Informative value of magnetic resonance imaging and EEG in the prognosis of infantile spasms

Prediction model for long-term seizure and developmental outcomes among children with infantile epileptic spasms syndrome

Introduction

Children with infantile epileptic spasms syndrome (IESS) are likely to experience poor outcomes. Researchers have investigated the factors related to its long-term prognosis; however, none of them developed a predictive model.

Objective

This study aimed to clarify the factors that influence the long-term prognosis of seizures and their development and to create a prediction model for IESS.

Materials and methods

We conducted a retrospective cohort study enrolling participants diagnosed with IESS at the Tottori University Hospital. We examined the seizure and developmental status at 3 and 7 years after the IESS onset and divided the participants into favorable and poor outcome groups. Subsequently, we analyzed the factors associated with the poor outcome group and developed a prediction model at 3 years by setting cutoff values using the receiver operating characteristic curve.

Results

Data were obtained from 44 patients with IESS (19 female patients and 25 male patients). Three years after epileptic spasms (ES) onset, seizure and development were the poor outcomes in 15 (34.9%) and 27 (61.4%) patients, respectively. The persistence of ES or tonic seizures (TS) after 90 days of onset, moderate or severe magnetic resonance imaging abnormalities, and developmental delay before IESS onset were significantly associated with poor outcomes. Seven years after the onset of ES, seizures and development were the poor outcomes in 9 (45.0%) and 13 (72.2%) patients, respectively. We found that no factor was significantly associated with poor seizure outcomes, and only developmental delay before IESS onset was significantly associated with poor developmental outcomes. Our prediction model demonstrated 86.7% sensitivity and 64.3% specificity for predicting poor seizure outcomes and 88.9% sensitivity and 100% specificity for predicting poor developmental outcomes.

Conclusion

Our prediction model may be useful for predicting the long-term prognosis of seizures and their development after 3 years. Understanding the long-term prognosis during the initial treatment may facilitate the selection of appropriate treatment.

Generalized epilepsies

Idiopathic generalized epilepsies (IGE) are characterized by normal background EEG activity and generalized interictal spike-and-wave discharges in the absence of any evidence of brain lesion. Absence epilepsies are the prototypes of IGEs. In childhood and juvenile absence epilepsies, by definition, all patients manifest absence seizures associated with an EEG pattern of generalized spike-wave (GSW) discharges. In juvenile myoclonic epilepsy, myoclonic jerks, usually affecting shoulders and arms bilaterally and appearing upon awakening, are the most characteristic clinical feature. Myoclonic jerks are accompanied on the EEG by generalized spike/polyspike-and-wave (GSW, GPWS) complexes at 3.5-6Hz. Idiopathic generalized epilepsy with generalized tonic-clonic seizures only is a broad and nonspecific category including all patients with generalized tonic-clonic seizures and an interictal EEG pattern of GSW discharges. Despite the strong heritability and the recent advances in genetic technology, the genetic basis of IGEs remains largely elusive and only in a small minority of patients with classic IGE phenotypes is a monogenic cause identified. Early myoclonic encephalopathy (EME), early infantile encephalopathy with suppression bursts, West syndrome, and Lennox-Gastaut syndrome, once classified among the generalized epilepsies, are now considered to be epileptic encephalopathies. Among them, only Lennox-Gastaut syndrome is characterized by prominent generalized clinical and EEG features.

White Matter Abnormality Correlates with Developmental and Seizure Outcomes in West Syndrome of Unknown Etiology

BACKGROUND AND PURPOSE

West syndrome is an epileptic encephalopathy characterized by epileptic spasms, a specific pattern on electroencephalography of hypsarrhythmia, and developmental regression. Our aim was to assess white matter abnormalities in West syndrome of unknown etiology. We hypothesized that diffusion tensor imaging reveals white matter abnormalities, especially in patients with poor seizure and developmental outcomes.

MATERIALS AND METHODS

We enrolled 23 patients with new-onset West syndrome of unknown etiology. DTI was performed at 12 and 24 months of age. Fractional anisotropy images were compared with those of controls by using tract-based spatial statistics. We compared axial, radial, and mean diffusivity between patients and controls in the fractional anisotropy skeleton. We determined correlations of these parameters with developmental quotient, electroencephalography, and seizure outcomes. We also compared DTI with hypometabolism on fluorodeoxyglucose positron-emission tomography.

RESULTS

At 12 months of age, patients showed widespread fractional anisotropy reductions and higher radial diffusivity in the fractional anisotropy skeleton with a significant difference on tract-based spatial statistics. The developmental quotient at 12 months of age correlated positively with fractional anisotropy and negatively with radial and mean diffusivity. Patients with seizure and abnormal findings on electroencephalography after initial treatments had lower fractional anisotropy and higher radial diffusivity. At 24 months, although tract-based spatial statistics did not show significant differences between patients and controls, tract-based spatial statistics in the 10 patients with a developmental quotient of <70 had significant fractional anisotropy reduction. In patients with unilateral temporal lobe hypometabolism on PET, tract-based spatial statistics showed greater fractional anisotropy reduction in the temporal lobe ipsilateral to the side of PET hypometabolism.

CONCLUSIONS

Diffuse abnormal findings on DTI at 12 months of age suggest delayed myelination as a key factor underlying abnormal findings on DTI. Conversely, asymmetric abnormal findings on DTI at 24 months may reflect underlying focal pathologies.

Neuro-lmages of Patients with Infantile Spasm

With the intention of assessing the neuro-imaging, clarifying the percentages of symptomatic, idiopathic and cryptogenic cases and identifying the underlying causes, records were reviewed retrospectively of 30 children with infantile spasm admitted to Hamad Medical Corporation, Doha, Qatar. Twenty-three patients were symptomatic, four idiopathic and three cryptogenic. Brain CT and MRI scans of 13 cases detected similar neuro-imaging findings in nine cases while MRI provided more information in another four cases. Three patients had normal neuro-images despite persistently abnormal EEGs. We conclude that MRI scans are superior to CT scans in detecting areas of cortical dysgenesis, disorders of neuronal migration, or disorders of myelination although more advanced studies are required for patients with persistently abnormal EEGs but normal MRIs.

Clinical profile of infants with hypsarrhythmia

OBJECTIVE

The present study was done in order to obtain a baseline profile of infantile spasms and associated neurological disorders.

PATIENT AND METHODS

The study included 50 patients with infantile spasm in Queen Rania Hospital for children in Jordan. The following data were obtained: sex, age at onset of spasms, details of seizure, family history of epilepsy, significant pre-/peri/ post-natal insults, Electroencephalography and detailed neuro imaging evaluation , detailed neurological, neuro developmental ,assessment were done by. Broad categories of possible etiologies were used the results were recorded for further study.

RESULTS

Age of onset of infantile spasms ranged from 1month to 1 year and 6 months , (mean 4.8 months). The mean time of presentation was 9.4 months . A male preponderance was noted (74 %). flexor spasms (52%) was the commonest . Other types of seizures also accompanied infantile spasm in 44% children . (84%) were born of normal delivery, History of birth asphyxia was obtained in 48%, 3 (6%) had positive family history Developmental delay was recognized prior to onset of spasms in 52%, microcephaly was the commonest associated problem, Imaging studies of the brain revealed abnormality in 18 patients. 78% patients were classified as symptomatic and 22 % as cryptogenic.

CONCLUSION

the pattern of infantile spasm in our country do not differ from that of developed countries, further researches is required to prevent both chronic epilepsy and psychomotor retardation and .preventive measurement to prevent birth asphyxia is recommended.

Epilepsy in children

10.5 million children worldwide are estimated to have active epilepsy. Over the past 15 years, syndrome-oriented clinical and EEG diagnosis, and better aetiological diagnosis, especially supported by neuroimaging, has helped to clarify the diversity of epilepsy in children, and has improved management. Perinatal and postinfective encephalopathy, cortical dysplasia, and hippocampal sclerosis account for the most severe symptomatic epilepsies. Ion channel defects can underlie both benign age-related disorders and severe epileptic encephalopathies with a progressive disturbance in cerebral function. However, the reasons for age-related expression in children are not understood. Neither are the mechanisms whereby an epileptic encephalopathy originates. Several new drugs have been recently introduced but have provided limited therapeutic benefits. However, treatment and quality of life have improved because the syndrome-specific efficacy profile of drugs is better known, and there is heightened awareness that compounds with severe cognitive side-effects and heavy polytherapies should be avoided. Epilepsy surgery is an important option for a few well-selected individuals, but should be considered with great caution when there is no apparent underlying brain lesion.

Profile of West syndrome in North Indian children

To study the profile of West syndrome (WS) in North Indian Children, 165 cases of WS were analyzed. Details of seizure semiology, prenatal and perinatal events, developmental milestones, treatment received, physical and neurological examination and investigations were recorded. The response of seizures to various therapeutic modalities and the final developmental status were taken as primary outcome variables. Analysis was done to find the factors influencing these outcome variables. The age of onset of infantile spasms ranged from 1 to 19 (mean 6.1 +/- 3.4) months. Age at presentation ranged from 1.5 months to 4.5 years (mean 14.7 +/- 11.4 months); 74% had flexor spasms. Other types of seizures were associated in 31 children. Antenatal problems and adverse perinatal events were reported in 26.7 and 59.4%, respectively. Developmental delay was recognized in 69.7% prior to and in 27.9% after onset of spasms. Microcephaly was seen in 72.7%. Interictal EEG showed hypsarrhythmia in 44; generalized spike and slow waves in 31% and burst suppression in 7%. Computed tomography scan done in 94 cases showed cerebral atrophy in 15%, infarcts in 8%, tubers in 7%, developmental malformations in 5%. Magnetic resonance imaging done in 77 cases showed periventricular T2WI white matter hyper intensities in 33.8% and cerebral atrophy in 21%. Prednisolone and ACTH were used in 57 and 35 cases, respectively. Complete control of seizures was seen in 49 and 46% cases. No significant difference in seizure control or developmental outcome was found in the two groups. Overall, 42.4, 30.9 and 16% children showed complete, partial and no control of seizures. After therapy, developmental improvement was seen in 55.8% and no change in 23.6% cases. The type of spasms had no correlation with the other parameters including etiology, seizure or developmental outcome. An early age of onset correlated with presence of antenatal problems (P < 0.05). Seizure control and developmental improvement correlated significantly (P < 0.005). Developmental outcome was better in cryptogenic as compared to symptomatic cases (P < 0.05). No other significant correlations were found. In India WS is often diagnosed late because of lack of awareness. Adverse perinatal events are important etiological factors. Non-affordability of ACTH and Vigabatrin prompts the use of prednisolone in most cases.