Aim Infantile spasms usually begin in the first year of life and have been attributed to various underlying aetiologies. Aetiology remains unknown in a substantial proportion despite full investigation while variation in outcome remains difficult to explain and the role of environmental factors has received little attention. Cognitive problems often precede the spasms in symptomatic cases but may be progressive. The possibility that nutritional factors play a role in this epilepsy, with its typically encephalopathic onset, has received little attention, although vitamin B12 deficiency without macrocytic anaemia has been reported and iron deficiency is common in febrile convulsions. Low haematocrit may be a risk factor for poor outcome in infants predisposed to developmental disorders. We therefore undertook an audit of our cases.
Method We reviewed the available haematology for cases of infantile spasms with hypsarrthmia on electroencephalography over a 5 year period (2005-2010). Haemoglobin, Haematocrit and Mean Cell Volume (MCV) were compared to age specific values by calculating the standard deviation (Z) score.
Results Red cell indices were available from 7 of 15 children with infantile spasms. Five had red cell indices consistent with iron deficiency anaemia at presentation with z scores for Haemoglobin, Haematocrit and MCV less than 2 standard deviations below the age specific mean. Serum ferritin was available in 3 with values of 18, 24 and 34 μg/L, with the lower limit of normal for our laboratory being 18 μg/L.
Discussion Iron deficiency, anaemia or hypoxia may alter the expression of epilepsy genes. Iron deficiency may facilitate the development of secondary bilateral synchrony in a child with a focal epileptogenic lesion, perhaps in the context of associated hypoxaemia or other systemic effects. Another possible aetiological link is cerebral venous sinus thrombosis, for which West's syndrome is an outcome and which is associated with iron deficiency anaemia. In addition to the well-recognised global cognitive problems common to both, the lack of social interaction reported in children with infantile spasms is also a feature of iron deficiency. Prospective studies should include full assessment of iron status, e.g. transferrin saturation, as measurement of ferritin may be falsely high if there is inflammation.