A therapeutic regimen for 3-hydroxyisobutyryl-CoA hydrolase deficiency with exercise-induced dystonia.

3-Hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency is a recently described disease resulting from mutations in HIBCH with no effective treatment. Here, we report a female Chinese patient presenting with exercise-induced dystonia and bilateral symmetrical hyperintensities of the globus pallidus on brain MRI associated with novel HIBCH mutations (c.1027C>G;p. H343D and c.383T>A;p.V128D). After treatment for 1 year with a low-valine diet, both clinical symptoms and brain lesions improved substantially. We propose that HIBCH deficiency should be considered in the differential diagnosis for patients with exercise-induced dystonia, particularly if bilateral symmetrical lesions in the globus pallidus are present. A low-valine diet is a potentially promising treatment for HIBCH deficiency.

The glucose transporter type 1 (Glut1) syndromes.

The glucose transporter type 1 (Glut1) is the most important energy carrier of the brain across the blood-brain barrier. In the early nineties, the first genetic defect of Glut1 was described and known as the Glut1 deficiency syndrome (Glut1-DS). It is characterized by early infantile seizures, developmental delay, microcephaly, and ataxia. Recently, milder variants have also been described. The clinical picture of Glut1 defects and the understanding of the pathophysiology of this disease have significantly grown. A special form of transient movement disorders, the paroxysmal exertion-induced dyskinesia (PED), absence epilepsies particularly with an early onset absence epilepsy (EOAE) and childhood absence epilepsy (CAE), myoclonic astatic epilepsy (MAE), episodic choreoathetosis and spasticity (CSE), and focal epilepsy can be based on a Glut1 defect. Despite the rarity of these diseases, the Glut1 syndromes are of high clinical interest since a very effective therapy, the ketogenic diet, can improve or reverse symptoms especially if it is started as early as possible. The present article summarizes the clinical features of Glut1 syndromes and discusses the underlying genetic mutations, including the available data on functional tests as well as the genotype-phenotype correlations. This article is part of the Special Issue "Individualized Epilepsy Management: Medicines, Surgery and Beyond".

[Alternating hemiplegia of childhood: ATP1A3 gene analysis in 16 patients]. / Hemiplejía alternante de la infancia: estudio del gen ATP1A3 en 16 pacientes.

BACKGROUND AND OBJECTIVE: Alternating hemiplegia in childhood (AHC) is a disease characterized by recurrent episodes of hemiplegia, tonic or dystonic crisis and abnormal ocular movements. Recently, mutations in the ATP1A3 gene have been identified as the causal mechanism of AHC. The objective is to describe a series of 16 patients with clinical and genetic diagnosis of AHC. PATIENTS AND METHOD: It is a descriptive, retrospective, multicenter study of 16 patients with clinical diagnosis of AHC in whom mutations in ATP1A3 were identified. RESULTS: Six heterozygous, de novo mutations were found in the ATP1A3 gene. The most frequent mutation was G2401A in 8 patients (50%) followed by G2443A in 3 patients (18.75%), G2893A in 2 patients (12.50%) and C2781G, G2893C and C2411T in one patient, respectively (6.25% each). CONCLUSIONS: In the studied population with AHC, de novo mutations were detected in 100% of patients. The most frequent mutations were D801N y la E815K, as reported in other series.

Paroxysmal exercise-induced dyskinesia, writer's cramp, migraine with aura and absence epilepsy in twin brothers with a novel SLC2A1 missense mutation.

We report two monochorionic twins that progressively developed, between ages 5 and 10, a combination of episodic neurological disorders including paroxysmal exercise-induced dyskinesia, migraine without or with aura, absence seizures and writer's cramp. CSF/serum glucose ratio was moderately decreased in both patients. Mutational analysis of SLC2A1 gene identified a de novo heterozygous missense mutation in exon 4. This novel mutation has been previously showed to disrupt glucose transport in vitro. Both patients showed immediate and near-complete response to ketogenic diet. This clinical observation suggests that a high index of suspicion for GLUT1 deficiency syndrome is warranted in evaluating patients with multiple neurological paroxysmal events.

[Neuroradiologic findings of glutaric aciduria type I]. / Hallazgos neurorradiológicos de la Acidosis Glutárica tipo I.

Glutaric aciduria type I is a rare disorder of organic acid metabolism caused by deficiency of glutaryl-CoA dehydrogenase, a mitochondrial enzyme. Improper degeneration of amino acids: tryptophan, lysine, and hydroxylysine, results in increased levels of glutaric acid, which typically becomes clinically manifest as an acute dystonic crisis in young children. Accumulation of glutaric acid causes neurotoxicity in the basal ganglia and fronto-temporal cortex which can lead to progressive dystonia, hypotonia, permanently impaired speech and seizures. Because dietary and drug therapy may alter the natural history of the disease, early diagnosis of such patients is critical. We report the magnetic resonance (MR) imaging findings in a 16 year-old girl with this disorder who presented with a chronic dystonic syndrome and previously diagnosed of brain paralysis. MR imaging demonstrated bilateral involvement of the putamina and periventricular white matter, and bilateral temporal atrophy and widened Silvian fissures.

Cannabinoid agonists in the treatment of blepharospasm--a case report study.

The benign essential blepharospasm is a subliminal form of primary torsion dystonia with still uncertain aetiology. It is characterized by involuntary convulsive muscle contractions of the M. orbicularis occuli, accompanied by unbearable pain of the cornea, eye bulb and the muscle itself. It has been suggested that blepharospasm is neurobiologically based on a dysfunction of the basal ganglia and an impairment of the dopamine neurotransmitter system. Therefore, therapy of blepharospasm contains administration of anticholinergic- and tranquillizing drugs as well as botulinum toxin as neuromuscular blocking agent. However serious side effects can be observed as well as failure of therapy. In the brain a dense co-localisation of cannabinoid (CB1) and dopamine (D2)-receptor was identified which had been associated with the influence of cannabinoids on the dopaminergic reward system. Additionally, it has been demonstrated that cannabinoids may have an impact on the central GABAergic and glutaminergic transmitter system and thus might be involved in the influence of movement control. In the present case we administered the cannabinoid receptor agonist Dronabinol (Delta-9-Tetrahydrocannabinol) to a woman suffering from severe blepharospasm. Multiple treatments with botulinum toxin did not reveal a long-lasting beneficial effect. By contrast, treatment with 25 mg Dronabinol for several weeks improved the patients' social life and attenuated pain perception remarkably. This case study demonstrates that the therapy with a cannabinoid agonist may provide a novel tool in the treatment of blepharospasm and maybe of other multifactorial related movement disorders.