The underlying etiology of infantile spasms (West syndrome): information from the United Kingdom Infantile Spasms Study (UKISS) on contemporary causes and their classification.
OBJECTIVE
To examine the underlying etiology of infantile spasms from the United Kingdom Infantile Spasms Study (UKISS), using the pediatric adaptation of ICD 10.


METHODS
Infants were enrolled in a randomized controlled trial or a parallel epidemiologic study. Etiological information included history, examination, and investigations. The infants were classified as proven etiology, if a neurologic disease was identified; as no identified etiology, if no neurologic disease was identified; and as not fully investigated, if a major piece of information was missing. Proven etiology was subclassified using the pediatric adaptation of ICD 10. The results were then examined to identify further methods of classification.


RESULTS
Of 207 infants, 127 (61%) had proven etiology, 68 (33%) had no identified etiology, and 12 (6%) were not fully investigated. Etiologies were prenatal in 63, perinatal in 38, postnatal in 8, and 18 other. The most common etiologies were: hypoxic-ischemic encephalopathy (HIE) 21 (10%), chromosomal 16 (8%), malformations 16 (8%), stroke 16 (8%), tuberous sclerosis complex (TSC) 15 (7%), and periventricular leukomalacia or hemorrhage 11 (5%). The remaining 32 etiologies were all individually uncommon. Response to treatment is given for individual etiologies.


CONCLUSIONS
Our method of classification allows the reporting of results by individual diseases, disease groups, or categories and is structured and clear. It avoids the use of poorly defined terms such as symptomatic and cryptogenic. It can adapt to new neurologic diseases, such as gene defects, and can be used for comparison of different groups of infants, thereby aiding meta-analysis.
Osborne
John P
JP
The School for Health, University of Bath, Claverton Down, Bath, United Kingdom. mpsjpo@bath.ac.uk
Lux
Andrew L
AL
Edwards
Stuart W
SW
Hancock
Eleanor
E
Johnson
Anthony L
AL
Kennedy
Colin R
CR
Newton
Richard W
RW
Verity
Christopher M
CM
O'Callaghan
Finbar J K
FJ
D005260:Female; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000150:complications / Q000175:diagnosis; D007223:Infant; D007231:Infant, Newborn; D038801:International Classification of Diseases / Q000706:statistics & numerical data; D008297:Male; D015337:Multicenter Studies as Topic; D009422:Nervous System Diseases / Q000145:classification* / Q000150:complications / Q000175:diagnosis*; D009421:Nervous System Malformations / Q000150:complications / Q000175:diagnosis; D011247:Pregnancy; D011296:Prenatal Diagnosis; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D013036:Spasms, Infantile / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D009626:Terminology as Topic; D016896:Treatment Outcome; D014402:Tuberous Sclerosis / Q000150:complications / Q000175:diagnosis; D006113:United Kingdom / Q000453:epidemiology