Abstracts

Rationale: fMRI is useful for identifying eloquent cortex including in epilepsy patients prior to surgical intervention. Most fMRI clinical work has been done in adults. Children down to 8 or 9 years have been included in larger clinical series, with younger cases being rarely reported (Gaillard et al 07; Hertz-Pannier et al 02; Kesavada et al 07; Stapleton et al 97). No fMRI study to date focuses on epileptic children 8 years and below or on language fMRI with cases under 6 years of functional age. We sought to validate previously published fMRI in children 8 years and below and report the youngest chronological and developmental clinical series of motor and language fMRI. Methods: We reviewed pre-surgical fMRI scans in eight patients age 8 years or less, with six being 5 and 6 years. Each patient had undergone neuropsychological testing. Three patients functioned below average, with adaptive functioning age scores being 3 to 4 years. 5 patients did self-paced finger tapping of thumb and fingers alternating with the opposite side. A 6th child tapped with the contralateral side only. A 7th participated intermittently with the relevant digits, with the mother moving them; the child kept the other hand still throughout. The 8th was not given this task. 4 of 8 patients silently generated verbs in response to pictures and/or words alternating with a fixation cross contrast. We modify this task with younger children, using the same (not novel) stimuli for extensive practice ahead of time and for use in the scanner. Subject preparation involved techniques previously published, including having experienced staff work with patients and providing external stimulation in the scanner. 6 of 8 patients had extensive training/practice prior to the procedure. In the 2 youngest patients, this training included use of a mock scanner. Scanning was performed in a 3T Siemens Trio. Data analysis with Siemen's commercial software generated maps of t-statistics for active versus control. Results: All cases yielded successful imaging. Tapping in all 7 patients demonstrated focal motor activation in the frontal-parietal region with expected activation elsewhere including in the cerebellum. 3 of 4 patients had expected verb generation task activations, with left hemisphere dominance. Case 3 was not only 6 years of age, but functioned at the 3-year-9-month level. Case 8, an above-average IQ 8-year-old, was the only one not prepared prior to the verb scanning session and failed this task due to movement artifact. Conclusions: Despite the challenges of successfully using fMRI in very young and clinically involved patients, we successfully performed pre-operative fMRI on chronologically younger (5 or 6 years) and developmentally younger (3 to 4 years) patients, using a variety of preparation and cooperation-enhancing strategies. A role for fMRI in these younger patients need not be rejected out of hand. Kesavadas et al, Ped Rad 2007;37:964. Stapleton et al, Ped Neurosurg 1997;26:68. Gaillard et al, Neurol 2007;69:1761. Hertz-Pannier et al, Brain 2002;125:361.