Long-term Follow-up of Patients with Benign Partial Epilepsy in Infancy

Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset

OBJECTIVES

To determine: i) seizure recurrence; ii) developmental disability; iii) co-morbidities and risk factors in self-limited familial neonatal and/or infantile epilepsy (SeLFE) in a multigenerational study.

METHODS

Families were retrospectively recruited from epilepsy databases (2021-2022) in 2 paediatric hospitals, Sydney, Australia. Eligible families had 2 first degree relatives with seizures and underwent genetic testing. Demographics/clinical data were collected from interviews and medical records. Vineland Adaptive Behaviour Scales-Third Edition measured adaptive function.

RESULTS

Fifteen families participated. Fourteen had a genetic diagnosis (93%): 11 pathogenic; PRRT2 (n=4), KCNQ2 (n=3), SCN2A (n=4), 3 likely pathogenic; KCNQ2 (n=1), SCN8A (n=2). Seizures affected 73 individuals (ages 1-76 years); 30 children and 20 adults had in-depth phenotyping. Ten of 50 individuals (20%) had seizure recurrence, aged 8-65 years. Median time from last neonatal/infantile seizure was 11.8/12.8 years. Predictors of recurrence were high seizure number (p=0.05) and longer treatment duration (p=0.03). Seven children had global developmental delay (GDD): mild (n=4), moderate (n=1) and severe (n=2). Vineland-3 identified 3 had low-average and 3 had mild-moderately impaired functioning. The majority (82%) were average. GDD was associated with older age at last seizure (p=0.03), longer epilepsy duration (p=0.02), and higher number of anti-seizure medications (p=0.05). Four children had speech delay, 5 (10%) had Autism Spectrum Disorder. Paroxysmal kinesiogenic dyskinesia (n=5) occurred in 4 families and hemiplegic migraine (n=8) in 3 families.

CONCLUSIONS

Individuals with SeLFE have a small risk of recurrent seizures (20%) and neurodevelopmental disability. Significant predictors are higher seizure number and longer epilepsy duration. Developmental surveillance is imperative.

PRRT2-positive self-limited infantile epilepsy: Initial seizure characteristics and response to sodium channel blockers

OBJECTIVE

Self-limited infantile epilepsy (SeLIE) has distinctive clinical features, and the PRRT2 gene is known to be a considerable genetic cause. There have been a few studies on PRRT2-positive SeLIE only, and anti-seizure medications are often required due to frequent seizures at initial seizure onset. This study aimed to provide clinical information for the early recognition of patients with PRRT2-positive SeLIE and to propose effective anti-seizure medications for seizure control.

METHODS

We retrospectively reviewed 36 patients diagnosed with SeLIE with genetically confirmed pathogenic variants of PRRT2. In addition, six atypical cases with neonatal-onset seizures and unremitting after 3 years of age were included to understand the expanded clinical spectrum of PRRT2-related epilepsy. We analyzed the initial presentation, clinical course, and seizure control response to anti-seizure medications.

RESULTS

Patients with PRRT2-related epilepsy had characteristic seizure semiology at the initial presentation, including all afebrile, clustered (n = 23, 63.9%), short-duration (n = 33, 91.7%), and bilateral tonic-clonic seizures (n = 26, 72.2%). Genetic analysis revealed that c. 649dupC was the most common variant, and six patients had a 16p11.2 microdeletion containing the PRRT2 gene. One-third of the patients were sporadic cases without a family history of epilepsy or paroxysmal movement disorders. In the 33 patients treated with anti-seizure medications, sodium channel blockers, such as carbamazepine, were the most effective in seizure control.

SIGNIFICANCE

Our results delineated the clinical characteristics of PRRT2-positive SeLIE, differentiating it from other genetic infantile epilepsies and discovered the effective anti-seizure medications for initial clustered seizure control. If afebrile bilateral tonic-clonic seizures develop in a normally developed infant as a clustered pattern, PRRT2-positive SeLIE should be considered as a possible diagnosis, and sodium channel blockers should be administered as the first medication for seizure control.

Neonatal seizures: diagnostic updates based on new definition and classification

Neonatal seizures are the most common neurological symptoms caused by various etiologies in the neonatal period, but their diagnosis and treatment are challenging because their pathophysiology and electroclinical manifestations differ from those of patients in older age groups. Many seizures present as electrographic-only events without clinical signs or as obscure clinical manifestations that are difficult to distinguish from other neonatal behaviors. Accordingly, a new definition and classification of neonatal seizures was recently proposed by the International League Against Epilepsy Task Force on neonatal seizures, highlighting the role of electroencephalography in diagnosing and treating neonatal seizures. Neonatal seizures are defined as electrographic events with sudden, paroxysmal, and abnormal alteration of activity and divided into electroclinical seizures and electrographic-only seizures according to their clinical signs, thus excluding clinical events without an electrographic correlation. Seizure types are described by their predominant clinical features and divided into motor (automatisms, clonic, epileptic spasms, myoclonic, tonic, and sequential), nonmotor (autonomic and behavioral arrest), and unclassified. Although many neonatal seizures are acute reactive events caused by hypoxic-ischemic encephalopathy or vascular insults, structural, genetic, or metabolic etiologies of neonatal-onset epilepsy should also be thoroughly evaluated to determine their appropriate management.

Sodium channel blockers are effective for benign infantile epilepsy

OBJECTIVE

To examine the efficacy and tolerance of the antiseizure medications lacosamide (LCM) and levetiracetam (LEV) in patients with benign infantile epilepsy (BIE).

METHODS

The clinical data of 24 children with BIE seen between 2014 and 2020 were collected retrospectively, and treatment, effectiveness, and adverse effects were examined. PRRT2 gene analysis was performed using Sanger sequencing.

RESULTS

Of the 24 children with BIE, 14 were treated with antiseizure medications. PRRT2 gene analysis was performed in 14 children, and mutations were identified in 4, including a pair of siblings. All five children treated with LCM became seizure-free, similar to those treated with carbamazepine. The LCM does was 2 mg/kg/day in all cases. There were no adverse effects in any patient treated with LCM. By contrast, both patients treated with LEV had seizure recurrence. In one patient, LEV was replaced with CBZ, resulting in seizure freedom.

CONCLUSIONS

Low-dose LCM was effective and well tolerated in patients with BIE, whereas LEV was insufficiently effective.

Risk factors predicting intractability in focal epilepsy in children under 3 years of age: A cohort study

BACKGROUND

Focal onset epilepsy carries a higher risk of intractability than generalized onset epilepsy. Knowledge of the risk factors of intractability will help guide the treatment of children with focal epilepsy. In addition to risk factors present at initial diagnosis, the evolution of clinical and electroencephalographic features may also play a role in predicting intractability.

METHODS

A prospective cohort study was done on children aged one month to three years with newly diagnosed focal epilepsy. Initial treatment of carbamazepine was given according to a standard protocol after assessment of clinical manifestations, neurologic and developmental status, EEG, and brain MRI. Depending on response to therapy, subjects may also receive valproic acid or phenobarbitone following the protocol. Follow-up was done in the second week and every month thereafter. At the end of the study period, seizure type was re-assessed and a repeat neurological and developmental examination and EEG was obtained to evaluate the role of clinical and EEG evolution in predicting intractability.

RESULTS

Out of 71 subjects, 21 (29.6%) had intractable epilepsy at the end of the study period. Age of onset (p = 0.216) and neurological status (p = 0.052) were not associated with intractable epilepsy. On logistic regression analysis, evolution of seizure type (p < 0.001; RR 56.45; 95%CI 6.56 to 485.85) and evolution of background EEG rhythm (p < 0.001; RR 56.51; 95%CI 2.77 to 1152.16) were significantly associated with intractable epilepsy.

CONCLUSIONS

Changes in seizure type and baseline EEG rhythm may predict intractability in children one month to three years of age with focal epilepsy.

Splenial Lesions in Benign Convulsions With Gastroenteritis Associated With Rotavirus Infection

OBJECTIVE

To investigate clinical risk factors for acute magnetic resonance imaging (MRI) abnormalities in patients with benign convulsions with mild gastroenteritis or benign infantile epilepsy.

STUDY DESIGN

We investigated clinical and diffusion-weighted imaging findings in 32 patients with benign convulsions with mild gastroenteritis and 22 patients with benign infantile epilepsy who underwent MRI within seven days of seizure onset between 2010 and 2015.

RESULTS

Diffusion-weighted imaging showed signal hyperintensity in the splenium of the corpus callosum in seven patients with benign convulsions with mild gastroenteritis, but no abnormalities in patients with benign infantile epilepsy. Patients with benign convulsions with mild gastroenteritis with splenial lesions showed a higher rate of rotavirus detection from feces (P = 0.006), higher serum level of C-reactive protein (P = 0.04), and shorter interval between seizure onset and MRI (P = 0.002) than patients with benign convulsions with mild gastroenteritis without splenial lesions. Multivariate analysis revealed rotavirus infection as a significant risk factor for splenial lesions on diffusion-weighted imaging in patients with benign convulsions with mild gastroenteritis (P = 0.02).

CONCLUSIONS

Splenial lesions are often seen during acute period in patients with benign convulsions with mild gastroenteritis. Rotavirus infection is a risk factor for splenial lesions in patients with benign convulsions with mild gastroenteritis, suggesting the role of rotavirus to cause edema in the corpus callosum. From our observations, benign convulsions with mild gastroenteritis with a splenial lesion on diffusion-weighted imaging suggests good outcomes, and extensive evaluation of these patients may be unnecessary.

Risk factors for the recurrence of convulsions with mild gastroenteritis in children

PURPOSE

To identify risk factors for the recurrence of convulsions with mild gastroenteritis (CwG)¹ in children.

METHODS

Altogether, 613 children with CwG admitted to Children's Hospital of Shanxi Province from January 2010 to December 2015 were selected, their clinical data were retrospectively analyzed, and patients were followed up for 4-10 years. Risk factors for the recurrence of CwG were analyzed based on the clinical characteristics of the children.

RESULTS

Relapse occurred in 35 patients (6.3 %). Recurrence occurred within 6 months after the first CwG in majority of the patients (80 %), and recurrence occurred once in most patients (91.4 %). Risk factors associated with CwG recurrence were age at first attack of ≤18 months (recurrence rates at ages ≤ and >18 months were 8.7 %, and 3.1 %, respectively; χ2 = 4.856, P = 0.028), and a history of convulsions in first-degree relatives (recurrence rates in first-degree relatives with and without a history of convulsion were 20 % and 6.2 %, respectively; χ2 = 5.501, P = 0.019).

CONCLUSIONS

Children with CwG have a possibility of recurrence. The risk of recurrence within 6 months of onset is high and such patients should be carefully observed. Furthermore, the age of onset of ≤18 months and history of convulsions in first-degree relatives are risks factors for CwG recurrence; therefore, these children should be closely followed up.

A novel SCN1A mutation: A case report

Introduction:

Dravet syndrome (DS) is characterized by severe infant-onset myoclonic epilepsy with delayed psychomotor development and increased premature mortality. The seizures triggered by fire have been gradually decreased over time, and finally they start to occur without fever at the age of 2–3 years. Along with its initiation of myoclonic seizures in the early period, other types such as atypical absence, versive, and complex partial seizures occur between 1 and 4 years of age.

Case Report:

A 3-year-old male patient with refractory epilepsy and neuromotor developmental retardation was admitted to our clinic. The patient initially had seizures in the afebrile period, when he was 4 months old, and he had a total of five seizures by the age of 1 year. Neuromotor developmental retardation developed over time in patients with normal neuromotor development in the early stages of his life. His cranial magnetic resonance imaging and metabolic test findings were normal. The SCN1A mutation was investigated, and a new variant mutation of SCN1A, homozygous (p.Y1599Ffs*19-c.4796delA) was detected. The patient’s family was also screened and this new mutation was detected as heterozygous mutation. The patient had hepatomegaly. The etiology of hepatomegaly was investigated but no cause was found.

Conclusion:

Variant mutations of DS should be kept in mind and diagnostic genetic testing should be done in patients with neuromotor developmental retardation starting with afebrile seizures. In DS, hepatomegaly is not an expected condition. Maybe this new mutation might have caused hepatomegaly.

Clinical outcome of recurrent afebrile seizures in children with benign convulsions associated with mild gastroenteritis

PURPOSE

To assess the clinical outcome and evolution of recurrent afebrile seizures in children initially diagnosed with benign convulsions associated with mild gastroenteritis (CwG).

METHODS

We reviewed and analyzed the medical records of 37 patients who were diagnosed as CwG at onset, followed by recurrent afebrile seizures and followed up for at least 24 months.

RESULTS

The follow-up period ranged from 2 to 7 years (median, 40.1 months).Three patterns of recurrent afebrile seizures were recorded: afebrile seizures associated with gastrointestinal infection (AS-GI, n = 25), afebrile seizures associated with non-gastrointestinal infection (AS-nGI, n = 9), and unprovoked seizures (US, n = 3). Twenty eight patients (75.7%) had a second episode within 6 months after the first seizures. Five cases (13.5%) suffered three episodes of afebrile seizures. Seizure characteristics of the three patterns were similar, manifesting as clustered seizures in the majority. Focal epileptic activities in interictal EEG were found in 3 cases (9.4%) at onset, 10 cases (28.6%) at the second episode, respectively. Six patients were prescribed anti-epileptic drugs with apparently good responses. During at least 2 years' follow-up, all the cases showed normal psychomotor development. Only one patient was diagnosed with epilepsy.

CONCLUSIONS

All the recurrent afebrile seizures initially diagnosed as CwG, irrespective of the kinds and frequency of relapses, showed favorable prognoses. CwG maybe falls within the category of situation-related seizures, rather than epilepsy.

Focal seizures and epileptic spasms in a child with Down syndrome from a family with a PRRT2 mutation

We describe a girl with Down syndrome who experienced focal seizures and epileptic spasms during infancy. The patient was diagnosed as having trisomy 21 during the neonatal period. She had focal seizures at five months of age, which were controlled with phenobarbital. However, epileptic spasms appeared at seven months of age in association with hypsarrhythmia. Upon treatment with adrenocorticotropic hormone, her epileptic spasms disappeared. Her younger brother also had focal seizures at five months of age. His development and interictal electroencephalogram were normal. The patient's father had had infantile epilepsy and paroxysmal kinesigenic dyskinesia. We performed a mutation analysis of the PRRT2 gene and found a c.841T>C mutation in the present patient, her father, and in her younger brother. We hypothesized that the focal seizures in our patient were caused by the PRRT2 mutation, whereas the epileptic spasms were attributable to trisomy 21.

Characteristics of patients with benign partial epilepsy in infancy without PRRT2 mutations

Mutations in the proline-rich transmembrane protein 2 gene (PRRT2) are known to cause clinical symptoms of paroxysmal kinesigenic dyskinesia (PKD), benign partial epilepsy in infancy (BPEI), and infantile convulsions with choreoathetosis (ICCA) syndrome; however, not all patients with BPEI have PRRT2 mutations, and the genetic backgrounds for such patients are still unknown. To characterize BPEI patients without PRRT2 mutations, we analyzed unrelated 63 patients with BPEI. Sanger sequencing identified PRRT2 mutations in 33 probands (52%). The most common insertion, c.649dup, was identified in 28 probands. Two novel truncation mutations, c.232dup and c.503_504del were identified independently. 16p11.2 microdeletion was not detected in patients without PRRT2 mutations. PRRT2 mutation detection rates were 21/31 (68%) and 12/32 (38%) in probands who were positive or negative for family history, respectively, indicating a significant difference between the two groups. In this study, 20 probands with BPEI were negative for family history of BPEI and negative for PRRT2 mutation. BPEI in these probands may be due to complex genetic predispositions. Because the possibility remains that a second gene contributes to BPEI, further studies are necessary in patients with BPEI but no PRRT2 mutation, especially in Asian people.

Difficulty of Early Diagnosis and Requirement of Long-Term Follow-Up in Benign Infantile Seizures

PURPOSE

We investigated whether benign infantile seizures can be diagnosed in the acute phase.

METHODS

We retrospectively analyzed the medical records of 44 patients initially diagnosed with acute phase benign infantile seizures. All patients were followed for more than 12 months, and we reviewed patients' psychomotor development and presence or absence of seizure recurrence at the last visit. Patients were divided into the following three groups according to the final diagnosis: benign infantile seizures, benign infantile seizures associated with mild gastroenteritis, and non-benign infantile seizures. We defined benign infantile seizures associated with mild gastroenteritis and benign infantile seizures as those associated with normal psychomotor development and no seizure recurrence 3 months after onset of the first seizure, whereas non-benign infantile seizures were associated with delayed psychomotor development and/or seizure recurrence after 3 months of onset of the first seizure. We analyzed the clinical features in the acute phase and compared them between the groups.

RESULTS

The median age of seizure onset was 7.6 months. A final diagnosis of benign infantile seizures associated with mild gastroenteritis was made in three patients. In the remaining 41 patients, the final diagnosis was benign infantile seizures in 30 (73.2%) and non-benign infantile seizures in 11 (26.8%). In the non-benign infantile seizure group, intellectual disability was diagnosed in eight patients and seizure recurrence in six. There were no significant differences in clinical features between the groups in the acute phase, such as seizure type or seizure duration.

CONCLUSION

About 30% of patients initially diagnosed as having benign infantile seizures did not experience a benign clinical course. Our findings suggest that clinical features in the acute phase are not helpful for predicting benign outcomes in benign infantile seizures and that only long-term follow-up can discriminate benign infantile seizures from non-benign infantile seizures.

Single nucleotide variations in CLCN6 identified in patients with benign partial epilepsies in infancy and/or febrile seizures

Nucleotide alterations in the gene encoding proline-rich transmembrane protein 2 (PRRT2) have been identified in most patients with benign partial epilepsies in infancy (BPEI)/benign familial infantile epilepsy (BFIE). However, not all patients harbor these PRRT2 mutations, indicating the involvement of genes other than PRRT2. In this study, we performed whole exome sequencing analysis for a large family affected with PRRT2-unrelated BPEI. We identified a non-synonymous single nucleotide variation (SNV) in the voltage-sensitive chloride channel 6 gene (CLCN6). A cohort study of 48 BPEI patients without PRRT2 mutations revealed a different CLCN6 SNV in a patient, his sibling and his father who had a history of febrile seizures (FS) but not BPEI. Another study of 48 patients with FS identified an additional SNV in CLCN6. Chloride channels (CLCs) are involved in a multitude of physiologic processes and some members of the CLC family have been linked to inherited diseases. However, a phenotypic correlation has not been confirmed for CLCN6. Although we could not detect significant biological effects linked to the identified CLCN6 SNVs, further studies should investigate potential CLCN6 variants that may underlie the genetic susceptibility to convulsive disorders.

Evaluation of clinical course and neurocognition in children with self-limited infantile epilepsy in a Turkish cohort study

The outcome of children with self-limited infantile epilepsy was reported to be normal psychosocial and cognitive development as a characteristic criterion. We aimed to investigate the clinical course and neurocognitive outcome in children with self-limited infantile epilepsy in a Turkish cohort. The clinical course, electroencephalographic (EEG) characteristics, neuroimaging, treatment, and outcome of children with self-limited infantile epilepsy were retrospectively analyzed. All infants were reevaluated with the Denver Developmental Screening Test in addition to neurologic examination. Of 44 patients, self-limited familial infantile epilepsy was diagnosed in 8 infants (18.2%) and self-limited nonfamilial infantile epilepsy in 28 (63.6%). Interictal EEGs and neurologic examinations were normal in all cases. Fine motor and gross motor skills, language, adaptive personal/social skills were near-normal in all patients with self-limited familial infantile epilepsy. Delay in language parameters was observed in 2 infants with self-limited nonfamilial infantile epilepsy. Language skills should be thoroughly evaluated with detailed neurocognitive screening tests in patients with self-limited infantile epilepsy.

Long-term follow-up in children with benign convulsions associated with gastroenteritis

BACKGROUND

The outcome of benign convulsions associated with gastroenteritis (CwG) has generally been reported as being excellent. However, these data need to be confirmed in studies with longer follow-up evaluations.

AIM

To assess the long-term neurological outcome of a large sample of children presenting with CwG.

METHODS

We reviewed clinical features of 81 subjects presenting with CwG (1994-2010) from three different Italian centers with a follow-up period of at least 3 years.

RESULTS

Follow-up period ranged from 39 months to 15 years (mean 9.8 years). Neurological examination and cognitive level at the last evaluation were normal in all the patients. A mild attention deficit was detected in three cases (3.7%). Fourteen children (17.3%) received chronic anti-epileptic therapy. Interictal EEG abnormalities detected at onset in 20 patients (24.7%) reverted to normal. Transient EEG epileptiform abnormalities were detected in other three cases (3.7%), and a transient photosensitivity in one (1.2%). No recurrence of CwG was observed. Three patients (3.7%) presented with a febrile seizure and two (2.5%) with an unprovoked seizure, but none developed epilepsy.

CONCLUSIONS

The long-term evaluation of children with CwG confirms the excellent prognosis of this condition, with normal psychomotor development and low risk of relapse and of subsequent epilepsy.

Phenotypes and PRRT2 mutations in Chinese families with benign familial infantile epilepsy and infantile convulsions with paroxysmal choreoathetosis

BACKGROUND

Mutations in the PRRT2 gene have been identified as the major cause of benign familial infantile epilepsy (BFIE), paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions with paroxysmal choreoathetosis/dyskinesias (ICCA). Here, we analyzed the phenotypes and PRRT2 mutations in Chinese families with BFIE and ICCA.

METHODS

Clinical data were collected from 22 families with BFIE and eight families with ICCA. PRRT2 mutations were screened using PCR and direct sequencing.

RESULTS

Ninety-five family members were clinically affected in the 22 BFIE families. During follow-up, two probands had one seizure induced by diarrhea at the age of two years. Thirty-one family members were affected in the eight ICCA families, including 11 individuals with benign infantile epilepsy, nine with PKD, and 11 with benign infantile epilepsy followed by PKD. Two individuals in one ICCA family had PKD or ICCA co-existing with migraine. One affected member in another ICCA family had experienced a fever-induced seizure at 7 years old. PRRT2 mutations were detected in 13 of the 22 BFIE families. The mutation c.649_650insC (p.R217PfsX8) was found in nine families. The mutations c.649delC (p.R217EfsX12) and c.904_905insG (p.D302GfsX39) were identified in three families and one family, respectively. PRRT2 mutations were identified in all eight ICCA families, including c.649_650insC (p.R217PfsX8), c.649delC (p.R217EfsX12), c.514_517delTCTG (p.S172RfsX3) and c.1023A > T (X341C). c.1023A > T is a novel mutation predicted to elongate the C-terminus of the protein by 28 residues.

CONCLUSIONS

Our data demonstrated that PRRT2 is the major causative gene of BFIE and ICCA in Chinese families. Site c.649 is a mutation hotspot: c.649_650insC is the most common mutation, and c.649delC is the second most common mutation in Chinese families with BFIE and ICCA. As far as we know, c.1023A > T is the first reported mutation in exon 4 of PRRT2. c.649delC was previously reported in PKD, ICCA and hemiplegic migraine families, but we further detected it in BFIE-only families. c.904_905insG was reported in an ICCA family, but we identified it in a BFIE family. c.514_517delTCTG was previously reported in a PKD family, but we identified it in an ICCA family. Migraine and febrile seizures plus could co-exist in ICCA families.

PRRT2 mutation in Japanese children with benign infantile epilepsy

Mutations in PRRT2 genes have been identified as a major cause of benign infantile epilepsy and/or paroxysmal kinesigenic dyskinesia. We explored mutations in PRRT2 in Japanese patients with BIE as well as its related conditions including convulsion with mild gastroenteritis and benign early infantile epilepsy. We explored PRRT2 mutations in Japanese children who had had unprovoked infantile seizures or convulsion with mild gastroenteritis. The probands included 16 children with benign infantile epilepsy, 6 children with convulsions with mild gastroenteritis, and 2 siblings with benign early infantile epilepsy. In addition, we recruited samples from family members when PRRT2 mutation was identified in the proband. Statistical analyses were performed to identify differences in probands with benign infantile epilepsy according to the presence or absence of PRRT2 mutation. Among a total of 24 probands, PRRT2 mutations was identified only in 6 probands with benign infantile epilepsy. A common insertion mutation, c.649_650insC, was found in 5 families and a novel missense mutation, c.981C>G (I327M), in one. The family history of paroxysmal kinesigenic dyskinesia was more common in probands with PRRT2 mutations than in those without mutations. Our study revealed that PRRT2 mutations are common in Japanese patients with benign infantile epilepsy, especially in patients with a family history of paroxysmal kinesigenic dyskinesia.

Benign convulsions in newborns and infants: occurrence, clinical course and prognosis

BACKGROUND

During early development severe epilepsies may appear, some with well established occurrence. Benign non-epileptic and epileptic paroxysmal syndromes with excellent prognosis occur in the same period. There are no exact data on their occurrence.

AIM

We have reviewed medical histories of children with benign non-epileptic or benign epileptic events: benign myoclonus of early infancy, benign neonatal sleep myoclonus, benign sleep myoclonus in infancy, benign partial epilepsy in infancy (BPEI) and benign infantile familial convulsions (BIFC) were established. The occurrence, clinical characteristics and prognosis of these syndromes were evaluated.

METHODS

Inclusion criteria were met in 31 children. Research included retrospective analysis of clinical characteristics, laboratory values, neuroimaging and neurophysiological assessments, followed by evaluation of psychosocial development with the use of the Strengths and Difficulties Questionnaire (SDQ), fulfilled by parents.

RESULTS

In our group the incidence of benign non-epileptic convulsions was 6.69 per 10 000 live births and the incidence of benign epileptic convulsions was 1.35 per 10 000. Male/female ratio in the group of children with non-epileptic events was 2.1:1. Among non-epileptic group 5 out of 23 children and among epileptic group 3 out of 8 children had minimal, mild or moderate abnormalities at neurological assessment at the time of the first clinical examination. Nonspecific changes in laboratory values were seen in 6 out of 23 in the non-epileptic and in 1 out of 8 children in the epileptic group. Neurophysiological assessments showed subtle changes in 4/23 in the non-epileptic and 6/8 in the epileptic group. Neuroimaging was not optimal in 5/23 with non-epileptic and 3/8 with epileptic events. Analysis of SDQ did not show significant deviations in psyhosocial development. Statistically significant deviation was observed only in relations with peers (p = 0.009).

CONCLUSIONS

Benign neonatal and infantile convulsions are more frequent than severe epilepsies of the same age period. Results show higher proportion of males with benign non-epileptic conditions. No deviations in further development was found. Laboratory values, neuroimaging and neurophysiological assessments were normal or nonspecifically changed.

Benign convulsions with mild gastroenteritis: is it associated with sodium channel gene SCN1A mutation?

Benign convulsions with mild gastroenteritis were afebrile seizures associated with gastroenteritis in previously healthy infants or young children. It has been thought to be a continual spectrum of benign infantile convulsions because of overlapping clinical pictures. Recently, molecular genetic studies have suggested a channelopathy in benign infantile convulsions. The authors prospectively studied the clinical features of benign convulsions with mild gastroenteritis in Taiwanese children and clarified the relationship between neuronal sodium channel alpha 1 subunit (SCN1A) gene and benign convulsions with mild gastroenteritis. The clinical pictures in their patients were similar to those of previous studies except for the low rate of positive rotavirus antigen in the stool, which may indicate a season-related viral infection. No mutations in the SCN1A gene were identified in all patients. This study suggested that SCN1A mutations are probably not associated with benign convulsions with mild gastroenteritis. Other possible pathogenic mechanisms need to be researched in the future.

Transiently reduced water diffusion in the corpus callosum in infants with benign partial epilepsy in infancy

Neuroimaging findings are usually normal in children with benign partial epilepsy in infancy. However, we found a transient reduction of water diffusion in the corpus callosum in two patients with probable benign partial epilepsy in infancy. The patients were admitted to our hospital because of seizure clusters. No delay in the developmental milestones was seen, and no neurological abnormalities were observed during the interictal period. Interictal electroencephalography was normal in both infants. However, the diffusion-weighted images showed abnormal high intensities in both the genu and splenium in one patient and in the splenium only in the other. No diffusion abnormalities were observed in follow-up magnetic resonance imaging. The clustered seizures may be related to the transient callosal lesions seen in our patients.

Benign familial and non-familial infantile seizures (Fukuyama-Watanabe-Vigevano syndrome): a study of 14 cases from Saudi Arabia

PURPOSE

Benign infantile seizures [BIS], familial and non-familial, represent a benign, age-related idiopathic syndrome of infancy. The aim of the current paper is to document the presence of the syndrome in Saudi Arabia and in Arab populations and to discuss the characteristic electroclinical features and the benign nature of this syndrome.

PATIENTS AND METHODS

A case series of 275 patients with epileptic seizures (age range: 2 months-13 years) were followed over a period of 3 years and 7 months. The inclusion criteria for BIS were as follows (1) age of seizure onset between 2 and 24 months, (2) normal development before, during and after the onset of seizures, (3) normal interictal EEG, (4) normal brain imaging, and (5) good response to treatment. We analyzed these infants with respect to age at seizure onset, sex, physical and neurological examination, consanguinity, frequency and type of convulsions, associated conditions and laboratory and radiological investigations. A waking and sleeping interictal EEG was performed on all patients, and for one patient (No. 1), ictal EEG and video clips were recorded.

RESULTS

Fourteen infants (12.0%) showed electroclinical features consistent with BIS. Eleven patients fulfilled the criteria of benign non-familial infantile seizures (BNFIS), and for three patients, their family pedigrees showed the possibility of benign familial infantile seizures (BFIS). All of the patients responded to anti-epileptic treatment, and 50% of them responded within 3 months.

CONCLUSIONS

To our knowledge, this is the first study to document the presence of BIS (Fukuyama-Watanabe-Vigevano syndrome) in Saudi Arabian and Arab populations. We highlighted the characteristic features of BIS and demonstrated the benign nature of the syndrome.

Usefulness of single-channel amplitude-integrated electroencephalography for continuous seizure monitoring in infancy: a case report

We continuously monitored clustered seizures using single-channel amplitude-integrated electroencephalography (aEEG) in a 6-month-old girl with probable benign partial epilepsy in infancy (BPEI). The patient was admitted with clustered seizures, and aEEG using three disposable electrodes was started by a non-expert pediatrician. During the recording, seven seizures were detected. The last seizure was nearly overlooked on clinical observation, but was later confirmed on the basis of aEEG findings. The efficacy of antiepileptic drugs could also be objectively assessed from aEEG findings. Our results show that aEEG is useful for the continuous monitoring of seizures even in older children.

"One swallow does not make a summer" ... or does it?

A Single Episode of Neonatal Seizures Permanently Alters Glutamatergic Synapses. Cornejo BJ, Mesches MH, Coultrap S, Browning MD, Benke TA. Ann Neurol 2007;61(5):411–426. OBJECTIVE: The contribution of seizures to cognitive changes remains controversial. We tested the hypothesis that a single episode of neonatal seizures (sNS) on rat postnatal day (P) 7 permanently impairs hippocampal-dependent function in mature (P60) rats because of long-lasting changes at the synaptic level. METHODS: sNS was induced with subcutaneously injected kainate on P7. Learning, memory, mossy fiber sprouting, spine density, hippocampal synaptic plasticity, and glutamate receptor expression and subcellular distribution were measured at P60. RESULTS: sNS selectively impaired working memory in a hippocampal-dependent radial arm water-maze task without inducing mossy fiber sprouting or altering spine density. sNS impaired CA1 hippocampal long-term potentiation and enhanced long-term depression. Subcellular fractionation and cross-linking, used to determine whether glutamate receptor trafficking underlies the alterations of memory and synaptic plasticity, demonstrated that sNS induced a selective reduction in the membrane pool of glutamate receptor 1 subunits. sNS induced a decrease in the total amount of N-methyl-d-aspartate receptor 2A and an increase in the primary subsynaptic scaffold, PSD-95. INTERPRETATION: These molecular consequences are consistent with the alterations in plasticity and memory caused by sNS at the synaptic level. Our data demonstrate the cognitive impact of sNS and associate memory deficits with specific alterations in glutamatergic synaptic function.

Ictal EEG in benign partial epilepsy in infancy

The aim of this study is to further clarify ictal electroencephalographic findings of patients with benign partial epilepsy in infancy in order to better understand its neurophysiologic features. The study group consisted of 13 infants with definite benign partial epilepsy in infancy, in whom ictal electroencephalograms were recorded and its benignity was confirmed at 8 years or more. The seizure manifestation was reviewed on the basis of video findings in eight patients in whom simultaneous video-electroencephalography recording was available. In the other five patients, the seizure manifestations were determined according to the observations of physicians, nurses, or technicians. Thirteen seizures from eight patients were complex partial, and six seizures from six patients were secondarily generalized ones. Ictal discharges at the onset of a seizure were focal in all seizures. The site of the origin of seizures was in the temporal area in 10 of 13 complex partial seizures, whereas it was in the parietal or occipital area in all 6 secondarily generalized seizures. Among 13 complex partial seizures, paroxysmal discharges remained focal throughout the seizures in 6 seizures, whereas they spread to one hemisphere in the other 7 seizures. Motion arrest or decreased responsiveness was uniformly observed. Lateral eye deviation was commonly recognized in complex partial seizures, whereas head rotation was observed only in seizures in which hemispheric propagation of ictal discharges was observed. Ictal electroencephalographic findings of patients with benign partial epilepsy in infancy were relatively uniform, suggesting the homogeneity of patients with benign partial epilepsy in infancy.

Antiepileptic treatment against clustered seizures in benign partial epilepsy in infancy

We performed detailed review of clinical course of clustered seizures in patients with benign partial epilepsy in infancy in order to determine the optimal treatment during the acute period. We retrospectively investigated the details of antiepileptic treatment for clustered seizures in 20 patients with benign partial epilepsy in infancy. The temporal course of seizures and the use of antiepileptic drugs were investigated in each patient. Drugs were judged as effective when seizure cessation was achieved after administration of the drug. As the first drug, diazepam/bromazepam was effective in 14% and phenobarbital in 60%. As the second drug, diazepam/bromazepam was effective in 13% and phenobarbital in 40%. As the third drug, phenobarbital was effective in 56%. The efficacy rate of the first dose of phenobarbital was relatively higher than that of diazepam/bromazepam. Persistence of seizures after treatment was relatively shorter and the number of seizures after treatment was relatively smaller in patients treated with PB as the first 2 drugs. In conclusion, the efficacy of diazepam/bromazepam or phenobarbital was insufficient for the cessation of clustered seizures in benign partial epilepsy in infancy.

Benign partial epilepsy in infancy long-term outcome and marginal syndromes

Benign partial epilepsy in infancy (BPEI) is an infantile epilepsy with excellent seizure and developmental outcome proposed by Watanabe et al. Our telephone interview survey revealed that the long-term outcome of patients with BPEI was also excellent over 8 years of age. Six of 39 patients did not fulfill the criteria of BPEI by the last follow-up. Two patients had a recurrence of unprovoked seizure beyond 2 years of age, three had cognitive problems (mild mental retardation in two and Asperger syndrome in one) and the other had both a recurrence of seizure and mild mental retardation. These results indicates that a large majority of patients diagnosed as possible BPEI at 2 years of age did not have a recurrence of unprovoked seizures and mental problems beyond 8 years of age. Our study also suggested a presence of some marginal syndromes of BPEI. An association of paroxysmal kinesigenic choreoathetosis was observed in three patients. Another three patients had experienced seizures with mild gastroenteritis. The seizure outcome of three patients with mild cognitive problems was quite excellent. These patients can be grouped as a marginal syndrome of BPEI.