The diagnostic value of sleep and vigilance tests in central disorders of hypersomnolence.

Study Objectives: This retrospective cross-sectional observational study explored the diagnostic value of selected sleep and vigilance tests (SVT) beyond the multiple sleep latency test to differentiate between various central disorders of hypersomnolence (CDH) and fatigue syndromes.

Methods: Data from patients who underwent the multiple sleep latency test and at least one additional SVT were extracted from the Bern sleep database (1997-2018). One thousand three hundred fifty-two patients with a CDH (106 narcolepsy type 1, 90 narcolepsy type 2, 119 idiopathic hypersomnia, 192 nonorganic hypersomnia, 205 insufficient sleep syndrome), fatigue syndromes (n = 183), and a subgroup of patients with sleep apnea (n = 457) were analyzed.

A Thalamic-Fronto-Parietal Structural Covariance Network Emerging in the Course of Recovery from Hand Paresis after Ischemic Stroke.

Aim: To describe structural covariance networks of gray matter volume (GMV) change in 28 patients with first-ever stroke to the primary sensorimotor cortices, and to investigate their relationship to hand function recovery and local GMV change.

Methods: Tensor-based morphometry maps derived from high-resolution structural images were subject to principal component analyses to identify the networks. We calculated correlations between network expression and local GMV change, sensorimotor hand function and lesion volume.

Authorship in scientific publications: analysis and recommendations.

In 2008, a Swiss Academies of Arts and Sciences working group chaired by Professor Emilio Bossi issued a "Memorandum on scientific integrity and the handling of misconduct in the scientific context", together with a paper setting out principles and procedures concerning integrity in scientific research. In the Memorandum, unjustified claims of authorship in scientific publications are referred to as a form of scientific misconduct - a view widely shared in other countries. In the Principles and Procedures, the main criteria for legitimate authorship are specified, as well as the associated responsibilities.

Sleepiness and performance is disproportionate in patients with non-organic hypersomnia in comparison to patients with narcolepsy and mild to moderate obstructive sleep apnoea.

Background/aims: Clinical differentiation between organic hypersomnia and non-organic hypersomnia (NOH) is challenging. We aimed to determine the diagnostic value of sleepiness and performance tests in patients with excessive daytime sleepiness (EDS) of organic and non-organic origin.

Methods: We conducted a retrospective comparison of the multiple sleep latency test (MSLT), pupillography, and the Steer Clear performance test in three patient groups complaining of EDS: 19 patients with NOH, 23 patients with narcolepsy (NAR), and 46 patients with mild to moderate obstructive sleep apnoea syndrome (OSAS).

Interhemispheric cerebral blood flow balance during recovery of motor hand function after ischemic stroke--a longitudinal MRI study using arterial spin labeling perfusion.

Background: Unilateral ischemic stroke disrupts the well balanced interactions within bilateral cortical networks. Restitution of interhemispheric balance is thought to contribute to post-stroke recovery. Longitudinal measurements of cerebral blood flow (CBF) changes might act as surrogate marker for this process.

Insular and caudate lesions release abnormal yawning in stroke patients.

Abnormal yawning is an underappreciated phenomenon in patients with ischemic stroke. We aimed at identifying frequently affected core regions in the supratentorial brain of stroke patients with abnormal yawning and contributing to the anatomical network concept of yawning control. Ten patients with acute anterior circulation stroke and ≥3 yawns/15 min without obvious cause were analyzed.

Vertical bias in neglect: a question of time?

Neglect is defined as the failure to attend and to orient to the contralesional side of space. A horizontal bias towards the right visual field is a classical finding in patients who suffered from a right-hemispheric stroke. The vertical dimension of spatial attention orienting has only sparsely been investigated so far.

EEG correlation and power during maintenance of wakefulness test after sleep-deprivation.

Objectives: To investigate whether there are any objective EEG characteristics that change significantly between specific time periods during maintenance of wakefulness test (MWT) and whether such changes are associated with the ability to appropriately communicate sleepiness.

Methods: After a night of total sleep deprivation, 12 healthy young subjects underwent a MWT whilst being instructed to communicate the experience of subjective sleepiness by pressing a button. EEG analysis consisted of average relative power and correlation between EEG signals.

Why do we yawn? The importance of evidence for specific yawn-induced effects.

Gallup (this issue) believes that our recent review on the function of yawning (Guggisberg et al., 2010) is unbalanced and that it ignores evidence for his thermoregulation hypothesis. Here we address these criticisms and show them to be untenable.

Interference with gesture production by theta burst stimulation over left inferior frontal cortex.

Objective: The traditional view of a predominant inferior parietal representation of gestures has been recently challenged by neuroimaging studies demonstrating that gesture production and discrimination may critically depend on inferior frontal lobe function. The aim of the present work was therefore to investigate the effect of transient disruption of these brain sites by continuous theta burst stimulation (cTBS) on gesture production and recognition.

Methods: Fourteen healthy subjects participated in the study.

Spontaneous recovery of visually-triggered saccades after focal lesions of the frontal and parietal eye fields: a combined longitudinal oculomotor and fMRI study.

Objective: To analyze oculomotor recovery in a patient with ischemic lesions restricted to the left frontal eye field (FEF) and the left parietal eye field (PEF).

Methods: Two, three, and four weeks after the stroke, saccades were measured and mean gain and latency were calculated. At the same time intervals and 2 months after stroke, the same oculomotor paradigm was performed during fMRI.

Assessing periodicity of periodic leg movements during sleep.

Background: Periodic leg movements (PLM) during sleep consist of involuntary periodic movements of the lower extremities. The debated functional relevance of PLM during sleep is based on correlation of clinical parameters with the PLM index (PLMI). However, periodicity in movements may not be reflected best by the PLMI.

Poisson distribution to analyze near-threshold motor evoked potentials.

Motor unit action potentials (MUAPs) evoked by repetitive, low-intensity transcranial magnetic stimulation can be modeled as a Poisson process. A mathematical consequence of such a model is that the ratio of the variance to the mean of the amplitudes of motor evoked potentials (MEPs) should provide an estimate of the mean size of the individual MUAPs that summate to generate each MEP. We found that this is, in fact, the case.

Treatment of hemispatial neglect by means of rTMS--a review.

Hemispatial neglect - defined as the failure to attend, explore, and act upon the contralesional side of space - is a frequent and disabling neurological syndrome. Interhemispheric rivalry is considered as a major pathophysiological mechanism underlying hemispatial neglect. According to this account, the contralesional, intact hemisphere undergoes a pathological hyperactivity due to a deficient transcallosal inhibition from the damaged hemisphere.

Sleepiness is not always perceived before falling asleep in healthy, sleep-deprived subjects.

Objective: To test whether subjects spontaneously signal sleepiness before falling asleep under monotonous conditions.

Methods: Twenty-eight healthy students were deprived of sleep for one night and then underwent a "maintenance-of-wakefulness test" (MWT) consisting of four 40-min trials. They were told to give a signal as soon as they felt sleepy and to try to stay awake as long as possible.

Cerebral air embolism caused by a bronchogenic cyst.

An unusual case is presented of a tourist who developed fatal cerebral air embolism, pneumomediastinum and pneumopericardium while ascending from low altitude to Europe's highest railway station. Presumably the air embolism originated from rupture of the unsuspected bronchogenic cyst as a result of pressure changes during the ascent. Cerebral air embolism has been observed during surgery, in scuba diving accidents, submarine escapes and less frequently during exposure to very high altitude.

Why do we yawn?

Yawning is a phylogenetically old behaviour that can be observed in most vertebrate species from foetal stages to old age. The origin and function of this conspicuous phenomenon have been subject to speculations for centuries. Here, we review the experimental evidence for each of these hypotheses.

Interplay between yawning and vigilance: a review of the experimental evidence.

Background: Yawning is a phylogenetically old behavior of ubiquitous occurrence. The origin and function of this conspicuous phenomenon have been subject to speculation for centuries. A widely held hypothesis posits that yawning increases the arousal level during sleepiness; thus, providing a homeostatic regulation of vigilance.

Improvement of non-paraneoplastic voltage-gated potassium channel antibody-associated limbic encephalitis without immunosuppressive therapy.

We describe a 61-year-old patient with clinical evidence of limbic encephalitis who improved with anticonvulsant treatment only, that is, without the use of immunosuppressive agents. Three years following occurrence of anosmia, increasing memory deficits, and emotional disturbances, he presented with new-onset temporal lobe epilepsy, with antibodies binding to neuronal voltage-gated potassium channels and bitemporal hypometabolism on FDG-PET scan; the MRI scan was normal. This is most likely a case of spontaneous remission, illustrating that immunosuppressive therapy might be suspended in milder courses of limbic encephalitis.

Anosognosia for cerebral achromatopsia--a longitudinal case study.

Cerebral achromatopsia is a rare disorder of colour vision caused by bilateral damage to the occipito-temporal cortex. Patients with cerebral achromatopsia are commonly said to suffer due to their disturbed colour sense. Here, we report the case of a patient with cerebral achromatopsia who was initially unaware of his deficit, although three experiments with eye movement recordings demonstrated his severe inability to use colour information in everyday tasks.

Campylobacter jejuni abscess, encephalomyelitis, and acute polyradiculoneuropathy.

We report an unusual case of spinal epidural Campylobacter jejuni abscess associated with acute polyradiculoneuropathy and parainfectious encephalomyelitis. Decompressive surgery, antibiotics, intravenous immunoglobulin (IVIg) therapy, and intravenous methylprednisolone resulted in rapid clinical improvement. C.