[Cervical myelopathy in a newborn with achondroplasia]

Patients with achondroplasia have an increased risk of apnoea due to cervical myelopathy. The indication for operative decompression can not be made by MRI alone, because signal alteration and osseous compression of the cervico-medullary region without functional relevance are frequent in this disease.

We report on a male new-born with achondroplasia who displayed apnoeas from the first day of life. Two times, mask ventilation had to be performed. After exclusion of other diseases potentially causing apnoeas, an MRI of the skull and cervical spine revealed cervico-medullary compression due to foramen magnum stenosis, but no signal alterations of brain stem and cervical mark. Recording of somato-sensory evoked potentials (SSEP) of the median nerve showed normal potentials at Erb's point. By contrast, cortical potentials were distinctly abnormal during left-sided stimulation and could not be recorded during right-sided stimulation. Based on these findings, operative decompression of the craniocervical region was performed which led immediately to complete remission of clinical symptoms. At follow-up, MRI revealed a normal width of the foramen magnum and SSEP were markedly improved.

In newborns with Achondroplasia, SSEP can confirm the functional relevance of osseous compression of the cervico-medullary region, and facilitate the decision for operative decompression.