Clinical study on localization-related epilepsy in infancy without underlying disorders

Paroxysmal non-epileptic events in infants and toddlers: A phenomenologic analysis

AIM

The aim of this study was to analyze in detail the clinical phenomenology of paroxysmal non-epileptic events (PNEE) in infants and toddlers.

METHODS

We studied all children aged ≤2 years who were diagnosed with PNEE based on video-electroencephalographic (VEEG) recordings. We analyzed the following four clinical domains of each clinical event: (i) motor manifestations (body/limb jerking, complex motor, and asymmetric limb posturing); (ii) oral/vocal (crying, vocalization, sighing); (iii) behavioral change (arrest of activity, staring); (iv) and autonomic (facial flushing, breath holding).

RESULTS

Thirty-one of 81 (38.3%) infants and toddlers had 38 PNEE recorded during the study period (12 girls and 19 boys, mean age 10.5 months). The predominant clinical features were as follows: motor in 26/38 events, oral/verbal in 14/38 events, behavioral in 11/38 events, and autonomic in 8/38 events. Epileptic seizures and PNEE coexisted in four children (12.9%). Seventeen children (54.8%) had one or more risk factors suggestive of epilepsy. Twelve children (38.7%) had a normal neurologic examination, 10 (32.3%) had developmental delay, and eight (25.8%) had a family history of epilepsy or seizures.

CONCLUSION

VEEG recorded PNEE in nearly 40% of 81 infants and toddlers referred for unclear paroxysmal events in our cohort. Non-epileptic staring spells and benign sleep myoclonus were the most common events recorded, followed by shuddering attacks and infantile masturbation. In addition, greater than one-half of the infants and toddlers had risk factors, raising a concern for epilepsy in the family and prompting the VEEG evaluation, suggesting that paroxysmal non-epileptic seizures may frequently coexist in young children with epilepsy.

Benign Partial Epilepsy in Infancy: Myth or Reality?

PURPOSE

Benign partial epilepsy in infancy (BPEI) was first described by Watanabe in 1987. The aim of this study is to describe a series of infants from the United States to characterize this entity further.

METHODS

Among patients with the diagnosis of epilepsy followed up at our institution between 2002 and 2004, those satisfying the criteria for BPEI were included in a retrospective study.

RESULTS

Sixteen (10.2%) of 150 patients with new onset of epilepsy younger than 2 years were identified. The mean age at seizure onset was 8 months. Four (25%) infants had a family history of benign seizures. All infants were neurologically and developmentally normal at the onset of seizures. The seizures occurred in clusters in 75% of patients, predominantly in wakefulness. The initial manifestation was behavioral arrest with staring (69%) and apnea with cyanosis or pallor (37.5%). These symptoms were followed by deviation of eyes or head or both (56%), mild clonic movements (31%), or increased limb tone (35%). Secondary generalization was noticed in 37.5% of patients. All infants had normal interictal EEGs and brain MRIs. Ictal EEGs disclosed electrographic seizures in 50% of patients (temporal origin in 62% and central in 38%). Fifteen (94%) patients were treated with AEDs with good response. The mean duration of treatment was 12.4 months. The final developmental assessment of all patients was normal.

CONCLUSIONS

We believe that BPEI exists as a unique entity and should be included in the differential diagnosis of epilepsies in infancy with partial origin.

Hypomotor seizures in infants and children

PURPOSE

Hypomotor seizures (characterized by diminished behavioral activity with indeterminate level of consciousness) have been identified as an important seizure type in infants. Our goal was to investigate further the clinical and EEG features of hypomotor seizures.

METHODS

We retrospectively reviewed 110 hypomotor seizures from 34 patients recorded with video-EEG.

RESULTS

Twenty-seven (79%) patients were younger than 48 months, and seven (21%) were aged 4 to 15 years. Seventy-one (64%) seizures had regional or lateralized EEG onset, arising predominantly from temporal or parietal lobe regions. The other 39 (35%) seizures had generalized onset, usually with abrupt onset of diffuse rhythmic high-amplitude theta activity or diffuse electrodecrement and only rarely (two patients) with slow spike-wave complexes or 3-Hz spike-wave complexes. Hypomotor seizures with generalized EEG onset were significantly shorter than those with regional or lateralized onset (p = 0.01, GEE model). Unsustained head or eye movements and subtle mouth automatisms were commonly seen in hypomotor seizures with either focal or generalized onset. Seventeen percent of hypomotor seizures with focal onset evolved to include version of head and eyes or jerking of one arm, whereas 2% of generalized hypomotor seizures evolved to a cluster of spasms.

CONCLUSIONS

Hypomotor seizures may be either focal or generalized. Regional EEG onsets were most often temporal or parietal, suggesting that focal hypomotor seizures may be a bland form of "complex partial" seizures with no or minimal automatisms, seen predominantly in infants. Generalized hypomotor seizures were rarely associated with an ictal pattern of generalized spike-wave complexes, suggesting a different mechanism from absence seizures seen later in life.

Short duration of benign partial epilepsy in infancy

It has previously been reported that benign partial epilepsy in infancy constitutes up to 29% of the epilepsies presenting in the first 2 years of life. To determine the proportion of benign partial epilepsy in our epilepsy population, we retrospectively reviewed 331 patients with greater than two afebrile seizures in the first 2 years of life between 1993 and 2000. Inclusion criteria were (1) partial seizures with or without secondary generalization, (2) normal development, (3) no other neurologic abnormalities, (4) normal interictal electroencephalograms (EEGs), and (5) good response to treatment. Exclusion criteria included seizures that (1) were caused by acute central nervous system insult, (2) occurred only within the first month of life, and (3) lasted longer than 30 minutes. Of 331 patients, 22 (6.6%) fulfilled the criteria with a minimum of 2 years and a mean of 4 years of follow-up off antiepilepsy drug treatment. Six (27%) had complex partial seizures, and 16 (73%) had complex partial seizures with secondary generalization. Neuroimaging studies were normal in all patients. Of the 6 patients with ictal EEGs, 3 had a temporal lobe focus, 1 had an occipital lobe focus, and the remaining 2 had dual foci. Median onset was 4.0 months (range 0.8-9.3). Seizures remitted within 4 months in 20 (91%). Mean duration of seizure persistence was 2.1 months (range 0-8.3) and was longer in treated patients. Median age at last seizure was 6.4 months (range 2-18). Nineteen were treated with antiepilepsy drugs. At last follow-up (mean duration of 52.2 months), all patients were seizure free and off antiepilepsy drugs. Benign partial epilepsy in infancy is an epilepsy syndrome of short duration and is easily recognized using accepted classification criteria. Benign partial epilepsy in infancy appears to be an idiopathic localization-related epilepsy with a favorable prognosis. The incidence in our population is not as common as previously reported. Based on our findings, we suggest weaning of antiepilepsy drugs 6 months after seizure onset.

Early recognition of benign partial epilepsy in infancy

PURPOSE

The aim of this study is to determine how precisely we can recognize the outcome in infants with epilepsy beginning in the first year of life.

METHODS

We performed a prospective 5-year follow-up study on 63 patients who developed epilepsy in the first year of life. We first judged that patients met the criteria of "possible benign partial epilepsy in infancy (BPEI)" on enrollment in this study. At 2 years of age, we reevaluated the seizure and developmental outcome in the patients who were diagnosed as having "possible BPEI." We finally judged that patients met the criteria of "definite BPEI" at age 5 years. "Possible BPEI" was defined as epilepsy meeting all the following conditions: (a) complex partial seizures and/or secondarily generalized seizures; (b) normal psychomotor development and neurologic findings before onset; (c) normal interictal electroencephalograms; (d) normal cranial computed tomography (CT) and magnetic resonance imaging (MRI) findings; and (e) no seizures during the first 4 weeks of life. "Definite BPEI" was defined as epilepsy meeting all the following criteria in addition to those of "possible BPEI": (a) normal psychomotor development beyond age 5 years, and (b) no seizures beyond age 2 years.

RESULTS

Thirty-two of the 63 patients met the inclusion criteria completely and were included in the "possible BPEI" group. Twenty-five of the 32 patients completed the 5-year follow-up. At age 2 years, four patients were excluded from the "possible BPEI" group because of seizure recurrence and/or delayed development. By age 5 years, one had a recurrence of seizures, and another exhibited mildly delayed psychomotor development. We finally diagnosed 19 patients as having "definite BPEI." "Definite BPEI" accounted for 76% of the patients diagnosed as having "possible BPEI" at the first presentation and 90% of those who met the conditions on reevaluation at age 2 years.

CONCLUSIONS

Recognition of BPEI is possible, to some extent, at the first presentation, and reevaluation at age 2 years is useful for a more precise diagnosis.

Epilepsy in the first year of life: a review

The prevalence of epilepsy is highest during the first year of life. Approximately 50% of patients with seizure onset between 1 and 12 months of age suffer from West syndrome. The rest have one of 12 well-delineated epilepsy syndromes, or in most cases have what are classified as generalized or partial seizures. The outcome of infants with partial seizures is significantly worse than that of patients with generalized seizures. This is true not only for symptomatic partial seizures but also for a subgroup of infants with cryptogenic partial seizures.