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Biomedical subjects

B Estañol

Publications and source records attributed to B Estañol.

At least 37 records · Page 2Linked to original sources

Mechanisms of hydrocephalus in cerebral cysticercosis: implications for therapy.

Patients with hydrocephalus secondary to cerebral cysticercosis are a highly heterogeneous group. The mechanisms of hydrocephalus in these patients are multiple. Intraventricular cysts may be found in the 3rd and 4th ventricles, the sylvian aqueduct, and the foramen of Monro. Intraventricular cysts can be suspected when the 3rd and 4th ventricles or aqueduct remain enlarged despite shunting. Intraventricular contrast medium demonstrates the presence of the parasites. The intraventricular cysts should be removed surgically. Hydrocephalus due to cisternal cysticercosis can be diagnosed by isotope cisternography. These patients should receive shunts, but the long term prognosis is probably poor. Guidelines for the management of hydrocephalus due to cysticercosis are suggested.

Adult↗

Neuro-otology of the lateral medullary infarct syndrome.

Nine patients had a lateral medullary infarction. Examination during the acute phase of the lesion to determine oculomotor and oculovestibular functions showed that all patients had hypermetric saccades and increased gain of the vestibulo-ocular reflex (VOR) to the side of the lesion and hypometric saccades and decreased gain of the VOR to the side opposite the lesion. These abnormalities may be the consequence of the isolation of the vestibular nuclei from the flocculus, with loss of saccadic and vestibular gains by the cerebellum.

Adult↗

Diverse clinical manifestations of pheochromocytomas.

Many difficulties are encountered by clinicians in attempting to diagnose pheochromocytomas. We describe several patients with unusual clinical features. These include sudden death, cerebral hemorrhage, refractory congestive heart failure, acute abdominal pain, and hypercalcemia. In 2 patients, the rare association of this tumor and pregnancy was observed. Two subjects had sudden death, 1 during a pneumoencephalogram and another during an epidural block. The clinicians should be aware of these manifestations of pheochromocytomas.

Adrenal Gland Neoplasms↗

Coincidence of cerebrovascular accident and silent myocardial infarction.

Although it is well known that a myocardial and a cerebral infarction may be coincident, the nature of this association is not clear. The problem is further complicated because the myocardial infarction may be silent. This is a report of 3 patients with cerebral infarct in whom a silent recent myocardial infarction was found. All patients with cerebrovascular disease should be screened for a possible myocardial lesion.

Adult↗

Optokinetic and vestibular interaction in normal man.

When we move our head with our eyes open the optokinetic and the vestibular systems are simultaneously activated. The optokinetic and the vestibular systems interact in a complex way. A full field optokinetic system can suppress or enhance vestibular reflexes according to the needs of the organism. It is likely that the summation of optokinetic and vestibular nystagmus is not linear, rather, the organism encodes retinal slip velocity as the important input.

Adolescent↗

Findings in computerized axial tomography of tuberculous encephalopathy.

A 24 year-old woman with miliary tuberculosis of the lungs, developed a diffuse encephalopathy with signs of increased intracraneal pressure and without meningitis. A CAT scanner disclosed decreased density of the white matter and multiple nodular lesions enhanced with the infusion of contrast media. To our knowledge, this is the first description of the findings in computerized axial tomography of a patient with miliary tuberculosis and hematogenous dissemination associated to diffuse encephalopathy without meningitis.

Adult↗

Oculomotor and oculovestibular functions in a hemispherectomy patient.

Oculomotor and oculovestibular functions in a patient who had undergone a left hemispherectomy were examined under a variety of visual and vestibular stimuli. The main findings were an inability to hold left eccentric gaze, resulting in gaze-evoked nystagmus to that side; inaccurate saccades to the right; defective smooth pursuit to the left; asymmetrical vestibulo-ocular responses (VOR) in the dark due to the interaction of the VOR with the "spasticity of conjugate gaze", decreased gain of the visuo-vestibulo-ocular reflexes to both sides, more marked to the right, when rotated fixating on a stationary wall target or the environment, due to abnormal smooth and optokinetic systems; and failure to inhibit the VOR when rotated to the left with visual fixation.

Adult↗

Fourth ventricular cysticercosis.

This is a review of the clinical presentation and results of surgical treatment of 25 cases of cysticercosis of the 4th ventricle. All of the patients presented with hydrocephalus and, after shunting, dilatation of the 4th ventricle persisted while the supratentorial ventricular system returned to its normal size. We propose that, after a shunt procedure is performed, early direct surgical excision of the parasite should be done. Good or excellent results were achieved in 81.4% of the patients. Associated arachnoiditis and vasculitis were the major causes of poor outcomes.

Adult↗

[Thermodynamics and electrophysiology of the nervous system].

This study expresses a theory designed to associate the fundamental thermodynamic concepts to the electrophysiology of the nervous system. An analogy is drawn between the thermodynamic and electrical events of the myocardial cell during its mechanical phases with those thermodynamic and electrical events of the nerve cell during conduction. Although the myocardial and nerve cells are designed to perform different functions, their processes of membrane potential activation and corresponding directions of thermodynamic and entropy changes are basically the same. A thermodynamic view of nerve cell "active" potential corresponds to a passive downhill process during which the entropy of the system (nerve cell) increases. In contrast, the so called "resting" membrane potential corresponds to an active uphill process. Thus, there is a paradox because the nerve cell is thermodynamically passive during the "active" membrane potential, whereas it is thermodynamically active during the "resting" membrane potential. It is suggested that inhibition in the nervous system may be considered a thermodinamically active process. If the negentropic process fails, the result is the malfunctioning or the final destruction of the system.

Energy Metabolism↗

Diagnosis of reversible versus irreversible cerebral ischemia by the intravenous administration of naloxone.

Naloxone was given as an I.V. bolus of 0.8 mgs to four groups of patients with stroke: 1) 20 patients with C.T. proven cerebral infarcts of longer than 7 days duration; 2) 20 patients with acute cerebral ischemia of less than 24 hours; 3) 5 patients with C.T. proven intracerebral hemorrhage of less than 24 hours, and; 4) 3 patients with hyperacute cerebral ischemia which occurred during the performance of a cerebral angiogram. The patients with established cerebral infarctions of more than 7 days duration and the patients with intracerebral hematomas had no response to intravenous naloxone. Of 20 patients with acute cerebral ischemia of less than 24 hours duration, 7 had prompt, complete and long-lasting recovery. These patients had no subsequent evidence of cerebral infarct by C.T. scanner 48 hours after the onset of the cerebral ischemia and were asymptomatic when discharged. The 3 patients with hyperacute cerebral ischemia secondary to cerebral angiography had a dramatic response to the injection of naloxone. These findings suggest that intravenous naloxone may differentiate reversible versus irreversible cerebral ischemia.

Aged↗

POEMS syndrome: ultrastructural observations on the sural nerve.

POEMS is an acronym that stands for a multisystem disorder that includes progressive sensorimotor Polyneuropathy, Organomegaly, Endocrinopathy, an M component in blood and/or concentrated urine, and Skin changes. The morphology of the peripheral nerves was mentioned in some of these cases and ranged from normal to those with segmental demyelination and/or degeneration of myelinated axons. We analyzed quantitatively the sural nerves of two cases of POEMS syndrome. Both nerves showed a severe loss of myelinated fibers, with a minor degree of regeneration. Degeneration of unmyelinated axons was observed, but to a lesser degree. There was marked collagen deposition in the endoneurium. The pathogenesis of the changes in the peripheral nerves and other organs in POEMS syndrome is still to be elucidated.

Adult↗

[The other genome: the clinical concept of mitochondrial cytopathies or disorders of pxidative phosphorylation].

The investigations of mitochondrial DNA abnormalities and its relationship with derangements of oxidative phosphorylation and electron transport system, has yielded description a myriad of syndromes called mitochondrial diseases or cytopathies. The objective of this paper is to review the clinical relevant features of this heterogeneous group of diseases, to understand the board spectrum of signs and symptoms and suggest an algorithm for the diagnosis.

Cardiomyopathies↗

[Alexia without agraphia due to the lesion in the right occipital lobe in a right-handed man. Detection of hemispheric lateralization of handedness and language in a right-handed patient].

INTRODUCTION AND CLINICAL CASE: A 65 year-old man, right-handed, without any family history of left handiness, suddenly developed a left homonymous hemianopia and incapacity for reading. Neurological and neuropsychological examinations showed the presence of a profound alexia with preservation of writing to dictation and spontaneously. He was unable to read what he had written. He could spell the words letter by letter but he was unable to read the complete word. MRI showed an extensive infarct in the territory of the right posterior cerebral artery. The infarct extended anteriously to the right thalamus and to the medial temporal fifth or fusiform gyrus. The splenius was spared. Brain SPECT disclosed the area of the infarct and an extensive area of decreased cerebral perfusion over the right parietal and temporal areas. CONCLUSION: Alexia without agraphia has been reported in right-handed patients with left occipital lesions and in right occipital regions in left-handed patients but rarely if ever in right occipital lesions in right-handed patients.

Aged↗