Abstracts

Rationale: Data on motor, language, and behavior outcome of children after hemispherectomy is limited to small series with short follow up. We studied the long term functional and longitudinal seizure outcome in a large cohort of hemispherectomy patients from a single center.Methods: 187 children who had hemispherectomy (Jan 1997 - May 2009) at the Cleveland Clinic Foundation were studied. Using a structured questionnaire (17 questions), we contacted families by phone or mail to obtain data on seizure and functional status such as ambulation, visual symptoms, spoken language, reading, schooling and behavior. Questionnaire was drafted to assess function meaningful to the activities of daily life. Medical records were reviewed for pre-operative data. Kaplan-Meier statistics was used to estimate longitudinal seizure outcome. Categorical variables were analyzed with Chi-square test. Results: Of 187 children (110 males), 104 had right hemispherectomy. Median age for seizure onset was 8 months (1 day-14 yrs) and for surgery was 5 yrs (2 months-18 yrs). At a median follow up of 4.8 yrs (mean 5.3 + 3.3 yrs), 112 of 184 children (61%) were seizure free; additional 13 (7%) had questionable minor spells without habitual pre-operative seizures. 59 (32%) had seizure recurrence, 8 being seizure for 1 year and 16 had >90% reduction in seizures. Overall 149 children (81%) were either seizure free or had major improvement after surgery. On survival analysis, the estimated probability of seizure freedom was 76% at 1 yr, 64% at 3 yrs, 61% at 5 yrs, and stabilized at 56% at 6 years and beyond. Prior hemispheric surgery (n-29, p-0.001), bilateral PET changes (n-23, p- 0.003), presence of generalized seizures (n-67, p-<0.05), and bilateral motor deficits (n-8, p- <0.05) correlated with poor seizure outcome. Etiology and bilateral MRI abnormalities (n-64, 34%) did not influence the seizure outcome. Functional outcome using questionnaire was obtained in 124 children. 102 (83%) patients ambulated independently, 10 walked with assistance and 11 were unable to walk. 31 (25%) patients reported new visual symptoms. Significant behavior issues often requiring constant supervision was reported in 34 (27%), modest behavior issues not affecting social life outside home environment in 23 (19%) and 67 (54%) reported minor or no behavioral problems. 37 (40%) patients had severe spoken language deficits, 42 (34%) had language skills below age level, while 45 (36%) reported no speech issues. 65 (57%) had poor or no reading skills, 31 (27%) read significantly below their age level, and 18 (16%) had age appropriate reading skills. Of 88 children, 64 (73%) were in mainstream school with special services. Only, 6/26 (23%) adults were gainfully employed. Conclusions: The long-term seizure freedom rate following hemispherectomy was 61% at 5 years. After hemispherectomy, functional deficits in spoken language, reading skills, and behavior were more disabling over long term than ambulation and visual deficits. The findings of our study will assist in counseling families prior to hemispherectomy.