Globus pallidus calcification in Down syndrome with progressive neurologic deficits

Pantothenate kinase-associated neurodegeneration (PKAN) in a child with Down syndrome. A case report and follow-up with MRI

Neurodegeneration with brain iron accumulation (NBIA) is a subtype of inherited metabolic disorders. It includes pantothenate kinase-associated neurodegeneration (PKAN), which is a rare autosomal recessive disorder caused by the mutation of pantothenate kinase 2-gene (PANK2). It affects the deep grey matter nuclei causing progressive extrapyramidal motor impairment.1 We present a case of genetically proven PKAN in a child with mosaic trisomy 21 in which T2- hyperintensity of the basal ganglia was seen followed by the classic eye-of-the-tiger sign in a follow-up MRI.

Genetics and molecular biology of brain calcification

Brain calcification is a common neuroimaging finding in patients with neurological, metabolic, or developmental disorders, mitochondrial diseases, infectious diseases, traumatic or toxic history, as well as in otherwise normal older people. Patients with brain calcification may exhibit movement disorders, seizures, cognitive impairment, and a variety of other neurologic and psychiatric symptoms. Brain calcification may also present as a single, isolated neuroimaging finding. When no specific cause is evident, a genetic etiology should be considered. The aim of the review is to highlight clinical disorders associated with brain calcification and provide summary of current knowledge of diagnosis, genetics, and pathogenesis of brain calcification.

Asymptomatic moyamoya syndrome, atlantoaxial subluxation and basal ganglia calcification in a child with Down syndrome

Down syndrome, the most common chromosomal abnormality, may be associated with various neurologic complications such as moyamoya syndrome, cervical spinal cord compression due to atlantoaxial subluxation, and basal ganglia damage, as well as epileptic seizures and stroke. Many cases of Down syndrome accompanied by isolated neurologic manifestations have been reported in children; however, Down syndrome with multiple neurologic conditions is rare. Here, we have reported a case of Down syndrome in a 10-year-old girl who presented with asymptomatic moyamoya syndrome, atlantoaxial subluxation with spinal cord compression, and basal ganglia calcification. To the best of our knowledge, this is the first report of Down syndrome, in a child, which was accompanied by these 3 neurologic complications simultaneously. As seen in this case, patients with Down syndrome may have neurologic conditions without any obvious neurologic symptoms; hence, patients with Down syndrome should be carefully examined for the presence of neurologic conditions.

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.

New onset focal weakness in children with Down syndrome

New onset focal weakness is relatively common in patients with Down syndrome (DS), and has broad differential diagnosis. Ten cases of new onset focal weakness in patients with DS were encountered or are currently being followed in two DS clinics, with a combined population of patients of approximately 850, for a clinic population prevalence of 1.2%. The median age at presentation was 4 years old (range 1 month-44 years). The causes of new onset focal weakness were: stroke from Moyamoya disease (two patients); stroke from vaso occlusive disease (one patient); stroke from venus sinus thrombosis (one patient); traumatic subdural hematoma (one patient); brain abscess (one patient); spinal cord injury (SCI) from cervical spinal stenosis (two patients); SCI from atlantoaxial instability (AAI) (one patient); and brachial plexus injury (one patient). Of the 10 patients with focal weakness, 8 had potentially treatable conditions, and 5 had surgery. The differential diagnosis of new onset focal weakness in DS is broad, with diseases reported involving all levels of the nervous system from brain to muscle. For some diagnoses, expeditious diagnosis may improve outcome.

Neuropsychiatric disorders, myoclonus, and dystonia in calcification of basal ganglia pathways

Two cases of basal ganglia calcification involving the globus pallidus are presented. Both patients had cognitive dysfunction, temporal lobe-like symptoms (including amnestic state, perceptual distortions, or complex visual hallucinations), and myoclonus. Patient 1 manifested depression, auditory hallucinations, anxiety, paranoia, and postural tremor; patient 2 manifested multifocal dystonia with dystonic tremor. These cases supplement other reports of psychotic features and dementia associated with pallidal pathology. Additionally, the phenomena encountered in these cases are considered in light of recent advances in our understanding of basal ganglia functional pathways. These cases afford a potential pathophysiological window to the possible role of the globus pallidus in these neuropsychiatric conditions. In concert with other recent findings, these cases suggest specific pathway involvement in hallucinations, paranoia, depression, myoclonus, and dystonia. Further research will indicate if these pathways play a role in schizophrenia, mood disorders, and anxiety disorders.

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

We report a case of rhabdomyolysis in a 13-year-old Down syndrome patient with progressive quadriplegia, choreoathetosis and dystonia. Cranial CT demonstrated bilateral basal ganglia calcification. He experienced the sudden onset of high fever, cloudiness of consciousness, muscle rigidity and severe opisthotonus. The diagnosis was made on the basis of the marked increases in serum creatine kinase and myoglobin. There was remarkable elevation of 5-hydroxyindoleacetic acid, homovanillic acid and methoxy-hydroxyphenyl glycol in the cerebrospinal fluid during hyperpyrexia. This case exhibited almost all the diagnostic criteria of the neuroleptic malignant syndrome. It was suggested that abnormalities of monoamines in the central nervous system may be related to the pathologic etiology of this state and rhabdomyolysis.