Pathophysiology of Infantile Spasms
- 293 Downloads
The spasms are generalized seizures which consist of brief muscle extension, flexion, or mixed flexion-extension jerks involving the neck, trunk, or extremities.47,49 Lateralizing or localizing clinical features may be present during the spasms.
Infantile spasms can be associated with a wide variety of neurological conditions, including metabolic, dysplastic or dysgenetic abnormalities, and various prenatal, perinatal, and postnatal insults.51 In the symptomatic category, a specific neurological condition can be identified, whereas in the cryptogenic sub-group an underlying condition is suspected based on clinical features, EEG or other tests, but a specific diagnosis cannot be made.
There is a small group (<5%) of infants with spasms, the idiopathic subgroup, which is believed not to be associated with any underlying condition. Neurodevelopment is normal at presentation, and there is a lack of focal features on clinical examination, seizure semiology or EEG. Reappearance of hypsar-rhythmia between consecutive spasms in a cluster is said to be an important feature in this subgroup.34 There is rapid response of the spasms to medical treatment and an ultimately benign course is expected. This rare situation may represent a case in which, during development, there is a chemical or physiological disturbance resulting in spasms, but which can be totally reversed with medical treatment.
With rare exceptions,38 the spasms typically begin between age 3 and 8 months and disappear by age 2 to 3 years. In other words, there appears to be a developmental window during which various brain abnormalities may result in infantile spasms as one manifestation of the underlying disorder.
Although the vast majority of brain lesions that have been identified in patients with infantile spasms involve the cerebral cortex, their locations are not specific to any cortical region.
With some exceptions, the spasms do not appear to respond to conventional anticonvulsants, but rather, to therapeutic agents not typically used in epilepsy, such as corticosteroids. If the spasms respond to such treatment, the response is often abrupt and dramatic rather than graded, as is seen in other forms of epilepsy.
KeywordsPositron Emission Tomography Partial Seizure Infantile Spasm Kynurenic Acid Lenticular Nucleus
Unable to display preview. Download preview PDF.
- 1.Airaksinen, E., Mustonen, K., and Tuomisto, L. ACTH therapy in infantile spasms: Effects on cerebrospinal amino acids, HVA, 5-hydroxyindoleacetic acid, and histamineCleve Clin. J. Med.56 (1989) S-269.Google Scholar
- 10.Chiron, C., Dulac, O., Beaumont, D., Palacios, L., Pajot, N., and Mumford, J. Therapeutic trial of vigabatrin in refractory infantile spasms, JChild Neurol.6 (Suppl. 2) (1991) S52–S59.Google Scholar
- 26.Dalla Bernardina, B., Colamaria, V, and Capoville, G. Epileptic syndromes and cerebral malformations in infancy: multicentric studyBoll Lega Ital. Epil.45/46 (1984) 65–67.Google Scholar
- 31.Dreifuss, F.E. and Santilli, N.Valproic acid hepatic fatalities: Analysis of US casesNeurology, 36 (Suppl. 1) (1986) 175.Google Scholar
- 32.Dulac, O., Chiron, C., Jambaque, I., Plouin, P., and Raynaud, C. Infantile spasmsProgress in Clin. Neurosci.2 (1987) 97–109.Google Scholar
- 34.Dulac, O. and Plouin, P. Cryptogenic/Idiopathic West Syndrome. In: O. Dulac, H.T. Chugani and B.D. Bernardina (Eds.)Infantile Spasms and West SyndromeWB Saunders, London (1994) pp. 232–243.Google Scholar
- 40.Hrachovy, R.A. and Frost, J.D. Jr. Infantile spasms: A disorder of the developing nervous system. In: P. Kellaway and J.L. Noebels (Eds.)Problems and Concepts in Developmental NeurophysiologyJohns Hopkins University Press, Baltimore (1989) pp. 131–147.Google Scholar
- 47.Jeavons, P.M. and Bower, B.D.Infantile spasms: A review of the literature and a study of 112 cases Clinics in Develop. Med. No.15Spastic Society and Heinemann, London (1964).Google Scholar
- 51.Lacy, J.R. and Penry, J.K. Infantile Spasms, Raven Press, New York (1976).Google Scholar
- 57.Menkes, J.Textbook of Child Neurology4th Ed. Lea & Febiger, Philadelphia. London (1990) pp. 31–35.Google Scholar
- 60.Miyazaki, M., Hashimoto, T., Tayama, M., and Kuroda, Y. Brainstem involvement in infantile spasms: a study employing brainstem evoked potentials and magnetic resonance imagingNeuropediatrics24 (1993) 126–130.Google Scholar
- 61.Morimatsu, Y, Murofushi, R., Handa, T., Shinoara, T., and Shiraki, H. Pathological studies of several physically and mentally handicapped-with special reference to four cases of infantile spasmsAdv. Neurot Sei.16 (1972) 465–470.Google Scholar
- 65.Ogata, H., Mitsudome, A., Yokota, K., and Pachibana, H. Three cases of infantile spasms with brain cystic lesionsBrain & Dev.7 (1985) 184.Google Scholar
- 66.Palm, D.G., Brandt, M., and Korinthenberg, R. West syndrome and Lennox-Gastaut syndrome in children with porencephalic cysts: long-term follow-up after neurosurgical treatment. In: E. Niedermeyer and R. Degen (Eds.)The Lennox-Gastaut syndromeAlan R. Liss, New York (1988) pp. 419–426.Google Scholar
- 73.Shewmon, D.A., Shields, WD., Chugani, H.T., and Peacock, W.J. Contrasts between pediatric and adult epilepsy surgery: Rationale and strategy for focal resectionJ. Epilepsy3 (suppl. 1) (1991) 141–155.Google Scholar
- 74.Shewmon, D.A., Shields, W.D., Olson, D.M., Peacock, WJ., and Chugani, H.T. Multifocal independent epileptogenicity in children treated by focal cortical resectionEpilepsia30 (1989) 660.Google Scholar
- 75.Shields, W.D., Shewmon, D.A., Chugani, H.T., and Peacock, W.J. The role of surgery in the treatment of infantile spasmsJ Epilepsy3 (Suppl.) (1990) 321–324.Google Scholar