Search for Dark-Matter-Nucleon Interactions via Migdal Effect with DarkSide-50

Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ionization electron adds to the energy deposited by the recoiling nuclear system and allows for the detection of interactions of sub-GeV/c^{2} mass dark matter. We present new constraints for sub-GeV/c^{2} dark matter using the dual-phase liquid argon time projection chamber of the DarkSide-50 experiment with an exposure of (12 306±184)  kg d. The analysis is based on the ionization signal alone and significantly enhances the sensitivity of DarkSide-50, enabling sensitivity to dark matter with masses down to 40  MeV/c^{2}. Furthermore, it sets the most stringent upper limit on the spin independent dark matter nucleon cross section for masses below 3.6  GeV/c^{2}.

Search for Dark Matter Particle Interactions with Electron Final States with DarkSide-50

We present a search for dark matter particles with sub-GeV/c^{2} masses whose interactions have final state electrons using the DarkSide-50 experiment's (12 306±184)  kg d low-radioactivity liquid argon exposure. By analyzing the ionization signals, we exclude new parameter space for the dark matter-electron cross section σ[over ¯]_{e}, the axioelectric coupling constant g_{Ae}, and the dark photon kinetic mixing parameter κ. We also set the first dark matter direct-detection constraints on the mixing angle |U_{e4}|^{2} for keV/c^{2} sterile neutrinos.

Prevalence and phenotype of the c.1529C>T SPG7 variant in adult-onset cerebellar ataxia in Italy

BACKGROUND AND PURPOSE

Hereditary ataxias are heterogeneous groups of neurodegenerative disorders, characterized by cerebellar syndromes associated with dysarthria, oculomotor and corticospinal signs, neuropathy and cognitive impairment. Recent reports have suggested mutations in the SPG7 gene, causing the most common form of autosomal recessive spastic paraplegia (MIM#607259), as a main cause of ataxias. The majority of described patients were homozygotes or compound heterozygotes for the c.1529C>T (p.Ala510Val) change. We screened a cohort of 895 Italian patients with ataxia for p.Ala510Val in order to define the prevalence and genotype-phenotype correlation of this variant.

METHODS

We set up a rapid assay for c.1529C>T using restriction enzyme analysis after polymerase chain reaction amplification. We confirmed the diagnosis with Sanger sequencing.

RESULTS

We identified eight homozygotes and 13 compound heterozygotes, including two novel variants affecting splicing. Mutated patients showed a pure cerebellar ataxia at onset, evolving in mild spastic ataxia (alternatively) associated with dysarthria (~80% of patients), urinary urgency (~30%) and pyramidal signs (~70%). Comparing homozygotes and compound heterozygotes, we noted a difference in age at onset and Scale for the Assessment and Rating of Ataxia score between the two groups, supporting an earlier and more severe phenotype in compound heterozygotes versus homozygotes.

CONCLUSIONS

The SPG7 c.1529C>T (p.Ala510Val) mutants accounted for 2.3% of cerebellar ataxia cases in Italy, suggesting that this variant should be considered as a priority test in the presence of late-onset pure ataxia. Moreover, the heterozygous/homozygous genotype appeared to predict the onset of clinical manifestation and disease progression.

Prognostic factors in ectopic Cushing's syndrome due to neuroendocrine tumors: a multicenter study

OBJECTIVE

Evidence is limited regarding outcome of patients with ectopic Cushing's syndrome (ECS) due to neuroendocrine tumors (NETs).

DESIGN

We assessed the prognostic factors affecting the survival of patients with NETs and ECS.

METHODS

Retrospective analysis of clinicopathological features, severity of hormonal syndrome, treatments from a large cohort of patients with NETs and ECS collected from 17 Italian centers.

RESULTS

Our series included 110 patients, 58.2% female, with mean (±s.d.) age at diagnosis of 49.5 ± 15.9 years. The main sources of ectopic ACTH were bronchial carcinoids (BC) (40.9%), occult tumors (22.7%) and pancreatic (p)NETs (15.5%). Curative surgery was performed in 56.7% (70.2% of BC, 11% of pNETs). Overall survival was significantly higher in BC compared with pNETs and occult tumors (P = 0.033) and in G1-NETs compared with G2 and G3 (P = 0.007). Negative predictive factors for survival were severity of hypercortisolism (P < 0.02), hypokalemia (P = 0.001), diabetes mellitus (P = 0.0146) and distant metastases (P < 0.001). Improved survival was observed in patients who underwent NET removal (P < 0.001). Adrenalectomy improved short-term survival.

CONCLUSIONS

Multiple factors affect prognosis of ECS patients: type of NET, grading, distant metastases, severity of hypercortisolism, hypokalemia and diabetes mellitus. BCs have the highest curative surgical rate and better survival compared with occult tumors and pNETs. Hypercortisolism plays a primary role in affecting outcome and quality of life; therefore, prompt and vigorous treatment of hormonal excess by NET surgery and medical therapy should be a key therapeutic goal. In refractory cases, adrenalectomy should be considered as it affects outcome positively at least in the first 2 years.

Understanding the effect of acromegaly on the human skeleton

Acromegaly, caused in most cases by Growth Hormone (GH)-secreting pituitary adenomas, is characterized by increased skeletal growth and enlargement of the soft tissue, because GH and its effector Insulin-like Growth factor-1 are important regulators of bone homeostasis and have a central role in the longitudinal bone growth and maintenance of bone mass. Areas covered: Despite the anabolic effect of these hormones is well known, as a result of the stimulation of bone turnover and especially of bone formation, many acromegalic patients are suffering from a form of secondary osteoporosis with increased risk of fractures. Expert commentary: In this review, we summarize the pathophysiology, diagnosis, clinical picture, disease course and management of skeletal complications of acromegaly, focusing in particular on secondary osteoporosis and fracture risk in acromegaly.

Factors predicting pasireotide responsiveness in somatotroph pituitary adenomas resistant to first-generation somatostatin analogues: an immunohistochemical study

AIM

To gather data regarding factors predicting responsiveness to pasireotide in acromegaly.

PATIENTS AND METHODS

SSTR2a, SSTR3, SSTR5, AIP, Ki-67 and the adenoma subtype were evaluated in somatotroph adenomas from 39 patients treated post-operatively with somatostatin analogues (SSAs). A standardized SSTR scoring system was applied (scores 0-3). All patients received first-generation SSAs, and 11 resistant patients were subsequently treated with pasireotide LAR.

RESULTS

None of the patients with negative or cytoplasmic-only SSTR2a expression (scores 0-1) were responsive to first-generation SSAs, as opposed to 20% (score 2) and 50% of patients with a score of 3 (P=0.04). None of the patients with an SSTR5 score of 0-1 were responsive to pasireotide, as opposed to 5/7 cases with a score of 2 or 3 (P=0.02). SSTR3 expression did not influence first-generation SSAs or pasireotide responsiveness. Tumours with low AIP were resistant to first-generation SSAs (100 vs 60%; P=0.02), while they had similar responsiveness to pasireotide compared to tumours with conserved AIP expression (50 vs 40%; P=0.74). Tumours with low AIP displayed reduced SSTR2 (SSTR2a scores 0-1 44.4 vs 6.7%; P=0.006) while no difference was seen in SSTR5 (SSTR5 scores 0-1 33.3 vs 23.3%; P=0.55). Sparsely granulated adenomas responded better to pasireotide compared to densely granulated ones (80 vs 16.7%; P=0.04).

CONCLUSION

The expression of SSTR5 might predict responsiveness to pasireotide in acromegaly. AIP deficient and sparsely granulated adenomas may benefit from pasireotide treatment. These results need to be confirmed in larger series of pasireotide-treated patients.

Impulse control behaviours in patients with Parkinson's disease after subthalamic deep brain stimulation: de novo cases and 3-year follow-up

OBJECTIVE

To document the occurrence of impulse control behaviours (ICBs) in patients with Parkinson's disease after 3 years of continuous deep brain stimulation (DBS) of the subthalamic nucleus (STN).

METHODS

Detailed neurological and ICB assessments were performed before STN DBS and up to 3 years after implant.

RESULTS

13 out of 56 patients (23.2%) had ICBs at baseline; they took higher doses of dopamine agonists (DAA). Three years after implant 11 had fully remitted with a 60.8% reduction of DAA medication; the remaining two, who had a similar medication reduction, had only compulsive eating, having recovered from hypersexuality. Six of the 43 patients without ICBs at baseline (14%) developed transient de novo ICBs after implant; none of them had ICBs at the 3-year observation.

CONCLUSIONS

ICBs were abolished in patients 3 years after STN DBS and DAA dosages were lowered. New ICBs may occur after implant and are transient in most cases. Compulsive eating may be specifically related to STN stimulation.

Genetics of Alzheimer's Disease and Frontotemporal Dementia

The genetics of neurodegenerative diseases has an important role to clarify the pathogenetic mechanism, the diagnosis and finally the therapeutic and ethical implications. Moreover, the genetic approach to the study of the main clinical forms of dementia (Alzheimer's disease-AD and Frontotemporal Dementia-FTD) suggests clinical guidelines for helping families to navigate through these complexities. AD and FTD are multifactorial, genetically complex diseases involving many candidate genes. Mutations in three genes (i.e. Amyloid Precursor Protein, APP; presenilin 1, PSEN1; presenilin 2, PSEN2) have been linked to 50% of all familial forms of AD (FAD). Genome wide association studies (GWAS) have involved an increasing number of genes with a possible role in the disease pathogenesis. Up to now, the genetics of familial forms of FTD is related to 7 genes: the microtubule-associated protein tau (MAPT) progranulin (GRN), the valosin-containing protein (VCP), chromatin-modifying 2B (CHMP2B), the TARDNA binding protein 43 encoding gene (TARBDP), fused in sarcoma (FUS) and the last hexanucleotide expansion repeats in the open reading frame of chromosome 9 (C9orf72). Pre-test counseling and the identification of genetic defects are important in both patients and asymptomatic at risk family members.

Hypothalamitis: a diagnostic and therapeutic challenge

To report an unusual case of biopsy-proven autoimmune hypophysitis with predominant hypothalamic involvement associated with empty sella, panhypopituitarism, visual disturbances and antipituitary antibodies positivity. We present the history, physical findings, hormonal assay results, imaging, surgical findings and pathology at presentation, together with a 2-year follow-up. A literature review on the hypothalamic involvement of autoimmune hypophysitis with empty sella was performed. A 48-year-old woman presented with polyuria, polydipsia, asthenia, diarrhea and vomiting. The magnetic resonance imaging (MRI) revealed a clear suprasellar (hypothalamic) mass, while the pituitary gland appeared atrophic. Hormonal testing showed panhypopituitarism and hyperprolactinemia; visual field examination was normal. Pituitary serum antibodies were positive. Two months later an MRI documented a mild increase of the lesion. The patient underwent biopsy of the lesion via a transsphenoidal approach. Histological diagnosis was lymphocytic "hypothalamitis". Despite 6 months of corticosteroid therapy, the patient developed bitemporal hemianopia and blurred vision, without radiological evidence of chiasm compression, suggesting autoimmune optic neuritis with uveitis. Immunosuppressive treatment with azathioprine was then instituted. Two months later, an MRI documented a striking reduction of the hypothalamic lesion and visual field examination showed a significant improvement. The lesion is stable at the 2-year follow-up. For the first time we demonstrated that "hypothalamitis" might be the possible evolution of an autoimmune hypophysitis, resulting in pituitary atrophy, secondary empty sella and panhypopituitarism. Although steroid treatment is advisable as a first line therapy, immunosuppressive therapy with azathioprine might be necessary to achieve disease control.

Treatment with octreotide LAR in clinically non-functioning pituitary adenoma: results from a case-control study

Surgical cure cannot be achieved in most patients with invasive non-functioning pituitary macroadenoma (NFPA). Short-term residual tumor treatment with somatostatin analogs has produced disappointing results. This prospective case-control study assessed the efficacy of chronic treatment with long acting octreotide (octreotide LAR) on tumor volume in patients harboring post-surgical NFPA residue. The study population comprised 39 patients with NFPAs not cured by surgery. All patients underwent somatostatin receptor scintigraphy at least 6 months after the last surgery. Patients with a positive pituitary level octreoscan at (n = 26) received octreotide LAR (20 mg every 28 days) for ≥ 12 months (mean follow-up 37 ± 18 months) (Treated group). Moreover, a fragment of tumor tissue from patients in the treated group was retrospectively collected to assess the immunohistochemical expression of somatostatin receptor subtypes (SSTRs). The patients with a negative octreoscan (n = 13) formed the control group (mean follow-up 37 ± 16 months). Hormonal, radiological and visual field parameters were periodically assessed. In the treated group, all tumors expressed at least one SSTR subtype. The SSTR5 subtype was the most abundant, followed by SSTR3. The tumor residue increased in five of 26 patients (19%) in the treated group and in seven of 13 controls (53%). Visual field and pituitary function did not change in any patient. This study indicates that SSTR5 and SSTR3 are the most frequently expressed SSTR subtypes in NFPAs and supports a potential role of SSTR subtypes in stabilization of tumor remnant from NFPAs.

Lack of association between GSTM1, GSTP1, and GSTT1 gene polymorphisms and asthma in adult patients from Rome, central Italy

BACKGROUND

Asthma is a complex multifactorial disease that is not yet fully understood. Oxidative stress due to an imbalance between the oxidative forces and the antioxidant defense systems has been implicated in asthma pathogenesis. However, much debate still surrounds the key genetic factors involved in the development of this disease. Candidate genes include the glutathione S-transferases (GSTs). In particular, mu, pi, and theta classes of GSTs play an important role in regulating inflammatory responses. However, few and contradictory data are available on the association between asthma development and GST gene polymorphisms (GSTM1, GSTP1, and GST1).

OBJECTIVE

To investigate whether GSTM1, GSTT1, and GSTP1 polymorphisms are associated with asthma development.

METHODS

We recruited 200 unrelated healthy individuals and 199 asthmatic patients from Rome in Central Italy. Genotyping of GSTMI and GSTT1 genes was performed by a multiplex polymerase chain reaction (PCR) while the GSTP1 polymorphism (rs1695) was determined using PCR-restriction fragment length polymorphism analysis.

RESULTS

Our results suggest that the GST polymorphisms analyzed are not associated with asthma, confirming the uncertain role of GST genes in the development of asthma.

CONCLUSIONS

Oxidative stress is certainly involved in the development of asthma, and GSTs may therefore influence asthma risk, although, as our results show, their role in pathogenesis remains to be elucidated. Future studies should focus on the interactions of GST genes with the environment and other antioxidant genes to shed light on the role of GSTs in asthma.

Whole body cholesterol metabolism is impaired in Huntington's disease

We previously reported impaired cholesterol biosynthesis in rodent Huntington Disease (HD) models and HD patients' fibroblasts and post mortem brains. We also found that plasma levels of 24S-hydroxycholesterol (24OHC), the brain specific elimination product of cholesterol considered a marker of brain cholesterol turnover, were significantly reduced in HD patients at any disease stage. In the present study we analysed by mass spectrometry the fasting plasma levels of cholesterol, its biosynthetic precursors lanosterol and lathosterol, of the whole-body elimination products 27-hydroxycholesterol and of brain 24OHC in a cohort of premanifest and HD patients at different disease stages. We found that the cholesterol precursors lanosterol and lathosterol (both index of whole body cholesterol synthesis), the levels of the bile acid precursor 27-hydroxycholesterol, and of the brain specific 24OHC, were all significantly reduced in manifest HD patients, suggesting that whole-body and brain cholesterol homeostasis are both impaired in HD.

IgM monoclonal gammopathy-associated neuropathies with different IgM specificity

BACKGROUND AND PURPOSE

  Antibodies directed against myelin-associated glycoprotein (MAG) are believed to be the most frequent biologic marker of the neuropathies associated with IgM monoclonal gammopathy of undetermined significance (MGUS). The objective of this study was to examine the prevalence of antiganglioside and/or sulfatide-positive patients and their clinical findings, including therapeutic response, compared to anti-MAG-positive or seronegative patients.

METHODS

  We prospectively followed 46 patients with MGUS who were diagnosed in our tertiary referral centers for polyneuropathy since 1997. All patients underwent nerve conduction studies and were tested for anti-MAG, gangliosides, and sulfatide antibodies. All the anagraphic and clinical data (including symptoms, disability scale, therapy, secondary malignancy development) were recorded in a database and compared between three patients' groups (anti-MAG-positive; antiganglioside/sulfatide-positive; no reactivity).

RESULTS

  Anti-MAG reactivity was present in 17 (37%) patients; other 17 patients (37%) had antiganglioside/sulfatide reactivity and 12 (26%) had no reactivity. Patients with antiganglioside/sulfatide positivity, although heterogeneous by a clinical and neurophysiological point of view, had the most severe neuropathic manifestations and a higher disability score at nadir (P < 0.001). These patients had a better response to both intravenous immunoglobulin therapy and rituximab.

CONCLUSIONS

  Our results suggest that antiganglioside/sulfatide-positive patients form a relevant portion of patients with MGUS-associated polyneuropathy seen in tertiary care centers and should be considered in future studies on treatment response.

Behavioral and personality features in patients with lateralized Parkinson's disease

BACKGROUND

Dopamine neurotransmission plays a key role in several brain activities, including motor, cognitive, and behavioral functions. Parkinson's disease (PD) typically begins with asymmetrical motor features related to asymmetrical dopamine denervation. This study was designed to examine whether distinct cognitive, behavioral, and personality features are related to this asymmetry.

METHODS

Fifty-six patients with mild PD and lateralized motor features were grouped according to dominant side of motor features and evaluated using a neuropsychological assessment focused on attention and executive functions, impulse control disorders, and personality inventory.

RESULTS

There were no differences in neuropsychological functions between patients with right and left lateralized PD, but differences occurred in personality features. Patients with motor impairment predominant on the left-hand side had prevalence of hypomania and conversion profile.

CONCLUSIONS

This study suggests that side dominance of dopaminergic denervation may be related to personality features in patients with PD that could influence behavioral aspects.

Regional distribution and clinical correlates of white matter structural damage in Huntington disease: a tract-based spatial statistics study

BACKGROUND AND PURPOSE

HD entails damage of the WM. Our aim was to explore in vivo the regional volume and microstructure of the brain WM in HD and to correlate such findings with clinical status of the patients.

MATERIALS AND METHODS

Fifteen HD gene carriers in different clinical stages of the disease and 15 healthy controls were studied with T1-weighted images for VBM and DTI for TBSS. Maps of FA, MD, and λ∥ and λ⊥ were reconstructed.

RESULTS

Compared with controls, in addition to neostriatum and cortical GM volume loss, individuals with HD showed volume loss in the genu of the internal capsule and subcortical frontal WM bilaterally, the right splenium of the corpus callosum, and the left corona radiata. TBSS revealed symmetrically decreased FA in the corpus callosum, fornix, external/extreme capsule, inferior fronto-occipital fasciculus, and inferior longitudinal fasciculus. Areas of increased MD were more extensive and included arciform fibers of the cerebral hemispheres and cerebral peduncles. Increase of the λ∥ and a comparatively more pronounced increase of the λ⊥ underlay the decreased FA of the WM in HD. Areas of WM atrophy, decreased FA, and increased MD correlated with the severity of the motor and cognitive dysfunction, whereas only the areas with increased MD correlated with disease duration.

CONCLUSIONS

Microstructural damage accompanies volume decrease of the WM in HD and is correlated with the clinical deficits and disease duration. MR imaging-based measures could be considered as a biomarker of neurodegeneration in HD gene carriers.

Magnetization transfer MR imaging demonstrates degeneration of the subcortical and cortical gray matter in Huntington disease

BACKGROUND AND PURPOSE

GM is typically affected in HD since the presymptomatic stage. Our aim was to investigate with MT MR imaging the microstructural changes of the residual brain subcortical and cortical GM in carriers of the HD gene and to preliminarily assess their correlation with the clinical features.

MATERIALS AND METHODS

Fifteen HD gene carriers with a range of clinical severity and 15 age- and sex-matched healthy controls underwent MT MR imaging on a 1.5T scanner. The MT ratio was measured automatically in several subcortical and cortical GM regions (striatal nuclei; thalami; and the neocortex of the frontal, temporal, parietal, and occipital lobes) by using FLS tools.

RESULTS

The MT ratio was significantly (P < .05 with Bonferroni correction for multiple comparison) decreased in all subcortical structures except the putamen and decreased diffusely in the cerebral cortex of HD carriers compared with controls. Close correlation was observed between the subcortical and cortical regional MT ratios and several clinical variables, including disease duration, motor disability, and scores in timed neuropsychological tests.

CONCLUSIONS

MT imaging demonstrates degeneration of the subcortical and cortical GM in HD carriers and might serve, along with volumetric assessment, as a surrogate marker in future clinical trials of HD.

Glutathione S-transferase gene polymorphisms and air pollution as interactive risk factors for asthma in a multicentre Italian field study: A preliminary study

BACKGROUND

Asthma is one of the most common chronic diseases. Several studies have indicated that oxidative stress impairs pulmonary function. Glutathione S-transferases (GSTs) are believed to be critical in the protection of cells from reactive oxygen species.

AIM

In this case-control study we analysed the possible association between polymorphism in several cytosolic GST genes, air pollution and asthma development.

METHODS

Genotyping of GSTM1 and GSTT1 genes was carried out by a multiplex PCR; GSTA1, GSTO1, GSTO2, GSTP1 polymorphisms were determined using the PCR-RFLP method. Data on atmospheric pollutants were collected by the regional air-quality monitoring network.

RESULTS

Among all the polymorphisms studied, the frequencies of GSTA1, GSTM1, GSTO2 and GSTT1 genotypes found in the group of asthmatic patients seem to differ from the frequencies of those found in the control group. Air pollutants were analysed and the air quality parameters considered proved to be significantly different, and therefore suitable for this study.

CONCLUSION

The final result of this research should hopefully lead to a better understanding of gene-environment interactions, so allowing earlier prediction and diagnosis of asthma disease and providing an efficient means of prevention.

Brain structural damage in Friedreich's ataxia

OBJECTIVE

Neuropathological descriptions of the brain in Friedreich's ataxia (FRDA) were obtained before availability of the current molecular genetic tests for this disease. Voxel-based morphometry (VBM) enables an unbiased whole-brain quantitative analysis of differences in gray matter (GM) and white matter (WM) volume.

METHODS

Using VBM, we assessed the brain structural damage in 22 patients with genetically confirmed FRDA and 25 healthy controls. The results were correlated with the disease duration and the severity of the patients' clinical deficits--evaluated using the International Cerebellar Ataxia Rating Scale and Inherited Ataxia Clinical Rating Scale.

RESULTS

In patients with FRDA, VBM showed a symmetrical volume loss in dorsal medulla, infero-medial portions of the cerebellar hemispheres, the rostral vermis and in the dentate region. No volume loss in cerebral hemispheres was observed. The atrophy of the cerebellum and medulla correlated with the severity of the clinical deficit and disease duration.

CONCLUSIONS

In patients with FRDA, significant GM and WM loss was observed only in the cerebellum and dorsal medulla. These structural changes correlate with the severity of the clinical deficit and disease duration.

Influence of impaired T- and B-cell compartments on efficacy of IVIg in dysimmune neuropathies

Autoimmune mechanisms are postulated to play a role in the development and progression of dysimmune neuropathies (DN). We investigated the relation between lymphocyte number and marker expression, and disease activity in 20 patients with DN under intravenous immunoglobulins (IVIg) treatment. B- and T-lymphocyte markers were studied by flow cytometry of the expression of CD5, CD25, CD23 and CD38 markers on B cells and of CD3, CD4 and CD8 markers, respectively. These parameters were compared with those obtained from matched healthy volunteers. The proportions of CD38+ B cells were higher in patients compared with those of controls. Proportions of activated CD4+ and CD8+ T cells were comparable in peripheral blood mononuclear cells of patients and controls, but a significant reduction of the absolute numbers of CD3+, CD4+ and CD8+ cells were observed in DN patients. The percentages of CD25+ memory T cells were instead significantly increased in DN patients. Lastly, T-cell reduction and the CD19/CD38 ratio over total B (CD19+) cells directly correlated with a poor response to IVIg therapy. In DN, whereas T-cell number is reduced, activated T and B cells are increased, thus suggesting an intrinsic defect of the immune response.

Morphometry and 1H-MR spectroscopy of the brain stem and cerebellum in three patients with fragile X-associated tremor/ataxia syndrome

SUMMARY

Morphometry and spectroscopy were performed in 3 patients with fragile X-associated tremor/ataxia syndrome (FXTAS). The brain stem and cerebellum were atrophic and satisfied criteria for olivopontocerebellar atrophy in 2 patients. However, the vermis was relatively spared and the basis pontis maintained its oval shape. The only spectroscopic abnormality was a decrease of the pontine N-acetylaspartate/creatine ratio in 1 patient. Atrophy and metabolic changes in FXTAS differ to some extent from those of olivopontocerebellar atrophy.

Brainstem neurodegeneration correlates with clinical dysfunction in SCA1 but not in SCA2. A quantitative volumetric, diffusion and proton spectroscopy MR study

Magnetic resonance (MR) techniques enable in vivo measurement of the atrophy of the brainstem and cerebellum in spinocerebellar ataxia type 1 (SCA1) and 2 (SCA2) patients, which is accompanied by a decrease in the concentration of N-acetyl aspartate (NAA) or of the NAA/creatine ratio in the pons and cerebellum. Mean diffusivity (D) is emerging as an additional sensitive and quantitative MR parameter to investigate brain diseases. In order to explore differences between the MR features of SCA1 and SCA2 and correlate the MR and clinical findings in the two conditions, we examined 16 SCA1 patients, 12 SCA2 patients and 20 healthy control subjects. The MR protocol included T1-weighted 3D gradient echo sequences, single-voxel proton spectroscopy of the right cerebellar hemisphere (dentate and peridentate region) and of the pons with a PRESS sequence and an external reference quantitation method, and (in nine patients with SCA1 and nine patients with SCA2) diffusion-weighted echo-planar images with reconstruction of the D maps. The patients were evaluated with the Inherited Ataxia Clinical Rating Scale (IACRS). Compared with control subjects, the SCA1 and SCA2 patients showed a decrease (P < 0.01) in the volume of the brainstem and cerebellum and in the concentration of NAA in the pons and cerebellar hemisphere, whereas D of the brainstem and cerebellum was increased. No significant difference was observed between the SCA1 and SCA2 patient groups. No correlation between cerebellar volume and dentate and peridentate NAA concentration was found in SCA1 or SCA2 patients. The volume of the brainstem, D of the brainstem and cerebellum and the concentration of NAA in the pons were correlated (P < 0.05) with the IACRS score in SCA1 but not in SCA2. This discrepancy is in line with the clinical observation that the clinical deficit has a later onset and faster progression in SCA1 and an earlier onset and slower progression in SCA2, and suggests that neurodegeneration of the brainstem is a comparatively more rapid process in SCA1. In conclusion, our study indicates that SCA1 and SCA2 substantially exhibit the same MR features. The correlation in SCA1 between clinical severity and quantitative volumetric, diffusion MRI and proton MR spectroscopy findings in the brainstem indicates that these measurements might be employed for longitudinal studies and hopefully as surrogate markers in future pharmacological trials of this condition.

Ataxia with isolated vitamin E deficiency: neurological phenotype, clinical follow-up and novel mutations in TTPAgene in Italian families

Ataxia with vitamin E deficiency (AVED) is a rare autosomal recessive neurodegenerative disorder due to mutations in the alpha-tocopherol transfer protein (TTPA) gene on chromosome 8q13. AVED patients have progressive spinocerebellar symptoms and markedly reduced plasma levels of vitamin E. We studied neurological phenotype at diagnosis, and long-term effect of vitamin E supplementation in 16 patients from 12 Italian families. The most common mutations were the 744delA and 513insTT. Two novel TTPA mutations were identified: a severe truncating mutation (219insAT) in a homozygous patient, and a Gly246Arg missense mutation (G246R) in a compound heterozygous patient. The missense mutation was associated with a mild and slowly progressive form of the disease. Vitamin E supplementation therapy allowed a stabilization of the neurological conditions in most of the patients. However, development of spasticity and retinitis pigmentosa was noted in a few patients during therapy. Prompt genetic characterization of AVED patients may allow an effective early treatment and an adequate genetic counseling.

Safety and tolerability of cyclophosphamide 'pulses' in multiple sclerosis: a prospective study in a clinical cohort

To assess the safety and tolerability of cyclophosphamide (CTX) 'pulse' therapy in progressive or very active multiple sclerosis (MS), we reviewed our experience in a cohort of MS patients who have been treated and prospectively followed-up in our Department since 1997. One hundred and twelve patients received intravenous CTX in monthly 'pulses' for 12 months at the dosage of 700 mg/m2 of body surface, then bimonthly for another 12 months. We evaluated the frequency and the severity of side-effects, as well as overall tolerability by the patient perspective using a visual analogue scale (VAS). Side-effects resulted in the discontinuation of therapy in 20 (18%) cases. Serious side-effects were observed in 24 patients (21.4%), most commonly definitive amenorrhea (33.3% of fertile women), hypogammaglobulinemia (5.4%), and hemorrhagic cystitis (4.5%). Malignancies were diagnosed in four (3.6%) subjects, three of whom were previously treated with azathioprine (AZA). Finally, 81.8% of the patients judged the treatment regimen as very or relatively acceptable and tolerable. Our data point to a reasonable safety and tolerability of CTX 'pulse' therapy. Further trials are needed to definitively assess the efficacy of CTX as an alternative therapeutic option for progressive or very active MS.

Progressive dysarthria: definition and clinical follow-up

Progressive dysarthria is a common sign of several degenerative disorders of the central nervous system; it may also be a distinct nosographic entity. We identified nine patients in which progressive dysarthria remained the sole neurological sign for at least 2 years after onset. At least a year after hospital admission, the following diagnoses were made: two cases of corticobasal degeneration, one of frontotemporal dementia, one of primary progressive aphasia, one of motor neuron disease (MND)-dementia, one of ALS, and one of ALS-aphasia. In the remaining two patients progressive dysarthria remained the only neurological sign at latest examination. We conclude that in most cases progressive dysarthria is the presenting sign of an established neurodegenerative disease (generally degenerative dementia or motor neuron disease), although the possibility that progressive dysarthria is a distinct entity cannot be excluded. To clarify this issue, studies (probably multicenter) on more patients with longer clinical follow-up and pathological confirmation are required.

Distal-proximal differences in limb apraxia in corticobasal degeneration but not progressive supranuclear palsy

Limb apraxia is an important diagnostic sign of cortico-basal degeneration (CBD), although it is also found in progressive supranuclear palsy (PSP). We investigated whether the severity of apraxia differed between proximal and distal arm movements in the two diseases, as suggested by their differing patterns of motor impairment. We studied 24 CBD patients, 25 PSP patients, and 19 healthy controls using a battery of cognitive tests and an ideomotor apraxia test that examined imitation of hand and of whole arm gestures separately. CBD and PSP patients did not differ in general characteristics or disability and were similarly impaired in cognitive performance. Within-group differences between distal and proximal gesture scores were significant only for CBD patients ( p=0.007), in whom distal movements were more compromised. This finding suggests the presence of limb kinetic apraxia in CBD, perhaps in association with ideomotor apraxia.

A study of arm movements in Huntington's disease under visually controlled and blindfolded conditions

The so-called bradykinesia of Huntington's disease (HD) seems not due to reduced movement speed alone but may also be task-dependent. We therefore investigated the influence of visual control on the ability of HD patients to perform a motor task. Ten HD patients, never treated with neuroleptic drugs and with mild functional impairment in activities of daily living, performed the task blindfolded and not blindfolded, as did 10 age- and education-matched healthy controls. The task was to use the dominant hand to trace out the contours of a 20 x 20 cm square in a clockwise direction, pausing at each corner. The square was marked on the table at which the subject sat. Accuracy was stressed rather than speed. A videocamerabased system recorded movement trajectories, from which kinematic and error parameters were derived. Patients and controls moved at comparable speeds but patients took longer to complete the task due to more curvilinear and hence longer trajectories. Patients spent more time in the deceleration phase of the movement, and in the blindfold condition had more variable movements as indicated by greater error variability scores. Correlation analysis showed that kinematic parameters in patients did not correlate with involuntary movement scores. These findings indicate that abnormalities of motor control are present in HD when movement accuracy (and not velocity) is required. HD patients are more dependent on visual control than normal subjects.

Cognitive and psychiatric characterization of patients with Huntington's disease and their at-risk relatives

We examined cognitive and psychiatric disturbances in patients with Huntington's disease (HD) in comparison to at-risk asymptomatic subjects. Cognitive and psychiatric scales and an HD motor scale were administered to 40 HD patients, 17 pre-symptomatic HD gene carriers (AR+) and 28 non gene carriers (AR-). HD patients did worse than AR+ and AR- in all motor, cognitive and psychiatric measures, while AR+ and AR-subjects did not differ between each other. HD patients had high scores for negative psychiatric symptoms, but there was no correlation between illness duration and psychiatric or cognitive performance. In HD, disease course and symptomatology are heterogeneous and negative psychiatric symptoms are common.

Genetic and clinical analysis of spinocerebellar ataxia type 8 repeat expansion in Italy

BACKGROUND

The spinocerebellar ataxias (SCAs) are clinically heterogeneous disorders caused by triplet repeat expansions in the sequence of specific disease genes. Spinocerebellar ataxia type 8 (SCA8), originally described in a family characterized by pure cerebellar ataxia with slow disease progression, presents with expansion of combined CTA/CTG repeats.

OBJECTIVE

To perform SCA8 repeat expansion analysis in a heterogeneous group of ataxic patients, to determine the prevalence of this mutation in our patients and establish the frequency of expanded CTA/CTG repeats in a large group of control subjects.

PATIENTS

One hundred sixty-seven patients affected by sporadic, autosomal dominant and recessive hereditary ataxia were clinically examined and analyzed for SCA8 expansion. We further studied 161 control subjects and 125 patients with psychiatric disorders.

RESULTS

We found abnormally expanded CTA/CTG repeats in 5 ataxic patients, 3 of them characterized by pure cerebellar ataxia. One patient had vitamin E deficiency and 1 patient with a sporadic case was affected by gluten ataxia. No evidence of expanded alleles was found in healthy control subjects and in patients with psychiatric disorders.

CONCLUSIONS

Our data support the evidence that CTG expansions may be linked to SCA8, since the pathogenic expansions have been found only among patients with genetically unidentified forms of hereditary and sporadic ataxia. Patients carrying expanded alleles present peculiar phenotypic features, thus suggesting that unknown additional factors could probably predispose to the disease.

Clinical and genetic analysis of hereditary and sporadic ataxia in central Italy

We have clinically and genetically evaluated 24 affected patients belonging to 22 Italian Friedreich ataxia (FA) families, 52 patients from 32 kindreds with proven autosomal dominant cerebellar ataxia (ADCA), 9 patients belonging to 5 families with autosomal recessive hereditary ataxia (ARCA) and 103 sporadic cases, 89 of which affected by idiopathic late onset cerebellar ataxia (ILOCA). Genotype-phenotype correlation analyses in FA patients have evidenced an inverse relationship between GAA repeat expansion length and age of onset, disease duration, and presence of cardiomyopathy. Among autosomal dominant types, spinocerebellar ataxia 2 (SCA2) genotype has been found in 31% of our ADCA families, resulting the most frequent form of ataxia. Phenotypic analysis of the various SCA subtypes evidenced a marked heterogeneity of symptoms with a substantial overlap between different syndromes.

Association between 5-HT(2A) receptor polymorphism and psychotic symptoms in Alzheimer's disease

BACKGROUND

The aim of this study is to analyze the segregation of the 102T/C polymorphism in the serotonin 2A receptor gene in patients affected by sporadic and familial Alzheimer's disease (FAD) with and without psychotic symptoms.

METHODS

The polymorphism was analyzed in 275 subjects. A semistructured interview was used to obtain information about delusions, hallucinations, and other specific behavioral signs occurring during the disease.

RESULTS

Fifty-two percent of AD patients with psychotic symptoms were homozygous for the C102 allele, as compared with 6.9% of AD patients without psychosis. Similarly, the C102/C102 genotype was significantly more frequent in FAD patients with psychosis than in FAD patients without (46.5% vs. 7.8%).

CONCLUSIONS

Our data strongly confirm and extend to FAD previous studies suggesting that the genetic variation at this locus is associated with prominent psychotic features in AD and that the 102C allele could play an important role in late-onset AD.

Acute effects of bilateral subthalamic nucleus stimulation on clinical and kinematic parameters in Parkinson's disease

After implantation with subthalamic stimulators, nine patients with advanced Parkinson's disease were studied on the task of tracing out, as accurately as possible, the four corners of a square with the dominant hand. The task was performed in four treatment conditions: on stimulation-off medication, off stimulation-off medication, off stimulation-on medication, and on stimulation-on medication. Movement times and peak velocities improved significantly only in the on stimulation-on medication condition compared to off stimulation-off medication. The improvement in clinical parameters with stimulation only (relative to off stimulation off medication) was of borderline significance, while consistent and significant clinical improvement was only obtained with addition of medication (on medication-on stimulation). This study provides quantitative evidence of the effect of subthalamic stimulation on kinematic measures in Parkinson's disease (PD) and suggests that combined treatment (medication and stimulation) is superior to either treatment alone.

Risperidone in idiopathic and symptomatic dystonia: preliminary experience

Risperidone is a heterocyclic neuroleptic with prominent antiserotoninergic (5HT2) as well as antidopaminergic (D2) activity. We studied the efficacy of risperidone in the treatment of idiopathic and symptomatic dystonias in seven patients using the Fahn and Marsden rating scale for torsion dystonia before and after four weeks of treatment (2-6 mg/day). The twisting and involuntary movements with abnormal postures decreased in all the patients treated, with a statistically significant mean improvement (41%; p = 0.009, CI 95%). Our results suggest that risperidone is useful in idiopathic and symptomatic dystonia.

Double-blind, crossover, placebo-controlled clinical trial with L-acetylcarnitine in patients with degenerative cerebellar ataxia

Despite the different genetic defects underlying degenerative ataxias, it has been suggested that mitochondrial energy production and antioxidative metabolism dysfunction may be common biochemical alterations related to these diseases. Acetylcarnitine, a cholinomimetic substance, is involved in oxidative metabolism and is a potential source of acetyl groups for the synthesis of acetylcholine in the mammalian brain. To determine whether treatment with L-acetylcarnitine may improve some clinical conditions of patients with ataxia, a double-blind crossover study with L-acetylcarnitine was performed in 24 patients with degenerative cerebellar diseases. Patients were selected from an ongoing prospective follow-up study at the Department of Neurology at the University of Florence, Italy. Each treatment phase with L-acetylcarnitine or placebo lasted 6 months, after which patients were crossed over to the other treatment phase. Ataxia was documented and quantified with use of a clinical score. After the trial, we observed a statistically significant improvement of some symptoms and a slow progression of the disease in both groups of patients.

No implication of apolipoprotein E polymorphism in Italian schizophrenic patients

Numerous studies have provided evidence for a genetic association of the Apolipoprotein E (ApoE) epsilon4 allele and late onset familial and sporadic Alzheimer's disease (AD). Clinical observations show that a proportion of schizophrenic patients may suffer from severe cognitive impairment. That could reflect a particular clinical aspect of this mental disorder or a common, yet unknown, neurodegenerative mechanism. We analysed the ApoE gene polymorphism in a sample of 69 Italian patients with schizophrenia, 140 AD patients and 121 controls. In schizophrenic patients, the distribution of ApoE genotypes does not significantly differ from that of controls. No effect of the ApoE genotype on age of onset was found. The frequency of ApoE alleles in Italian schizophrenic patients is comparable with control values, suggesting that ApoE polymorphism does not represent a risk factor for schizophrenia.

Implication of alpha1-antichymotrypsin polymorphism in familial Alzheimer's disease

A common polymorphism in the alpha1-antichymotrypsin (ACT) gene has been shown to modify the Apolipoprotein E (ApoE) epsilon4-associated Alzheimer's disease (AD) risk identifying the combination of the ACT/AA and ApoE epsilon4/epsilon4 genotypes as a potential susceptibility marker for AD. Using the polymerase chain reaction, we analyzed the segregation of the ACT and ApoE polymorphisms in familial Alzheimer's disease (FAD) patients carrying mutations in Presenilin (PS) and APP genes and in both early onset (EO) and late onset (LO) FAD patients without known mutations. Our data suggest that ACT does not represent an additional risk factor for PS and APP mutated families. However, in LOFAD patients a high frequency of the combined ACT/AA and ApoE epsilon4/epsilon4 genotypes suggest that ACT may interact with ApoE and play a role in LOFAD.

Inherent abnormalities in oxidative metabolism in Alzheimer's disease: interaction with vascular abnormalities

Extensive studies over the last 20 years have documented the existence of inherent abnormalities in oxidative/energy metabolism in Alzheimer's disease (AD). These abnormalities can be linked to characteristics of AD by plausible pathophysiological mechanisms for which there is abundant, robust evidence. The inherent abnormalities in cerebral metabolism of oxygen and glucose can reasonably be expected to interact synergistically with vascular compromise of cerebral oxygen and glucose metabolism in causing brain damage in AD.

Presenilin-1 gene intronic polymorphism in sporadic and familial Alzheimer's disease

A recent observation has shown a genetic association between an intronic polymorphism in the Presenilin-1 (PS-1) gene and late onset Alzheimer's disease (AD). The homozygosity of the 1 allele in the PS-1 gene was associated with a doubling of the risk for late onset AD. However, contrasting results have been published. We analyzed the distribution of the PS-1 intronic polymorphism in patients with sporadic AD and in seven familial AD (FAD) families carrying pathogenetic mutations in the amyloid precursor protein (APP) and Presenilin (PS-1 and PS-2) genes. Significant differences in PS-1 allele frequencies were observed in the Presenilin genes mutated families but not in late onset AD patients and in APP mutated families.