The cognitive profile of prion disease: a prospective clinical and imaging study.

Objectives: Prion diseases are dementing illnesses with poorly defined neuropsychological features. This is probably because the most common form, sporadic Creutzfeldt-Jakob disease, is often rapidly progressive with pervasive cognitive decline making detailed neuropsychological investigation difficult. This study, which includes patients with inherited, acquired (iatrogenic and variant) and sporadic forms of the disease, is the only large-scale neuropsychological investigation of this patient group ever undertaken and aimed to define a neuropsychological profile of human prion diseases.

Tic Phenomenology and Tic Awareness in Adults With Autism.

Tics are common in people with autism spectrum disorder (ASD). However, their phenomenology and characteristics have not been studied in detail. Based on video sequences of 21 adults with ASD without intellectual disability and 16 adults with Gilles de la Tourette syndrome (GTS), tic severity, tic repertoires, and tic awareness were determined.

Late Emergence of Parkinsonian Phenotype and Abnormal Dopamine Transporter Scan in Chorea-Acanthocytosis.

Chorea-acanthocytosis (ChAc) is a neurodegenerative condition predominantly manifesting with chorea and often acanthocytes on peripheral blood film. Abnormal appearances with I-FP-CIT single-photon emission computed tomography (SPECT) have not previously been reported in ChAc. We describe 2 cases with typical presentations of ChAc and late development of parkinsonism with asymmetric reduction in presynaptic striatal uptake on I-FP-CIT SPECT.

Molecular mechanism of Spinocerebellar Ataxia type 6: glutamine repeat disorder, channelopathy and transcriptional dysregulation. The multifaceted aspects of a single mutation.

Spinocerebellar Ataxia type 6 (SCA6) is an autosomal dominant neurodegenerative disease characterized by late onset, slowly progressive, mostly pure cerebellar ataxia. It is one of three allelic disorders associated to CACNA1A gene, coding for the Alpha1 A subunit of P/Q type calcium channel Cav2.1 expressed in the brain, particularly in the cerebellum.

"A disorder which occurs on standing": The Earliest Account of Orthostatic Tremor by Pazzaglia.

The earliest account of orthostatic tremor (OT) dates back to 1970, when Pazzaglia and colleagues reported on three patients with a peculiar disorder only occurring on standing. Although Pazzaglia et al. did not use the term OT, they first provided both the clinical and neurophysiological features of such a condition.

Stiff Limb Syndrome Mimicking Corticobasal Syndrome.

Stiff limb syndrome (SLS) is a focal variant of the spectrum of stiff person syndrome. Its presentation with stiffness, limb posturing, and freezing-of-gait (FOG)-like episodes, together with the relative rareness of the disorder, make it conceivable that SLS might be misdiagnosed as atypical parkinsonism, in particular, corticobasal syndrome (CBS). To illustrate this, we present two cases of established SLS resembling CBS and discuss the distinguishing features that may alert the clinician to the correct diagnosis, with its obvious therapeutic and prognostic implications.

Abnormalities of Masseteric Inhibitory Reflex in Hereditary Geniospasm: Evidence for a Brainstem Myoclonus.

We studied two unrelated families with several members suffering from geniospasm. Here, we aim to clarify the pathophysiology underlying the hereditary geniospasm through testing of brainstem excitability by the recovery cycles of the blink reflex (BR) and the masseteric inhibitory reflex (MIR). The R2 component of the BR and the SP2 component of the MIR and their recovery cycle were analyzed in 3 patients and 8 healthy, age-matched subjects as the control group.

Molecular mechanism underlying the impact of vitamin D on disease activity of MS.

Objective: Some previous studies suggest modest to strong effects of 25-hydroxyvitamin D (25(OH)D) on multiple sclerosis (MS) activity. The objective of this study was to explore the mechanistic rationale that may explain potential clinical effects of 25(OH)D.

Methods: This study measured serum 25(OH)D levels and global gene expression profiles over a course of up to 2 years in patients starting treatment with interferon beta-1b (IFNB-1b) after a clinically isolated syndrome.

A comprehensive assessment of resting state networks: bidirectional modification of functional integrity in cerebro-cerebellar networks in dementia.

In resting state fMRI (rs-fMRI), only functional connectivity (FC) reductions in the default mode network (DMN) are normally reported as a biomarker for Alzheimer's disease (AD). In this investigation we have developed a comprehensive strategy to characterize the FC changes occurring in multiple networks and applied it in a pilot study of subjects with AD and Mild Cognitive Impairment (MCI), compared to healthy controls (HC). Resting state networks (RSNs) were studied in 14 AD (70 ± 6 years), 12 MCI (74 ± 6 years), and 16 HC (69 ± 5 years).

Shaking on Standing: A Critical Review.

Orthostatic tremor is a rare condition, though its exact prevalence is unknown, which is clinically characterized by a feeling of unsteadiness or being about to fall on standing and which disappears on walking, sitting, or lying down. It is generally accepted that classic orthostatic tremor manifests with a high-frequency tremor (>13 Hz) of the legs when standing. However, a number of patients initially reported as orthostatic tremor did not actually have such electrophysiological features.

The Semiology of Tics, Tourette's, and Their Associations.

Gilles de la Tourette syndrome (GTS) is a prototypical neuropsychiatric disorder breaking the boundary of disciplinary dualism between neurology and psychiatry. The diagnosis of GTS is clinical and, in most cases, straightforward. Tics as a hallmark of GTS are usually easy to recognize and distinguish from other movement disorders as fragmented, repetitive, exaggerated movements resembling normal motor behavior, but appearing out of context.

Characteristic "Forcible" Geste Antagoniste in Oromandibular Dystonia Resulting From Pantothenate Kinase-Associated Neurodegeneration.

Geste antagonistes are usually considered typical of primary dystonia, although rarely they have been described in secondary/heredodegenerative dystonias. We have recently come across a particular geste antagoniste in 5 of 10 patients with pantothenate kinase-associated neurodegeneration (PKAN) who had prominent oromandibular involvement with severe jaw-opening dystonia. It consists of touching the chin with both hands characteristically clenched into a fist with flexion at the elbows.

The Clinical Syndrome of Paroxysmal Exercise-Induced Dystonia: Diagnostic Outcomes and an Algorithm.

Paroxysmal exercise-induced dyskinesia (PED) is characterized by recurrent episodes of involuntary movement disorders usually precipitated by sustained walking or running. Recently, mutations in the gene encoding for glucose transporter type 1 (GLUT-1) were described in a number of families with autosomal dominant PED. However, the underlying etiology of PED is quite heterogeneous.

Adult-Onset Primary Dystonic Tics: A Different Entity?

Based on their phenomenology, tics can be classified as clonic, dystonic, and tonic. Although tic syndromes are considered to be childhood disorders, there are reports on (clonic) tics developing late in life. Literature on dystonic tics is sparse, and it is unclear whether adult-onset dystonic tics are part of the same disorder spectrum that includes Tourette's syndrome or represent a discrete entity.

Tonic GABAA conductance decreases membrane time constant and increases EPSP-spike precision in hippocampal pyramidal neurons.

Because of a complex dendritic structure, pyramidal neurons have a large membrane surface relative to other cells and so a large electrical capacitance and a large membrane time constant (τm). This results in slow depolarizations in response to excitatory synaptic inputs, and consequently increased and variable action potential latencies, which may be computationally undesirable. Tonic activation of GABAA receptors increases membrane conductance and thus regulates neuronal excitability by shunting inhibition.

Gamma oscillatory amplitude encodes stimulus intensity in primary somatosensory cortex.

Gamma oscillations have previously been linked to pain perception and it has been hypothesized that they may have a potential role in encoding pain intensity. Stimulus response experiments have reported an increase in activity in the primary somatosensory cortex (SI) with increasing stimulus intensity, but the specific role of oscillatory dynamics in this change in activation remains unclear. In this study, Magnetoencephalography (MEG) was used to investigate the changes in cortical oscillations during four different intensities of a train of electrical stimuli to the right index finger, ranging from low sensation to strong pain.

Symmetric diffeomorphic modeling of longitudinal structural MRI.

This technology report describes the longitudinal registration approach that we intend to incorporate into SPM12. It essentially describes a group-wise intra-subject modeling framework, which combines diffeomorphic and rigid-body registration, incorporating a correction for the intensity inhomogeneity artifact usually seen in MRI data. Emphasis is placed on achieving internal consistency and accounting for many of the mathematical subtleties that most implementations overlook.