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11 recordsLinked to original sources
PubMed1978

Megalencephaly in infants and children. The possible role of increased dural sinus pressure.

Seven children studied because of clinical macrocephaly and suspected hydrocephalus ultimately proved to have megalencephaly apparently due to an increase in sagittal sinus venous pressure as established from infusion studies. Unexplainably, these patients were all males. All were seen initially between 2 and 8 months of age. Head enlargement exceeded two standard deviations in all seven. Pneumoencephalography, ventriculography, or computerized tomography demonstrated normal or minimally enlarged ventricles that did not progress in size. Isotope cisternography was abnormal. Studies of CSF formation and absorption demonstrated normal absorption rates but high calculated sagittal sinus pressures. Though therapy was usually not required, in one unusual infant, severe progressive macrocephaly with minimal hydrocephalus required a shunt. Another had a transient episode of acute hydrocephalus associated with a low CSF absorption rate and ventricular enlargement. In this report, we review the intracranial hydrodynamics of benign intracranial hypertension (BIH), communicating hydrocephalus, and the pathogenesis of megalencephaly. Benign intracranial hypertension and the type of megalencephaly demonstrated by our patients appear to develop similarly except that the presence of open cranial sutures may allow a transient nonhydrostatic loading of brain parenchyma in infants, resulting in mild, nonprogressive macrocephaly.

Brain↗
PubMed1978

Megalencephaly and chromosomal anomaly.

A 6-year-old mentally retarded boy died after cardiac surgery for Fallot's tetralogy. The brain was of enormous size, weighing 2230 grams and showing widespread polymicrogyria and dysdifferentiation to regular large pyramidal neurons without increased DNA content. Nuclear Barr bodies indicated a XXY-chromosomal (Klinefelter) syndrome, which has not been previously reported in megalencephaly. True megalencephaly (excluding the symptomatic forms) should remain a pathological diagnosis and restricted to cases with an abnormally high brain weight in addition to morphological alterations. There is evidence for a genetic base in many cases of megalencephaly, and chromosomal studies may yield more information in this respect

Autopsy↗
PubMed1978

The radiographic features of unilateral megalencephaly.

Unilateral megalencephaly is a rare anomaly of the brain which causes enlargement of a lobe or an entire hemisphere. The radiological features of the disease are a poorly defined unusual mass effect on PEG, angiography and CT scan. Pathologically, the disease is thought to be due to abnormal cell migration in the 3rd month in utero.

Brain↗
PubMed1979

Unilateral megalencephaly, cerebral cortical dysplasia, neuronal hypertrophy, and heterotopia: cytomorphometric, fluorometric cytochemical, and biochemical analyses.

A 13-month-old boy with intractable seizures, left hemiparesis, and psychomotor retardation due to right unilateral megalencephaly, died in hypovolemic shock 1 day after hemispherectomy. The gyral pattern of the hypermegalic hemisphere was simplified and coarse. The cortical cytoarchitecture was disarrayed by a population of giant neurons. Hippocampus and calcarine cortex were cytoarchitectonically normal, as was the entire left cerebral hemisphere. Neuronal heterotopias were present in the right centrum semiovale and both cerebellar hemispheres. Cytomorphometric study of parietal cortex of each cerebral hemisphere revealed a 4-fold increase in neuronal nuclear, and 11-fold increase in neuronal nucleolar, volume in the hypermegalic hemisphere, whereas glial nuclear volume was only one-third as great, in part because of edema of the left hemisphere. Microfluorometric cytochemical analysis demonstrated a 16% increase in neuronal DNA, 40% increase in total neuronal RNA, 12% increase in glial DNA, and 15% increase in glial RNA on the right. Biochemical analysis of tissue extracts disclosed increases in the right hemisphere of 40%, 56%, and 66%, respectively, for DNA, RNA, and protein. The data suggest heteroploidy of chromosomal DNA and enhanced transcription and translation in the hypermegalic hemisphere. Thus, a defect in regulation of cell metabolism may account for the morphologic and clinical abnormalities.

Brain↗
PubMed1979

Normal children with large heads--benign familial megalencephaly.

Fifteen normal children with large heads (circumference greater than 0.5 cm above the 98th centile) were studied. CAT scans were pefrormed to exclude hydrocephalus, and ventricular size was compared with that of hydrocephalic children. In 11 of the 13 families in which the parents' heads were measured, one parent (10 fathers and one mother) was found to have a large head, as had 6 of 17 siblings. Head circumference at birth was large in 7 of 10 babies and rate of head growth was excessive in 8 of 13. Skull x-ray showed suture diastasis in 7 infants. These families have a benign familial megalencephaly. It is important to recognise this so as to avoid unnecessary investigation and anxiety about normal children with large heads.

Brain↗
PubMed1978

Malformation of the cerebral cortex with heterotopia of the gray matter.

Developmental malformation of the cerebral cortex with heterotopia of the gray matter is a rare condition. It can present as unilateral megalencephaly, a localized mass, or focal cortical dysplasia. Four histologically confirmed cases are described in this report, and the findings from computed tomography as well as from other radiological diagnostic procedures are discussed.

Brain Neoplasms↗
PubMed1978

Re-evaluation of the approach to an enlarging head in infancy.

Computerized axial tomography is a safe, non-invasive technique for measurement of ventricular size. A review of 44 children without myelodysplasia who were evaluated for inappropriately enlarging heads, documented a group of 20 children presenting at five months to two years of age with megalencephaly or mild communicating hydrocephalus. Of these, only two required shunts. At their most recent examination, the great majority of these children are developmentally normal. Serial neurological examination, developmental evaluation and head-circumference measurements, in association with computerized axial tomography, have proved effective in the assessment and management of this particular group of children with large heads.

Age Factors↗
PubMed1977

Verbal auditory agnosia in children.

Four (possibly five) boys are described with a profound comprehension deficit for acoustic language, leading to severe or complete abolition of expressive speech. One boy had presumed megalencephaly from birth but was of superior intelligence. He had a severe articulation deficit from early childhood, with delayed acquisition of speech. Another boy is thought to have a small angiomatous anomaly in the depth of the left parietal lobe. No brain lesions are known in the other three. Evidence for bilateral brain dysfunction consists of minor motor abnormalities in three boys, oromotor deficits in two boys, and bilaterally synchronous diffuse or independent focal paroxysmal discharges in the EEG of three, possibly four, of the boys. Seizures have occurred in only three boys, and have been easily controlled with anticonvulsants. One boy with a grossly abnormal EEG has had no clinical seizures to date and has not benefited frome one year of anticonvulsant therapy. Two of the boys are brothers, including the boy in whome the diagnosis is questionable since speech was never normal and since he has had neither seizures for an abnormal EEG. The severity of EEG abnormalities did not correlate closely with the course of the language deficit. The relationship of this syndrome to acquired aphasia in children, to Wernicke's aphasia and pure word deafness in adults, and to developmental lagnuage disability with predominantly receptive deficits, is discussed. One child illustrated the close association between writing and phonologic encoding and decoding operations, and two children the preservation of linguistic skills provided the acoustic channel was by-passed and language presented visually. This latter point has been emphasized because of its implications for the remedial education of children with this syndrome.

Agnosia↗
PubMed2024

Expanding the phenotype and genotype spectrum of TAOK1 neurodevelopmental disorder and delineating TAOK2 neurodevelopmental disorder.

PURPOSE: The thousand and one kinase (TAOK) proteins are a group of serine/threonine-protein kinases involved in signaling pathways, cytoskeleton regulation, and neuronal development. TAOK1 variants are associated with a neurodevelopmental disorder (NDD) characterized by distinctive facial features, hypotonia, and feeding difficulties. TAOK2 variants have been reported to be associated with autism and early-onset obesity. However, a distinct TAOK2-NDD has not yet been delineated. METHODS: We retrospectively studied the clinical and genetic data of individuals recruited from several centers with TAOK1 and TAOK2 variants that were detected through exome and genome sequencing. RESULTS: We report 50 individuals with TAOK1 variants with associated phenotypes, including neurodevelopmental abnormalities (100%), macrocephaly (83%), and hypotonia (58%). We report male genital anomalies and hypoglycemia as novel phenotypes. Thirty-seven unique TAOK1 variants were identified. Most of the missense variants clustered in the protein kinase domain at residues that are intolerant to missense variation. We report 10 individuals with TAOK2 variants with associated phenotypes, including neurodevelopmental abnormalities (100%), macrocephaly (75%), autism (75%), and obesity (70%). CONCLUSION: We describe the largest cohort of TAOK1-NDD to date, to our knowledge, expanding its phenotype and genotype spectrum with 30 novel variants. We delineated the phenotype of a novel TAOK2-NDD associated with neurodevelopmental abnormalities, autism, macrocephaly, and obesity.

Humans↗