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Biomedical subjects

I Sartori

Publications and source records attributed to I Sartori.

At least 19 recordsLinked to original sources
PubMed2006

Surgical treatment of drug-resistant nocturnal frontal lobe epilepsy.

Of the cases with nocturnal frontal lobe epilepsy (NFLE) approximately 30% are refractory to antiepileptic medication, with several patients suffering from the effects of both ongoing seizures and disrupted sleep. From a consecutive series of 522 patients operated on for drug-resistant focal epilepsy, 21 cases (4%), whose frontal lobe seizures occurred almost exclusively (>90%) during sleep, were selected. All patients underwent a comprehensive pre-surgical evaluation, which included history, interictal EEG, scalp video-EEG monitoring, high-resolution MRI and, when indicated, invasive recording by stereo-EEG (SEEG). There were 11 males and 10 females, whose mean age at seizure onset was 6.2 years, mean age at surgery was 24.7 years and seizure frequency ranged from <20/month to >300/month. Nine patients reported excessive daytime sleepiness (EDS). Prevalent ictal clinical signs were represented by asymmetric posturing (6 cases), hyperkinetic automatisms (10 cases), combined tonic posturing and hyperkinetic automatisms (4 cases) and mimetic automatisms (1 case). All patients reported some kind of subjective manifestations. Interictal and ictal EEG provided lateralizing or localizing information in most patients. MRI was unrevealing in 10 cases and it showed a focal anatomical abnormality in one frontal lobe in 11 cases. Eighteen patients underwent a SEEG evaluation to better define the epileptogenic zone (EZ). All patients received a microsurgical resection in one frontal lobe, tailored according to pre-surgical evaluations. Two patients were operated on twice owing to poor results after the first resection. Histology demonstrated a Taylor-type focal cortical dysplasia (FCD) in 16 patients and an architectural FCD in 4. In one case no histological change was found. After a post-operative follow-up of at least 12 months (mean 42.5 months) all the 16 patients with a Taylor's FCD were in Engel's Class Ia and the other 5 patients were in Engel's Classes II or III. After 6 months post-surgery EDS had disappeared in the 9 patients who presented this complaint pre-operatively. It is concluded that patients with drug-resistant, disabling sleep-related seizures of frontal lobe origin should be considered for resective surgery, which may provide excellent results both on seizures and on epilepsy-related sleep disturbances. An accurate pre-surgical evaluation, which often requires invasive EEG recording, is mandatory to define the EZ. Further investigation is needed to explain the possible causal relationships between FCD, particularly Taylor-type, and sleep-related seizures, as observed in this cohort of NFLE patients.

Adolescent↗
PubMed2006

Stereo-EEG in children.

BACKGROUND: Stereotactic placement of intracerebral multilead electrodes for chronic EEG recording of seizures or stereoelectroencephalography (SEEG) was introduced 50 years ago at Saint Anne Hospital in Paris, France for the presurgical evaluation of patients with drug-resistant focal epilepsy. SEEG explorations are indicated whenever the noninvasive tests fail to adequately localize the epileptogenic zone (EZ). INDICATIONS: Currently, approximately 35% of our operated-on children require a SEEG evaluation. Arrangement of electrodes is individualized according to the peculiar needs of each child, to verify a predetermined hypothesis of localization of the EZ based on pre-SEEG anatomo-electro-clinical findings. Multilead intracerebral electrodes are designed to sample cortical structures on the lateral, intermediate, and mesial aspect of the hemisphere, as well as deep-seated lesions. Stereotactic stereoscopic teleangiograms and coregistered 3-D MRI are employed to plan avascular trajectories and to accurately target the desired structures. Pre-SEEG stereotactic neuroradiology and electrode implantation are usually performed in separate procedures. Electrodes are removed once video-SEEG monitoring is completed. INTRACEREBRAL ELECTRICAL STIMULATIONS: Intracerebral electrical stimulations are used to better define the EZ and to obtain a detailed functional mapping of critical cortical and subcortical regions. MORBIDITY: Surgical morbidity of SEEG is definitely low in children. SEEG-GUIDED RESECTIVE SURGERY: In 90% of evaluated children, SEEG provides a guide for extratemporal or multilobar resections. SEEG-guided resective surgery may yield excellent results on seizures with 60% of patients in Engel's Class I.

Brain Mapping↗
PubMed2005

Selective down-regulation of [(125)I]Y0-alpha-conotoxin MII binding in rat mesostriatal dopamine pathway following continuous infusion of nicotine.

Prolonged exposure to nicotine, as occurs in smokers, results in up-regulation of all the neuronal nicotinic acetylcholine receptor subtypes studied so far, the only differences residing in the extent and time course of the up-regulation. alpha6beta2*-Nicotinic acetylcholine receptors are selectively enriched in the mesostriatal dopaminergic system and may play a crucial role in nicotine dependence. Here we show that chronic nicotine treatment (3mg/kg/day for two weeks, via s.c. osmotic minipumps) caused a significant decrease (36% on average) in the binding of [(125)I]Y(0)-alpha-conotoxin MII (a selective ligand for alpha6beta2*-nicotinic acetylcholine receptors in this system) to all the five regions of the rat dopaminergic pathway analyzed in this study. After one week of withdrawal, binding was still lower than control in striatal terminal regions (namely the caudate putamen and the accumbens shell and core). In somatodendritic regions (the ventral tegmental area and the substantia nigra) the decrease was significant at the end of the treatment and recovered within one day of withdrawal. This effect was not due to displacement of [(125)I]Y(0)-alpha-conotoxin MII binding by residual nicotine. In fact the binding was not changed by 565 ng/g nicotine (obtained with a single injection of nicotine), a concentration much higher than that found in the brain of rats chronically treated with nicotine (240 ng/g). In addition, consistent with previous studies reporting an up-regulation of other subtypes of nicotinic acetylcholine receptors, we found that nicotine exposure significantly increased (40% on average) the binding of [(125)I]epibatidine (a non-selective agonist at most neuronal heteromeric nicotinic acetylcholine receptors) in three up to five regions containing only alpha-conotoxin MII-insensitive [(125)I]epibatidine binding sites, namely the primary motor, somatosensory and auditory cortices. In conclusion, this work is the first to demonstrate that alpha6beta2*-nicotinic acetylcholine receptors, unique within the nicotinic acetylcholine receptor family, are down-regulated following chronic nicotine treatment in rat dopaminergic mesostriatal pathway, a finding that may shed new light in the complex mechanisms of nicotine dependence.

Animals↗
PubMed2005

Intracerebral recordings of minor motor events, paroxysmal arousals and major seizures in nocturnal frontal lobe epilepsy.

The clinical features of nocturnal frontal lobe epilepsy (NFLE) consist of a spectrum of paroxysmal motor manifestations ranging from minor motor events (MMEs) to paroxysmal arousals (PAs) and major seizures. During MMEs and PAs scalp EEG generally does not show definite ictal abnormalities. We describe the clinical and electrophysiological features of three patients affected by drug-resistant NFLE studied with intracerebral electrodes during a presurgical evaluation. The stereo-EEG (SEEG) investigation revealed that MMEs can be fragments of the major seizure and occur during a brief epileptic discharge or on the following arousal. PAs, in the same subject, do not show a definite stereotypy despite the morphological and topographic similarity of the epileptic discharges, thus indicating that other variables may influence the clinical features of PAs.

Adult↗
PubMed2005

Sleep-related hyperkinetic seizures: always a frontal onset?

Hyperkinetic seizures are considered a typical manifestation of nocturnal frontal lobe epilepsy (NFLE). Patients with temporal lobe epilepsy with mainly sleep-related seizures have been described; however they commonly lack hyperkinetic activity and seizure frequency is low. We retrospectively analysed our population of 442 consecutive patients surgically treated between January 1996 and January 2004. Among these there were 25 patients with sleep-related hyperkinetic epileptic seizures, with a frontal lobe onset in 18 cases and a temporal lobe onset in 7. Patients with sleep-related hyperkinetic seizures with temporal lobe origin had anamnestic and clinical features strikingly similar to those with a frontal onset, with agitated movements, high seizure frequency and no history of febrile convulsions. We confirm our previous findings that this kind of epileptic manifestation is not only peculiar to frontal lobe epilepsy.

Adolescent↗
PubMed2004

Sleep-related hyperkinetic seizures of temporal lobe origin.

Sleep-related hyperkinetic seizures are a common feature of nocturnal frontal lobe epilepsy. Although sleep-related seizures with a temporal lobe origin have been reported, they commonly lack hyperkinetic activity. The authors describe three patients with sleep-related seizures characterized by frenetic, agitated, hyperactive movements (bimanual/bipedal activity, rocking, axial, pelvic, and hemiballistic movements), in whom stereo-EEG investigation and surgical outcome demonstrated a temporal lobe origin of the attacks.

Adult↗
PubMed2004

Concurrent pharmacological MRI and in situ microdialysis of cocaine reveal a complex relationship between the central hemodynamic response and local dopamine concentration.

The mechanisms underlying the signal changes observed with pharmacological magnetic resonance imaging (phMRI) remain to be fully elucidated. In this study, we obtained microdialysis samples in situ at 5-min intervals during phMRI experiments using a blood pool contrast agent to correlate relative cerebral blood volume (rCBV) changes with changes in dopamine and cocaine concentrations following acute cocaine challenge (0.5 mg/kg iv) in the rat over a duration of 30 min. Three brain areas were investigated: the dorsal striatum (n = 8), the medial prefrontal cortex (mPFC; n = 5), and the primary motor cortex (n = 8). In the striatum and mPFC groups, cocaine and dopamine temporal profiles were tightly correlated, peaking during the first 5-min period postinjection, then rapidly decreasing. However, the local rCBV changes were uncorrelated and exhibited broader temporal profiles than those of cocaine and dopamine, attaining maximal response 5-10 min later. This demonstrates that direct vasoactivity of dopamine is not the dominant component of the hemodynamic response in these regions. In the motor cortex group, microdialysis revealed no local change in dopamine in any of the animals, despite large local cocaine increase and strong rCBV response, indicating that the central hemodynamic response following acute iv cocaine challenge is not driven directly by local dopamine changes in the motor cortex. The combination of phMRI and in situ microdialysis promises to be of great value in elucidating the relationship between the phMRI response to psychoactive drugs and underlying neurochemical changes.

Animals↗
PubMed2002

Hallucinations and sleep-wake cycle in PD: a 24-hour continuous polysomnographic study.

Twenty-four-hour ambulatory polysomnography was performed in 20 patients with PD who were having visual hallucinations (12 men and 8 women, mean age 70 +/- 6 years). Visual hallucinations were clearly related to daytime NREM sleep or nocturnal REM sleep in 33% of the instances. The data reinforce the hypothesis that neural mechanisms implicated in generating sleep and, in particular, in dream imagery play a role in the occurrence of visual hallucinations in PD.

Aged↗
PubMed2000

Sleep hygiene in adult epilepsy patients: a questionnaire-based survey.

Two hundred and seventy epilepsy patients referred to the Epilepsy Centre of the "C. Mondino" Institute of Neurology and 230 healthy subjects comparable for age, sex and education completed a sleep questionnaire of 112 multiple choice questions including those that concern sleep hygiene practice. The percentage of subjects with habitually inappropriate sleep hygiene habits was significantly higher in controls than in epilepsy patients for 7 out of the 9 sleep hygiene practices considered (P at chi square less than 0.05). No significant relationship between kind and/or severity of epilepsy and the degree of sleep hygiene practice was found. The data show that sleep hygiene practice is more adequate in epilepsy than in control subjects. It is possible that the appropriate sleep hygiene practice of epilepsy patients derives from the fact that they habitually refrain from a lot of practices which possibly aggravate both the course of epilepsy and seizure-related complications.

Adolescent↗
PubMed1998

Epileptic skew deviation.

We describe a 43-year-old neurologically intact patient who reported episodes of diplopia and oscillopsia associated with a right-beating nystagmus and a skew deviation. These symptoms and signs were related to a left posterior epileptic EEG discharge. We suggest that these ocular motor signs derived from an ictal activation of the vestibular cortex, which in turn activated descending projections to the vestibular nuclei, leading to both a dynamic (right-beating nystagmus) and a static (skew deviation) vestibular imbalance.

Adult↗
PubMed1997

Poor sleep in adolescents: a study of 869 17-year-old Italian secondary school students.

Subjective sleep quality and its related factors were investigated in 869 (530 F, 339 M) 17-year-old adolescents, who were selected from the pupils of state-run secondary schools in the city of Pavia in the north west of Italy. The study was conducted cross sectionally, and it consisted of a questionnaire based survey. One hundred and forty-two subjects (16.5% of the whole sample, 19% of the females and 11.7% of the males) met the criteria chosen for definition as poor sleepers (namely, a complaint of 'non restorative nocturnal sleep', 'often' or 'always' over the previous 12 mo). A significant association was found between chronic poor sleep and (1) gender (female) (2) emotional factors, such as worries, anxiety and depression (3) poor sleep hygiene (4) arousal related parasomnia. Only 4% of poor sleepers took sleep promoting drugs (including benzodiazepines, homeopathic products and other medications), generally without seeking medical advice.

Adolescent↗
PubMed1996

Efficacy and safety of topiramate in refractory epilepsy: a long-term prospective trial.

The effects of topiramate in 15 patients with drug refractory epilepsy or Lennox-Gastaut syndrome were assessed in an open, add-on prospective study. After a follow-up of 14-21 months, six patients are still on topiramate (mean dosage 583 mg/day, range 400-800 mg/day), and nine have discontinued treatment because of adverse events (n = 6), inefficacy (n = 2) or poor compliance (n = 1). Nine patients (69%) continued to have > or = 50% reduction in seizure frequency during the last two months of treatment, and one has been seizure-free for the last 19 months. The most common adverse events were somnolence, weight loss, mental slowing, fatigue, ataxia and irritability. Most of these events were reversible, but withdrawal of treatment was required in six cases as a result of ataxia (two patients), somnolence, metabolic acidosis, irritability or psychotic symptoms (one patient each). It is concluded that topiramate is a valuable agent for long-term management of refractory epilepsy.

Adult↗
PubMed1996

Estimating reliability of evoked potential measures from residual scores: an example using tibial SSEPs.

A normative study of tibial SSEPs was performed in 74 healthy subjects, and the effects of the variables sex, age and height on SSEP parameters were assessed. In a subgroup of 20 subjects a test-retest study was also performed, which allowed us to estimate the reliability of the different parameters by means of the intraclass correlation coefficient. We demonstrated that the intraclass correlation coefficient may be biased by predictable effects of subject-related variables (such as age, height and sex), if it is computed from raw original values. This bias can be eliminated by estimating reliability indices on residual scores calculated as the differences between observed values and those predicted by subject's age, height and sex.

Adolescent↗
PubMed1996

Partial epileptic seizures of different origin variably affect cardiac rhythm.

PURPOSE: The present study was aimed at evaluating electrocardiographic (ECG) changes associated with partial epileptic seizures without seizure activity secondarily generalized. METHODS: We assessed heart rate (HR) changes occurring during 100 partial epileptic seizures, as recorded by ambulatory EEG-ECG in 50 outpatients. Consecutive R-R intervals were measured for the 30 s immediately preceding the onset and for the first 10-s period of discharge. In addition, HR was sampled at 10-s intervals during EEG paroxysmal discharge and for 1 min after the end of discharge. RESULTS: The highest and lowest respective HR peaks achieved during these seizures were 186 and 44 beats/ min. Analysis of the R-R intervals during the first 10-s period of EEG discharge showed a significant early HR increase in 49% of the seizures; the corresponding figure for an early HR reduction was 25.5%. Eighty percent of the seizures showing an early HR decrease were of temporal lobe origin. No severe cardiac arrhythmias were noted during the seizures. CONCLUSIONS: Our data suggest that an early HR decrease is more probable in temporal lobe seizures than in seizures of other origin. An accurate HR measurement, focused on discharge onset, may provide both a reliable way of evaluating the possible effect of partial seizures on HR and valuable information about the cerebral sites involved in the control of cardiac rhythm.

Adolescent↗
PubMed1995

Breathing during sleep in myasthenia gravis.

The aim of this study was to assess breathing patterns during sleep in patients with generalized mild myasthenia gravis. Fourteen patients (13 F; 1M, age range 20-40 years) in a stable clinical and functional state underwent a sleep questionnaire, baseline respiratory function tests and standard nocturnal polysomnography. All of the patients had normal daytime blood-gas values, except one who showed mild hypoxemia. No patient complained of disturbed sleep; six patients reported snoring. In five patients nocturnal polysomnography showed the occurrence of short and infrequent central apneas mainly during REM sleep, together with a drop in HbSaO2 levels of more than 5% of the baseline wakefulness value. Our data indicate that, in patients with mild generalized MG in a stable functional state, breathing pattern instability during sleep is infrequent and, when it occurs, is mild and mainly related to REM sleep.

Adult↗
PubMed1993

Somatosensory evoked potentials by median nerve stimulation recorded with cephalic and non-cephalic references. I). Normative study.

Somatosensory evoked potentials by median nerve stimulation were obtained in 50 healthy subjects (aged 15-70 years) with cephalic and non cephalic references. Most parameters were influenced by one or more independent variables (sex, age, arm lengths). The coefficients of the appropriate linear models are reported to compute correct individual normal limits.

Adolescent↗