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Biomedical subjects

J J Rivas

Publications and source records attributed to J J Rivas.

At least 37 records · Page 2Linked to original sources
PubMed1996

Irreversible tetraplegia after tracheal resection.

The case of a 21-year-old woman without previous cervical pathology in whom irreversible tetraplegia developed after operation for tracheal stenosis is reported. After tracheal resection the neck was kept in extreme flexion and after extubation she was moved to a sitting position. The different causal agents that could produce the neurologic damage remain unclear, although we think that the combination of relative arterial hypotension secondary to the sitting position and disturbed autorregulation, caused by extreme neck flexion, could result in ischemic spinal cord injury.

Adult↗
PubMed1996

[Vertigo as an atypical symptom of intraspinal cord tumor].

Vertigo is an unpleasant sensation of movement of the subject or of his surroundings. There are many causes of vertigo. Traditionally these are divided into 'central' and 'peripheral'. It is unusual to find it as a symptom of myelopathy. We describe the case of a 67 year-old woman with no significant previous clinical history who complained of the sudden onset of vertigo a few hours previously, which worsened on turning her neck towards the left. On examination, the vertigo recurred on turning her neck to the left after a latent period of a few seconds together with the appearance of ipsilateral conjugated nystagmus, which gradually disappeared. On neurological examination, there was amyotrophy of both arms with weakness, considerably reduced reflexes, except for clonus of the left wrist. There was slight paraparesia with bilateral cutaneoplantar flexion and a level of sensitivity at C2-C3. The sensitivity disorder was more marked in the arms with a bilateral distribution approximately at C5-C7 affecting predominantly thermoanalgesia. Cervical MRI showed a mass consistent with ependymoma. This was removed surgically 2 weeks after admission. The findings of the intraoperative biopsy confirmed the radiological diagnosis. The vertigo improved one week after admission, although the patient died of pneumonia one month after operation. Despite the vertigo was an atypical symptom, it was the clue that led to the diagnosis. Hypotheses about the cause of vertigo are discussed.

Aged↗
PubMed1994

[Surgery in goiter with a primary mediastinal manifestation].

Eight patients with mediastinal masses and occupational syndrome were presented. Seven were diagnosed prior to surgery, allowing the staff to plan the procedure. The cervical route is advisable. It provides the best exposure that provides the safest surgery, but the incision must often be enlarged for the patient's safety. Results of surgery are excellent, with immediate relief of compressive symptoms. Postoperative infection of the wound is a possible complication. Results of medium- and long-term follow-up lead us to advise concomitant medical treatment along with surgery, given the risk of recurring goiter.

Adult↗
PubMed1994

Changes in systemic blood pressure and cardiac rhythm induced by therapeutic compression of the trigeminal ganglion.

Percutaneous compression of the trigeminal ganglion, which is currently being used for the control of trigeminal neuralgia, induces marked intraoperative elevations of the systemic blood pressure and heart rate changes, which may increase the risk of cardiovascular complications. We have analyzed the characteristics of the arterial hypertensive response and the cardiac rhythm changes induced by percutaneous compression of the trigeminal ganglion in 42 consecutive, unselected patients undergoing operations for essential trigeminal neuralgia under three different regimens of anesthesia. The first 22 patients (Group 1) underwent operations under brief general anesthesia without endotracheal intubation. The following 10 patients (Group 2) had general anesthesia with intubation and mechanical ventilation and received larger doses of hypnotic and analgesic agents. Finally, 10 more patients (Group 3), who had general anesthesia with intubation, underwent local anesthetic blockade of Meckel's cave (injection of 1 ml of 1% lidocaine) before ganglion compression. Foramen ovale puncture elicited bradycardia in the majority of the patients of Groups 2 and 3, but only four patients (18%) of Group 1 showed bradycardia. Ganglion compression caused marked tachycardia in all patients of Groups 1 and 2; about one-third of the patients also had extrasystoles. By contrast, patients of Group 3, who had local anesthetic blockade of Meckel's cave before ganglion compression, did not develop tachycardia or extrasystoles. Foramen ovale puncture elicited marked elevations of the systemic blood pressure in all patients. Ganglion compression further increased blood pressure, except in patients of Group 3, who had local anesthetic blockade of Meckel's cave.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Comparison of the clinical presentation of symptomatic arteriovenous malformations (angiographically visualized) and occult vascular malformations.

The authors compared the clinical presentations of angiographically apparent arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain in 188 consecutive patients treated when computed tomography and magnetic resonance were available. There were 133 patients (70.7%) with AVMs and 55 patients (29.2%) with AOVMs. AOVMs tended to occur more frequently in male patients and in the posterior fossa and to present earlier clinically than AVMs, but differences were not significant. One distinctive feature was the greater size of AVMs, as compared with AOVMs. Presentation by hemorrhage occurred in 64.3% of the patients with AVMs and in 61.8% of those with AOVMs. Malformations of both types located in the posterior fossa presented with hemorrhage more frequently (84.2% of AVMs and 78.5% of AOVMs) than similar lesions lying above the tentorium (60.8% of AVMs and 56% of AOVMs). Bleeding was more severe in patients with AVMs than in those with AOVMs, as indicated by the higher mortality associated with hemorrhage (7.5 vs. 3.6% of the cases) and the more frequent and marked decrease in the level of consciousness observed at admission (34 vs. 16.2% of drowsy or comatose patients). Brain hematomas caused by AVMs were on average bigger than those caused by AOVMs (58.8 and 20% of large hematomas, respectively), and intraventricular and subarachnoid hemorrhages were also more common and profuse in patients with AVMs. However, AOVMs bled subsequently more times than AVMs (61.7 vs. 15.6%), before they were diagnosed and treated, leading to a higher nonoperative morbidity (16.3 vs. 13.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Head-injured patients who talk and deteriorate into coma. Analysis of 211 cases studied with computerized tomography.

Of 838 patients with severe head injuries admitted since the introduction of computerized tomography, 211 (25.1%) talked at some time between trauma and subsequent deterioration into coma. Of these 211 patients, 89 (42.2%) had brain contusion/hematoma, 46 (21.8%) an epidural hematoma, 35 (16.6%) a subdural hematoma, and 41 (19.4%) did not show focal mass lesions. Thus, four of every five patients who deteriorated into coma after suffering an apparently nonsevere head injury had a mass lesion potentially requiring surgery: the mass was intracerebral in 52.3% of the cases and extracerebral in 47.6%. Patients aged 20 years or less had a 39% chance of having a nonfocal mass lesion (diffuse brain damage), a 29% chance of having an epidural hematoma, and a 32% chance of having an intradural mass lesion; patients over 40 years had only a 3% chance of having a nonfocal mass lesion, an 18% chance of having an epidural hematoma, and a 79% chance of having a intradural mass lesion. Sixty-eight (32.2%) patients died and 143 (67.8%) survived. The following were independent outcome predictors (in order of significance): Glasgow Coma Scale score following deterioration into coma, the highest intracranial pressure during the patient's course, the degree of midline shift, the type of intracranial lesion, and the age of the patient. In contrast, the mechanism of injury, the verbal Glasgow Coma Scale score during the lucid interval, and the length of time until deterioration or until operative intervention did not influence the final result.

Adult↗
PubMed1990

Percutaneous microcompression of the gasserian ganglion for trigeminal neuralgia.

The authors report 144 cases of trigeminal neuralgia treated by percutaneous microcompression of the trigeminal ganglion (PMTG). The operation was performed under short-lasting barbiturate anesthesia without endotracheal intubation. Meckel's cave was cannulated with a No. 4 Fogarty catheter and the balloon was inflated for 1 minute. The average intraluminal pressure required for adequate compression of the ganglion was about 1200 mm Hg. All patients were initially relieved of their neuralgia. In a follow-up period ranging from 6 months to 4 1/2 years, 14 patients (9.7%) developed recurrence of pain between 10 and 35 months after surgery. Eleven patients underwent a second PMTG. All nine early failures and 10 of the 11 late recurrences occurred in cases with technical deficiencies. Most of the minor surgical complications observed were also related to avoidable technical errors. There were no anesthetic complications and no deaths. All patients developed mild to moderate postoperative hemifacial numbness with or without objective hypesthesia. Both subjective and objective deficits gradually diminished with time and were well tolerated. One year after the operation nearly 40% of the patients still had patches of slightly decreased sensation in one or more trigeminal divisions and 16% had mild dysesthesia. Anesthesia dolorosa or keratitis was not reported. The PMTG procedure is easy to perform and requires a short operative time and a brief period of hospitalization. It is well tolerated by patients, who describe it as a totally pain-free experience. Morbidity is minimal and recurrence of neuralgia does not seem to be higher than with alternative procedures.

Catheterization↗
PubMed1989

Subarachnoid haemorrhage of unknown aetiology.

The authors review the literature on subarachnoid haemorrhage of unknown aetiology (SAHUE) and analyze a personal series of 212 patients diagnosed as SAHUE. These patients represent 30% of all cases of primary SAH admitted over a 14.5 year period. The age, sex, antecedents and initial clinical presentation of patients with SAHUE were indistinguishable from those of patients with subarachnoid haemorrhage due to ruptured aneurysm (SAHRA). However, the present series of SAHUE compare favourably with both a personal and a previously reported series of SAHRA insofar as clinical grade on admission (94% of patients in grades I-II of Botterell), presence of blood on CT (51%), vasospasm (5%), ischaemic deficits (3.3%), persistent hydrocephalus (3.5%), rebleeding (6%) and fatal result (3.9%) are concerned. The amount of blood on CT scan in our patients with SAHUE was associated with a significantly higher incidence of brain ischaemia and hydrocephalus but did not correlate with the Botterell grade on admission or final outcome, which were good in the majority of cases regardless of the presence or not of visible cisternal haemorrhage. The results of the present series confirm that the final prognosis of patients with primary SAH showing normal four-vessel cerebral angiography is essentially favourable.

Adolescent↗
PubMed1988

Cerebral hemisphere swelling in severe head injury patients.

The clinical course and the intracranial pressure (ICP) changes in 66 severe head injury patients presenting bulk enlargement of one cerebral hemisphere within a few hours of trauma have been analyzed. These patients represent 11% of a series of 589 severe head injury cases studied with computerized tomography (CT). Cerebral hemisphere swelling, which was associated with an ipsilateral subdural haematoma of variable extent in 58 patients (88%), or a large epidural haematoma in 5 patients (7%), and occurred as an isolated lesion in 3 patients (4%), carried the highest incidence of uncontrollable intracranial hypertension, the highest mortality rate and the shortest survival period after trauma in the authors' severe head injury series. The high incidence of arterial hypotension and/or hypoxaemia at admission (48% of cases), and the severity of clinical presentation (82%) of patients scored 5 patients or less in the Glasgow Coma Scale, 77% had uni- or bilateral mydriasis and 82% initial ICP above normal limits) correlated with the very poor final outcome (85% mortality). Only one of the 12 patients with normal initial ICP continued to have low pressure throughout the course. High dose thiopental failed to control severe intracranial hypertension in 29 patients (44%) who had a fulminant, malignant course. A transient decrease in ICP elevation was achieved in 17 patients (26%) and a definitive control in 12 patients (18%), among them the 10 survivors in this series. In the authors experience once ICP is controlled, and unless haemodynamic instability compells action to the contrary, barbiturate should not be discontinued until a control CT scan shows complete disappearance of the mass effect.

Adolescent↗
PubMed1988

Extradural hematoma: analysis of factors influencing the courses of 161 patients.

The clinical and computed tomographic (CT) findings in a series of 161 consecutive patients operated upon for postraumatic extradural hematoma are analyzed. Thirteen (8%) patients had delayed epidural hematoma formation. The overall mortality for the series was 12%, significantly lower than that observed during the prior "angiographic" period at the same unit (30%). Because all but 1 of the deaths occurred among the 66 patients unconscious at the time of operation (27% mortality in this subgroup), the authors sought differential factors between comatose and noncomatose patients at operation. There were no significant differences between these groups in age, sex, mechanism of injury, preoperative course of consciousness (lucid interval or not), or epidural hematoma location and shape. In contrast, significant differences were seen between the two subgroups in trauma-to-operation interval, hematoma volume, CT hematoma density (mixed low-high CT density vs. homogeneous hyperdensity), midline displacement, severity of associated intracranial lesions, and postoperative intracranial pressure (ICP). Patients comatose at operation usually evidenced a more rapid clinical deterioration (a shorter trauma-to-operation interval) and tended to have a large hematoma volume, a higher incidence of mixed CT density clot (hyperacute bleeding), more marked shift of midline structures, more severe associated lesions, and higher postoperative ICP levels.

Adolescent↗
PubMed1988

Acute epidural hematoma: an analysis of factors influencing the outcome of patients undergoing surgery in coma.

Mortality due to epidural hematoma is virtually restricted to patients who undergo surgery for that condition while in coma. The authors have analyzed the factors influencing the outcome of 64 patients who underwent epidural hematoma evacuation while in coma. These patients represented 41% of the 156 patients operated on for epidural hematoma at their centers after the introduction of computerized tomography (CT). Eighteen patients (28.1%) died, two (3.1%) became severely disabled, and 44 (68.8%) made a functional recovery. The mortality rate for the entire series was 12%, significantly lower than the 30% rate observed when only angiographic studies were available. A significant correlation was found between the final result and the mechanism of injury, the interval between trauma and surgery, the motor score at operation, the hematoma CT density (homogeneous vs. heterogeneous), and the hematoma volume. The patient's age, the course of consciousness before operation (whether there was a lucid interval), and the clot location did not correlate with the final outcome. The mortality rate was significantly higher in patients operated on within 6 hours or between 6 and 12 hours after injury than in those undergoing surgery 12 to 48 hours after injury. Compared with the patients operated on later, the patients undergoing surgery in the early period were, on the average, older and had more rapidly developing symptoms, more pupillary changes, lower motor scores at surgery, larger hematomas, a higher incidence of mixed CT density clots, more severe associated intracranial lesions, and higher postoperative intracranial pressure (ICP). The mechanism of trauma seems to influence the course of consciousness before and after surgery. Passengers injured in traffic accidents had a lower incidence of a lucid interval and longer postoperative coma than patients with low-speed trauma, suggesting more frequent association of diffuse white matter-shearing injury. The duration of postoperative coma correlated with the morbidity rate in survivors. Forty-eight patients (75%) had one or more associated intracranial lesions, and 70% of these required treatment for elevation of ICP after hematoma evacuation. An ICP of over 35 mm Hg strongly correlated with poor outcome; administration of high-dose barbiturates was the only effective means for lowering ICP in nine of 15 patients who developed severe intracranial hypertension after surgery. This study attempts to identify patients at greater risk for presenting postoperative complications and to define a strategy for control CT scanning and ICP monitoring.

Acute Disease↗
PubMed1988

Posttraumatic cerebral hemispheric swelling. Analysis of 55 cases studied with computerized tomography.

The authors have analyzed the clinical course and intracranial pressure (ICP) changes in 55 severely head-injured patients presenting with bulk enlargement of one cerebral hemisphere within a few hours after trauma. These patients represent 10.5% of a series of 520 patients with severe head injury studied with computerized tomography (CT). Cerebral hemispheric swelling has the highest mortality rate and the shortest survival period after trauma in all series of severe head injury. In this series, it was associated with an ipsilateral subdural hematoma of variable size in 47 patients (85%) or with a large epidural hematoma in five patients (9%); in three patients (5.4%) it occurred as an isolated lesion. Evacuation of an associated extracerebral hematoma, which was performed within 4 hours after injury in only 20% of cases, scarcely changed the patients' preoperative neurological status. The high incidence of arterial hypotension and/or hypoxemia at admission (47% of cases) and the severity of the clinical presentation (82% of patients scored 5 points or less on the Glasgow Coma Scale, 74% had unilateral or bilateral mydriasis, and 80% had an initial ICP above normal) correlated with a very poor final outcome (87% mortality). Only one of the 11 patients with normal initial ICP continued to have normal pressure throughout the course. High-dose thiopental failed to control severe intracranial hypertension in 24 patients (51%) who had a fulminant, malignant course. A transient decrease in ICP elevation was achieved in 15 patients (31.4%) and definitive control in eight patients (17%), among whom were the seven survivors in this series. In the authors' experience, once ICP is controlled, barbiturate administration should not be discontinued until a control CT scan shows complete disappearance of the mass effect.

Adolescent↗
PubMed1988

Clinical, radiological, and pathological spectrum of angiographically occult intracranial vascular malformations. Analysis of 21 cases and review of the literature.

The clinical, radiological, and histopathological features of 21 cases of angiographically occult intracranial vascular malformations (AOIVM's) are analyzed, and a review of 241 additional appropriately documented, histologically verified cases collected from the literature is presented. In all, there were 115 (43.8%) arteriovenous malformations, 82 (31.2%) cavernous angiomas, 26 (9.9%) venous angiomas, 10 (3.8%) cases of capillary telangiectasis, and 29 (11%) mixed or unclassified angiomas. The result of the analysis shows that there are no essential differences in the patterns of clinical presentation, the computerized tomography (CT) appearance, or the surgical prognosis among these pathological types of vascular malformations. Certain histological features common to all AOIVM's (such as the small caliber, the more or less complete thrombosis of the malformed vessels, and the changes induced in the surrounding brain tissue by repeated microhemorrhages) seem to determine the biological behavior of the anomaly rather than the predominant type of vessel involved. Thus, subdivision of AOIVM's into the four classical pathological types has little practical value. Most AOIVM's are visualized by the CT scan and show a rather typical appearance. Surgical removal, which prevents rebleeding and ameliorates or suppresses seizure activity, is usually easy to perform and represents the treatment of choice for patients with clinically symptomatic AOIVM's.

Adolescent↗
PubMed1987

Post-traumatic diffuse brain swelling: isolated or associated with cerebral axonal injury. Clinical course and intracranial pressure in 18 children.

Eighteen children with severe head injuries and diffuse brain swelling were studied. They were separated into two groups based on the computed tomography (CT) findings. Seven patients had small ventricles in the normal location and small or absent cisterns. Eleven had these signs plus small deep-seated intraparenchymal hemorrhagic foci and/or intraventricular hemorrhage. Patients in the first group were in relatively good neurological condition; their intracranial pressure was easily controlled and all had a favourable outcome. On contrast, children in the second group had a more severe clinical presentation, frequently had uncontrollable intracranial hypertension, and more than 50% died.

Axons↗
PubMed1987

Applications of CT-adapted stereotaxis for the diagnosis and treatment of intracranial lesions.

Two hundred twenty five patients with intracranial lesions underwent diagnostic and therapeutic stereotactic surgery during the period 1978-1985. In the first 98 cases target coordinates were determined by transferring the information from the CT images to the standard stereotactic films. In the remainder, a simple, CT adapted stereotactic system has been used. Operations were as a rule performed under local anaesthesia. Positive histological diagnosis using paraffin embedding was achieved in 96% of the patients (biopsy success rate). Therapeutic procedures included abscess and cyst aspiration, cyst shunting, interstitial (Ir 192) or intracavitary (Y 90) irradiation and ventriculocisternostomy. Stereotactic surgery implied a refinement of the eventual therapeutic management in 90% of the cases. Transient neurological deficit occurred in 5.7% of the patients and there were three deaths (mortality rate 1.3%). Infection or other complications were not seen. The rationale and indications for non-functional stereotaxis are discussed.

Adolescent↗
PubMed1987

Intraventricular morphine for intractable cancer pain: rationale, methods, clinical results.

The experience with the administration of intraventricular morphine for the control of malignant pain in 197 patients is analyzed. Small doses of morphine injected via a ventricular reservoir provided satisfactory control of otherwise intractable pain in terminal cancer-patients. Complete analgesia together with a favourable behavioral response was obtained without noticeable neurological changes or side-effects annoying or severe enough for the patients to discontinue therapy. Tolerance was much less marked than with parenteral opiates. Chronic intraventricular therapy can be safely performed on an outpatient basis by injecting the opiate once or twice a day. The method may be improved by using refillable continuous-infusion devices and new drugs, able to retain the analgesic effects of morphine while eliminating the unwanted ones.

Adolescent↗
PubMed1986

Post-traumatic diffuse axonal brain injury. Analysis of 78 patients studied with computed tomography.

A group of 78 severe head injury patients showing computerized tomography (CT) findings of the so-called "diffuse axonal injury" is analyzed. These patients represent 20% of the authors' series of severe head injury. Twenty-three patients showed small intraparenchymal haemorrhages in the CT scan study, 15 intraventricular haemorrhage and 40 patients had both intraparenchymal and intraventricular haemorrhages. Signs of brainstem haemorrhagic contusion were seen in 29 (38%) patients. Generalized brain swelling superimposed on the above findings was present in 75% of the cases. Raised intracranial pressure, which was found in 50% of the patients, correlated with the presence of ventriculocisternal collapse in the CT scan and an unfavourable outcome. Only 4 patients in this series made a good recovery, 13 developed a moderate disability, 11 a severe disability, 12 became vegetative and 38 (49%) died. The prognosis with this post-traumatic lesion is the worst in the authors' severe head injury series after excluding cases with subdural haematoma.

Adolescent↗