DNAJC5, which encodes the cysteine string protein (CSPα), a presynaptic protein implicated in neurodegeneration, causes autosomal dominant Kufs disease. The leucine residues at positions 115 and 116 are hotspots for mutations and result in a homogeneous phenotype of progressive myoclonus epilepsy with onset around 30 years old.

Resolution of SPAM following cordectomy: implications for understanding pathophysiology.

STUDY DESIGN: Case report. OBJECTIVE: To describe the clinical benefit of a spinal cordectomy with the aim of limiting neurological deterioration related to the development of a subacute posttraumatic ascending myelopathy (SPAM) supporting previously described mechanism for SPAM formation. SETTING: National Spinal Injuries Centre, Stoke Mandeville Hospital, UK. METHOD AND RESULTS: A 38-year old patient presented 6 months after spinal cord injury substantial neurological deterioration expanding from the initial T4-injury level through C4. Magnetic resonance imaging revealed intra-medullary haemorrhage at the site of injury and subsequent-ascending cord oedema. A cordectomy was performed leading to neurological stabilisation and complete resolution of SPAM. CONCLUSION: Cordectomy can be an effective intervention in case of rapid progressive neurological deterioration.

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

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.

Progressive encephalomyelitis with rigidity and myoclonus: glycine and NMDA receptor antibodies.

BACKGROUND: The syndrome of progressive encephalopathy with limb rigidity has been historically termed progressive encephalomyelitis with rigidity and myoclonus (PERM) or stiff-person syndrome plus. METHODS: The case is presented of a previously healthy 28-year-old man with a rapidly fatal form of PERM developing over 2 months. RESULTS: Serum antibodies to both NMDA receptors (NMDAR) and glycine receptors (GlyR) were detected postmortem, and examination of the brain confirmed an autoimmune encephalomyelitis, with particular involvement of hippocampal pyramidal and cerebellar Purkinje cells and relative sparing of the neocortex. No evidence for an underlying systemic neoplasm was found. CONCLUSION: This case displayed not only the clinical features of PERM, previously associated with GlyR antibodies, but also some of the features associated with NMDAR antibodies. This unusual combination of antibodies may be responsible for the particularly progressive course and sudden death.

Outcome in surgically treated Rathke's cleft cysts: long-term monitoring needed.

OBJECTIVE: To clarify the outcome of all cases of Rathke's cleft cysts (RCC) treated surgically and followed up in Oxford during a long-term period. SUBJECTS AND METHODS: The records of all patients with RCC seen in the Department of Endocrinology between January 1978 and June 2009 were reviewed. RESULTS: A total of 33 patients (20 females, median age 43 years) were identified. At presentation, major visual field defects were detected in 58% of patients and gonadotrophin, ACTH and TSH deficiency in 60, 36 and 36% of patients respectively. Desmopressin treatment was required in 18% of patients. Treatment consisted of cyst evacuation combined with or without biopsy/removal of the wall. Post-operatively, visual fields improved in 83% of patients with impairment, whereas there was no reversal of ACTH or TSH deficiency or of diabetes insipidus. All but one subject had imaging follow-up during a mean period of 48 months (range 2-267). Cyst relapse was detected in 22% of patients at a mean interval of 29 months (range 3-48 months); in 57% of them, the recurrence was symptomatic. Relapse-free rates were 88% at 24-months and 52% at 48-months follow-up. At last assessment, at least quadrantanopia was reported in 19% of patients, gonadotrophin, ACTH and TSH deficiency in 50, 42 and 47% of patients respectively. Desmopressin treatment was required in 39% of patients. CONCLUSIONS: In this study of patients with RCC and long-term follow-up, we showed a considerable relapse rate necessitating long-term monitoring. Surgical intervention is of major importance for the restoration of visual field defects, but it does not improve endocrine morbidity, which in the long-term affects a substantial number of patients.

Nelson's syndrome.

Nelson's syndrome is a potentially life-threatening condition that does not infrequently develop following total bilateral adrenalectomy (TBA) for the treatment of Cushing's disease. In this review article, we discuss some controversial aspects of Nelson's syndrome including diagnosis, predictive factors, aetiology, pathology and management based on data from the existing literature and the experience of our own tertiary centre. Definitive diagnostic criteria for Nelson's syndrome are lacking. We argue in favour of a new set of criteria. We propose that Nelson's syndrome should be diagnosed in any patient with prior TBA for the treatment of Cushing's disease and with at least one of the following criteria: i) an expanding pituitary mass lesion compared with pre-TBA images; ii) an elevated 0800 h plasma level of ACTH (>500 ng/l) in addition to progressive elevations of ACTH (a rise of >30%) on at least three consecutive occasions. Regarding predictive factors for the development of Nelson's syndrome post TBA, current evidence favours the presence of residual pituitary tumour on magnetic resonance imaging (MRI) post transsphenoidal surgery (TSS); an aggressive subtype of corticotrophinoma (based on MRI growth rapidity and histology of TSS samples); lack of prophylactic neoadjuvant pituitary radiotherapy at the time of TBA and a rapid rise of ACTH levels in year 1 post TBA. Finally, more studies are needed to assess the efficacy of therapeutic strategies in Nelson's syndrome, including the alkylating agent, temozolomide, which holds promise as a novel and effective therapeutic agent in the treatment of associated aggressive corticotroph tumours. It is timely to review these controversies and to suggest guidelines for future audit.

Juvenile ALS with basophilic inclusions is a FUS proteinopathy with FUS mutations.

BACKGROUND: Juvenile amyotrophic lateral sclerosis (ALS) with basophilic inclusions is a form of ALS characterized by protein deposits in motor neurons that are morphologically and tinctorially distinct from those of classic sporadic ALS. The nosologic position of this type of ALS in the molecular pathologic and genetic classification of ALS is unknown. METHODS: We identified neuropathologically 4 patients with juvenile ALS with basophilic inclusions and tested the hypothesis that specific RNA binding protein pathology may define this type of ALS. Immunohistochemical findings prompted us to sequence the fused in sarcoma (FUS) gene. RESULTS: Motor symptoms began between ages 17 and 22. Disease progression was rapid without dementia. No family history was identified. Basophilic inclusions were strongly positive for FUS protein but negative for TAR DNA binding protein 43 (TDP-43). Granular and compact FUS deposits were identified in glia and neuronal cytoplasm and nuclei. Ultrastructure of aggregates was in keeping with origin from fragmented rough endoplasmic reticulum. Sequencing of all 15 exons of the FUS gene in 3 patients revealed a novel deletion mutation (c.1554_1557delACAG) in 1 individual and the c.1574C>T (P525L) mutation in 2 others. CONCLUSION: Juvenile ALS with basophilic inclusions is a FUS proteinopathy and should be classified as ALS-FUS. The FUS c.1574C>T (P525L) and c.1554_1557delACAG mutations are associated with this distinct phenotype. The molecular genetic relationship with frontotemporal lobar degeneration with FUS pathology remains to be clarified.

The treatment of femoral neuropathy due to pseudotumour caused by metal-on-metal resurfacing arthroplasty.

Concerns now exist about the long-term biological effects of exposure to orthopaedic metal alloys, particularly serum cobalt and chromium ions derived from metal-on-metal wear debris in these patients. A pseudotumour mass complicating metal-on-metal resurfacing arthroplasty has been recognized by orthopaedic oncologists and specialist hip units. Pseudotumours may also present with a major nerve palsy. Two cases of femoral neuropathy due to pseudotumour masses caused by metal-on-metal resurfacing arthroplasty are presented. Preoperative neurophysiological studies showed severe and irreversible pathological changes to nerve function with neurohistopathological evidence of complete nerve destruction with a previously unreported pathological appearance. This may represent a previously unrecognized pathological process, possibly 'toxic' in nature, resulting from metal-on-metal wear debris. Prolonged follow-up and detailed clinical assessment of patients after hip resurfacing arthroplasty is advocated with planned and expeditious revision of any patient in whom evidence of femoral neuropathy develops.

Collision lesions of the sella: co-existence of craniopharyngioma with gonadotroph adenoma and of Rathke's cleft cyst with corticotroph adenoma.

Collision lesions of the sellar region are relatively uncommon. Most contributions include a pituitary adenoma or a cyst/cystic tumor, particularly a Rathke cleft cyst. The association of craniopharyngioma with an adenoma is particularly rare. Among reported cases, some have included secondary prolactin cell hyperplasia due to pituitary stalk section effect. Herein, we report two collision lesions, including a gonadotroph adenoma with adamantinomatous craniopharyngioma and a corticotroph adenoma with Rathke's cleft cyst. Clinicopathologic correlation and a review of the literature are undertaken.

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

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.

Nonsurgical cerebrospinal fluid rhinorrhea in invasive macroprolactinoma: incidence, radiological, and clinicopathological features.

CONTEXT: Macroprolactinomas (MPRLs) may result in nonsurgical (spontaneous or dopamine agonist induced) cerebrospinal fluid (CSF) rhinorrhea; however, the incidence of and mechanisms underlying this phenomenon are poorly understood. OBJECTIVE: The objective of the study was to determine the incidence of nonsurgical rhinorrhea and identify biochemical, radiological, and histopathological factors associated with leakage. DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of MPRL patients (n = 114) was compared with patients with nonfunctioning pituitary adenoma (NFA) (n = 181) seen over a 19-yr period (1985-2004). MAIN OUTCOME MEASURES: Incidence of CSF rhinorrhea, factors predictive of leakage, and differential expression of candidate markers of invasiveness were measured. RESULTS: Nonsurgical CSF rhinorrhea occurred in 8.7% of MPRLs (10 of 114) [2.6% spontaneous (three of 114), 6.1% dopamine agonist induced (seven of 114)], whereas no NFAs developed nonsurgical rhinorrhea. There was a clear male preponderance in MPRLs with nonsurgical rhinorrhea (males to females, 9:1, P = 0.008). Dopamine agonist resistance was more frequent in MPRLs with rhinorrhea than with MPRLs without rhinorrhea [30% (n = 10) vs. 5% (n = 104) P = 0.003]. Baseline prolactin levels, rate of prolactin decline in response to dopamine agonists, and tumor volume at diagnosis did not predict CSF leakage. Candidate markers of invasiveness, specifically the protease-activated receptor 1 and e-cadherin expression scores and tumor macrophage density, were not significantly different between groups; MPRL+CSF rhinorrhea (n = 6), MPRL without CSF rhinorrhea (n = 9), and NFAs (n = 9). CONCLUSIONS: The incidence of nonsurgical CSF rhinorrhea in MPRL patients (8.7%) is higher than expected. Dopamine agonist resistance is more common in MPRLs with CSF rhinorrhea; however, whether this is a mechanistic relationship requires further study. Protease-activated receptor 1 expression, e-cadherin expression, and macrophage infiltration rates do not distinguish tumors with from those without CSF rhinorrhea.

Amyloid in neurosurgical and neurological practice.

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.

Immature teratoma arising from a benign cortical abnormality.

CASE REPORT: The authors report the case of an immature teratoma of the left parieto-occipital region in a 13-year-old girl. The patient had a computed tomographic (CT) scan of the brain aged 10 months old, following a minor head injury. This demonstrated an abnormality in the same region, which had been reported as 'a cortical malformation'. DIAGNOSIS: We propose that the lesion on the original imaging is a mature teratoma or other silent dystopic germ cell element that subsequently transformed into the immature teratoma. DISCUSSION: The potential triggers for such a transformation and the management of patients with similar incidental radiological findings are discussed.