The neurological complications of achondroplasia

The genetics of achondroplasia are discussed, and then the clinical feature s. The respiratory complications are only considered when related to the ne urological ones which are the concern of this paper; and their effects on m orbidity and mortality. Cervicomedullary compression can cause pain, ataxia , incontinence, apnea, and respiratory arrest. One of the signs can be prog ressive quadriparesis which can be a presenting symptom; and may be caused by a vascular lesion as well as by cord compression. Also nerve root compre ssion in the neural foramina can cause symptoms and signs in the limbs. Enl argement of the head is a feature of achondroplasia. This may be due to sub dural haematoma related to the wide subarachnoid spaces, and to trauma. Hyd rocephalus is common, and may be non-communicating and due to aqueduct sten osis, but is much more often communicating and the result of raised intracr anial venous pressure. Shunting may be necessary, but surgery directed towa rds relieving the venous pressure may be more logical. Otitis media often a ffects these children, and can cause deafness and subsequently delayed lang uage development. Sleep disturbances can be the result of both neurological and respiratory complications. Apart from the treatment for hydrocephalus the most important decision is often the question of operating on the cervi cal medullary compression. Risk factors such as brisk reflexes, small foram en magnum, and central hypopnea, can be an indication for surgery; but timi ng can be difficult as the cord compression can resolve spontaneously. The intelligence levels of these children are usually normal, and studies have shown a surprisingly high level of satisfaction with the services provided. (C) 2000 Elsevier Science B.V. All rights reserved.