[1] Univ Med Ctr Hamburg Eppendorf, Dept Neurosurg, Martinistr 52, D-20246 Hamburg, Germany
[2] Univ Med Ctr Hamburg Eppendorf, Int Ctr Lysosomal Disorders ICLD, Hamburg, Germany
[3] Univ Med Ctr Hamburg Eppendorf, Dept Pathol, Hamburg, Germany
[4] Univ Med Ctr Mannheim, Dept Pediat Neurosurg, Mannheim, Germany
[5] Univ Med Ctr Hamburg Eppendorf, Dept Trauma & Orthoped Surg, Div Spine Surg, Hamburg, Germany