K. Haginoya et al., The origin of hypsarrhythmia and tonic spasms in West syndrome: evidence from a case of porencephaly and hydrocephalus with focal hypsarrhythmia, BRAIN DEVEL, 21(2), 1999, pp. 129-131
We report on a 3-year-old girl with West syndrome and with focal hypsarrhyt
hmia. The left hemisphere of the patient was virtually completely defective
and continuous hypsarrhythmia was only seen in the residual right frontal
cortex, where an interictal single photon emission computed tomography (SPE
CT) showed hyperperfusion. Despite a focal epileptic pattern, the tonic spa
sms were quite symmetrical. In our patient, spasms might not require the se
nsorimotor cortex, but the brainstem containing the descending pathways tha
t control spinal reflexes and other infratentorial structures seem to be es
sential for the occurrence of spasms. This is in accordance with the result
of an ictal SPECT that showed hyperperfusion of the brainstem and cerebell
um. These findings suggest that hypsarrhythmia originates from cortical les
ions, while subcortical structures may be primarily responsible for the ton
ic spasms in this patient. (C) 1999 Elsevier Science B.V. All rights reserv
ed.