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Biomedical subjects

Athanasios Covanis

Publications and source records attributed to Athanasios Covanis.

12 recordsLinked to original sources
PubMed2006

Panayiotopoulos syndrome: a benign childhood autonomic epilepsy frequently imitating encephalitis, syncope, migraine, sleep disorder, or gastroenteritis.

BACKGROUND: Panayiotopoulos syndrome is a common idiopathic childhood-specific seizure disorder formally recognized by the International League Against Epilepsy. An expert consensus has defined Panayiotopoulos syndrome as "a benign age-related focal seizure disorder occurring in early and mid-childhood. It is characterized by seizures, often prolonged, with predominantly autonomic symptoms, and by an EEG [electroencephalogram] that shows shifting and/or multiple foci, often with occipital predominance." OBJECTIVE: The purpose of this review is to provide guidance for appropriate diagnosis and management of Panayiotopoulos syndrome. CLINICAL FEATURES: Autonomic epileptic seizures and autonomic status epilepticus are the cardinal manifestations of Panayiotopoulos syndrome. Autonomic seizures in Panayiotopoulos syndrome consist of episodes of disturbed autonomic function with emesis as the predominant symptom. Other autonomic manifestations include pallor (or, less often, flushing or cyanosis), mydriasis (or, less often, miosis), cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility. In approximately one fifth of the seizures the child becomes unresponsive and flaccid (ictal syncope) before or often without convulsions. Cardiorespiratory arrest is exceptional. More-conventional seizure symptoms often appear after the onset of autonomic manifestations. The child, who was initially fully conscious, becomes confused and unresponsive. Eyes turn to one side or gaze widely open. Only half of the seizures end with brief hemiconvulsions or generalized convulsions. Convulsive status epilepticus is extremely rare. Autonomic symptoms may be the only features of the seizures. Half of the seizures in Panayiotopoulos syndrome last for >30 minutes, thus constituting autonomic status epilepticus, which is the more common nonconvulsive status epilepticus in normal children. Two thirds of seizures occur during sleep. EPIDEMIOLOGY: Panayiotopoulos syndrome probably affects 13% of children aged 3 to 6 years who have had 1 or more afebrile seizures and 6% of such children in the 1- to 15-year age group. DIAGNOSTIC TESTS: An electroencephalogram is the only investigation with abnormal results, usually showing multiple spikes in various brain locations. PATHOPHYSIOLOGY: Panayiotopoulos syndrome is probably the early-onset and Rolandic epilepsy the late-onset phenotype of a maturation-related benign childhood seizure-susceptibility syndrome. Ictal epileptic discharges in Panayiotopoulos syndrome, irrespective of their location at onset, activate autonomic disturbances and emesis, to which children are particularly vulnerable. The symptoms/sequence of autonomic seizures and autonomic status epilepticus in Panayiotopoulos syndrome are specific to childhood, and they do not occur in adults. PROGNOSIS: Panayiotopoulos syndrome is remarkably benign in terms of seizure frequency and evolution. Autonomic status epilepticus imparts no residual neurologic deficit. The risk of epilepsy in adult life seems to be no higher than in the general population. However, autonomic seizures are potentially life-threatening in the rare context of cardiorespiratory arrest, an area in which additional study is required. MISDIAGNOSIS: The clinical features of Panayiotopoulos syndrome are frequently mistaken as nonepileptic conditions such as acute encephalitis, syncope, migraine, cyclic vomiting syndrome, motion sickness, sleep disorder, or gastroenteritis. The consequence is avoidable misdiagnosis, high morbidity, and costly mismanagement. MANAGEMENT: Education about Panayiotopoulos syndrome is the cornerstone of management. Prophylactic treatment with antiepileptic medication may not be needed for most patients. Autonomic status epilepticus in the acute stage needs thorough evaluation; aggressive treatment may cause iatrogenic complications including cardiorespiratory arrest.

Adolescent↗
PubMed2006

Evaluation of CACNA1H in European patients with childhood absence epilepsy.

CACNA1H was evaluated in a resource of Caucasian European patients with childhood absence epilepsy by linkage analysis and typing of sequence variants previously identified in Chinese patients. Linkage analysis of 44 pedigrees provided no evidence for a locus in the CACNA1H region and none of the Chinese variants were found in 220 unrelated patients.

Asian People↗
PubMed2006

Panayiotopoulos syndrome: a consensus view.

The aim of this paper is to promote the correct classification of, and provide guidelines on, the diagnosis and management of Panayiotopoulos syndrome (PS). An international consortium of established researchers in the field collaborated to produce a consensus document. The resulting document defines PS, characterizes its electro-clinical features, considers its likely pathogenesis, and provides guidance on appropriate management. We conclude that PS is a common idiopathic, benign seizure disorder of childhood, which should be classified as an autonomic epilepsy, rather than an occipital epilepsy.

Child↗
PubMed2006

Exploration of the genetic architecture of idiopathic generalized epilepsies.

PURPOSE: Idiopathic generalized epilepsy (IGE) accounts for approximately 20% of all epilepsies and affects about 0.2% of the general population. The etiology of IGE is genetically determined, but the complex pattern of inheritance suggests an involvement of a large number of susceptibility genes. The objective of the present study was to explore the genetic architecture of common IGE syndromes and to dissect out susceptibility loci predisposing to absence or myoclonic seizures. METHODS: Genome-wide linkage scans were performed in 126 IGE-multiplex families of European origin ascertained through a proband with idiopathic absence epilepsy or juvenile myoclonic epilepsy. Each family had at least two siblings affected by IGE. To search for seizure type-related susceptibility loci, linkage analyses were carried out in family subgroups segregating either typical absence seizures or myoclonic and generalized tonic-clonic seizures on awakening. RESULTS: Nonparametric linkage scans revealed evidence for complex and heterogeneous genetic architectures involving linkage signals at 5q34, 6p12, 11q13, 13q22-q31, and 19q13. The signal patterns differed in their composition, depending on the predominant seizure type in the families. CONCLUSIONS: Our results are consistent with heterogeneous configurations of susceptibility loci associated with different IGE subtypes. Genetic determinants on 11q13 and 13q22-q31 seem to predispose preferentially to absence seizures, whereas loci on 5q34, 6p12, and 19q13 confer susceptibility to myoclonic and generalized tonic-clonic seizures on awakening.

Chromosome Mapping↗
PubMed2005

Photosensitivity in idiopathic generalized epilepsies.

Photosensitivity is an abnormal visual sensitivity of the brain in reaction to flickering light sources or patterns and is expressed in the electroencephalogram as generalized spike-and-wave discharge and in more susceptible individuals as clinical seizures. The most common types of seizures are generalized tonic-clonic, followed by myoclonic and absence. The photosensitive epilepsies are classified as pure photosensitive, where seizures occur only with the flickering light source/pattern or during intermittent photic stimulation (IPS) in the laboratory, and epilepsy with photosensitivity, where spontaneous seizures also occur. Positive response to IPS in idiopathic epilepsy syndromes, which are included in the International Classification or are in development, is reported to range from 7.5% in juvenile absence epilepsy to 100% in pure photosensitive epilepsy. The treatment of photosensitivity and pure photosensitive epilepsy with rare seizures includes general and specific protective measures. For most patients, however, combination treatment with antiepileptic drugs is necessary. Valproic acid monotherapy has a success rate of 73-86%. Levetiracetam appears to be a new alternative therapeutic option. Clobazam, lamotrigine, ethosuximide, and topiramate also have been recommended as second-choice therapies.

Anticonvulsants↗
PubMed2004

Treatment of photosensitivity.

Not all visually sensitive patients need antiepileptic drug treatment, and even those who do can benefit from additional preventive measures. Visually provoked seizures, in particular, can be prevented or treated by avoiding or altering the triggering stimulus. Apart from individual preventive measures (use of specific television or video screens, colored glasses, etc.), prevention and warning on a larger scale are helpful. The choice for drug treatment will depend on the type of stimulus, the environment in which the person has to live and work, the frequency and severity of seizures, and the type of epileptic syndrome. A review is given of all treatment options with focus on the specific nonpharmacologic and pharmacologic tools used in clinical practice.

Anticonvulsants↗
PubMed2003

A study of 43 patients with panayiotopoulos syndrome, a common and benign childhood seizure susceptibility.

PURPOSE: To determine prevalence, clinical, EEG features, and prognosis of Panayiotopoulos syndrome and to examine the proposition that clinical manifestations are more important than EEG findings. METHODS: We analyzed retrospectively the clinical and EEG records of 1,340 children with one or more focal seizures seen in the last 18 years, supplemented with a prospective study from 1998. Panayiotopoulos syndrome was defined by clinical criteria, mainly ictal emesis, irrespective of EEG findings. RESULTS: We analyzed 43 of 90 patients with Panayiotopoulos syndrome who were seizure free >2 years. Girls predominated. Mean age at first seizure was 5 years. Seizures consisted mainly of autonomic manifestations; ictal emesis was often the first symptom, culminating in vomiting in 86%. Of nonautonomic manifestations, lateral eye deviation was the most common; visual symptoms were exceptional. Impairment of consciousness ensued in all seizures, half of which ended with hemi or generalized convulsions. Nearly 46.5% of cases had at least one seizure >30 min, constituting autonomic status epilepticus. Seizures during sleep (84%) were more common than those in wakefulness. EEG showed occipital spikes in 29 patients. Of the other 14 cases, five had extraoccipital abnormalities or brief generalized discharges, and nine had normal awake and sleep EEG. Prognosis was excellent. All 43 children have been free of seizures for > or =2 years, 53% having a single seizure, and 47%, an average two to three seizures. CONCLUSIONS: Panayiotopoulos syndrome is common and needs wider recognition. EEG shows occipital or extraoccipital abnormalities, is normal in one third of patients, and does not determine clinical manifestations or prognosis, which is excellent despite the high prevalence of lengthy seizures.

Autonomic Nervous System Diseases↗
PubMed2003

Exploration of a putative susceptibility locus for idiopathic generalized epilepsy on chromosome 8p12.

PURPOSE: A recent genome-wide scan revealed a major susceptibility locus for idiopathic generalized epilepsies (IGEs) in the chromosomal region 8p12 in 32 IGE families without members with juvenile myoclonic epilepsy (JME). This study explored the presence of an IGE locus in the chromosomal region 8p12. METHODS: Our study included 176 multiplex families of probands with common IGE syndromes. Parametric and nonparametric multipoint linkage analyses were carried out between the IGE trait and six microsatellite polymorphisms encompassing the putative susceptibility locus. To explore the associated phenotype-genotype relation, two distinct subgroups of families were selected by the presence (n = 64) or absence (n = 112) of a family member with JME. To adjust the phenotypic spectrum toward adolescent-onset IGEs, a third subgroup of 28 families without JME was chosen through an IGE proband with seizure onset at age 10-20 years. RESULTS: Parametric and nonparametric multipoint linkage analyses provided no evidence for linkage between IGE and markers encompassing the putative IGE locus in the chromosomal region 8p12. Furthermore, we found no hint of linkage along the candidate region in any of the three family subgroups. CONCLUSIONS: We failed to provide evidence for a major IGE locus in the chromosomal region 8p12. On the contrary, these parametric linkage results provide strong evidence against linkage across the candidate region under a broad range of genetic models. If there is a susceptibility locus for IGE in the chromosomal region 8p12, then the size of the effect or the proportion of linked families is too small to detect linkage in the investigated family sample.

Adult↗
PubMed2003

Children with Rolandic spikes and ictal vomiting: Rolandic epilepsy or Panayiotopoulos syndrome?

Centrotemporal spikes are the EEG marker of Rolandic epilepsy, while ictus emeticus is one of the main seizure manifestations of Panayiotopoulos syndrome. Ictus emeticus has not been reported in Rolandic epilepsy. Out of a population of 1340 children with focal afebrile seizures we studied 24 children who had emetic manifestations in at least one seizure and centrotemporal spikes in at least one EEG. They were of normal neurological status and had a follow-up of at least two years after the last seizure. All children had sleep EEG following sleep deprivation. Two groups of patients were identified. Group A (12 patients) with EEG centrotemporal spikes only and group B (12 patients) with centrotemporal spikes and spikes in other locations. In 21 patients, ictal emetic manifestations culminated in vomiting and in three only nausea or retching occurred. The commonest presentation was ictus emeticus at onset followed by deviation of the eyes or staring, loss of contact and floppiness. In 79%, seizures occurred during sleep. Autonomic status epilepticus occurred in 37.5%. The mean age at onset was 5.3 years. Overall analysis of the clinical and EEG data points out that the vast majority of these patients primarily suffer from Panayiotopoulos syndrome. Twenty patients (83%) had ictal semiology typical of Panayiotopoulos syndrome, but five also had concurrent Rolandic symptoms and four later developed pure Rolandic seizures. The other four patients (17%) had typical Rolandic seizures with concurrent ictus emeticus. These findings suggest a link between Rolandic epilepsy and Panayiotopoulos syndrome, the two most important phenotypes of the benign childhood seizure susceptibility syndrome.

Adolescent↗
PubMed2002

Evaluation of the positional candidate gene CHRNA7 at the juvenile myoclonic epilepsy locus (EJM2) on chromosome 15q13-14.

A previous study of 34 nuclear pedigrees segregating juvenile myoclonic epilepsy (JME) gave significant evidence of linkage with heterogeneity to marker loci on chromosome 15q13-14 close to the candidate gene CHRNA7 (Hum. Mol. Genet. 6 (1997) 1329). The aim of this work was to further evaluate the putative aetiological role of CHRNA7 in JME within the 34 families originally described, and to assess the contribution of this locus to a broader phenotype of idiopathic generalised epilepsy (IGE). Multipoint linkage analysis and intrafamilial association studies were performed with microsatellite markers that encompass both CHRNA7 and its partial duplication (CHRFAM7A). A maximum HLOD of 3.45 [alpha=0.58; (Zall=2.88, P=0.0008)] was observed 8 cM distal to D15S1360, a CHRNA7 intragenic marker. Significant exclusion lod scores were obtained across the region in 12 mixed phenotype JME/IGE families. Mutation screening of the CHRNA7 gene (and consequently exons 5-10 of CHRFAM7A) and its putative promoter sequence identified a total of 13 sequence variants across 23 of 34 JME-affected families. Two variants (c.1354G>A and c.1466C>T) are predicted to result in amino acid changes and one (IVS9+5G>A) is predicted to result in aberrant transcript splicing. However, none of the variants alone appeared either necessary or sufficient to cause JME in the families in which they occurred. In conclusion, linkage analyses continue to support the existence of a locus on chromosome 15q13-14 that confers susceptibility to JME but not to a broader IGE phenotype. Causal sequence variants in the positional candidate CHRNA7 have not been identified but the presence of multiple segmental duplications in this region raises the possibility of undetected disease-causing genomic rearrangements.

Chromosome Mapping↗
PubMed2002

Epilepsy in children with congenital hemiplegia: correlation between clinical, EEG and neuroimaging findings.

OBJECTIVES: the aim of this retrospective, multicentre study was to investigate the relationship between epilepsy, clinical, electroencephalographic (EEG) and neuroimaging findings in children with congenital hemiplegia (CH). PATIENTS AND METHODS: two hundred and three children with CH were assessed by history, neurological and developmental examination. Electroencephalogram (EEG) and CT/MRI brain imaging were performed in 150 of them (81/150 had an MRI and 69/150 had a CT scan). Patients were re-evaluated every six months for, at least, a two-year follow-up period (range 2-14 yrs). RESULTS: the EEG was abnormal in 76% of patients; epileptic seizures developed in 38.9% of them. The frequency of epilepsy paralleled the degree of EEG abnormality, approaching 85% in patients with severe EEG abnormalities and was also closely related to the extent of neuroimaging findings (up to 79% in patients with cerebral malformations). The prevalence of epilepsy in 12/62 patients (19.4%) with mild hemiplegia was significantly lower as compared to 67/141 (47.5%) of patients with moderate or severe hemiplegia. 36.7% of the children had their first seizure between the 1st and the 5th year of life, and 26.5% during the first year of life. CONCLUSIONS: epileptic seizures developed in more than one third of patients with CH, although EEG abnormalities were evident in the majority of them. The prevalence of epilepsy is closely related to the severity of hemiparesis, the extent of neuroimaging findings and the degree of EEG abnormalities. The absence of EEG abnormalities and/or normal (or minor) neuroimaging findings was negatively related to the occurrence of epilepsy.

Child↗