title: Early impairment of somatosensory evoked potentials in very young children with achondroplasia with foramen magnum stenosis.
abstract: OBJECTIVE
  To evaluate the contribution of somatosensory evoked potentials after median nerve (MN-SEPs) and posterior tibial nerve (PTN-SEPs) stimulation in functional assessment of cervical and lumbar spinal stenosis in children with achondroplasia.
  
  
  METHODS
  We reviewed MN-SEPs, PTN-SEPs, and spinal magnetic resonance imaging (MRI) examinations performed in 58 patients with achondroplasia (25 males, 33 females; age range 21d-16y 10mo; mean age 4y 3mo [SD 4y 1mo]). Patients were subdivided into four age categories: <2 years, between 2 to 4 years, between 4 to 8 years, and ≥8 years. The peak latency of P37 for PTN-SEPs, the peak latencies of N11, N13, P14, and N20, and the N13-N20 interpeak latency (IPL) for MN-SEPs were collected; the diagnostic accuracy measures of these parameters (analysis of receiver operating characteristic [ROC] curves) with respect to the presence of foramen magnum or lumbar spinal stenosis were analysed in each age category.
  
  
  RESULTS
  The ROC curve analysis showed that the most sensitive parameter in detecting the presence of foramen magnum stenosis was P37 latency in the first two age categories (<2y and ≥2-4y; sensitivity 0.63, specificity 1.00, and sensitivity 1.00, specificity 0.75 respectively). In the third age category (≥4-8y), the most sensitive parameter in detecting the presence of foramen magnum stenosis was IPLs N13-N20 (sensitivity 0.73, specificity 0.87), whereas in the last age category (≥8y), the most important parameter was N20 latency (sensitivity 0.75, specificity 0.77).
  
  
  CONCLUSIONS
  In children with achondroplasia, the cortical component of PTN-SEPs is more sensitive than the cortical component and central conduction time of MN-SEPs in detection of cervical spinal cord compression at early ages.
authors.affiliation: Head-Neck and Neuroscience Department, Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Fornarino
authors.affiliation: Head-Neck and Neuroscience Department, Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Daniela Paola
authors.initials: DP
authors.lastname: Rossi
authors.affiliation: Neuroradiology Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Mariasavina
authors.initials: M
authors.lastname: Severino
authors.affiliation: Epidemiology and Biostatistics Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Pistorio
authors.affiliation: Department of Paediatrics, Istituto Giannina Gaslini, University of Genova, Genova, Italy.
authors.forename: Anna Elsa Maria
authors.initials: AE
authors.lastname: Allegri
authors.affiliation: Head-Neck and Neuroscience Department, Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Martelli
authors.affiliation: Head-Neck and Neuroscience Department, Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Doria Lamba
authors.affiliation: Head-Neck and Neuroscience Department, Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Lanteri
mesh_terms: D000130:Achondroplasia / Q000150:complications* / Q000000981:diagnostic imaging; D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005539:Foramen Magnum / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012372:ROC Curve; D011930:Reaction Time / Q000502:physiology; D013116:Spinal Cord / Q000000981:diagnostic imaging; D013979:Tibial Nerve / Q000503:physiopathology