An 8-year-old girl with unilateral facial and ear pain and isolated frontal headaches.

An 8 1/2-year-old with chronic but fluctuating unilateral facial pain, earache, frontal headache and facial swelling is presented. Her journey through the health care system provides an instructional lesson for all who deal with patients with unusual or difficult to recognize conditions.

Chromosome 18q paracentric inversion in a family with mental retardation and hearing loss.

We report on a mother and child with a paracentric inversion of the long arm of chromosome 18: 46,XX,inv(18)(q21.1q23). The child had findings in common with those seen in 18q- syndrome including: microcephaly, epicanthal folds, midface hypoplasia, and abnormally modeled ears, dermatoglyphic whorls on fingertips, clubfeet, hearing loss, and developmental delay. The mother and several maternal relatives had mild mental retardation and hearing loss. Magnetic resonance imaging of the child's brain showed abnormal myelination. Molecular studies including PCR-based markers for the MBP locus and fluorescent in situ hybridization with a P1 genomic clone on mother and child demonstrated only one copy of the MBP locus (18q23) with the deletion extending beyond the MBP locus. Therefore, the deletion in the MBP region may account for the abnormal myelination seen in the patient. The other clinical findings, including mental retardation and hearing loss in this family, may reflect disruption of distal or proximal genes within the deleted MBP region or at the more proximal breakpoint 18q21.1, and may represent a contiguous gene syndrome. Further study of this family may help define those genes functioning in the MBP region that contribute to the phenotype of 18q- syndrome.

Magnetic resonance imaging demonstrates incomplete myelination in 18q- syndrome: evidence for myelin basic protein haploinsufficiency.

Magnetic resonance imaging (MRI) and MRI relaxometry were used to investigate disturbed brain myelination in 18q- syndrome, a disorder characterized by mental retardation, dysmorphic features, and growth failure. T1-weighted and dual spin-echo T2-weighted MR images were obtained, and T1 and T2 parametric image maps were created for 20 patients and 12 controls. MRI demonstrated abnormal brain white matter in all patients. White matter T1 and T2 relaxation times were significantly prolonged in patients compared to controls at all ages studied, suggesting incomplete myelination. Chromosome analysis using fluorescence in situ hybridization techniques showed that all patients with abnormal MRI scans and prolonged white matter T1 and T2 relaxation times were missing one copy of the myelin basic protein (MBP) gene. The one patient with normal-appearing white matter and normal white matter T1 and T2 relaxation times possessed two copies of the MBP gene. MRI and molecular genetic data suggest that incomplete cerebral myelination in 18q- is associated with haploinsufficiency of the gene for MBP.

Growth hormone deficiency associated in the 18q deletion syndrome.

The 18q- syndrome is one of the commonest deletion syndromes. Clinical characteristics are variable but may include: hypotonia, tapered digits, "carp-like" mouth, mental retardation, and hearing impairment. Growth failure (GF; both weight and height < 3%) was reported in 80% of affected individuals. We evaluated growth hormone (GH) sufficiency in 5 18q- syndrome patients, 3 of whom had growth failure (< 3% weight and height); the remaining 2 had normal growth parameters. Laboratory evaluation of growth included measurement of IGF-1, IGFBP-3, bone ages and GH response to pituitary provocative agents. Three patients failed to produced adequate GH following stimulation testing. Of 3 patients with inadequate GH production, 1 had normal growth (above 3%). Only 1 of 5 patients had normal GH production and normal growth parameters. Our findings to date suggest that GH deficiency is common in individuals with the 18q- syndrome. The pathogenesis of this finding is unknown. We postulate that a gene(s) on 18q is involved in GH production.

Hypoplasia of the cerebellar vermis in neurogenetic syndromes.

There are conflicting reports on the relationship between cerebellar vermal lobule hypoplasia and autism. Using quantitative magnetic resonance image analysis, we measured the cerebellar vermis in 125 normal individuals with a broad age range and 102 patients with a variety of neurogenetic abnormalities. We conclude that hypoplasia of cerebellar vermal lobules VI and VII is a nonspecific finding that even occurs in several conditions with-out autistic behavior. This suggests that it is not a specific neuroanantomical marker for autism, nor is cerebellar dysgenesis likely to be solely responsible for clinical autistic behaviors.

Functional imaging and language: evidence from positron emission tomography.

Positron emission tomography (PET) provides an unprecedented opportunity to study the organization of cognitive functions in the working brain of normal individuals. A number of PET experiments, based on well-established paradigms derived from cognitive psychology, have investigated several aspects of language processing. These studies show that word processing is carried out by a distributed network of cortical areas with functional specificity. Results of this research sometimes confirm--sometimes clearly contradict--classic axioms of language organization. This article illustrates some of the methodological issues in PET research, then provides an overview of the most relevant studies using PET. Integrated with other functional imaging methodologies and with behavioral data from cognitive psychology and lesion studies, PET will certainly continue to represent a precious tool to enhance our knowledge of the functional organization of language.

Paroxysmal kinesigenic dystonia after methylphenidate administration.

We report a patient who developed paroxysmal kinesigenic dystonia shortly after initiation of therapy with methylphenidate for presumed attention deficit-hyperactivity disorder. Attacks persisted long after methylphenidate was discontinued and responded completely to treatment with carbamazepine. Though it is possible that methylphenidate caused this syndrome in our patient, it is more likely that the stimulant triggered the onset of a genetically determined disorder.

Rostral transfontanel herniation.

Upward transtentorial herniation as a result of mass effect in the posterior fossa has been described in adults by several authors. We report the case of a premature infant, small for gestational age, who experienced rostral herniation of a portion of frontal lobe through the anterior fontanel as the result of a hemorrhagic cerebellar infarction followed by a large parieto-occipital intracerebral hemorrhage.

The floppy infant: recent advances in the understanding of disorders affecting the neuromuscular junction.

The clinician is often asked to evaluate the floppy infant. Numerous conditions that cause hypotonia in infancy are briefly outlined in this article. These conditions may affect the brain, spinal cord, or motor unit. Several disorders of neuromuscular transmission, including four distinct and recently described congenital myasthenic syndromes and infant botulism, are discussed thereafter.

The bovine renal parathyroid hormone (PTH) receptor has equal affinity for two different amino acid sequences: the receptor binding domains of PTH and PTH-related protein are located within the 14-34 region.

Previous studies examining the interaction of PTH and PTH-related protein (PTHrP) with target tissue have for the most part emphasized the similarity between the two hormones in binding to and activating receptors. This observation that two peptides with limited homology have equal affinities for the same receptor is unusual. In this report we investigated two aspects of PTH/PTHrP-receptor interactions. First, the nonhomologous 14-34 regions of PTH and PTHrP were synthesized and evaluated. Second, hybrid peptides containing the 7-18 fragment of one hormone combined with the 19-34 region of the other hormone were studied to determine whether interactions between these two regions are required for receptor recognition. All four peptides were examined in bovine renal cortical membrane and rat osteosarcoma (ROS 17/2.8) cell PTH-binding and PTH-stimulated adenylate cyclase assays. The results indicate that the receptor-binding domains of PTH and PTHrP lie outside of the 1-13 region, the region containing sequence homology shared by the two hormones, and that two peptides of different amino acid sequence bind with equal affinity to the bovine renal PTH receptor. However, in the absence of the N-terminal region, the rat bone PTH receptor displays a preference for the C-terminal (19-34 sequence) region of PTHrP.

Colpocephaly: pitfalls in the diagnosis of a pathologic entity utilizing neuroimaging techniques.

Colpocephaly has been described as the persistence of the fetal configuration of the lateral ventricles. The pathologic picture is characterized by multiple features of disturbed or arrested development of the brain, which results in diminished thickness of the cerebral white matter in the posterior portion of the centrum semiovale, giving rise to large occipital horns of the lateral ventricles. This ventricular configuration allows the clinician to suspect the presence of this developmental disturbance utilizing computed tomographic images. In this paper, we present a case that demonstrates that not every patient with enlargement of the posterior horns of the lateral ventricles has the underlying developmental abnormalities that constitute colpocephaly as described by Yakovlev and Wadsworth. Furthermore, we point out the difficulties that can arise in the attempt to make a diagnosis of a pathologically defined condition on the basis of neuroimaging results alone.

Modifications of position 12 in parathyroid hormone and parathyroid hormone related protein: toward the design of highly potent antagonists.

Truncated N-terminal fragments of parathyroid hormone (PTH), [Tyr34]bovine PTH(7-34)NH2, and parathyroid hormone related protein (PTHrP), PTHrP(7-34)NH2, inhibit [Nle8,18,[125I]iodo-Tyr34]-bPTH(1-34)NH2 binding and PTH-stimulated adenylate cyclase in bone and kidney assays. However, the receptor interactions of these peptides are 2-3 orders of magnitude weaker than those of their agonist counterparts. To produce an antagonist with increased receptor-binding affinity but lacking agonist-like properties, structure-function studies were undertaken. Glycine at position 12 (present in all homologues of PTH and in PTHrP), which is predicted in both hormones to participate in a beta-turn, was examined by substituting conformational reporters, such as D- or L-Ala, Pro, and alpha-aminoisobutyric acid (Aib), in both agonist and antagonist analogues. Except for N-substituted amino acids, which substantially diminished potency, substitutions were well tolerated, indicating that this site can accept a wide latitude of modifications. To augment receptor avidity, hydrophobic residues compatible with helical secondary structure were introduced. Incorporation of the nonnatural amino acids D-Trp, D-alpha-naphthylalanine (D-alpha-Nal), or D-beta-Nal into either [Tyr34]bPTH(7-34)NH2 or [Nle8,18,Tyr34]bPTH(7-34)NH2 resulted in antagonists that were about 10-fold more active than their respective 7-34 parent compound. Similarly, [D-Trp12]PTHrP(7-34)NH2 was 6 times more potent than the unsubstituted peptide but retained partial agonistic properties, although markedly reduced, similar to PTHrP(7-34)NH2. The antagonistic potentiating effect was configurationally specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Extensive wormian bones in a patient with the Hallermann-Streiff syndrome.

A case is reported of a 5-month-old girl with Hallermann-Streiff syndrome who was evaluated for possible premature closure of the cranial sutures. Skull radiographs revealed numerous Wormian bones along sutures in the parietal skull bilaterally. Hallermann-Streiff syndrome is added to the list of diseases in which extensive Wormian bones can appear.

Reversible treatment-related leukoencephalopathy.

We present two children with acute lymphocytic leukemia who developed leukoencephalopathy following administration of a combination of intravenous ara = C and methotrexate during the consolidation phase of chemotherapy. Cranial magnetic resonance imaging showed widespread, abnormally high signal intensity in the deep white matter in both patients, though one patient had normal cranial computed tomographic scan. Treatment was modified, symptoms resolved in 1 to 2 weeks, and the white-matter changes resolved over 6 to 12 months. Intravenous cytarabine and methotrexate appear to act synergistically to enhance the potential for central nervous system toxicity. Awareness of this potentially serious complication of chemotherapy can facilitate timely recognition of leukoencephalopathy with the use of magnetic resonance imaging.

A new highly potent parathyroid hormone antagonist: [D-Trp12,Tyr34]bPTH-(7-34)NH2.

Based upon N-terminal parathyroid hormone (PTH) analog structure-activity relationship studies, position 12 was found to possess a wide structural latitude and was chosen as a site for single amino acid substitutions. Replacement of the naturally-occurring Gly with D-Trp at position 12 in the PTH antagonists [Tyr34]bPTH-(7-34)NH2 and [Nle8,18,Tyr34]bPTH-(7-34)NH2 increased in vitro receptor affinity. The D-Trp12 containing analogs were 12-fold more potent than their unsubstituted counterparts as inhibitors of PTH binding to renal and bone PTH receptors and 13-27-fold more potent as inhibitors of PTH-stimulated renal and bone adenylate cyclase activity. Based upon Scatchard analyses of saturation binding experiments and Schild analyses of adenylate cyclase experiments, [D-Trp12,Tyr34]bPTH-(7-34)NH2 was shown to interact with PTH receptors in a competitive manner. These studies demonstrate, therefore, that D-Trp12 substitution in PTH antagonists improves inhibitory properties in vitro and is compatible with a helical conformation at this position as a new direction for the design of PTH antagonists.

Macro cisterna magna: a marker for maldevelopment of the brain?

Enlargement of the cisterna magna occurs in as many as 0.4% of reported patients and generally has been believed to represent a normal variant. Differentiation from Dandy-Walker malformations and other cystic structures has been emphasized. We reviewed 1,260 consecutive computed tomography reports in patients younger than 21 years of age and examined all scans in which enlargement of the cisterna magna was considered an isolated finding. Fourteen patients were identified (incidence: 1%). The primary reasons for obtaining computed tomographic scans included various clinical conditions but excluded symptoms indicative of posterior fossa disease. Developmental or neurologic abnormalities were present in 62% of these patients. Macro cisterna magna should not be dismissed as a normal variant, although the neurologic findings may not be specifically localized to the posterior fossa. This finding may be a marker for abnormal brain function most likely due to subtle disturbances in brain development.

Infantile botulism.

We present the first two known cases of infantile botulism in Oklahoma. The first case was due to type B toxin; the second was due to type A toxin. Both cases demonstrate most of the classic features of what now appears to be the most common form of botulism. Infantile botulism is an underrecognized but reversible cause of hypotonia. In most cases, the prognosis is excellent with institution of appropriate supportive care. The recognition of cranial nerve palsies or a history of constipation should raise the suspicion of infantile botulism. Aminoglycoside antibiotics and other agents that may precipitate or exacerbate neuromuscular blockade should be used with extreme caution in hypotonic infants until the cause of the hypotonia is clearly identified.