Improving Detection of Underlying Neurologic Etiology for Pediatric Cavovarus Foot Deformity: We Can Do Better
Michelle Christie1, Rusty Hartman3, Jacob Zide2, Michael O’Sullivan2, Anthony Riccio2
1Neurology, 2Orthopedics, Scottish Rite for Children, 3Scottish Rite for Children
Objective:
Assess the diagnostic yield of MRI and EMG/NCS verses genetic testing in pediatric cavovarus foot deformity.
Background:
Neurologic evaluation of cavovarus foot deformity (CVD) is necessary however no standardized method of assessment exists and the yield of diagnostic measures remains unstudied. We compare the yield of traditional methods of assessment of pediatric CVD versus more advanced diagnostics.
Design/Methods:
An IRB-approved retrospective review of patients for bilateral or unilateral CVD was performed over a 19-year period. Patients with a known etiology were excluded. Neurologic evaluation of all remaining patients was conducted using one of two diagnostic algorithms. The traditional diagnostic algorithm (TDA) consisted of clinical examination, MRI of the brain and spinal cord and/or EMG/NCV. The advanced diagnostic algorithm (ADA) included all components of the TDA in addition to genetic testing, and/or muscle/nerve biopsy and/or repeat EMG/NCV testing. These diagnostic algorithms were compared.
Results:
108 patients (average age 9.7 years) were included. 96 patients were assessed via the TDA detecting a diagnosis in 56 (58%). 15 had central neurologic disease, 35 had peripheral neuropathies and 6 had combined central and peripheral neuropathology. 40 patients remained undiagnosed using the TDA, 21 were further assessed using the ADA which revealed a diagnosis in 15 (71%), thereby increasing the diagnostic yield to 71/77 patients (92%) when the ADA was incorporated, 71/96 (74%) overall. 23 of the 41 patients (56%) diagnosed with polyneuropathy by TDA received a more specific diagnosis when TDA was combined with ADA. Definitive diagnosis was achieved solely by genetic testing without utilization of the TDA in 12 patients, 75% of whom had variants of Charcot-Marie-Tooth disease.
Conclusions:
Etiology remains undetected in 42% of children with CVD using solely neuroaxis imaging and electrodiagnostic testing. The cause for deformity can be increased by over 30% through the incorporation of genetic testing and other components of the ADA.