Risk factors for developing brain herniation during diabetic ketoacidosis.

The charts were reviewed of children admitted in diabetic ketoacidosis (DKA) to one hospital within 12 years. The frequency of brain herniation after admission was nine of 153 children admitted for one or more episodes of DKA. The severity of acidosis and hypercapnea were the most reliable risk factors. None of the children who maintained a blood pH greater than 7.1 and a capillary blood partial pressure of carbon dioxide (PCO2) greater than 20 mm Hg manifested brain herniation. The rate of initial fluid administration in severe DKA was also a risk factor. Of 119 patients having a blood pH less than 7.1 or PCO2 less than 20 mm Hg, none of 32 receiving less than 25 mL/kg, one of 42 receiving 25-50 mL/kg, and eight of 40 receiving more than 50 mL/kg of intravenous fluid during the first (in Patient 9, the second) 4 hours of therapy sustained brain herniation. Equally dehydrated unaffected patients initially receiving 25-50 mL/kg/4 hours of intravenous fluid did not develop signs of hypovolemia or worsening DKA. In this series, hydrating at a rate greater than 50 mL/kg during the first 4 hours offered no advantage and was associated with an increased risk of brain herniation.

Cataplexy and monoamine oxidase deficiency in Norrie disease.

Norrie disease (ND) is an X-linked recessive disorder causing ocular atrophy, mental retardation, deafness, and dysmorphic features. Virtually absent monoamine oxidase (MAO) type-A and -B activity has been found in some boys with chromosome deletions. We report the coexistence of cataplexy and abnormal REM sleep organization with ND. Three related boys, referred for treatment of medically refractory atonic spells and apneas, underwent extended EEG-video-polysomnographic monitoring. They demonstrated attacks of cataplexy and inappropriate periods of REM sleep during which they were unarousable. One boy also had generalized tonic-clonic seizures. Previous testing revealed that all three have complete ND gene deletions. In all subjects, platelet MAO-B activity was absent, serum serotonin levels were markedly increased, and plasma catecholamine levels were normal. Data from the canine narcolepsy syndrome model implicate abnormal catecholaminergic and cholinergic activities in the pathogenesis of cataplexy. Our findings suggest that abnormal MAO activity or an imbalance between serotonin and other neurotransmitter levels may be involved in the pathogenesis of human cataplexy.

Mitochondrial DNA deletion in a girl with manifestations of Kearns-Sayre and Lowe syndromes: an example of phenotypic mimicry?

Lowe oculocerebrorenal syndrome is an X-linked recessive disease whose locus has been assigned to Xp25. However, several reports of affected females without obvious chromosomal abnormalities suggest genetic heterogeneity of the Lowe phenotype. Although the biochemical defect in typical Lowe syndrome is not known, there is evidence suggesting that mitochondrial metabolism may be impaired. We have studied a girl who presented with an oculocerebrorenal syndrome, but later developed symptoms and signs of mitochondrial encephalomyopathy. Molecular genetic analysis of muscle mitochondrial DNA showed the presence of a population of partially deleted mtDNAs (heteroplasmy). The deletion was 7803 bp long and encompassed several genes encoding subunits of the respiratory chain enzymes. Our results suggest that mitochondrial DNA deletions may mimic several symptoms of the Lowe phenotype and reinforce the concept that a defect of mitochondrial metabolism could be involved in the pathogenesis of the X-linked disease.

Acute paraparesis secondary to Arnold-Chiari type I malformation and neck hyperflexion.

A 2-year-old child experienced clinical manifestations of Arnold-Chiari Type I malformation, rare in early childhood, after a mild hyperflexion injury of the neck that resulted in acute paraparesis. Recovery occurred after decompressive laminectomy.

Lipomembranous polycystic osteodysplasia (brain, bone, and fat disease): a genetic cause of presenile dementia.

Progressive presenile dementia with lipomembranous polycystic osteodysplasia was first described by Jarvi and Hakola in an isolated region of Finland. We report the occurrence of this disorder in 4 of 10 siblings in an American family of Czechoslovakian ancestry. Characteristics of the disease include multiple bone cysts with pathologic fractures, progressive dementia with seizures and abnormal EEG, calcification of basal ganglia, and death in the fourth to six decades. Autosomal-recessive inheritance is likely. Electronmicroscopy of fat cells reveals peculiar membrane convolutions. Limited neuropathologic material has shown gliosis and demyelination of white matter, senile plaques, and neurofibrillary tangles. Leukemia and a disorder of intestinal motility may be associated findings. Prevalence of the disorder is unknown, partly because it may be confused with Alzheimer disease and fibrous dysplasia of bone. Radiographs of hands and feet should be part of the evaluation of patients with unexplained presenile dementia.