Urinary metabolites in congenital hyperuricosuria.

The excretion of oxypurine metabolites in urine of patients with congenital hyperuricosuria exceeds, on a creatinine basis, that observed in any previously recognized metabolic anomaly. The ratio of hypoxanthine to xanthine is from 2:1 to 3:1 and results from increased hypoxanthine excretion, in contrast to other hyperuricosuric conditions where ratios of less than one have been reported. Administration of allopurinol (a xanthine-oxidase inhibitor) reduces the excretion of uric acid but results in an equivalent increase in xanthine and hypoxanthine. These features appear to be unique to congenital hyper-uricosuria.

Focal encephalopathy following methotrexate therapy. Administration via a misplaced intraventricular catheter.

Two patients with lymphoreticular malignant neoplasms and leptomeningeal tumor spread were treated with intraventricular administration of methotrexate via an Ommaya reservoir. The intraventricular instillation of methotrexate resulted in focal CNS damage in brain parenchyma inadvertently pierced by the shunt. Disorientation, aphasia, and right hemiparesis developed in both patients. Computed tomography disclosed a contrast-enhancing, low-density mass in the left cerebral cortex where the distal shunt tip was lodged. In one case the lesion was pathologically consistent with chronic inflammation. A lesion occurred in one patient despite repositioning of the shunt prior to methotrexate instillation. Shunt removal and administration of systemic corticosteroids resulted in resolution of symptoms in one patient.

Vertebral artery dissection and alternating hemiparesis in an adolescent.

A case report of vertebral artery dissection and alternating hemiparesis in an adolescent boy is presented. The diagnosis was confirmed by findings on a computed tomographic brain scan and a four-vessel cerebral arteriogram. The patient has been treated with aspirin for 2 years and has had no further transient ischemic attacks.

Neurologic outcome after electroencephalographically proven neonatal seizures.

Infants in whom neonatal seizures were confirmed by randomly recorded ictal electroencephalographic (EEG) tracings were retrospectively examined to determine their global neurologic outcome and the specific frequency of epilepsy, development delay, and cerebral palsy. Perinatal and postnatal clinical and EEG variables were also examined for their relevance to the neurologic outcome. Forty infants with EEG documented seizures of diverse etiologies were studied. The 27 survivors were followed up at a mean of 31 months. The outcome was unfavorable in 70%. The rate of epilepsy was 56%, of developmental delay 67%, and of cerebral palsy 63%. The etiology of seizures was an important factor influencing the outcome. Other clinical factors that showed a significant relationship with global or specific aspects of the neurologic outcome included the age at the onset of seizures, birth weight, and neurologic examination results. The EEG parameters that significantly predicted the neurologic outcome were interictal EEG background, increased seizure frequency, and decreased seizure duration.

Rickets associated with long-term anticonvulsant therapy in a pediatric outpatient population.

Over a 12-month period, an ambulatory pediatric population receiving long-term anticonvulsants was surveyed for the presence of biochemical and radiologic rickets. There were 74 treated children and 95 matched controls. Elevations of serum alkaline phosphatase activity occurred in 31 of the 74 (42%) treated children (23 of 47 children between 2 and 10 years and 8 of 21 children between 10 and 16 years). This frequency of abnormal values was significantly greater than that which occurred in our control population. Calcium and phosphorus abnormalities were minimal in both treated and control populations. Radiologic rickets occurred in 6 of the 74 (8%) of the treated children and in none of the control population. Neither the severity of the rickets nor the degree of hyperalkaline phosphatasemia were correlated with age of the patient, duration, and/or dose of anticonvulsant therapy.

Encephalitis in infectious mononucleosis: diagnostic considerations.

Four atypical cases of presumed infectious mononucleosis (IM) encephalitis are presented. To establish an etiologic diagnosis, Paul-Bunnell-Davidsohn heterophil titers (PBD), antibody titers to the antigens of the Epstein-Barr virus (EBV), and oropharyngeal excretion of EBV were determined. Criteria for a primary EBV infection are (1) an antiviral capsid antigen titer of 1:160 or greater, (2) the presence of antibody to the diffuse component of the early antigen, (3) absence of antibody to the nuclear antigen, and (4) excretion of the virus from the oropharynx. Three of the four cases met these criteria; of the three, one did not have a positive heterophil titer. The fourth case turned out not to be IM; there was a positive PBD heterophil, but there was no evidence of primary EBV infection. Although the PBD heterophil is usually a reliable test to diagnosis IM, it is not always present in children, and it is sometimes nonspecifically elevated. Some EBV titers can be nonspecifically elevated as well; however, the above criteria are diagnostic of primary EBV infection.

Cavernous angioma presenting as atypical facial and head pain.

Recurrent headache is a common pediatric problem. As the differential diagnosis of headache is extensive, physicians rely on the mode of presentation to focus any investigation. A report of an adolescent in whom atypical facial and head pain caused by a preexisting cerebellar cavernous angioma is presented. Facial pain and headache resolved following excision of the tumor.

Recent advances in the diagnosis, treatment, and prognosis of neonatal seizures.

Current knowledge about the diagnosis, treatment, and prognosis of neonatal seizures is reviewed. The pitfalls in establishing the diagnosis are emphasized and the usefulness of new electrodiagnostic techniques is discussed. A protocol for treating neonatal seizures is suggested. Finally, the clinical and electroencephalographic variables which are relevant in determining neurologic outcome are discussed.

Multiple sclerosis presenting at 4 years of age: clinical and MRI correlations.

The authors present a patient with multiple sclerosis (MS) whose onset of illness was at 4 years of age. Three separate and distinct episodes of central nervous system (CNS) dysfunction associated with cerebrospinal fluid (CSF) pleocytosis, electroencephalographic (EEG) abnormalities, and extensive CNS white matter demyelination on both computerized tomography (CT) and magnetic resonance imaging (MRI) characterized her clinical course. Two episodes responded well to prednisone therapy.

Pallid breath-holding spells. Evaluation of the autonomic nervous system.

Excessive vagal tone has been implicated as the cause of pallid breath-holding spells (PBHS) in children. The following study was undertaken to test the hypothesis that children with PBHS have underlying autonomic nervous system (ANS) dysfunction. Five patients (age 29-79 months old) who had experienced PBHS were evaluated at a time when they were clear of spells for ANS dysfunction. A battery of clinical bedside tests were given. The results were compared with test results of a control group of children (age 18-104 months) who had not experienced PBHS. Data collected included blood pressure, pulse rate, mean arterial pressure, the 30:15 R-R ratio upon standing, the expiratory:inspiratory (E:I) R-R ratio, pupillary response to conjunctival pilocarpine instillation, and plasma norepinephrine levels upon standing. Breath-holders displayed a statistically significant (p less than 0.05) percent decrease in mean arterial pressure (-10.2% PBHS vs. -4.1% controls) and an unsustained increase in pulse rate during the lying to standing maneuver. Two children with PBHS had "positive orthostatic signs," and one child with PBHS had a plasma norepinephrine level of 94 pg/ml (60% below the mean for both groups). There is evidence to suggest a subtle, underlying, generalized autonomic dysfunction in children with PBHS. A strong familial tendency toward syncope, breath-holding spells, and seizures was recognized in nine of ten subjects. Additionally, there was a strong influence from the maternal side of the family in seven of nine subjects.

The diagnostic value of electromyography in infantile hypotonia.

There is controversy over the usefulness of electromyography (EMG) in the examination of hypotonic infants with suspected neuromuscular disease. We compared the initial EMG findings of 51 such children under 1 year of age with their final clinical diagnoses determined by independent means. The EMG predicted the final diagnosis in 82% of infants less than 4 months of age and 85% of those over 4 months of age. Botulism was correctly identified by EMG in nine of 11 cases. The EMG diagnosis was identical to that obtained by muscle biopsy in 64% of cases in which biopsy was done, and diagnosis obtained by the two methods were inconsistent in only 14%. Electromyography is a sensitive and noninvasive diagnostic tool for the diagnosis of neuromuscular disease in infantile hypotonia.

Chronic inflammatory demyelinating polyneuropathy of infancy: a corticosteroid-responsive disorder.

We present the clinical, electrophysiological, and histopathological findings in 6 children with early-onset chronic inflammatory demyelinating neuropathy. The clinical features initially suggested a genetically determined disorder in each patient. Sural nerve biopsy showed changes of chronic demyelination with multifocal endoneurial edema and mononuclear cellular infiltrates. All children improved with corticosteroid therapy.

Late-onset nonketotic hyperglycinemia and spinocerebellar degeneration.

Investigation of a 15-year old boy with progressive optic atrophy and spinocerebellar degeneration revealed elevated plasma, cerebrospinal fluid, and urine glycine concentrations. During an oral glycine loading test, the patient's plasma glycine concentration rose to a higher level than control values, although the initial rate of rise was slower; there was no concomitant rise in the plasma serine concentration. An oral serine loading test resulted in a prompt rise of both glycine and serine serum concentrations. The renal glycine clearance was elevated, and the renal tubular glycine reabsorption was diminished. These findings of decreased intestinal uptake and increased renal tubular glycine clearance suggest that a generalized derangement of glycine entry into cells may account for the phenotypic manifestations of the disorder.