A human anti-neuronal autoantibody against GABA B receptor induces experimental autoimmune agrypnia.

In the serum and cerebrospinal fluid of a patient with recurrent acute episodes of respiratory crises, autonomic symptoms and total insomnia (agrypnia), we identified a novel anti-neural complement fixing antibody directed against GABA(B) receptor (GABA(B)R). Patient purified IgG recognized a band of approximately 110 kDa on protein extracts of mouse cerebellum, cortex and brainstem and immunolabelled cultured Chinese hamster ovary (CHO) cells, transfected with human GABA(B)R1 and rat GABA(B)R2 receptors. Western blot analysis of transfected CHO homogenates showed the same band using both patient purified IgG and anti-GABA(B)R1 antibody.

Obstructive sleep apnea in Costello syndrome.

Costello syndrome (CS) was initially described by Costello in 1971; it is caused by a germline mutation in HRAS proto-oncogene. The aim of the present study was to evaluate the respiratory activity during sleep in a group of subjects with CS. We studied 10 consecutive patients, 4 males and 6 females, aged 3-29 years, affected by CS.

Attentional load of the primary task influences the frontal but not the temporal generators of mismatch negativity.

According to the model hypothesized by Näätänen and Michie, the generation of the mismatch negativity (MMN) requires a mismatch detection, taking place in temporal areas, followed by the activation of frontal generators, underlying attention switching toward the deviant stimulus. We aimed at verifying whether the activation of temporal and frontal regions is dependent on the amount of attentional resources allocable toward the deviant stimulus. We recorded event-related potentials (ERPs) in nine healthy subjects while reading and during a demanding visual task (Multiple Features Target Cancellation, MFTC).

Rhythmic tongue movements during sleep: a peculiar parasomnia in Costello syndrome.

We describe a peculiar parasomnia observed in four Costello infants, characterized by periodic rhythmic movements of the tongue. Ten Costello patients (4 male; age range 9 months to 29 years) underwent 1 full-night laboratory-based video polysomnography. The four youngest patients (2 male and 2 female; age range 9-31 months) presented during sleep repeated stereotyped movements of the tongue, producing a sucking-like or licking-like movement, mostly during non-rapid eye movement (NREM) sleep.

Increase of brain-stem high-frequency SEP subcomponents during light sleep in seizure-free epileptic patients.

Objective: Three hertz spike-and-wave (SW) occurrence is caused by the abnormal functioning of the same thalamo-cortical loop generating sleep spindles. In fact, SW preferably occurs during light sleep and transitional phases of the vigilance status. Since high-frequency somatosensory evoked potentials (HF-SEPs) are powerfully modulated by sleep and arousal, we verified whether they can reveal abnormalities of arousal-related structures in two patients having showed sporadic SW discharges during light sleep.

Brain-stem components of high-frequency somatosensory evoked potentials are modulated by arousal changes: nasopharyngeal recordings in healthy humans.

Objective: Until now, the demonstration that early components of high-frequency oscillations (HFOs) evoked by electrical upper limb stimulation are generated in the brain-stem has been based on the results of scalp recordings. To better define the contribution of brain-stem components to HFOs building, we recorded high-frequency somatosensory evoked potentials (SEPs) in 6 healthy volunteers by means of a nasopharyngeal (NP) electrode. Moreover, since HFOs are highly susceptible to arousal fluctuations, we investigated whether eyes opening can influence HFOs at this level.

Influence of modafinil on somatosensory input processing in the human brain-stem.

Objective: Since high frequency oscillations (HFOs) evoked by upper limb stimulation are susceptible to arousal fluctuation, we verified whether administration of modafinil, a vigilance promoting drug, modifies such responses at different levels of the somatosensory system.

Methods: HFOs were obtained in 6 healthy volunteers by 500-700 Hz filtering of right median nerve somatosensory evoked potentials, before and 2 hours after the administration of 100 mg modafinil. Raw data were further submitted to brain electrical source analysis.

Abnormal gating of somatosensory inputs in essential tremor.

Objective: To study whether sensorimotor cortical areas are involved in Essential Tremor (ET) generation.

Background: It has been suggested that sensorimotor cortical areas can play a role in ET generation. Therefore, we studied median nerve somatosensory evoked potentials (SEPs) in 10 patients with definite ET.