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Biomedical subjects

M Manrique

Publications and source records attributed to M Manrique.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Vestibular suppression].

Evaluation of the function was carried out by using unilateral caloric test in different arousal status. The goal of this investigation is to further investigate the normal parameters of vestibular function. Maximum speed, latency, frequency, medium speed and number of beats of the slow component of nystagmus were calculated, as well as, the morphological pattern of the standard outline. Voluntary suppression of vestibular response was tested. A test request method was proposed as the best way to fix attention of subjects.

Adult↗
PubMed1982

Calcified cerebral hydatid cyst.

A case of calcified cerebral hydatid cyst recently treated in our neurosurgical service is reported. The frequency of calcified cerebral hydatid cyst (CCHC) is less than 1% of cerebral hydatid cysts. A review of the literature disclosed 13 cases of calcified cerebral hydatid cysts. The clinical presentation and radiological findings are discussed. The present case is, to the best of our knowledge, the first case studied by computerized tomography.

Adult↗
PubMed1981

Tissue damage after chronic cerebellar stimulation.

Two spastic patients undergoing chronic cerebellar stimulation are studied. Biopsies taken after three months of stimulation showed various tissue changes when compared with those taken at the moment of electrode implantation. The most important alterations in the cerebellar cortex were adhesions round the electrodes, with a scarring reaction, gliosis, and loss of Purkinje cells. These findings resemble those described in various experimental reports of chronic cerebellar stimulation.

Adult↗
PubMed1980

Long-term morphology of the alumina cream experimental epileptogenic focus.

A morpholigical study of an experimental epileptogenic focus in the cat, eighteen months after intracerebral injection of alumina cream, is presented. The most significant histological findings were cortical atrophy and reactive gloisis enclosing the implantedd particles. Subpial sclerosis and evidence of ischaemic neuronal lesions were also found. These findings confirm a close morphological relation between the alumina cream experimental focus obtained after a certain period of evolution and the human epileptogenic focus.

Aluminum↗
PubMed1980

Calcified telangiectatic hamartomas of the brain.

A case of calcified telangiectatic hamartoma in a 27-year-old patient having focal seizures is presented. The cases in the literature under the name of "hemangioma calcificans" are reviewed. Calcified telangiectatic hamartomas, as an anatomoclinical subgroup, are different from calcified cavernous angiomas.

Adult↗
PubMed1979

Medial frontal epilepsy: histological, histochemical, and ultrastructural study. Preliminary observations.

The authors have studied the histological, histochemical, and ultrastructural aspects of eight corticectomies of epileptogenic foci in the medial surfaces of frontal lobes. In all cases they were able to see more gliosis and fewer neurons than normal. The shape and number of dendritic spines were thought to be normal with the Golgi-Cox method. The histochemical study showed an increment of activity of Glucose-6-Phosphatase, Glucose-6-Phosphatedehydrogenase, adenosintriphosphatase, and acid phosphatase. The electron microscope showed, in every case, a variety of changes, among which the authors can point to perivascular lipid accumulation, and an increase of lipofuscin bodies in the cytoplasm of pyramidal cells.

Adolescent↗
PubMed1979

Chronic implanting of electrodes in the cerebellar vermis of the cat. Morphological findings.

The morphological modifications of the cerebellar cortex have been evaluated in eight cats with chronic electrodes implanted in the anterior vermis. In a control animal a silastic lamina without electrodes was implanted. Four animals received intermittent stimulations up to 11 hours in one case and 100 hours in the other 3. The stimulation was carried out with pulses of 0.5 msc, 200 cps, and a charge per phase of 0.68 muc. Microscopic examination of the cerebellum showed that the experimental implanting of prostheses of the cerebellar vermis produces tissue lesions consisting of fibrous reaction, imprinting of the cortex, gliosis, and loss of Purkinje cells. These lesions are independent of the electric stimulation, and seem to be related to the pressure of foreign material against the cortex.

Animals↗
PubMed1978

Cytological alterations in alumina cream experimental epilepsy.

The cellular changes in the neighbourhood of an alumina cream epileptogenic focus and in the mirror focus in chronic experiments in cats have been studied. According to the neuroglial morphology, four layers are described around the alumina cream lesion. At an ultrastructural level, and increase in gap junctions with a great amount of gliofilaments in astroglial processes are observed. There is a decrease in the number of neurons in the vicinity of the alumina cream. Some are coated by glial processes filled with gliofilaments. The dendrites of the pyramidal neurons in the mirror focus show long mitochondria. The possible significance of these data, in relation with the current theories about epileptogenicity, are discussed.

Aluminum Oxide↗
PubMed1978

Chronic paleocerebellar stimulation for the treatment of neuromuscular disorders. Four case report.

4 patients suffering severe neuromuscular diseases were subjected to a subtentorial implantation of electrodes over the anterior cerebellar lobe surface. Chronic stimulation was applied for 90 min to 7 h daily, with a rate of 20--180 Hz, 6--10 V and a schedule of 15 min "on", 15 min "off". Some improvement was observed in 3 patients treated with high frequency stimulation. 1 patient suffered seizures after three months of chronic stimulation. In 2 cases, posterior fossa explorations were necessary for revision of the stimulation apparatus and marked meningeal proliferation surrounding the electrodes was observed. Light and electron microscopic examination of the biopsies showed loss of Purkinje cells and gliofibrillar reaction. Effectiveness and side effects of chronic stimulation of the cerebellum are discussed.

Adult↗
PubMed1977

Cerebral blood flow and behavior during brain stimulation in the goat.

Cerebral blood flow, heart rate, arterial blood pressure, and behavior were studied in conscious goats during electrical stimulation of the diencephalon and mesencephalon. Stimulation of the subthalamic area produced a considerable increase in ipsilateral cerebral blood flow and heart rate, accompanied by either a small or a large increase in systemic arterial blood pressure. Cardiovascular effects were associated with changes in alertness. The increase in cerebral blood flow was partially abolished by previous administration of atropine directly into the internal maxillary artery. Stimulation of the mesencephalic reticular formation caused a marked increase in blood pressure with no change or with some decrease in cerebral blood flow. After administration of phentolamine into the internal maxillary artery, stimulation produced increase in cerebral blood flow. The behavioral response consisted of restlessness and attempted flight. These results suggest the existence of cholinergic vasodilator and adrenergic vasoconstrictor pathways to cerebral blood vessels that may be stimulated electrically.

Animals↗
PubMed1976

[Behavioral manifestations induced by electric stimulation of the anterior cingulate gyrus in man].

The electrical stimulation of a restricted part of area 24 in awake man elicits important behavioral changes. The present study is dealing with 83 epileptic patients whose brain activity was recorded in SEEG conditions, with a view to possible neurosurgery. In order to determine how seizures originate and propagate, 116 multileads electrodes (65 right, 51 left) were stereotaxically inserted in the anterior part of the cingular gyrus. 521 stimulations were performed. In 362 cases, this stimulation induced a particular behaviour which was characterized by an arousal, motor activities (involving fingers and hand, mouth, legs, eyes, associated movements of hand mouth, highly integrated movements), thymic modifications and hallucinatory manifestations. Topographical organization of the effective area in the cingular gyrus and the relation between the electrical responses and stimulation parameters are studied.

Adolescent↗
PubMedDate not supplied

[Immediate acoustic effect of the cochlear fistula in a guinen pig].

INTRODUCTION AND OBJECTIVES: To Evaluate objectively the effect that cochleostomy has in the cochlea as well as the exposition of the estria vascularis, through acoustic otoemissions immediatly after surgery. MATERIAL AND METHODS: Submandibular approach to the guinea pig's middle ear and cochlea. Triming of the timpanic and vestibular first turns and wide exposition of the estria vascularis in the first and second turns. Study of cochlear function through acoustic otoemissions of distortion products. CONCLUSIONS: Guinea Pig is a perfect experimentation animal for surgical work when monitoring functional state of the cochlea. Its acoustic response is similar to the one found in other mammals thoug its response is lower than that reported in other papers. The lack of intracochlear manipulation ensures the lower decrease hearing loss deterioration regarding the findings in the different methods of studying the acousting distortion. RESULTS: There is a decrease of amplitud in the audiograms of distortion for specific frequencies (4 and 6 KHz), located tonotopically near the cochleostomies carried out in the first turn (at the level of scala vestigularis and timpanic). Approadring the cochlea without intracochlear manipulation does not modify greathy the results of audiograms of distortion neither the growth slopes of the response. A lateral approach of the estric vascularis minimising the aggression to labrynth did not cause a significant acoustic deterioration.

Animals↗
PubMedDate not supplied

[Auditory neuropathy due to the Q829X mutation in the gene encoding otoferlin (OTOF) in an infant screened for newborn hearing impairment].

We report an infant with auditory neuropathy secondary to the Q829X mutation in the gene encoding otoferlin (OTOF). Included in a universal newborn hearing screening program, the subject passed the otoacoustic emission (OAEs) test. Given that the infant had a familial history of deafness auditory brainstem response (ABR) testing was performed, revealing a profound hearing impairment. The genetic study confirmed that the subject was homozygous for the Q829X mutation in OTOF. The patient underwent a cochlear implant, obtaining satisfactory results. The moderately high prevalence of this mutation in the Spanish population could produce a significant false negative rate in newborn hearing screening programs using OAEs.

Cochlear Nerve↗
PubMedDate not supplied

[Functional activity of auditory cortex studied with SPECT: methodology validation and application in bilateral profound deafness].

To evaluate the differences in the functional activity of the auditory cortex between normal hearing and profound deafness, a perfusion single photon emission tomography (SPECT) study was designed. SPECT stereotaxic localisation of the auditory cortex was previously validated in 2 brains by means of an anatomical study of the macroscopic localisation and cytoarchitecture of the auditory cortex. Additionally, 15 controls with normal hearing and 30 patients with profound bilateral deafness were scanned using external anatomical point sources (glabela, ineon) for stereotaxic location of the auditory cortex. The normal controls were scanned in auditive deprivation and, in 10 cases, during a monoaural tonal stimulation. Cerebral blood flow relative to cerebellum (relCBF) was assessed in the auditory cortex. The anatomical study showed that mean differences between the true auditory cortex size and the measured SPECT value were less than 2.5 mm. Nevertheless, only the caudal aspect of this area corresponded to the primary auditory cortex in the cytoarchitectonic study. During tonal stimulation, control subjects presented a significant increase of relCBF in the auditory cortex bilaterally, with significant differences in the asymmetry index (contralateral to the side of stimulation). The relCBF in the auditory cortex of controls in deprivation conditions was significantly higher than in deaf patients. There were no significant differences between groups of deaf patients, however the highest values were seen after cochlear implant. SPECT is a suitable method for studying changes in auditory cortex activity relative to different functional conditions, with a possible role in cochlear implant candidates in predicting the future benefit of the implantation.

English Abstract↗