Blog #31: Removal of Half of the Brain to Treat Epilepsy

(This blog was originally posted on February 6, 2013)

 

In 1938, K. G. McKenzie performed the first hemispherectomy, i.e., removal of one of the brain’s two cerebral hemispheres, in a young child to treat intractable, uncontrollable epilepsy that emanated from that abnormal half of the brain (1). Hemispherectomy is generally performed in infants or in very young children. This is because young brains are more capable than are adult brains of transferring functions of the damaged part to other parts of the brain.      

Children are sometimes born with severe damage to one of the two cerebral hemispheres. This can occur, for example, because of abnormal circulation in that hemisphere (known as a stroke-in-utero, which is a common cause of cerebral palsy), infections and maldevelopment. However, it is possible that some of these children still possess good intelligence with minimal weakness.

Removal of a cerebral hemisphere that harbors a focus for intractable seizures can be less daunting than one might think. It is common that the hemisphere already has significant damage that developed before birth or from conditions that developed after birth. Since paralysis and other handicaps are already present, added deficits tend not to be that severe by removing the injured cerebral hemisphere.

Moosa, et. al., studied 170 children with intractable epilepsy aged 18 years or younger who had hemispherectomy between 1997 and 2009 at the Cleveland Clinic’s Neurological Institute in Cleveland, Ohio to treat their uncontrollable epilepsy.  In most of these patients, seizures began before age 2 years. The average age at the time of surgery for these 170 participants was 7 years. There were no deaths due to the operation. One hundred twelve of the 170 (66%) children were seizure-free at the time of average follow-up of approximately 5.3 years. An additional sixteen patients had more than 90% reduction in their seizures. Overall, 80% were seizure-free or had major benefit from hemispherectomy in reducing seizure occurrence. Most who were not helped by this surgery demonstrated the failure by 4-6 months after the operation; seizure frequency was not improved (2).

In conclusion, removing large parts of an already damaged brain can offer hope for cure, or at least improved seizure control, in young children who have intractable epilepsy.

1.)                 McKenzie KG. The present status of a patient who had the right cerebral hemisphere removed. JAMA 1938; 111: 168-183.

2.)                 Moosa ANV, Gupta A, Jehi L, et. al. Longitudinal seizure outcome and prognostic predictors after hemispherectomy in 170 children. Neurology 2013;80:253-260.

 

 

 

 

Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. DINGS is his first novel.