Pontine activation during focal status epilepticus secondary to hamartoma of the floor of the fourth ventricle.
Epileptic seizures associated with hamartoma of the floor of the fourth ventricle (HFFV) are generally resistant to antiepileptic medication, may evolve into status epilepticus, and can respond favorably to surgical therapy. HFFV are rare, and during the neonatal or infantile period may be associated with repetitive and stereotyped attacks of hemifacial spasm, eye blinking, facial movements, head deviation and dysautonomic manifestations. Similarly, to gelastic seizures provoked by hypothalamic hamartomas, it has been suggested that these spells arise from within the HFFV, thus constituting a type of non-cortical seizure. We report an infant female patient that developed continuous left hemifacial attacks since she was 2-month-old, and that underwent presurgical investigation when she was 18-month-old. MRI disclosed a left sided HFFV, Video-EEG showed non-localizing and non-lateralizing findings, and SPECT aligned with MRI showed marked hyperperfusion within the hamartoma, spreading to ipsilateral cerebellar parenchyma and brainstem nuclei. Patient underwent lesionectomy and became seizure-free. We found two evidences on literature supporting the hypothesis of non-cortical seizures related to HFFV. The first, intra-cerebellar recordings surrounding hamartoma showed electrical activity related to seizures. The second, subtracted SPECT co-registered MRI showed hyperemia within hamartoma. The present report provides the third additional evidence. We found the involvement not only of the hamartoma, and pars of cerebellar hemisphere, but also an intense hyperemia involving brainstem nuclei during seizures. We believe that all these findings suggest a short subcortical network responsible for generating seizures in HFFV patients.
Pontes-Neto
Octávio M
OM
Department of Neurology (Epilepsy Surgery Center), Ribeirão Preto School of Medicine, University of São Paulo (USP), Ribeirão Preto, Brazil.
Wichert-Ana
Lauro
L
Terra-Bustamante
Vera C
VC
Velasco
Tonicarlo R
TR
Bustamante
Guilherme O
GO
Fernandes
Regina M F
RM
Azevedo-Marques
Paulo M
PM
Oliveira
Lucas F
LF
Santos
Antonio C
AC
Kato
Mery
M
Inuzuka
Luciana M
LM
Machado
Hélio R
HR
Sakamoto
Américo C
AC
D004828:Epilepsies, Partial / Q000473:pathology*; D005260:Female; D020546:Fourth Ventricle / Q000473:pathology*; D006222:Hamartoma / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D013226:Status Epilepticus / Q000209:etiology*; D015899:Tomography, Emission-Computed, Single-Photon