Multiple epiphyseal dysplasia as differenzial diagnosis in patients with L-Dopa responsive dystonia

Introduction: L-dopa-responsive dystonia (DRD) is an autosomal-dominant inherited movement disorder, which is characterized by heterogeneous, age-dependent symptoms, including gait disturbance, progressive dystonia and parkinsonian features. Diurnal variation is frequent. Confirmation of diagnosis is difficult, differenzial diagnoses are divers. On the basis of a clinical case we show the significance of multiple epiphyseal dysplasia (MED) as a differenzial diagnosis in patients with L-dopa-responsive dystonia.

Case description: We describe a 4-year old boy with intermitted exercise-dependent, partly painful gait disorder since his early childhood. Apart from the partly limping walking difficulties he showed an adequate age-based development. Early orthopaedic and radiologic assessment revealed no abnormalities. At the age of 3 years due to slightly pathological neurotransmitter analysis, an L-dopa-responsive dystonia was diagnosed. Treatment with L-dopa (±3mg/kg/d) was started. Despite an initial bettering, no long-term improvement was observed. By determination of GTPCH enzyme activity, which showed a normal result, a DRD could be excluded. Clinical and radiological reassessment revealed the suspected diagnosis of multiple epiphyseal dysplasia. Diagnosis was confirmed by a heterozygous mutation in the COMP-gene.

Conclusion: Movement disorders, in particular gait disorders are frequent in infants. Multiple epiphyseal dysplasia is one of the most common skeletal dysplasia. In patients with painful, exercise-dependent gait disorders especially in combination with short stature multiple epiphyseal dysplasia should be considered as differenzial diagnosis.