Bilateral subthalamic nucleus deep brain stimulation for refractory total body dystonia secondary to metabolic autopallidotomy in a 4-year-old boy with infantile methylmalonic acidemia

Abstract

<jats:p>The methylmalonic acidemias (MMAs) are a group of inborn errors of metabolism resulting in the accumulation of methylmalonic acid in body tissues and fluids. A recognized complication of MMA is bilateral liquefaction of the globus pallidi, resulting in a fulminant total body dystonia of childhood often refractory to medical treatment. This case of total body dystonia due to MMA in a 4-year-old boy had been medically refractory for 15 months. Complete metabolic destructive liquefaction of the pallidi, that is, autopallidotomy, necessitated an alternative, bilateral subthalamic nucleus (STN) target for deep brain stimulation (DBS) with a marked improvement in dystonia and reduction in pain. The case illustrates the efficacy of STN DBS in this condition and the technical challenges in targeting the STN in a small child.</jats:p>

Complications of Deep Brain Stimulation (DBS) for dystonia in children – The challenges and 10 year experience in a large paediatric cohort

“…Two patients with hemidystonia had unilateral implants (first -unilateral GPI and thalamus, second -unilateral GPI). Three patients had electrodes implanted in subthalamic nucleus (STN) bilaterally due to severe damage of globus pallidus, we reported previously early outcome of STN DBS in the first of these patients 16 . There were two patients with two pairs of electrodes in GPIs, one with additional pair implanted at revision and another with four electrodes implanted at initial procedure.…”

Status dystonicus: a practice guide

“…Further challenges exist with urgent DBS surgery in children compared with adults, as a result of anatomical and developmental factors (although it has been used in a child as young as 5 years with status dystonicus) . Where the globus pallidus interna was not an option (because of damage), the subthalamic nucleus may be targeted, as recently seen in a 4‐year‐old with severe methylmalonic acidaemia and refractory dystonia . Thus, evaluation for DBS must be considered on an individual basis.…”

Methylmalonic Aciduria: A Treatable Disorder of Which Adult Neurologists Need to Be Aware

“…Some cases respond to treatment with oral vitamin B12 and L‐carnitine supplementation and a low‐protein diet (in our patient, clinical improvement was accompanied by a drop in urinary methylmalonic acid level to 84 μmol/mmol of creatinine. Other treatments that have been reported with success in a small number of patients include liver or combined liver‐kidney transplantation and DBS surgery …”