Journal of Neurosurgery: Pediatrics
Robert T. Buckley, Tiffany Morgan, Russell P. Saneto, Jason Barber, Richard G. Ellenbogen and Jeffrey G. Ojemann
Functional hemispherectomy is a well-recognized surgical option for the treatment of unihemispheric medically intractable epilepsy. While the resultant motor deficits are a well-known and expected consequence of the procedure, the impact on other cortical functions has been less well defined. As the cortical control of swallowing would appear to be threatened after hemispherectomy, the authors retrospectively studied a pediatric population that underwent functional hemispherectomy for medically intractable epilepsy to characterize the incidence and severity of dysphagia after surgery.
A retrospective cohort (n = 39) of pediatric patients who underwent hemispherectomy at a single institution was identified, and available clinical records were reviewed. Additionally, the authors examined available MR images for integrity of the thalamus and basal ganglia before and after hemispherectomy. Clinical and video fluoroscopic assessments of speech pathology were reviewed, and the presence, type, and duration of pre- and postoperative dysphagia were recorded.
New-onset, transient dysphagia occurred in 26% of patients after hemispherectomy along with worsening of preexisting dysphagia noted in an additional 15%. Clinical symptoms lasted a median of 19 days. Increased duration of symptoms was seen with late (> 14 days postoperative) pharyngeal swallow dysfunction when compared with oral dysphagia alone. Neonatal stroke as a cause for seizures decreased the likelihood of postoperative dysphagia. There was no association with seizure freedom or postoperative hydrocephalus.
New-onset dysphagia is a frequent and clinically significant consequence of hemispherectomy for intractable epilepsy in pediatric patients. This dysphagia was always self-limited except in those patients in whom preexisting dysphagia was noted.
Anthony C. Wang, George M. Ibrahim, Andrew V. Poliakov, Page I. Wang, Aria Fallah, Gary W. Mathern, Robert T. Buckley, Kelly Collins, Alexander G. Weil, Hillary A. Shurtleff, Molly H. Warner, Francisco A. Perez, Dennis W. Shaw, Jason N. Wright, Russell P. Saneto, Edward J. Novotny, Amy Lee, Samuel R. Browd and Jeffrey G. Ojemann
The potential loss of motor function after cerebral hemispherectomy is a common cause of anguish for patients, their families, and their physicians. The deficits these patients face are individually unique, but as a whole they provide a framework to understand the mechanisms underlying cortical reorganization of motor function. This study investigated whether preoperative functional MRI (fMRI) and diffusion tensor imaging (DTI) could predict the postoperative preservation of hand motor function.
Thirteen independent reviewers analyzed sensorimotor fMRI and colored fractional anisotropy (CoFA)–DTI maps in 25 patients undergoing functional hemispherectomy for treatment of intractable seizures. Pre- and postoperative gross hand motor function were categorized and correlated with fMRI and DTI findings, specifically, abnormally located motor activation on fMRI and corticospinal tract atrophy on DTI.
Normal sensorimotor cortical activation on preoperative fMRI was significantly associated with severe decline in postoperative motor function, demonstrating 92.9% sensitivity (95% CI 0.661–0.998) and 100% specificity (95% CI 0.715–1.00). Bilaterally robust, symmetric corticospinal tracts on CoFA-DTI maps were significantly associated with severe postoperative motor decline, demonstrating 85.7% sensitivity (95% CI 0.572–0.982) and 100% specificity (95% CI 0.715–1.00). Interpreting the fMR images, the reviewers achieved a Fleiss’ kappa coefficient (κ) for interrater agreement of κ = 0.69, indicating good agreement (p < 0.01). When interpreting the CoFA-DTI maps, the reviewers achieved κ = 0.64, again indicating good agreement (p < 0.01).
Functional hemispherectomy offers a high potential for seizure freedom without debilitating functional deficits in certain instances. Patients likely to retain preoperative motor function can be identified prior to hemispherectomy, where fMRI or DTI suggests that cortical reorganization of motor function has occurred prior to the operation.