J Neurosurg 73:375-382,1990 Craniocervical decompression for cervicomedullary compression in pediatric patients with achondroplasia JOHN ARYANPUR, M.D., OREST HURKO, M.D., CLAIR FRANCOMANO, M.D., HENRY WANG, M.D., AND BENJAMIN CARSON, M.D. Departments of Neurosurgery, Neurology, Medical Genetics, and Neuroradiology, The Johns Hopkins Medical Institutions, Baltimore, Maryland ~," The congenital osseous abnormalities associated with achondroplasia include stenosis of the foramen magnum and the upper cervical spinal canal, In the pediatric achondroplastic patient, such stenosis may lead to cervicomedullary compression with serious sequelae, including paresis, hypertonia, delayed motor mile- stones, and respiratory compromise. Using a standardized protocol the authors have treated 15 young achondroplastic patients with documented cervicomedullary compression by craniocervical decompression and duroplasty. Following this procedure, significant improvement in presenting neurological or respiratory complaints was noted in all patients. The mortality rate in this series was zero. The major cause of morbidity associated with this procedure was perioperative cerebrospinal fluid (CSF) leakage from the surgical wound, presumably related to coexisting abnormalities of CSF dynamics. This problem was successfully managed by temporary or, when necessary, permanent CSF diversion procedures. It is concluded that craniocervical decompression is an effective and safe treatment for young achondroplastic patients with cervicomedullary compression. KEY WORDS 9 achondroplasia 9 spinal compression 9 craniocervical decompression 9 hydrocephalus children A CHONDROPLASIAis an autosomal-dominant con- dition characterized by dwarfism, macroceph- aly, rhizomelic shortening of the extremities, and other skeletal abnormalities, all resulting from a defect in endochondral bone formation. 16 Neurological dysfunction is frequent in achondroplasia, resulting from compression of the neuraxis at several distinct levels. 4'5"~2'~8"~9 In adult achondroplastic patients, spinal stenosis (due primarily to spondylosis in the setting of a congenitally narrowed spinal canal) has become well recognized and its treatment has been described by others. 4"5'j2'~9"2~ In the pediatric achondroplastic popu- lation, cervicomedullary compression secondary to os- seous and ligamentous abnormalities of the foramen magnum and upper cervical spine has been increasing- ly recognized as a cause of morbidity and mortal- ity.J.6,s,13,17.t8,25 The clinical manifestations of cervicomedullary compression in these patients may be subtle and are often overlooked or mistakenly attributed to coexistent congenital abnormalities. Furthermore, these coexistent malformations often complicate the surgical and anes- thetic management of these patients. For this reason, the diagnosis and treatment of clinically significant cervicomedullary compression in this population are not straightforward. Over the period from 1984 to 1989, 15 pediatric patients with achondroplasia and cervico- medullary compression were treated surgically at our institution. Our experience with the management of this difficult group of patients is presented. Clinical Material and Methods The records of all pediatric patients with heterozy- gous achondroplasia who were admitted to the Johns Hopkins Hospital for clinical evaluation between 1984 and 1989 were reviewed. Of this group of 58 patients, 15 had undergone craniocervical decompression for cervicomedullary compression. Comprehensive chart reviews were performed for these 15 patients. Clinical Evaluation The clinical evaluation protocol used was standard- ized for all patients and has been described previously. ~8 In brief, patients were evaluated by a multidisciplinary team including neurosurgeons, pediatric neurologists, J. Neurosurg. / Volume 73/September, 1990 375