Use of intrathecal baclofen in children and adolescents: interdisciplinary consensus table 2013.

In recent years, intrathecal baclofen (ITB) has attained an important role in the treatment of severe spasticity and dystonia in children. There are principal differences between the use of ITB in children and its use in neurology and oncology in adults. Here, we present a consensus report on best practice for the treatment of severe spastic and dystonic movement disorders with ITB. Using a problem-orientated approach to integrate theories and methods, the consensus was developed by an interdisciplinary group of experienced ITB users and experts in the field of movement disorders involving 14 German centers. On the basis of the data pooled from more than 400 patients, the authors have summarized their experience and supporting evidence in tabular form to provide a concise, but still a comprehensive information base that represents our current understanding regarding ITB treatment options in children and adolescents.

Muscle atrophy beyond the clinical effect after a single dose of OnabotulinumtoxinA injected in the procerus muscle: a study with magnetic resonance imaging.

BACKGROUND: Botulinum toxin is a powerful and often used agent to treat dynamic rhytides. Focal and reversible neurogenic atrophy is considered to be the relevant mechanism of action. OBJECTIVE: To investigate the loss and regain of muscular volume in relation to clinical wrinkle severity as assessed using standardized scales. METHODS: The facial procerus and corrugator supercilii muscles were injected in two drug-naïve men with 20 U of onabotulinumtoxinA at five injection points (onA). Two men served as controls (one with the same volume of placebo injection using saline solution, one without any intervention). All subjects underwent 3 Tesla magnetic resonance imaging before and after the injection and 1, 4, 6, 10, and 12 months after the injection. Standardized photographs were taken at each test point. RESULTS: Volumetric muscle analysis revealed a 46% to 48% reduction in procerus muscle volume lasting for 12 months after a single dose of onA; glabellar line severity returned to the drug-naïve status after 6 to 10 months. CONCLUSION: The gap between long-term focal muscular atrophy and regained function remains to be elucidated. Future studies will be needed to investigate the complex interaction between focal neurogenic atrophy and potential compensatory functional muscle changes.

Seizures and stupor during intravenous mannose therapy in a patient with CDG syndrome type 1b (MPI-CDG).

MPI-CDG (formally called CDG 1b), caused by phosphomannose isomerase (MPI) deficiency, leads to hypoglycaemia, protein losing enteropathy, hepatopathy, and thrombotic events, whereas neurologic development remains unaffected. Dietary supplementation of mannose can reverse clinical symptoms by entering the N-glycosylation pathway downstream of MPI. When oral intake of mannose in patients with MPI-CDG is not possible, e.g. due to surgery, mannose has to be given intravenously. We report a patient with MPI-CDG on intravenous mannose therapy that showed severe depression of consciousness and seizures without apparent cause. EEG and cranial MRI findings were compatible with metabolic coma whereas extended laboratory examinations including repeated blood glucose measurements were normal. Importantly, an intravenous bolus of glucose immediately led to clinical recovery and EEG improvement. Mannose did not interfere with glucose measurement in our assay. We suggest that in patients with MPI-CDG, intravenous mannose infusion can lead to intracellular ATP deprivation due to several mechanisms: (1) in MPI deficiency, mannose 6-P cannot be isomerised to fructose 6-P and therefore is unavailable for glycolysis; (2) animal data has shown that accumulating intracellular mannose 6-P inhibits glycolysis; and (3) elevated intracellular mannose 6-P may induce an ATP wasting cycle of dephosphorylation and rephosphorylation ("honey bee effect"). The mannose-induced metabolic inhibition may be overcome by high-dose glucose treatment. We caution that, in patients with MPI-CDG, life-threatening central nervous system disturbances may occur with intravenous mannose treatment. These may be due to intracellular energy failure. Clinical symptoms of energy deficiency should be treated early and aggressively with intravenous glucose regardless of blood glucose levels.

Muscle biopsy substantiates long-term MRI alterations one year after a single dose of botulinum toxin injected into the lateral gastrocnemius muscle of healthy volunteers.

Despite numerous clinical and experimental studies on botulinum toxin type A (BoNT/A), long-term alterations of muscle texture and fine structure following BoNT/A treatment have thus far not been studied in normal human skeletal muscle. After obtaining institutional review board approval, we performed a prospective, placebo-controlled, double-blinded follow-up study on two healthy adults using magnetic resonance imaging (MRI) and muscle biopsy to visualize long-term alterations after a single BoNT/A injection into the lateral head of the gastrocnemius muscle. MRI disclosed a high-signal-intensity pattern in short tau inversion recovery sequences, and a reduction of the cross-sectional area in the BoNT/A-injected, but not in the saline-injected contralateral control muscle (at 6 to 9 months in volunteer A: 73%, in B: 62%; at 12 months in A: 88%, and in B: 78%). Enzyme histochemistry, 12 months after injection, confirmed neurogenic atrophy of muscle fibers only in the BoNT/A-injected muscle. Electron microscopy revealed additional degenerative changes at the neuromuscular junction. The data confirm that MRI is a suitable tool to monitor the long-term effect of BoNT/A on skeletal muscle. Neurogenic muscle atrophy following a single BoNT/A injection should be taken into consideration when repeated BoNT/A injections into the same muscles are proposed.