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Biomedical subjects

M R Gomez

Publications and source records attributed to M R Gomez.

At least 73 records · Page 4Linked to original sources
PubMed1981

Pineal tumors in children and adolescents. Treatment by CSF shunting and radiotherapy.

Tumors of the pineal region account for 3% to 8% of pediatric intracranial tumors. The treatment of such tumors has been in a state of flux between conservative therapy (cerebrospinal fluid shunting and radiotherapy) and direct surgical removal. A brief history and review of the literature with analysis of both approaches is given, and the Mayo Clinic's experience with conservative treatment of tumors in the pineal region in patients 20 years old and younger (27 cases) is studied and analyzed. The series comprises 21 boys and six girls, with an age range of 1 to 20 years (mean 13.7 years). Follow-up examinations are complete and range from 1 to 24 years, with a mean follow-up period of 7.8 years. The median survival time for these patients treated with shunt and radiotherapy is 17.7 years. There was no mortality from treatment and complications were rare. The details of the clinical presentation, diagnostic findings, pathology, therapy, recurrence, and survival are presented. All patients under 6 years of age (six cases) had recurrences, 50% in other areas in the brain and 50% in the spinal cord, perhaps pointing to the need for whole-brain and spinal-axis irradiation in patients in this age group. The results of this study of the conservative approach form a standard against which results of any other type of therapy may be compared.

Adolescent↗
PubMed1981

Idiopathic ("congenital") spinal arachnoid diverticula. Clinical diagnosis and surgical results.

We reviewed the clinical records of all the patients examined at the Mayo Clinic who were operated on and found to have arachnoid diverticula of he cervical and thoracolumbar regions of the spinal column. Only patients whose lesion did not have a traumatic cause were selected for a study. There were 21 patients: 20 had been operated on at the Mayo Clinic and 1 was seen 43 years after surgery done elsewhere. The symptoms associated with the thoracolumbar lesions were, in order of decreasing frequency, pain, weakness, gait disorder, sensory symptoms, and sphincter dysfunction. The conditions associated with thoracic arachnoid diverticula included congenital pigmented nevus, diastematomyelia, multiple sclerosis, Marfan's syndrome, and syringomyelia.

Adolescent↗
PubMed1979

Cerebellotrigeminal and focal dermal dysplasia: a newly recognized neurocutaneous syndrome.

A female child with brachycephaly, hypertelorism, convergent strabismus, interstitial keratitis, analgesia on both sides of the face, absent corneal reflexes, and focal congenital alopecia of a zone of the occipital and posterior parietal scalp is presented. The patient also had generalized hypotonia in early life, and at age 4 years 9 months, she was found to be moderately mentally subnormal and to have severe cerebellar deficit consisting of gait and truncal ataxia. There was no clinical evidence of other cranial nerves being affected. It is postulated that the patient has a cerebellotrigeminal and focal dermal dysplasia due to a development arrest of the ectoderm, which gives rise to the alar plate of the rhombencephalon, the overlying epidermis, the motor nucleus of V, and the trigeminal placodes.

Alopecia↗
PubMed1979

Demyelination of the brain in tuberous sclerosis: computed tomography evidence.

Two patients with tuberous sclerosis are described in whom computed tomography of the head revealed areas of diffuse diminution of density suggestive of demyelination. Computed tomography is a sensitive test for the detection of intracerebral lesions in tuberous sclerosis, and the finding of areas of diminished density in the absence of evidence for tumor or ventricular obstruction correlates with the common histologic finding of diffuse demyelination. Serial studies with computed tomography are likely to determine whether such demyelination precedes the growth of hamartomas and calcification that characterize tuberous sclerosis.

Brain↗
PubMed1978

External hydrocephalus. Early finding in congenital communicating hydrocephalus.

Dilation of the subarachnoid channels overlying the cerebral hemispheres, ie, external hydrocephalus, can be an early anatomic-radiologic finding in some infants with congenital communicating hydrocephalus. This structural change may progress to ventricular dilation or internal hydrocephalus. Enlargement of the subarachnoid channels appears to occur during the first stage in the development of congenital communicating hydrocephalus, which is to say that the subarachnoid compartment allows accumulation of CSF before there is significant ventricular distention, at least in some infants. When a pneumoencephalogram or a CT scan is performed at this stage, the findings may falsely suggest "cerebral atrophy." In six patients who received this grave neuroradiologic diagnosis, five subsequently developed normally and the sixth has static incoordination or clumsiness and mild intellectual deficiency.

Humans↗
PubMed1978

Pineal tumors. A 53-year experience.

Thirty-four patients with pathologically confirmed primary pineal tumors were evaluated at the Mayo Clinic from 1923 through 1976. All tumors were of germ cell or pineal cell origin. Most patients were adolescent boys with subacute increased intracranial pressure and Parinaud's syndrome. Hypothalamic symptoms were surprisingly infrequent. Direct surgical intervention was associated with high mortality, but has been more successful in recent years.

Adolescent↗
PubMed1977

A new myasthenic syndrome with end-plate acetylcholinesterase deficiency, small nerve terminals, and reduced acetylcholine release.

A new myasthenic syndrome is described in a patient whose symptoms began soon after birth and included generalized weakness increased by exertion, easy fatigability, hyporeflexia, and refractoriness to anticholinesterase drugs. Electromyography showed a decremental response at all frequencies of stimulation and a repetitive response to single nerve stimulation. Miniature end-plate potentials (mepps) were of normal amplitude but of decreased frequency. The mepp duration and half-decay time were prolonged, and prostigmine was without any addtitional effect. The quantum content of the end-plate potential was decreased due to a reduced store of quanta immediately available for release, but the probability of release was normal. Quantitative electron microscopy demonstrated a 3-fold to 4-fold decrease of nerve terminal size and reduced postsynaptic membrane density. The postsynaptic folds showed focal degeneration, and many were distended by labyrinthine membranous networks that communicated with the synaptic space. Degenerating nuclei were found in the junctional sarcoplasm. The ultrastructural localization of the acetylcholine receptor protein was normal. Acetylcholinesterase (AChE) was absent from the motor end-plates by histochemical and electron cytochemical criteria. Biochemical studies indicated total absence of the end-plate-specific 16 S species of AChE and marked decrease in total muscle AChE. A congenital defect in the molecular assembly of AChE or in its attachment to the postsynaptic membrane might represent the basic abnormality and condition the morphological and physiological alterations.

Acetylcholine↗
PubMed1977

Failure of inactivation of Duchenne dystrophy X-chromosome in one of female identical twins.

Duchenne muscular dystrophy manifested in one of girl twins. The twins were monozygous on the basis of red cell and HL antigens and skin graft compatibility. Karyotyping, including banding techniques, showed a normal number of chromosomes and a normal configuration of the X-chromosome in both twins. The twins were identical in appearance until symptoms of Duchenne dystrophy developed in one at age 4 years. The maternal uncle had classic Duchenne dystrophy; the mother and the nonmanifesting twin showed evidence of being heterozygous for Duchenne dystrophy. The phenotypic difference in monozygous twins is readily explained by lyonization of the X-chromosome after twinning has occurred. The findings substantiate the existence of Duchenne dystrophy manifesting in females with normal karyotypes.

Child↗
PubMed1977

Computerized tomography in demyelinating disease of the young.

We have used computerized tomography (CT) to look for evidence of cerebral demyelination in children with progressive neurologic disorders. Fourteen patients with a clinical diagnosis of a demyelinating disorder were examined by CT, and five had CT findings suggesting cerebral demyelination. In two patients with a so-called myelinoclastic demyelinating disease, CT showed asymmetric, circumscribed areas of diminished radiodensity, and in three patients with a leukodystrophy, scans showed diffuse symmetric areas of low density in the centrum ovale. Autopsy examination in one patient confirmed the diagnosis of sudanophilic leukodystrophy and substantiated the abnormalities suspected from CT.

Adolescent↗
PubMed1976

Retinal lesions in tuberous sclerosis.

Retinal lesions in 116 patients with tuberous sclerosis included three types: the relatively flat, semitransparent, non-calcified tumors; the more commonly described nodular, calcified tumors; and a third lesion that possessed features of the other two. Other less definite pigmented and plaque-like lesions also were seen. The evolution of a relatively flat, noncalcified lesion into an elevated nodular, apparently calcified lesion during an interval of two decades was photographically recorded.

Eye Neoplasms↗
PubMed1976

Generalized sharp and slow wave and electrodecremental seizure pattern in subacute sclerosing panencephalitis.

Although subacute sclerosing panencephalitis (SSPE) often presents with a characteristic EEG pattern, a 13-year-old boy with a confirmed diagnosis of SSPE had several EEG features that are unusual for this condition, namely, generalized sharp and slow wave (slow spike and wave) discharges during the waking record, an electrodecremental pattern associated with clinical seizures, and activation of the typical periodic complexes of SSPE only during sleep.

Adolescent↗
PubMed1976

An aflatoxin in the liver of a patient with Reye-Johnson syndrome.

Liver specimens from 8 patients with Reye-Johnson syndrome, 2 patients with acute encephalopathy, and 10 patients without liver disease were analyzed for aflatoxins. An aflatoxin was obtained from the liver of one patient, a 15-year-old girl who had clinical, laboratory, and pathologic features of Reye-Johnson syndrome. Thin-layer chromatography, fluorescence emission, infrared spectroscopy, and derivatization studies characterized the aflatoxin as related structurally to but not identical with aflatoxin B1. This report is added to previous ones from Thailand, New Zealand, and Czechoslovakia in which the association of aflatoxins and fatty liver has been found in Reye-Johnson syndrome.

Adolescent↗