Acute paraparesis as consequence of lumbar bending in achondroplasia

Abstract

Achondroplasia is a bone growth disorder, with an estimated prevalence of 0.36–0.60 per 10,000 live births, caused by impaired endochondral bone formation which leads to disproportionate short stature [1]. The clinical features, such as small arms and legs, stumpy fingers, macrocephaly with protruding jaw, frontal bossing and mid-face hypoplasia, may play a role in delaying the development of gross motor skills during the first years of life in achondroplastic patients, although no cognitive impairment is usually evident. No treatment is currently available. Short interpedicular distance at L1 or conus level, hypertrophy of ligamentum flavum, spondyloarthrosis and vertebral instability at the thoraco-lumbar level represent at-risk conditions for developing paraparesis in achondroplastic patients [2]. Since neurological involvement often occurs progressively, as a consequence of skeletal abnormalities, careful clinical monitoring may prevent functional impairment and lead to surgery when appropriate [3]. Major spinal traumas should be cautiously avoided by patients, however, as these traumas can abruptly precipitate their neurological conditions [4]. To date, no author had reported the occurrence of a severe neurological deficit in an adult achondroplastic patient caused by an ordinary trunk movement performed during daily activity. Here, we describe the case of an achondroplastic man who suddenly developed marked flaccid paraparesis after a simple thoraco-lumbar flexion.