Neuroleptic malignant syndrome-like state in a patient with Down syndrome and basal ganglia calcification

Acute Movement Disorders in Childhood

Acute-onset movement disorders (MDs) are an increasingly recognized neurological emergency in both adults and children. The spectrum of possible causes is wide, and diagnostic work-up is challenging. In their acute presentation, MDs may represent the prominent symptom or an important diagnostic clue in a broader constellation of neurological and extraneurological signs. The diagnostic approach relies on the definition of the overall clinical syndrome and on the recognition of the prominent MD phenomenology. The recognition of the underlying disorder is crucial since many causes are treatable. In this review, we summarize common and uncommon causes of acute-onset movement disorders, focusing on clinical presentation and appropriate diagnostic investigations. Both acquired (immune-mediated, infectious, vascular, toxic, metabolic) and genetic disorders causing acute MDs are reviewed, in order to provide a useful clinician’s guide to this expanding field of pediatric neurology.

Movement disorder emergencies in childhood

The literature on paediatric acute-onset movement disorders is scattered. In a prospective cohort of 52 children (21 male; age range 2mo-15y), the commonest were chorea, dystonia, tremor, myoclonus, and Parkinsonism in descending order of frequency. In this series of mainly previously well children with cryptogenic acute movement disorders, three groups were recognised: (1) Psychogenic disorders (n = 12), typically >10 years of age, more likely to be female and to have tremor and myoclonus (2) Inflammatory or autoimmune disorders (n = 22), including N-methyl-d-aspartate receptor encephalitis, opsoclonus-myoclonus, Sydenham chorea, systemic lupus erythematosus, acute necrotizing encephalopathy (which may be autosomal dominant), and other encephalitides and (3) Non-inflammatory disorders (n = 18), including drug-induced movement disorder, post-pump chorea, metabolic, e.g. glutaric aciduria, and vascular disease, e.g. moyamoya. Other important non-inflammatory movement disorders, typically seen in symptomatic children with underlying aetiologies such as trauma, severe cerebral palsy, epileptic encephalopathy, Down syndrome and Rett syndrome, include dystonic posturing secondary to gastro-oesophageal reflux (Sandifer syndrome) and Paroxysmal Autonomic Instability with Dystonia (PAID) or autonomic 'storming'. Status dystonicus may present in children with known extrapyramidal disorders, such as cerebral palsy or during changes in management e.g. introduction or withdrawal of neuroleptic drugs or failure of intrathecal baclofen infusion; the main risk in terms of mortality is renal failure from rhabdomyolysis. Although the evidence base is weak, as many of the inflammatory/autoimmune conditions are treatable with steroids, immunoglobulin, plasmapheresis, or cyclophosphamide, it is important to make an early diagnosis where possible. Outcome in survivors is variable. Using illustrative case histories, this review draws attention to the practical difficulties in diagnosis and management of this important group of patients.

Mineralization of the basal ganglia: implications for neuropsychiatry, pathology and neuroimaging

This article examines the evidence for and against the existence of basal ganglia mineralization as a defined clinico-pathological entity. In reviewing the literature on basal ganglia mineralization, this article emphasizes evidence derived from different neuroimaging modalities, genetics, metabolic studies, postmortem series and their possible neuropsychiatric correlates. Relevant articles were collected through Medline and Index Medicus searches. Researchers have encountered multiple difficulties in accepting basal ganglia mineralization as a distinct entity. This syndrome lacks set clinical criteria or a unique etiology; not surprisingly, numerous articles have applied varied definitions. Because many of the reported cases have not been examined postmortem, both the extent and nature of their mineralization remains uncertain. Furthermore, researchers have considered small foci of basal ganglia mineralization a normal phenomenon of aging. However, when brain deposits are extensive, they are associated with a set of age-dependent, progressive clinical symptoms. They include cognitive impairment, extrapyramidal symptoms and psychosis. Most cases are related to abnormalities of calcium metabolism, but rare familial cases of idiopathic origin have been reported. Overabundant mineralization of the brain is judged pathological based on its amount, distribution and accompanying clinical symptoms. Although its relation with calcium dysregulation is well known, modern studies have emphasized abnormalities of iron and dopamine metabolism. The authors suggest that these metabolic abnormalities may link basal ganglia mineralization to psychotic symptomatology.

Rhabdomyolysis due to hereditary torsion dystonia

Following an acute dystonic crisis, a 6-year-old boy with hereditary torsion dystonia developed rhabdomyolysis. To our knowledge, hereditary torsion dystonia has never been reported as a cause of rhabdomyolysis. Early diagnosis and treatment of rhabdomyolysis should be considered in children with severe dystonia in order to prevent renal failure.