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Biomedical subjects

J L Antunes

Publications and source records attributed to J L Antunes.

At least 19 recordsLinked to original sources
PubMed1996

Intramedullary neuroma of the cervical spinal cord: case report.

OBJECTIVE AND IMPORTANCE: Intramedullary neuromas are rare tumors; only 37 cases have been described in the literature since 1931. CLINICAL PRESENTATION: The case of a 36-year-old woman presenting with an 8-month history of a progressive cervical myelopathy is reported. A diagnosis of a cervical intramedullary tumor was made by magnetic resonance imaging. INTERVENTION: A C3-C7 laminectomy and a near total resection were performed. Pathological examination revealed a neuroma; the various operative and pathological findings are presented. CONCLUSION: The existence of intraparenchymal neuromas is difficult to explain. Various pathogenic hypotheses are discussed. Microsurgical resection is considered the therapeutic option of choice for these entities.

Adult↗
PubMed1995

The peptidergic innervation of the human superficial temporal artery: immunohistochemistry, ultrastructure, and vasomotility.

The peptidergic innervation of the human superficial temporal artery was investigated by means of immunohistochemical, ultrastructural, and in vitro pharmacological techniques. A dense network of nerve fibers was found in the adventitia. The majority of the nerve fibers displayed immunoreactivity for tyrosine hydroxylase and neuropeptide Y (NPY). A moderate supply of perivascular nerve fibers displayed either acetylcholinesterase activity or immunoreactivity for vasoactive intestinal peptide (VIP), peptide histidine methionine-27 (PHM), and calcitonin gene-related peptide (CGRP). Only a few nerve fibers displayed substance P (SP), neurokinin A (NKA), and neuropeptide K (NPK) immunoreactivity. In double immunostained preparations, SP immunoreactivity was co-localized with NPK and CGRP in the same nerve fibers. Ultrastructural studies revealed the presence of numerous axon variocosities at the adventitial--medial border. NPY, VIP, and CGRP immunoreactivities occurred in the same type of large granular vesicles, but in morphological distinct nerve profiles. NPY had, in general, no direct vasoconstrictor effect. However, at a low concentration of NPY contractile response induced by NA (10(-7)-10(-6)M) was 9-15 times enhanced. The NPY-induced potentiation of the NA-induced contraction was not dependent on the presence of an intact endothelium. No significant difference was found between acetylcholine, VIP, and PHM in either potency or degree of relaxation. SP, NKA, and CGRP also acted as vasodilatory agents, with CGRP being more potent than the tachykinins. The response to SP, but not CGRP, was dependent on an intact endothelium. Pretreatment of the vessels with a low concentration of NPY did not change the responses to ACh, VIP, SP, or CGRP.

Acetylcholinesterase↗
PubMed1995

Atypical dominance for language in developmental dysphasia.

The authors report an association between developmental language disorder and acquired aphasia in a 13-year-old right-handed boy. Acquired aphasia was caused by a right-frontal abscess (crossed aphasia). It was non-fluent, with a disorder of auditory comprehension, an unusual feature of prerolandic lesions. This case shows that developmental language impairment can be associated not only with an atypical cerebral dominance, but also with unusual patterns of intrahemispheric specialization. The rapid and complete recovery of this boy's aphasia suggests that the cerebral plasticity for acquired lesions can be normal in such cases.

Adolescent↗
PubMed1995

Spontaneous cerebrospinal fluid fistula through the clivus: report of two cases.

There have been no previous reports of a spontaneous cerebrospinal fluid fistula through the clivus. We present two such cases, describe their management, and propose a physiopathological explanation. The pulsating effect of the basilar artery in Patient 1 and brisk increases in intracranial pressure through repeated Valsalva maneuvers, acting on a congenitally thin bone in Patient 2, seem to be the plausible causes for the clival leakage.

Adult↗
PubMed1995

[A diaphragmatic pacemaker in the treatment of ventilatory failure].

Diaphragmatic Pacing was used to treat ventilatory failure in a young boy with bilateral diaphragmatic palsy secondary to cervical cord injury, on chronic mechanical ventilation for 6 months. The indications for diaphragmatic pacing in ventilatory failure were discussed, as well as the assessment of phrenic nerve integrity and the pacing schedules utilized to slowly improve the diaphragm endurance and achieve a full-time weaning from mechanical ventilation.

Brain Injuries↗
PubMed1995

[Spinal epidural empyemas].

We report ten patients harbouring spinal epidural abscess, aiming to evaluate the factors that may lead to an early diagnosis and that can eventually influence the prognosis. There were seven males and 3 females, with ages comprised between 17 and 66 years. Abscesses were localised mainly in the dorsal region. The most important predisposing factors were infections or other disorders know to be related with compromise of the immunological system. Back pain with or without signs of spinal cord involvement was the most frequent clinical presentation. The pretreatment average time was 16,3 days. Staphylococcus aureus was the most commun organism isolated. Erythrocyte sedimentation rate (ERS) was uniformly elevated, being the most important laboratory data for the diagnosis of this situation. Diagnosis was frequently made on clinical grounds but it was always confirmed by myelography with computed tomography or magnetic resonance. All patients were submitted to surgical drainage. Two patients recovered totally, 5 partially, 2 did not recover at all and 1 died. We conclude that the prognosis is related to the surgical delay and that it depends on the identification of the predisposing factors and the recognition of a clinical picture of spinal cord involvement associated to an elevated ESR. Magnetic resonance is the most reliable imaging technique.

Abscess↗
PubMed1994

Subacute cervical epidural hematomas.

The authors report two cases of cervical epidural hematomas with atypical subacute clinical presentation; both were operated on with excellent results. The literature is reviewed and the etiologic factors, clinical presentation, diagnosis, and therapy are discussed. It is concluded that the clinical presentation and evolution of cervical epidural hematomas are more variable than previously described, including slow evolving forms and even cases with spontaneous resolution. Magnetic resonance imaging is the diagnostic procedure of choice. Early surgical decompression and evacuation of the lesion is the indicated therapy in most cases.

Acute Disease↗
PubMed1994

[Aneurysmal bone cysts of the spinal canal].

Aneurysmal bone cysts (ABC) are rare bone tumors of controversial pathogenesis. In 15% of cases, they are localized in the vertebrae. Despite the absence of anaplasia, their volume and localization are often responsible for incomplete surgical resection. The authors present 5 cases of primary vertebral ABC, 4 females and one male, localized in cervical (3 cases), dorsal (1 case) and lumbar (1 case) spine. Symptoms included rachialgia and torticollis. Radiological and histopathological examination disclosed the typical features of ABC. Pre-operative embolization (in 3 cases) and surgery (complete exeresis in all cases except one) were the therapeutic procedures. During a 39 month median period of follow-up, there was one local recurrence. The only case of incomplete exeresis show not did any evidence of progression until 36 months after operation.

Adolescent↗
PubMed1993

Renal tubular sodium and water metabolism in brain tumour patients submitted to craniotomy.

PURPOSE: To evaluate the effect of Brain Tomour (BT) and Neurosurgery (NS) on the renal handling of H2O and Na, and the clinical importance of SIADH in this setting. METHODS: Fourteen patients with BT pre-op for NS and 6 controls (C) pre-op for general surgery, were assessed in a controlled prospective trial. All patients were normovolaemic, with normal renal function. They received 400 mg of lithium carbonate (Li) 8 hours before each of two test periods (I and II) and a standard water load only before period II. Clearances studies were performed pre-op (period I) and 24 hours post-op (period II). RESULTS: Serum Na was normal at all times. Despite normovolaemia, a 1% decrement in serum osmolality and the water load, ADH dramaticaly increased from time I to II mainly in the BT group (36.2 +/- 9.4 vs 7.1 +/- 0.6 pmol/L, p = 0.02). FENa, FELi and FEUricA were significantly more elevated in the BT group pre and post-op (at time II respectively 4.6 +/- 1.6 vs 1.1 +/- 0.3%; 29.3 +/- 4.9 vs 22.6 +/- 5.5; 26.0 +/- 8.1 vs 11.3 +/- 2.2, p = 0.03). Proximal and distal H2O re-absorption and distal fractional Na re-absorption were identical in both groups pre and post-operatively. CONCLUSIONS: 1-BT and NS always induce a SIADH. 2-There was a primary Na loss at the proximal tubule level not explained by ADH increment, that did not significantly changed H2O handling. 3-To prevent hyponatraemia, hypotonic I.V. fluids should be avoided, but more importantly saline must be provided to this potentially salt-wasting condition.

Adult↗
PubMed1993

[Errors in medicine].

The author discusses the different kinds of errors that may be committed in clinical practice. The socioeconomic and professional factors that make doctors particularly vulnerable are briefly reviewed.

Clinical Medicine↗
PubMed1992

[Perimesencephalic hemorrhage].

Among 293 subarachnoid hemorrhages admitted to the Neurology and Neurosurgery departments of Sta Maria Hospital, 108 patients had a normal cerebral angiography. Twenty-three meet the radiological criteria for perimesencephalic hemorrhage (center of the hemorrhage located in front of the mesencephalon, without blood in the interhemispheric and lateral sylvian fissures, nor significant intraventricular hemorrhage). The clinical picture was one of sudden, severe headache with meningeal signs, without focal signs or decreased alertness. Evolution was benign: there was no intrahospital mortality, morbidity or rebleeds on follow-up (3.5 years). In this subgroup of subarachnoid hemorrhage there is no need for a repeated angiogram if the first angiography is considered normal.

Female↗
PubMed1992

[Neuroradiology in the physiopathologic diagnosis of subarachnoid hemorrhage--cerebral aneurysm].

The clinical importance of the cerebral aneurismatic lesion in well known. In Portugal we still do not have reliable statistics regarding the occurrence of the subarachnoid hemorrhage, however we can make a comparison through Kassel's and Drake's studies where they refer that annually 28,000 North-Americans suffer from subarachnoid hemorrhage attributed to the rupture of the cerebral aneurysm. This is a clinical situation that needs to be analyzed, more so because if it is not diagnosed and treated in time, it can cause a high level of morbidity and mortality. From 1984 to 1990, the authors studied 208 clinical cases of in-patients at the Santa Maria Hospital who had been diagnosed as having subarachnoid hemorrhage-cerebral aneurysm. They analyzed 172 cranium-encephalic Tomographies and 190 cerebral Angiographies. They found levels that overlapped the series already published with respect to the location of the lesion, dimensions and age groups involved. They tried to relate the presence aneurysm in the willis arterial circle with the occurrence of locoregional anatomic variants that were detected in 51% of the patients with aneurysm of the anterior communicating artery and in 33% of the cases in the posterior communicating artery. The high occurrence of serious forms of tomodensitrometric presentation should also be emphasized. As a matter of fact, 42.6% of the patients studied were grouped in degree IV of the Fisher Scale. This result translates the effort that is still required towards an early clinical and imaging diagnosis of warning hemorrhage to avoid or prevent a catastrophic hemorrhage recurrence.

Adult↗
PubMed1992

[Spinal cord tumors. Anatomoclinical study].

The authors review 36 cases of intramedullary spinal tumours, 17 ependymomas, 12 astrocytomas, 6 hemangioblastomas and 1 metastasis of leiomyosarcoma. The tumours were localized in the cervical region in 19 patients, in the thoracic region in 10 in the lumbar region in 4, and in the conus medullaris in 3. All patients presented a clinical picture of myelopathy. No differences were observed between the different hystological types. In 5 patients the tumour was associated with syringomyelia and one of these patients also presented a type I Chiari malformation. All patients were submitted to surgery (using microsurgical techniques in the last seven years). Radiation therapy was also given in 16 cases. Our results demonstrate that microsurgical resection is the only treatment that significantly improves the prognosis of these patients, from both the standpoint of the functional status and survival.

Adult↗
PubMed1989

Partial section of the corpus callosum: focal signs and their recovery.

A 30-year-old woman underwent surgical partial callosotomy (posterior half) for removal of an arteriovenous malformation. The patient submitted to neuropsychological evaluation before and after surgery for a period of 8 months. There was transient dysfunction attributable to disconnection of parietal, temporal, and occipital connections. Because the symptoms disappeared over time, we conclude that the transcallosal surgical approach can, in the long term, be considered a relatively harmless method.

Adult↗