Utility of subtraction ictal SPECT images in detecting focal leading activity and understanding the pathophysiology of spasms in patients with West syndrome.
OBJECTIVE
The aims of the study were to evaluate the detectability of focal leading activity in three cases of West syndrome having focal abnormal activity on EEG by comparing subtraction ictal images and raw ictal images, and to interpret the results in 16 cases.


METHODS
Subtraction images were constructed using iNeurostat (revision 2).


RESULTS
In three cases with focal abnormal activity on EEG, subtraction ictal images reflected the EEG findings; in contrast, raw ictal images did not. Diverse degrees of cortical hyperperfusion, ranging from zero to 10 sites, seen in the other 13 cases seemed to reflect spasm pathophysiology and rapid spasm propagation. Subtraction ictal images also allowed the ready detection of hyperperfusion of subcortical structures and of a tight cortico-subcortical relationship in a subset of cases.


CONCLUSIONS
We showed the superiority of subtraction ictal images in detecting the focal epileptic region and in showing propagation pathways from the cortex to subcortical structures. A subset of spasms in WS may be focal cortical-onset secondarily generalized seizures. We believe that subtraction analysis is valuable in patients with complex WS who have partial seizures and spasms simultaneously along with focal epileptic EEG activity, as they will likely be candidates for epilepsy surgery.
Kakisaka
Yosuke
Y
Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan.
Haginoya
Kazuhiro
K
Ishitobi
Mamiko
M
Togashi
Noriko
N
Kitamura
Taro
T
Wakusawa
Keisuke
K
Sato
Ikuko
I
Hino-Fukuyo
Naomi
N
Uematsu
Mitsugu
M
Munakata
Mitsutoshi
M
Yokoyama
Hiroyuki
H
Iinuma
Kazuie
K
Kaneta
Tomohiro
T
Higano
Shuichi
S
Tsuchiya
Shigeru
S
D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D013035:Spasm / Q000000981:diagnostic imaging* / Q000209:etiology*; D013036:Spasms, Infantile / Q000150:complications* / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*