Seizure disorders: functional MR imaging for diagnostic evaluation and surgical treatment--prospective study.
OBJECTIVE
To prospectively evaluate effect of functional magnetic resonance (MR) imaging on diagnostic work-up and treatment planning in patients with seizure disorders who are candidates for surgical treatment.


METHODS
Institutional review board approval was obtained; informed consent was obtained either from the patient or the parent or guardian in all patients. This study was conducted with Health Insurance Portability and Accountability Act compliance. Sixty consecutively enrolled patients (33 males, 27 females; mean age, 15.8 years +/- 8.7 [standard deviation]; range, 6.8-44.2 years) were prospectively examined. Forty-five (75%) patients were right handed, nine (15%) were left handed, and six (10%) had indeterminate hand dominance. Prospective questionnaires were used to evaluate diagnostic work-up, counseling, and treatment plans of the seizure team before and after functional MR imaging. Confidence level scales were used to determine effect of functional MR imaging on diagnostic and therapeutic thinking. Paired t test and 95% confidence interval analyses were performed.


RESULTS
In 53 patients, language mapping was performed; in 33, motor mapping; and in seven, visual mapping. The study revealed change in anatomic location or lateralization of language-receptive (Wernicke) (28% of patients) and language-expressive (Broca) (21% of patients) areas. Statistically significant increases were found in confidence levels after functional MR imaging in regard to motor and visual cortical function evaluation. In 35 (58%) of 60 patients, the seizure team thought that functional MR imaging results altered patient and family counseling. In 38 (63%) of 60 patients, functional MR imaging results helped to avoid further studies, including Wada test. In 31 (52%) and 25 (42%) of 60 patients, intraoperative mapping and surgical plans, respectively, were altered because of functional MR imaging results. In five (8%) patients, two-stage surgery with extra-operative direct electrical stimulation mapping was averted, and resection was accomplished in one stage. In four (7%) patients, extent of surgical resection was altered because eloquent areas were identified close to seizure focus.


CONCLUSIONS
Functional MR imaging results influenced diagnostic and therapeutic decision making of the seizure team; results indicated language dominance changed, confidence level in identification of critical brain function areas increased, patient and family counseling were altered, and intraoperative mapping and surgical approach were altered.
Department of Radiology, Health Outcomes, Policy and Economics Center, Brain Institute, Miami Children's Hospital, 3100 SW 62 Ave, Miami, FL 33155, USA. smedina@post.harvard.edu
L Santiago
LS
Medina
Byron
B
Bernal
Catalina
C
Dunoyer
Luisa
L
Cervantes
Marelis
M
Rodriguez
Esperanza
E
Pacheco
Prasanna
P
Jayakar
Glenn
G
Morrison
John
J
Ragheb
Nolan R
NR
Altman
D000293:Adolescent; D000328:Adult; D002648:Child; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010347:Patient Care Planning; D011446:Prospective Studies; D011795:Surveys and Questionnaires