Functional MRI signal fluctuations highlight altered resting brain activity in Huntington's disease

The fractional Amplitude of Low Frequency Fluctuations (fALFF) and the degree of local synchronization (Regional Homogeneity - ReHo) of resting-state BOLD signal have been suggested to map spontaneous neuronal activity and local functional connectivity, respectively. We compared voxelwise, independent of atrophy, the fALFF and ReHo patterns of 11 presymptomatic (ps-HD) and 28 symptomatic (sHD) Huntington's disease mutation carriers, with those of 40 normal volunteers, and tested their possible correlations with the motor and cognitive subscores of the Unified Huntington's Disease Rating Scale. In sHD patients, fALFF was mainly reduced bilaterally in parietal lobes (right precuneus being already affected in psHD), and in superior frontal gyri, and increased bilaterally in cerebellar lobules VI, VIII and IX, as well as in the right inferior temporal gyrus. In sHD, and to a lesser extent in psHD, ReHo was bilaterally reduced in putamina, cerebellar lobules III to VI, and superior medial frontal gyri, and increased in both psHD and sHD in fronto-basal cortices, and in the right temporal lobe. fALFF correlated inversely with cognitive scores in lobule IX of the cerebellum (mainly with total Stroop score, p < 0.0001), and in the medial portions of both thalami. These results are consistent with a reduced neuronal activity in the cortical components of the executive networks, known to be affected in Huntington's Disease, and with reduced local functional integration in subcortical and cerebellar components of the sensori-motor network. Cerebellar clusters of significant correlation of fALFF with executive function scores may be related to compensatory mechanisms.

Regulation of postsynaptic plasticity genes' expression and topography by sustained dopamine perturbation and modulation by acute memantine: relevance to schizophrenia

A relevant role for dopamine-glutamate interaction has been reported in the pathophysiology and treatment of psychoses. Dopamine and glutamate may interact at multiple levels, including the glutamatergic postsynaptic density (PSD), an electron-dense thickening that has gained recent attention as a switchboard of dopamine-glutamate interactions and for its role in synaptic plasticity. Recently, glutamate-based strategies, such as memantine add-on to antipsychotics, have been proposed for refractory symptoms of schizophrenia, e.g. cognitive impairment. Both antipsychotics and memantine regulate PSD transcripts but sparse information is available on memantine's effects under dopamine perturbation. We tested gene expression changes of the Homer1 and PSD-95 PSD proteins in models of sustained dopamine perturbation, i.e. subchronic treatment by: a) GBR-12909, a dopamine receptor indirect agonist; b) haloperidol, a D2R antagonist; c) SCH-23390, a dopamine D1 receptor (D1R) antagonist; and d) SCH-23390+haloperidol. On the last day of treatment, rats were acutely treated with vehicle or memantine. The Homer1a immediate-early gene was significantly induced by haloperidol and by haloperidol+SCH-23390. The gene was not induced by SCH-23390 per se or by GBR-12909. Expression of the constitutive genes Homer1b/c and PSD-95 was less affected by these dopaminergic paradigms. Acute memantine administration significantly increased Homer1a expression by the dopaminergic compounds used herein. Both haloperidol and haloperidol+SCH-23390 shifted Homer1a/Homer1b/c ratio of expression toward Homer1a. This pattern was sharpened by acute memantine. Dopaminergic compounds and acute memantine also differentially affected topographic distribution of gene expression and coordinated expression of Homer1a among cortical-subcortical regions. These results indicate that dopaminergic perturbations may affect glutamatergic signaling in different directions. Memantine may help partially revert dopamine-mediated glutamatergic dysfunctions.

Different effects of the NMDA receptor antagonists ketamine, MK-801, and memantine on postsynaptic density transcripts and their topography: role of Homer signaling, and implications for novel antipsychotic and pro-cognitive targets in psychosis

Administration of NMDA receptor antagonists, such as ketamine and MK-801, may induce psychotic-like behaviors in preclinical models of schizophrenia. Ketamine has also been observed to exacerbate psychotic symptoms in schizophrenia patients. However, memantine, a non-competitive NMDA receptor antagonist approved for Alzheimer's disease and proposed for antipsychotic augmentation, may challenge this view. To date, the molecular mechanisms by which these NMDA receptor antagonists cause different neurochemical, behavioral, and clinical effects are still a matter of debate. Here, we investigated by molecular imaging whether these agents could differently modulate gene expression and topographical distribution of glutamatergic postsynaptic density (PSD) proteins. We focused on Homer1a/Homer1b/PSD-95 signaling network, which may be implicated in glutamate-dependent synaptic plasticity, as well as in psychosis pathophysiology and treatment. Ketamine (25 and 50mg/kg) and MK-801 (0.8mg/kg) significantly induced the transcripts of immediate-early genes (Arc, c-fos, and Homer1a) in cortical regions compared to vehicle, whereas they reduced Homer1b and PSD-95 expression in cortical and striatal regions. Differently, memantine (5mg/kg) did not increase Homer1a signal compared to vehicle, whereas it induced c-fos in the somatosensory and in the medial agranular cortices. Moreover, memantine did not affect Homer1b and PSD-95 expression. When compared to ketamine and MK-801, memantine significantly increased the expression of c-fos, Homer1b and PSD-95. Overall, ketamine and MK-801 prominently increased Homer1a/Homer1b expression ratio, whereas memantine elicited the opposite effect. These data may support the view that ketamine, MK-801 and memantine exert divergent effects on PSD transcripts, which may contribute to their partially different behavioral and clinical effects.

Opioidergic system and N-methyl D-aspartate receptor (NMDA-R) hypofunction: Translational implications for the pathophysiology of psychosis and drug addiction

Enkephalin is an opioidergic neuromodulator that has been implicated in long-term behavioural sensitization after administration of drugs of abuse. Enkephalin is also a molecular marker of GABAergic neurons in the striato-pallidal pathway that is involved in sensory-motor gating and has been considered dysfunctional in the pathophysiology of psychosis.

In this study we investigated in male Sprague Dawley rats putative changes in Enkephalin transcripts by in situ hybridization after acute or subchronic administration of ketamine in either high or low subanaesthetic doses (50 mg/kg and 12 mg/kg respectively). Ketamine is a non-competitive NMDA-R antagonist that perturbs glutamate neurotransmission and provides a preclinical model of psychosis-like behaviour in rats.

In the acute paradigm the expression of Enkephalin was reduced in the motor, premotor, somatosensory cortices as well as in anterior cingulate. In the subchronic paradigm Enkephalin expression was reduced in the premotor cortex, in the ventromedial caudate-putamen and in the shell of nucleus accumbens. Comparative analysis showed that the relative decrement in gene expression was not significantly different between the acute and subchronic paradigm for each region of interest.

Changes in distribution of Enkephalin expression and correlation analysis of functionally related brain regions suggest that Enkephalin transcripts reduction may be implicated in the motivational aspects of drug addiction and may help explaining some aspects of the pathophysiology in ketamine-induced psychosis.

Inventory management

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

[Personality disorder and penal imputability: a case of uxoricide in a expert's report]

The personality disorders are generally described as a persistent pattern of inner experience that deviates strongly from the expectations of the culture of an individual in terms of cognition, affectivity, interpersonal functioning and impulse control. They are a complex area of defining and understanding for the clinical and forensic psychiatrist. A recent ruling by the Court of Cassation stated that personality disorder may be a result of reduction or cancellation of the ability to understand and will, if so serious as to affect the same. In the present work is explored, using a psycho-diagnostic protocol, the psychological profile of a person with a narcissistic personality disorder, charged for uxoricidio.

The clinical spectrum and natural history of gelastic epilepsy-hypothalamic hamartoma syndrome

PURPOSE

To delineate the clinical spectrum and patterns of evolution of epilepsy with gelastic seizures related to hypothalamic hamartoma (HH).

PATIENTS AND METHODS

We evaluated patients with HH, observed between 1986 and 2002 for whom at least one ictal video-EEG or EEG recording of gelastic seizures was available.

RESULTS

Six subjects (four male, two female) with sessile HH between 0.8 and 1.7 cm in diameter were identified. The onset of gelastic seizures was between 2 months and 20 years. It evolved to secondary generalized epilepsy in one case, and to drug-resistant partial epilepsy in the other five from 2 to 13 years after onset. No patient showed precocious puberty. Severe cognitive impairment developed in the patient with secondary generalized epilepsy, and a mild cognitive defect in two others. Patients with an HH below 1cm did not show neuropsychological or behavioural disturbances. Drug resistance occurred in all cases. Surgical removal of HH markedly improved the clinical evolution in two patients.

CONCLUSIONS

Gelastic epilepsy-HH syndrome can differ in severity and evolution. A catastrophic evolution and drug resistance can be reversed by surgical or by gamma-knife ablation of HH.

Spinal muscular atrophy and progressive myoclonic epilepsy: one case report and characteristics of the epileptic syndrome

INTRODUCTION

Spinal muscular atrophies (SMAs) are a group of degenerative diseases primarily affecting the anterior horn cells of the spinal cord and motor cells of cranial nerve nuclei. Even if the clinical picture is mainly dominated by the diffuse muscular atrophy, in some cases, patients may show associated, atypical clinical features ("SMA plus"). In particular, the association of SMA and progressive myoclonic epilepsy (PME) has been rarely described.

CASE REPORT

We present the clinical and electrophysiological data of a boy with childhood-onset SMA associated with PME and reviewed cases of the literature.

CONCLUSION

The association of SMA with PME may constitute a separate and, probably, genetically independent syndrome with unique clinical and electroencephalographic findings or, at least, a variant of a neurodegenerative or metabolic disease, due to yet unknown causes.

Bioptically demonstrated Lafora disease without EPM2A mutation: a clinical and neurophysiological study of two sisters

Lafora disease (LD) is an autosomal recessive inherited form of progressive myoclonic epilepsy with dementia and ataxia, usually presenting in the second decade of life and inexorably progressing until death. Neuropathological hallmarks are Lafora bodies, intracytoplasmic inclusions that can be found in neurons and in other tissues. LD gene (EPM2A), mapping on chromosome 6, encodes for a tyrosine phosphatase protein called laforin. However, up to 20% cases of LD are not genetically linked to chromosome 6. We report two sisters affected from bioptically diagnosed LD but without evidence of EPM2A mutation. Although familial cases of LD are already reported in literature, our observation leads to some considerations on clinical-electrophysiological evolution as well as to remark the genetic heterogeneity of this condition. In addition, we report the good effect of the Levetiracetam for the treatment of myoclonus in these patients, also demonstrated by the electrophysiological findings.

Epileptic seizures in multiple sclerosis: clinical and EEG correlations

Epileptic seizures occur more frequently in multiple sclerosis (MS) patients than in the general population. We evaluated clinical, electroencephalographic (EEG) and magnetic resonance imaging (MRI) findings, as well as EEG-MRI correlations and the response to antiepileptic drugs (AEDs) in 270 consecutive patients with definite MS referred to our Department from 1995 to 2002. Thirteen (4.8%) subjects experienced epileptic seizures. In four cases, seizures manifested within 1-2 years ("early-onset"), and in six cases within 8-23 years ("late-onset") of MS diagnosis. Seizures were usually partial with secondary generalization. Thus, acute symptomatic seizures occurred in three cases. Epilepsy usually appeared late in the course of disease, although a single episode or a cluster of seizures can represent the onset symptom or a relapse of MS. Prognosis of epilepsy during the course of MS is usually good but the choice of AEDs remains a matter of debate.