High-frequency ECoG oscillations in the site of onset of epileptic seizures during sleep.
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Adult↗
Biomedical subjects
Giacomo Della Marca
Publications and source records attributed to Giacomo Della Marca.
Giant subcortical high-frequency SEPs in idiopathic generalized epilepsy: a protective mechanism against seizures?
OBJECTIVE: Recently, we found that high-frequency somatosensory evoked potentials (HF-SEPs), which are modulated by arousal-related structures, were abnormally enhanced during N-REM sleep in two seizure-free IGE patients [Restuccia D, Rubino M, Valeriani M, Della Marca G. Increase of brainstem high-frequency SEP subcomponents during light sleep in seizure-free epileptic patients. Clin Neurophysiol 2005; 116: 1774-1778]. Here, we aimed at verifying whether similar HF-SEP abnormalities were significantly correlated to the clinical outcome in a larger population of untreated IGE patients. METHODS: Patients were classified as Juvenile Myoclonic epilepsy (JME; six patients) and Childhood or Juvenile Absence epilepsy (CAE and JAE, six patients). They were untreated because newly diagnosed, or because seizure-free. HF-SEPs from patients were compared with those obtained from 21 healthy volunteers. RESULTS: HF-SEPs were abnormally enhanced in all seizure-free CAE-JAE patients, whereas they were normal in all JME patients and in CAE-JAE patients with frequent seizures. Not only scalp distribution, but also dipolar source analysis suggested a subcortical origin for these enhanced subcomponents, possibly in the brainstem. CONCLUSIONS: The enhancement of HF-SEPs might reflect the hyperactivity of arousal-related brainstem structures; such an enhancement was found in all seizure-free CAE-JAE patients, while it was never observed in JME patients. SIGNIFICANCE: We speculate that the hyperactivity of arousal-related brainstem structures might account for the different clinical outcome among IGE subsyndromes.
Adolescent↗
Cerebellar damage impairs detection of somatosensory input changes. A somatosensory mismatch-negativity study.
Several recent studies support the view that the cerebellum's contribution to sensory processing is not limited to movement regulation. In a previous paper (Restuccia D, Valeriani M, Barba C, Le Pera D, Capecci M, Filippini V, Molinari M. Functional changes of the primary somatosensory cortex in patients with unilateral cerebellar lesions. Brain 2001; 124: 757-68) we showed that the cerebellum influences somatosensory input processing at very early stages. The present study was aimed at verifying whether an analogous influence is also exerted at higher levels. For some time it has been known that in the auditory modality a specific event-related potential (ERP), that is, mismatch negativity (MMN), reflects preattentive detection of changes in the incoming stimulus by comparing the new stimulus with sensory memory traces. To test the cerebellar influence on the processing of incoming somatosensory stimuli we first verified whether the electrical stimulation of fingers, according to an 'oddball' paradigm within a stimulus-ignored condition, was able to elicit event-related components specifically linked to the preattentive detection of change. We analysed scalp responses obtained from eight healthy volunteers during frequent and rare electrical stimulation of the first and fifth finger of the left hand, respectively. To ensure that responses to deviant stimuli were due to changes in detection mechanisms, rather than to activation of new afferents, we also analysed responses to rare stimulation alone ('standard-omitted' condition). The 'oddball' stimulation was able to elicit a parieto-occipital extra negativity that was different in scalp distribution and latency from the N140 response to the 'standard-omitted' stimulation. We considered that this response was related to changes in detection mechanisms and labelled it somatosensory mismatch negativity (S-MMN). When the same procedure was applied to six patients with unilateral cerebellar lesions we found that the S-MMN was clearly abnormal after stimulation of the affected hand (ipsilateral to the affected cerebellar hemisphere). Earlier ERPs, as well as ERPs elicited during the 'standard-omitted' condition, were fully normal. Present data indicate that cerebellar processing is involved in preattentive detection of somatosensory input changes. In conclusion, this study demonstrates the reliability of S-MMN recordings and indicates that subjects with cerebellar damage may be impaired in the cortical processing of incoming somatosensory inputs.
Adult↗
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. All patients underwent clinical, neurological, otholaryngologic and radiologic evaluation, and a full-night polysomnography in the sleep laboratory. Polysomnography showed that seven patients presented a relevant number of respiratory events of obstructive type during sleep. The apnea-hypopnea index (AHI) ranged from 0 to 19.2 events per hour (mean index = 7.5 +/- 6.9 events/hr). In one patient AHI was not evaluable because of tracheostomy. Apnea induced mild or moderate hemoglobin desaturations (mean of lowest SpO2 values = 85.4 +/- 5.5%). Only sporadic respiratory pauses of central type were observed (mean number of central apnea per study: 7.2 +/- 6.8 events/hr). Sleep structure was fragmented, with a high number of awakenings (mean number of awakenings was 13.2 +/- 8.1; of these, 4.8 +/- 2.5 lasted longer than 2 min). In all patients, otolaryngologic and radiologic observations revealed one or more sites of narrowing in the upper airways. Our results suggest that Costello patients have a high prevalence of obstructive sleep-related respiratory disorders, which need to be assessed by means of polysomnography.
Abnormalities, Multiple↗
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. Rhythmic tongue movements in Costello syndrome show the features of an NREM sleep parasomnia. Tongue movements during sleep probably originate from brainstem structures and could be facilitated by an impaired control of the oropharyngeal and tongue muscles.
Adolescent↗
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). Raw data were further evaluated by Brain Electrical Source Analysis (BESA). During the Reading condition, distraction toward the unattended auditory stimuli was reflected by the enhancement of the N1 response to frequent stimuli and by the elicitation of a P3a response to deviant ones. The MMN distribution was explained by bilateral temporal dipoles. During the MFTC condition, no P3a was detected, while source analysis showed the activation of a right frontal generator. Temporal dipoles showed no change between the two conditions: we thus conclude that the earlier mismatch detection is independent on the attentional load. By contrast, the activation of a right frontal subcomponent occurred only during the high-load task, independently on any actual attention shift reflected by the P3a component. We thus discuss the hypothesis whether the right frontal MMN generator, rather than subserving a simple attention switching toward the deviant stimulus, plays a role in modulating the auditory change detection system ("contrast enhancement" model).
Acoustic Stimulation↗
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. METHODS: We recorded right median nerve SEPs in two adult patients who suffered since the infancy from childhood absence epilepsy (CAE). Sleep stage-related changes of HF-SEPs were compared to those observed in five healthy volunteers. RESULTS: HF-SEPs decreased during sleep in controls. By contrast, the amplitude of the subcortical component dramatically increased in CAE patients during phase II NREM sleep. Simultaneous EEG showed normally represented sleep spindles, but not SW discharges. CONCLUSIONS: HF-SEP increase probably reflects the hyperactivation of brain-stem arousal-related structures. During such a hyperactivation no EEG abnormalities were observed. SIGNIFICANCE: We hypothesize that HF-SEP increase might reflect a protective mechanism against seizure occurrence during light sleep.
Adult↗
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. RESULTS: Modafinil significantly increased subcortical HFOs, as well as the strength of a dipolar source at the base of the skull. CONCLUSIONS: Our data suggest that modafinil exerts its action also at the level of the brain-stem, where it interferes with the processing of somatosensory ascending inputs.
Adult↗
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. METHODS: We recorded right median nerve SEPs from the ventral surface of the medulla by means of a NP electrode as well as from the scalp, in 6 healthy volunteers under two different arousal states (eyes opened versus eyes closed). SEPs have been further analyzed after digital narrow bandpass filtering (400-800 Hz). RESULTS: NP recordings demonstrated in all subjects a well-defined burst, occurring in the same latency window of the low-frequency P13-P14 complex. Eyes opening induced a significant amplitude increase of the NP-recorded HFOs, whereas scalp-recorded HFOs as well as low-frequency SEPs remained unchanged. CONCLUSIONS: Our findings demonstrate that slight arousal variations induce significant changes in brain-stem components of HFOs. According to the hypothesis that HFOs reflect the activation of central mechanisms, which modulate sensory inputs depending on variations of arousal state, our data suggest that this modulation is already effective at brain-stem level.
Adult↗
Microstructure of sleep in depressed patients according to the cyclic alternating pattern.
BACKGROUND: The aim of this study was to evaluate the microstructure of the EEG sleep of depressed subjects by cyclic alternating pattern (CAP) analysis. METHODS: 78 patients affected by major depression and 18 control subjects matched for age and sex underwent a full night polysomnographic study. RESULTS: A significant increase in CAP rate (60 versus 35%) was found in the patients group compared to controls while no significant difference was found with the traditional analysis. CONCLUSION: In depressed subjects CAP analysis is able to show a microstructural sleep impairment, which is not evident at the macrostructural level, providing an objective measure of sleep disturbance in those patients.
Adolescent↗
The tongue-base suspension using Repose bone screw system in a child with Simpson-Golabi-Behmel syndrome. Case report.
Obstructive sleep apnea syndrome is one of the most frequent manifestations of upper airway obstruction. Several approaches have been proposed to solve this problem with the aim to avoid tracheotomy especially in children. We observed a child affected by Simpson-Golabi-Behmel syndrome presenting severe OSAS. He underwent tongue-base suspension using the Repose system with significant improvement of the polysomnographic parameters and of the clinical conditions. Tongue suspension with this technique effectively prevent tongue-base collapse, avoiding tracheotomy or increased morbidity caused by a more invasive procedure. Besides it does not interfere with the patient's cranio-facial growth and future occlusion.
Bone Screws↗
The effects of reboxetine on human sleep architecture in depression: preliminary results.
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Adult↗
Sleep cyclic alternating pattern in normal school-age children.
OBJECTIVES: To evaluate cyclic alternating pattern (CAP) in sleep of school-age children in order to obtain a standardized database for CAP parameters in this age range. METHODS: CAP parameters were quantified in 10 normal healthy subjects (6 males and 4 females, mean age 8.3 years; range 6-10 years). All subjects underwent polysomnography recordings for two consecutive nights in a standard laboratory setting. Sleep data were stored on computer using a 16-channel polysomnography digital system. Sleep macrostructure was visually scored according to the criteria by Rechtschaffen and Kales (Brain Information Service/Brain Research Institute, University of California, Los Angeles, 1968); CAP was visually scored following the criteria by Terzano et al. (Sleep Med 2 (2001) 537). RESULTS: CAP rate showed a progressive increase with the deepness of sleep, with high values during slow wave sleep (SWS). CAP time showed its longest duration during non-REM (NREM) sleep stage 2 (S2), followed by SWS and sleep stage 1 (S1). No differences across NREM sleep stages were found for CAP cycle and phase B mean duration; on the contrary, phase A showed longer duration during SWS than in S1 and S2. Phases A1 were the most numerous (84.45%) followed by A3 (9.14%) and by A2 (6.44%). The distribution of phases A subtypes across NREM stages showed significant differences for the A1 subtypes that occurred more frequently during SWS than in S2 and S1 (and during S2 than in S1). Subtypes A3 were more frequent during S1 than SWS while no differences were found for subtype A2. The analysis of A1 interval distribution showed a log-normal-like distribution with a peak around 25 s for the A1 phases and no clear peak for A2-A3 phases. CONCLUSIONS: The analysis of CAP in school-age children is characterized by an increase of CAP rate during SWS and a high percentage of A1 phases. The distribution of interval between consecutive A1 phases showed a peak around 25 s.
Child↗