Biomedical subjects

F Vigevano

Publications and source records attributed to F Vigevano.

At least 19 recordsLinked to original sources

PubMed2006

Modulation of laser-evoked potentials by experimental cutaneous tonic pain.

The present study aimed to investigate whether tonic cutaneous pain exerts any effect on the cortical processing of nociceptive input and if this effect may involve only body parts in pain. Tonic cutaneous pain was obtained in nine healthy human subjects by infusion of a hypertonic saline (5%) in the s.c. tissue over the hypothenar muscles (10 ml/h for 20 min). Nociceptive cutaneous CO2 laser-evoked potentials were recorded after stimulation of the right hand dorsum, which was adjacent to the painful area, and the right perioral region, corresponding to the adjacent cortical sensory area. Laser-evoked potentials were obtained before saline injection, at the peak pain and 20 min after pain disappeared. During saline infusion, the laser-evoked pain to right hand stimulation was reduced and the vertex laser-evoked potentials (N2a-P2, mean latency 181 ms and 319 ms for the N2a and the P2 potentials, respectively), which are generated in the anterior cingulate cortex, were significantly decreased in amplitude compared with the baseline. Moreover, the topography of these potentials was modified by cutaneous pain, shifting from the central toward the parietal region. Dipolar modeling showed that the dipolar source in the anterior cingulate cortex moved backward during saline infusion. This result suggests that cutaneous pain may modify the relative activities of the anterior and posterior anterior cingulate cortex parts, which are thought to be devoted to encode different aspects of pain sensation. No laser-evoked potential change was observed after stimulation of the right perioral region, suggesting that functional changes in the nociceptive system are selective for the painful regions and not for areas with cortical proximity.

Adult↗

PubMed2006

Brainstem dysfunction in alternating hemiplegia of childhood: a neurophysiological study.

Six patients with alternating hemiplegia of childhood (AHC) underwent motor evoked potentials (MEPs), somatosensory evoked potentials (SEPs) and blink reflex recording. No SEP abnormality was found. As for MEP recording, central conduction time did not differ between patients studied during either interictal or ictal phase, and normal subjects, suggesting that the pyramidal system function is spared. In blink reflex recording, the latencies of both the ipsilateral (iR2) and contralateral (cR2) R2 components were significantly longer (P<0.01) in patients during the interictal phase than in normal subjects. Moreover, the iR2 and cR2 areas were significantly reduced (P<0.01) in patients during the interictal phase, compared with normal subjects. During the ictal phase, the ipsilateral R2 latency was significantly decreased after stimulation of the hemiplegic side, compared with the interictal phase (P<0.05). The blink reflex abnormalities suggest a brainstem dysfunction, which may be linked to the pathophysiological mechanisms of the disease.

Adolescent↗

PubMed2006

Role of valproate across the ages. Treatment of epilepsy in children.

In June 2005 a team of experts participated in a workshop with the objective of reaching agreement on the place of valproate use in the treatment of paediatric epilepsy patients. A general "consensus of the meeting" was that the initiation of antiepileptic drug (AED) treatment should be based on a seizure-syndromic approach in children. Participants of the meeting also agreed that valproate is currently the AED with the broadest spectrum across all types of seizures and syndromes. Its superiority has been shown over almost 40 years of clinical experience. The best results are seen in idiopathic generalized epilepsy with or without photosensitivity, idiopathic focal and symptomatic generalized tonic-clonic seizures (GTCS). Evidence supports the use of valproate, ethosuximide and lamotrigine in absence epilepsies and the use of carbamazepine, lamotrigine, oxcarbazepine, phenytoin, topiramate, valproate and phenobarbital for primary GTCS. For new AEDs trials have been undertaken to define their therapeutic role but studies comparing their role to 'old' broad-spectrum drugs in specific syndromes are missing. Experts concluded that intravenous (i.v.) valproate is a useful agent in the treatment of non-convulsive status epilepticus (SE). There is an easy transition to oral treatment following i.v. valproate use. The discussion also concluded that, despite the lack of studies, valproate is an interesting, underutilized alternative in convulsive SE but more controlled studies are needed. The side effects of valproate use are well documented. Its effect on cognition and behaviour is more favourable than many of the other AEDs which is an important consideration in children. Overall, the clinical consensus of the meeting was that valproate's well established therapeutic properties far outweigh the negative side effects. Contraindication or withdrawal should be assessed individually.

Anticonvulsants↗

PubMed2005

Segmental inhibition of cutaneous heat sensation and of laser-evoked potentials by experimental muscle pain.

The aim of the study was to evaluate the effect of tonic muscle pain evoked by injection of 5% hypertonic saline in the right brachioradialis muscle on the somatosensory sensation of laser-evoked heat pain and laser-evoked potentials. The heat pain pathways were studied in 9 healthy human subjects by recording the scalp potentials evoked by CO(2) laser stimuli delivered on four sites: the skin above the right brachioradialis muscle (ipsilateral local pain), the wrist area where muscle pain was referred in all subjects (ipsilateral referred pain), and two areas on the left arm symmetrical to both local and referred pain (contralateral local pain and contralateral referred pain). Laser-evoked potentials were obtained from 31 scalp electrodes before saline injection, during saline infusion (bolus injection with 0.3 ml saline infused over 20 s, followed by a steady infusion rate of 30 ml/h for the next 25 min), and 20 min after muscle pain had disappeared. While the early N1/P1 component (around 130 ms and 145 ms of latency after stimulation of the skin over the brachioradialis muscle and the wrist, respectively) was not affected by muscle pain, the amplitudes of the later vertex laser-evoked potentials (N2 latency of around 175 ms and 210 ms after stimulation of the skin over the brachioradialis muscle and the wrist, respectively; P2 latency of around 305 ms and 335 ms after stimulation of the skin over the brachioradialis muscle and the wrist, respectively) evoked from ipsilateral local pain, ipsilateral referred pain, and contralateral local pain sites were significantly decreased during muscle pain compared with the baseline recording, while they recovered after pain had disappeared. At the same stimulation sites, the rating of the laser-evoked pain sensation was reduced significantly during muscle pain as compared with the baseline and it recovered after pain had disappeared. On the contrary, muscle pain did not show any effect on both laser-evoked pain and laser-evoked potential amplitude when the contralateral referred pain site was stimulated. The muscle pain inhibitory effect on both heat pain sensation and laser-evoked potential amplitude is probably mediated by an ipsilateral and contralateral segmental mechanism which acts also on the referred pain area, while more general inhibitory mechanisms, such as a distraction effect or a diffuse noxious inhibitory control, are excluded by the absence of any effect of muscle pain on laser-evoked pain and laser-evoked potentials obtained from a remote site, such as the contralateral referred pain area. Since muscle pain induced by hypertonic saline injection is very similar to clinical pain, our results can be useful in understanding the pathophysiology of the somatosensory modifications which can be observed in patients with musculoskeletal pain syndromes.

Adult↗

PubMed2004

Indications for surgical treatment of epilepsy in childhood: a clinical and neurophysiological approach.

Resistant epilepsy is defined as the persistence of unacceptable seizures, despite correct drug treatment, or control of seizures at the cost of excessive side effects. About 30% of partial seizures are resistant to treatment; many of them is potentially a candidate for surgical treatment. Selection of patients is based fundamentally on precise identification of the epileptogenic area and on the evaluation that possible removal of that area will not be followed by serious neurological or neuropsychological deficits, or by onset of seizures in another part of the brain. To this end, careful clinical, neurophysiological and functional studies are conducted. Compared with adults, video-electroencephalographic (EEG) study of seizures in childhood is more difficult because of the lack of patient cooperation and, therefore, the lack of every subjective element in the seizures. Furthermore, the criteria for defining drug resistance in childhood are still under discussion, as many epilepsies are age dependent and seizures stop with growth. Despite this, the age at time of surgery has been steadily decreasing, in the conviction that the persistence of intractable partial epilepsy is detrimental to cognitive development and can damage brain areas that are apparently healthy. The clinical and EEG criteria for epilepsies that are secondary to some specific disorders have been defined, e.g. hemimegalencephalia and focal cortical dysplasias often produce epilepsy with onset in the first days of life characterized by partial seizures and subintrant spasms, EEG record of focal or hemispheric burst suppression and drug resistance that can be defined within the first months of life. Prolonged video-EEG monitoring is always necessary to establish congruence between the area in which the seizure originates and the brain lesion evidenced at neuroimaging. Correct monitoring of seizures means close cooperation between neurologist, neurophysiology technician and the patient, if the child is at least 5-6 y old. Absence of cooperation also limits the use of in-depth recording. Neuropsychological assessment of the child can be of great help in defining the area damaged by the epileptogenic site as well as the state of the other brain areas. Close cooperation between neurologist, radiologist, neuropsychologist and brain surgeon is necessary for a case-by-case assessment of indication for surgical treatment.

Anticonvulsants↗

PubMed2003

Experience with immunomodulatory treatments in Rasmussen's encephalitis.

The authors investigated immunomodulatory treatments in 15 patients with Rasmussen encephalitis (RE) (14 with childhood and one with adolescent onset RE). Positive time-limited responses were obtained in 11 patients using variable combinations of corticosteroids, apheresis, and high-dose IV immunoglobulins. Although surgical exclusion of the affected hemisphere is the only treatment that halts disease progression, immunomodulation can be considered when early surgery is not feasible, in late-onset patients with slower disease progression, and in the few cases of bilateral disease.

Adolescent↗

PubMed2003

Spectrum of SCN1A mutations in severe myoclonic epilepsy of infancy.

OBJECTIVES: SCN1A mutations were recently reported in several patients with severe myoclonic epilepsy in infancy (SMEI). The authors analyzed SCN1A mutations in 93 patients with SMEI and made genotype-phenotype correlation to clarify the role of this gene in the etiology of SMEI. METHODS: All patients fulfilled the criteria for SMEI. The authors analyzed all patients for SCN1A mutations using denaturing high performance liquid chromatography. If a patient's chromatogram was abnormal, the authors sequenced the gene in the patient and both parents. RESULTS: SCN1A mutations were identified in 33 patients (35%). Most mutations were de novo, but were inherited in three patients. Parents carrying the inherited mutations had either no symptoms or a milder form of epilepsy. A greater frequency of unilateral motor seizures was the only clinical difference between patients with SCN1A mutations and those without. Truncating mutations were more frequently associated with such seizures than were missense mutations. The percentage of cases with family history of epilepsy was significantly higher in patients with SCN1A mutations. CONCLUSIONS: Unilateral motor seizures may be a specific clinical characteristic of SMEI caused by SCN1A mutations. Ten percent of SCN1A mutations are inherited from an asymptomatic or mildly affected parent, suggesting that SMEI is genetically heterogeneous. The increased frequency of familial epilepsy indicates that other genetic factors may contribute to this disorder.

Adult↗

PubMed2003

Rasmussen's encephalitis: early characteristics allow diagnosis.

OBJECTIVE: To identify early manifestations of Rasmussen encephalitis (RE) that can prompt early and reasonably secure diagnosis, allowing medical or surgical therapies at an early stage when they may be more effective in slowing the disease. METHODS: The authors studied 12 patients with clinical and neuropathologic diagnosis of RE, followed from disease onset, assessing clinical history, imaging, and EEG and focusing on early characteristics. Anti-GluR3 antibody assays were also considered in 11 patients. RESULTS: By 4 months from first symptoms, all cases had 1) refractory focal seizures with a predominant motor component, 2) slow focal activity on EEG contralateral to the motor manifestations, and 3) focal contralateral white matter hyperintensity with insular cortical atrophy on neuroimaging. Less constant or later findings were epilepsia partialis continua, oligoclonal bands, and serum anti-GluR3 antibodies. CONCLUSIONS: The association of partial seizures with focal EEG and neuroimaging changes allows a tentative diagnosis of RE 4 to 6 months after first symptoms.

Adolescent↗

PubMed2001

Benign familial infantile convulsions: mapping of a novel locus on chromosome 2q24 and evidence for genetic heterogeneity.

In 1997, a locus for benign familial infantile convulsions (BFIC) was mapped to chromosome 19q. Further data suggested that this locus is not involved in all families with BFIC. In the present report, we studied eight Italian families and mapped a novel BFIC locus within a 0.7-cM interval of chromosome 2q24, between markers D2S399 and D2S2330. A maximum multipoint HLOD score of 6.29 was obtained under the hypothesis of genetic heterogeneity. Furthermore, the clustering of chromosome 2q24-linked families in southern Italy may indicate a recent founder effect. In our series, 40% of the families are linked to neither chromosome 19q or 2q loci, suggesting that at least three loci are involved in BFIC. This finding is consistent with other autosomal dominant idiopathic epilepsies in which different genes were found to be implicated.

Chromosome Mapping↗

PubMed2001

Video/EEG aspects of early-infantile epileptic encephalopathy with suppression-bursts (Ohtahara syndrome).

Early-infantile epileptic encephalopathy (EIEE) with suppression-bursts is a severe neonatal epileptic encephalopathy. The etiology is multiple, with cerebral malformations as the more frequent. We review the clinical and video/EEG aspects of eight infants with EIEE. These infants, aged between 4 and 70 days at the time of video/EEG recordings, were studied in relation to their clinical and video/EEG characteristics, evolution, persistence of suppression-burst pattern and etiology. Seven of the eight infants showed an ictal clinical sign correlated to the burst of the suppression-burst pattern, four of whom died within 11 months of age. The other three are alive. One, now aged 4 years, underwent surgery for hemimegalencephaly and is seizure-free, with good neurological outcome. One, now aged 9 months, was pyridoxine-dependent and she is seizure-free, and with normal neurological evolution under pyridoxine therapy. One, now aged 3 years and 9 months, is seizure-free, but with severe neurological and cognitive impairment. The only child who did not show a clinical ictal correlation of burst is also alive, now aged 3 years and 9 months, with drug-resistant epilepsy, and severe neurological and cognitive deficits. With regard to the etiology, three showed structural abnormalities, two more showed some signs of prenatal origin of neurological disease, and three had metabolic etiology. Our study confirms that EIEE is a severe age-dependent early epileptic encephalopathy. The etiology is mostly malformative. The prognosis is poor regarding motor and cognitive development, seizures, as well as life expectancies. The presence of an ictal burst of the suppression-burst pattern usually correlates with a negative outcome.

Brain↗

PubMed2001

Neurophysiology of spasms.

Spasms are a form of epileptic seizure typical of infancy. From a clinical point of view, the child presents a flexor-extensor movement involving the trunk and limbs and lasting about 1s. Although asymmetry can be present, the seizure involves both sides of the body. The ictal discharge most frequently associated with spasms in West syndrome (WS) is a diffuse triphasic slow high-amplitude wave and less frequently a low-amplitude brief rapid rhythm. The origin of the spasm in WS and classification as either partial or generalized seizure are the subject of much discussion. Factors supporting partial origin include: interictal electroencephalography (EEG) characterized by multifocal anomalies; high incidence of focal cortical lesions and remission of spasms following surgical removal of focal lesions. Factors supporting generalized origin are: clinical involvement of the entire body; mostly generalized ictal EEG pattern; existence of idiopathic cases and possibility of spasms immediately following a partial seizure like a particular form of secondary generalization. In our opinion, the categories of 'partial' and 'generalized' seizures are not applicable to spasms in WS. Sometimes the spasms in WS can be observed together with other types of partial or generalized seizures. Polygraphic recordings have demonstrated that despite being clinically similar, each spasm is different from the other because of a variable sequence in muscular contraction. These data support the peculiar nature of the spasm in WS that could be a subcortical phenomenon that requires a cortical trigger.

Brain↗

PubMed2001

The long-term use of felbamate in children with severe refractory epilepsy.

The aim of the study was to assess the efficacy and safety of felbamate (FBM) as add-on therapy in pediatric patients with severe uncontrolled seizures during a 3-year follow-up. Thirty-six patients were enrolled between February 1994 and February 1997. Patients suffered from partial epilepsy (n=13), Lennox-Gastaut syndrome (LGS) (n=9), infantile spasms (IS) n=8 or other forms of generalized epilepsy (n=6). FBM was titrated weekly from 15 up to 45 mg/kg. By February 1995, all patients had hematological and biochemical monitoring prior to FBM therapy and every 15 days during the study. The results achieved at different treatment durations were analyzed. Overall efficacy measured as > or =50% reduction in seizure frequency varied during follow-up: 69% at 3 months, progressively decreasing to 66% at 6 months, to 47% at 1 year and 41% of the initial cohort at the end of the study. Most frequent side effects were anorexia, weight loss, urinary retention, somnolence, nervousness and insomnia. FBM controlled a broad spectrum of otherwise refractory seizures. Best results were obtained against simple partial seizures with or without secondary generalization, tonic and atonic seizures. A substantial improvement in seizure control was maintained in one-third of the patients for at least 3 years.

Adolescent↗

PubMed2001

Benign idiopathic partial epilepsies in infancy.

In infancy, partial epilepsies have been considered with suspicion for their probable association with brain lesions. Japanese authors first described partial epilepsies in infancy with a favorable outcome and called them benign partial epilepsy in infancy with complex partial seizures. Similar, but familial, cases with onset during the first year of life were described some years later and called benign infantile familial convulsions. Similar familial cases with subsequent choreoathetosis were described in 1997 and called infantile convulsions and choreoathetosis. Benign infantile convulsions have also been described in association with mild gastroenteritis. Interictal electroencephalography (EEG) was always normal in all of these forms. More recently, a new epileptic syndrome characterized by partial seizures with onset between ages 13 and 30 months, a benign outcome, and characteristic EEG abnormalities in the vertex regions during sleep has been described. There is also an early-onset benign childhood occipital seizure susceptibility syndrome that can start in infancy.

Brain↗

PubMed2001

Tonic reflex seizures of early infancy: an age-related non-epileptic paroxysmal disorder.

Non-epileptic paroxysmal disorders (NEPD) include a heterogeneous group of disorders that can be confused with epileptic manifestations. They occur very frequently in the first year of life and are expressed predominantly as unusual movements. We report the clinical and EEG-polygraphic characteristics of 13 patients (nine male, four female) that we observed between 1988 and 1999, who presented non-epileptic tonic reflex seizures in the first months of life. All children had normal psychomotor development with no neurological antecedents. Onset of manifestations occurred between the first and third month of life. The seizure was characterized by diffuse tonic contraction with extension of four limbs, apnoea and cyanosis, and lasted 3-10 sec without loss of consciousness. Seizures occurred only while the child was awake and being held in a vertical position by an adult, and were triggered by movement or tactile stimulation. Ictal and interictal EEG were normal. Prognosis was benign with spontaneous remission within 2 months of onset. In our experience, this paroxysmal manifestation has not been described previously by other authors and represents a new NEPD which, in accordance with our first report of this entity, we suggest calling tonic reflex seizure of early infancy (TRSEI). (Published with videosequences.)

Age Factors↗

PubMed2001

Benign paroxysmal tonic upgaze of childhood with ataxia.

Paroxysmal tonic upgaze deviation (PTU) is a rare neuro-ophthalmological disorder with onset in infancy or early childhood. It consists of episodes of sustained, conjugate, upward deviation of the eyes, down beating saccades in attempted downgaze, apparently preserved horizontal eye movements, frequent association with mild ataxia or clumsiness at time of illness, normal metabolic, electroencephalographic and neuroradiological findings. Symptoms are frequently relieved by sleep and can be exacerbated by fatigue or illness. Although PTU generally tends to disappear spontaneously within a few months or years, subsequent case reports have demonstrated the heterogeneous nature of the syndrome with respect to outcome. To date, the pathogenesis of the condition is still unknown. We present a new case of PTU with ataxia occurring in an otherwise healthy child, as documented by video recording of the phenomenon.

Ataxia↗

PubMed2000

Early onset benign occipital susceptibility syndrome: video-EEG documentation of an illustrative case.

Early onset benign occipital susceptibility syndrome (EBOSS) is a recently delineated form of idiopathic childhood partial epilepsy, which is still not recognized by the International League Against Epilepsy as a distinct epileptic syndrome. It occurs with generally nocturnal, prolonged partial seizures, which can become a status epilepticus. The seizures are characterized by tonic eye deviation, vomiting, progressive impairment of consciousness, autonomic symptoms, frequent progression to hemiconvulsions or generalized tonic-clonic seizures. Age at onset is usually between 3 and 7 years, frequency is remarkably low (often a single seizure), and outcome is excellent. Interictal EEG shows occipital paroxysms with fixation-off sensitivity. We present the first video-EEG documentation of a typical case of EBOSS and discuss the clinical and EEG features of the case. The documentation is useful for a better definition of the syndrome and also permits a differential diagnosis with respect to other occipital forms of epilepsy and other sleep related paroxysmal disorders.

Age of Onset↗

PubMed2000

Dominant partial epilepsies. A clinical, electrophysiological and genetic study of 19 European families.

Nineteen families with autosomal dominant partial epilepsy were analysed clinically and electrophysiologically in detail. Seventy-one patients were studied as well as 33 non-epileptic at-risk family members. We subdivided the families into those with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) (n = 8), familial temporal lobe epilepsy (n = 7) and autosomal dominant partial epilepsy with variable foci (n = 4). However, the application of this nosology to certain families was difficult in cases of non-specific or conflicting clinical and electrophysiological evidence. This was underscored by the observation by depth electrode recordings in one patient that a so-called ADNFLE may originate in an extrafrontal area. The evolution of familial partial epilepsies, which exhibit great intrafamilial variability, is not always benign. The level of pharmacoresistance may reach 30%, close to that seen in classical cryptogenic partial epilepsies. The familial character of a partial epilepsy may be unrecognized in small families as some affected members may have only EEG abnormalities and are clinically asymptomatic, which reflects incomplete clinical penetrance. In view of the recent discoveries of mutations in the alpha4 nicotinic acetylcholine receptor subunit in a few families with ADNFLE, this genetic study focused on genes encoding nicotinic receptor subunits and a candidate region on chromosome 10q. No mutation was detected in the alpha4 and 012 nicotinic acetylcholine receptor subunits. Positive but not significant lod scores were obtained in four families with markers from the candidate region on chromosome 10q.

Adolescent↗

PubMed1999

Benign infantile familial convulsions: natural history of a case and clinical characteristics of a large Italian family.

We present a patient (3 months old) with partial and generalized seizures who has a family history of seizures with a onset during the first 12 months of life. We diagnosed benign infantile familial convulsions (BIFC) and we did not introduce any antiepileptic therapy. We present clinical data of her family where 18 out of 35 members were affected; to our knowledge this is the largest family with BIFC. BIFC is transmitted as an autosomal dominant trait; recently it has been reported that the gene for BIFC maps to the long arm of chromosome 19. We conducted linkage analysis in our family providing significant exclusion of linkage between the BIFC locus phenotype and chromosome 19 markers, suggesting that a second locus is involved in this family.

Child, Preschool↗