Cerebral blood flow abnormalities in symptomatic West syndrome: a single photon emission computed tomography study

Infantile spasm (IS) is an age-dependent epileptic encephalopathy of variable etiology. Although IS is well studied, its pathogenesis is unclear. Infantile spasm is usually considered a generalized epilepsy, but recent studies point to focal cerebral blood flow (CBF) abnormalities.

In six symptomatic IS patients, single photon emission computed tomography (SPECT) with [99Tc]-HMPAO, electroencephalography (EEG), magnetic resonance imaging (MRI)/computed tomography (CT) and their correlation were evaluated.

Single photon emission computed tomography showed unifocal (regional) cerebral hypoperfusion in two infants, multifocal (diffuse) cerebral hypoperfusion in three infants and normal perfusion in the other infant. Electroencephalograms obtained in near-time of the SPECT studies showed diffuse abnormalities in five infants with hypoperfusion on SPECT. Cranial MRI/CT showed diffuse and/or localized cerebral lesions in all infants, all of whom had corresponding areas of hypoperfusion on SPECT. In one patient whose spasms were stopped with anticonvulsants, SPECT was normal, in two patients SPECT showed unifocal lesions, while in another three patients whose spasms were decreased but not stopped, SPECT showed multifocal hypoperfusion.

This pilot study may indicate that there are CBF anomalies in symptomatic IS. The degree of CBF may be a predictor of prognosis and multifocal hypoperfusion may be a poor prognostic criteria in IS.