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Biomedical subjects

Z Domingo

Publications and source records attributed to Z Domingo.

At least 19 recordsLinked to original sources
PubMed2001

The stimulation of vascular smooth muscle oxidative metabolism by CSF from subarachnoid haemorrhage patients increases with Fisher and WFNS grades.

The purpose of this paper is to present an in vitro method for examining cerebral vasospasm after subarachnoid haemorrhage (SAH) which correlates to the patients' condition. The O2 consumption of the porcine carotid artery was monitored, using an oxygen electrode, after exposure to cerebrospinal fluid (CSF) from patients who had a SAH. The vessels were exposed to CSF from SAH patients at a 1 in 30 dilution. Force measurements were carried out using freeze-dried CSF, reconstituted in the organ bath equivalent to undiluted CSF. These observations were then compared to the patients' condition. We divided the patient CSF samples into those that stimulated oxygen consumption above 0.4 microM/min/g dry wt, and those that did not. It was found that there was a correlation between the stimulation of oxygen consumption and the Fisher grade as well as the World Federation of Neurosurgeons Grading System (WFNS) for the patients. Of the CSF tested, 24 stimulated oxygen consumption above our cut off, and 8 did not (0.84 +/- 0.34, n = 24 compared with the rate of 0.27 +/- 0.1 mumol/min/g dry wt, respectively; SD n = 8) at 180 minutes. We then examined the Fisher Grades of these two groups, the results were 3.21 +/- 0.88 vs 2.25 +/- 0.83 respectively (SD p < or = 0.01). When examining the WFNS System we found a similar difference between the groups that stimulated respiration and those who did not (WFNS Grades of 2.64 +/- 1.1 vs. 1.43 +/- 0.53; p < or = 0.01). The observed stimulation of oxygen consumption also correlated with tension generation in vitro. The CSF from subarachnoid haemorrhage patients stimulates the oxygen consumption of the porcine carotid artery. This stimulation correlated to the WFNS and Fisher Grades of the patients and can be performed using 1:30 dilution of CSF. We conclude that the metabolic changes that occur in the vessels during vasospasm are important parameters for assessing cerebral vasospasm.

Animals↗
PubMed2001

Craniocerebral gunshot injuries in South Africa--a suggested management strategy.

OBJECTIVE: To determine the outcome of craniocerebral gunshot injuries, analyse factors that affect prognosis and suggest a management protocol. DESIGN: A retrospective analysis of civilian craniocerebral gunshot injuries treated over a 7-year period. SETTING: Groote Schuur Hospital's neurosurgery and trauma unit service. PATIENTS: One hundred and eighty-one patients with craniocerebral gunshot injuries were admitted to the Department of Neurosurgery, Groote Schuur Hospital, University of Cape Town, over a 7-year period and a retrospective analysis of these patient records with regard to outcome and prognostic factors was carried out. RESULTS: Seventy-six patients sustained non-penetrating injuries, 8 (11%) of whom had underlying cerebral injury on computed tomography (CT) scan. The prognosis was good in the case of non-penetrating injuries. One hundred and five patients sustained penetrating injuries and 57% (62) had a poor outcome. A Glasgow Coma Score (GCS) of 5 or less following resuscitation was associated with a 98% mortality rate. CT scan evidence of transventricular injury was associated with 100% mortality, bihemispheric injury with 90% mortality, and diffuse cerebral swelling with 81% mortality. CONCLUSION: Patients with non-penetrating craniocerebral gunshot injuries should all undergo a CT scan as 10% will have cerebral injury. The prognosis is normally good. In penetrating craniocerebral gunshot injuries a GCS of 5 or less, or a GCS of 8 or less with CT scan findings of transventricular or bihemispheric injury have such a poor outcome that conservative treatment is indicated.

Adolescent↗
PubMed2000

Diffusion weighted imaging and magnetic resonance spectroscopy in a low flow ischaemia model due to endothelin induced vasospasm.

The aim of this MR study was to determine if vasospasm induced by application of endothelin-1 (ET-1) in the rat brain would model the abnormalities attributed to vasospasm described in patients with subarachnoid haemorrhage (SAH) with reversible neurological deficits. Following application of ET-1 in concentrations of 10(-4) M or 10(-6) M to the middle cerebral artery, there was an immediate drop in pH, an increase in the inorganic phosphate (P(i)) to phosphocreatine (PCr) ratio and elevated lactate. There was gradual recovery to control in the 10(-6) M group, but in the 10(-4) M group there was a loss of approximately 10% in the absolute signal intensities of PCr and adenosine triphosphate (ATP). In a second similarly treated group of animals, the area of the hemisphere with a low apparent diffusion coefficient (ADC) was 27 +/- 6% at 30 min and remained at about 20-21% at 90 min and beyond. Together these data suggest that the regions with persistently low ADC were metabolically compromised, with incomplete recovery of PCr and ATP, and represent irreversibly damaged tissue. This raises the possibility that MR spectroscopy and imaging could be a sensitive indicator of tissue viability. This is a potentially useful model of low flow as seen in clinical vasospasm following SAH.

Adenosine Triphosphate↗
PubMed1998

Role of ischaemia in the genesis of oedema surrounding meningiomas assessed using magnetic resonance imaging and spectroscopy.

Oedema surrounding meningiomas is well known, but its pathogenesis remains obscure. Perfusion and metabolism in this peritumoural parenchyma were studied preoperatively in eight patients using magnetic resonance imaging, dynamic perfusion scanning and proton spectroscopy. Relative cerebral blood volumes (CBV) and metabolite ratios were calculated for the tumour and peritumoural brain. All meningiomas showed gadolinium enhancement, high choline (Ch), low creatine (Cr) and low N-acetyl aspartate (NAA) [Ch: (Ch + Cr) 0.67, SD 0.13, NAA: (Ch + Cr) 0.18, SD 0.15]. Lactate was present in four tumours [lactate: (Ch + Cr) 0.32, SD 0.27]. Extremely low gadolinium passage and low CBV were seen in the 2 cm peritumoural region, with elevated lactate [lactate: (Ch + Cr) 0.26, SD 0.18]. Four centimetres from tumour margin the CBV was still reduced (65, SD 20% with less lactate [lactate: (Ch + Cr) 0.12, SD 0.01]. Relative CBV is reduced around meningiomas and is associated with lactate, suggesting that oligaemia and altered metabolism may be part of the pathology in peritumoural oedema. Such changes may be important in determining functional recovery after surgery.

Adult↗
PubMed1998

Discrepancies between cerebral perfusion and metabolism after subarachnoid haemorrhage: a magnetic resonance approach.

INTRODUCTION: There is a variable relation between angiographic vasospasm and delayed ischaemic neurological deficit (DIND). Magnetic resonance (MR) techniques have the potential to investigate the haemodynamic, metabolic, and structural changes occurring with these complications. These techniques have been applied to study DIND in patients recovering from subarachnoid haemorrhage. METHODS: Fifteen studies were performed on 11 patients, 10 with DIND. Vasospasm was diagnosed angiographically or with transcranial Doppler. The MR protocol consisted of T2 weighted imaging, contrast enhanced dynamic perfusion scanning, TI weighted imaging, and two dimensional localised proton spectroscopy. Relative cerebral blood volume maps were generated from perfusion scans. Metabolite ratios were calculated from proton spectra. RESULTS: All patients had cortical oedema on T2 weighted images, significantly more pronounced in patients of poor clinical grade (p<0.01). Spectra were normal in good grade patients. Lactate was increased and N-acetyl aspartate decreased in the poor grades, significantly worse in grade 4 compared with grade 3 patients (p<0.05). Spectral changes also correlated with the severity of oedema (p<0.05). Relative blood volumes were significantly higher in oedematous regions of poor compared with good grade patients (p<0.05). Lactate was seen in regions of the brain with increased relative blood volume. CONCLUSIONS: Despite the paramagnetic effects of haemorrhage, or of the coils and clips used to treat aneurysms, this study demonstrates that patients recovering from subarachnoid haemorrhage can undergo complex MR studies. Oedema, lactate, and increased relative blood volume correlate well with each other and with DIND and poor clinical grade.

Adult↗
PubMed1996

Midline developmental abnormalities of the posterior fossa: correlation of classification with outcome.

Fifty children with developmental retrocerebellar cysts of the posterior fossa, treated over an 11-year period, were assessed. The cysts were classified according to a morphological classification based on axial computerized tomography scans in order to assess the usefulness of this classification with regard to treatment and outcome. There were 35 patients with the Dandy-Walker complex and 15 patients with posterior fossa cysts. All surgically treated patients had cerebrospinal fluid shunting as the only form of treatment. Cystoperitoneal shunts were the treatment of choice. Although the morphological classification has relevance with regard to the embryological development of the cyst, it does not influence the selection of treatment nor the surgical outcome following shunt insertion.

Cerebellar Diseases↗
PubMed1995

Arteriovenous malformations of the scalp.

We report twenty-four patients with cirsoid aneurysms of the scalp. For nine patients (38%), the lesions were related to trauma. Each of the patients presented with a pulsatile scalp swelling with a bruit. No focal neurological deficits were noted in any of the patients. Scalp malformations in all patients were confirmed by selective internal and external carotid angiography, with no intracerebral component revealed in any of the patients. Twenty-one patients had the lesions surgically excised, with good results. The remaining three refused surgical intervention. Meticulous surgical technique, which includes removal of the pericranial component of the malformation, was paramount.

Adolescent↗
PubMed1994

Hydatid infestation of the brain: difficulties with computed tomography diagnosis and surgical treatment.

The radiological, surgical and pharmacological management of 11 children with cerebral hydatid disease is presented with special emphasis on the varying CT and MRI appearances and the surgical difficulties we have encountered. All but 2 had enhanced CT scanning and 2 had an MRI. The typical CT appearance of a large non-enhancing cyst of CSF density with minimal oedema was only seen in 3 children. Atypical appearances included irregularity of the cyst wall contour (2), enhancement of the surrounding rim (3), isodensity or heterogeneity of the cyst content (4), surrounding oedema (4) and globular as opposed to curvilinear calcification (2). Complete intact cyst removal was achieved in 3 patients. The reasons for puncturing the cysts or rupturing them at operation were failure to make a definitive pre-operative diagnosis (5), dense adhesions to the skull, dura or falx (3) and the misdiagnosis of an arachnoid cyst and the subsequent placement of a cystoperitoneal shunt (1). Pathological examination suggests that the degree of the inflammatory response to the ectocyst may determine the enhancement characteristics and the ease of surgical removal. There was 1 recurrence which responded well to four 28-day treatment cycles of albendazole.

Brain↗
PubMed1994

Low-velocity penetrating craniocerebral injury in childhood.

Fifty-four children with low-velocity penetrating injury of the skull and brain are described. The incidence of septic complications was 43%, which is significantly higher than that seen in adults. Nine percent of children developed vascular complications. Due to the high septic complication rate, a more aggressive management protocol consisting of craniectomy and dural repair under antibiotic cover is suggested.

Adolescent↗
PubMed1994

Clostridial brain abscesses.

Ten patients with clostridial abscesses of the brain are presented. Despite the presence of gas within the cerebral hemispheres and Clostridium welchii cultured from the pus obtained, the outcome of all patients managed with burrhole aspiration of the abscess was good. There were no deaths and eight of the ten patients had no residual deficit. Clostridial infections of the brain, unlike those of the soft tissues of the body, have a good outcome with conservative surgery and appropriate antibiotics.

Adolescent↗
PubMed1994

Brain abscess in childhood. A 25-year experience.

The presentation, treatment and outcome of 98 children with brain abscesses at Red Cross War Memorial Children's Hospital, Cape Town, is reviewed. Middle ear disease and trauma were the commonest sources of infection in 60% of patients. The usual presentation was that of meningitis and it is recommended that computed tomography be performed before lumbar puncture in those patients with associated middle ear disease, trauma or sinusitis. With early treatment of both the abscess and the underlying source of infection, the mortality rate was 16%.

Adolescent↗
PubMed1993

Proptosis as a presenting sign of extradural haematoma.

A conscious 15-year-old boy presented with progressive proptosis and a severe headache 2 weeks after minor blunt trauma to the head. No neurological deficit was present. Computed tomography demonstrated intracranial and intraorbital cyst-like masses. At craniotomy a subacute extradural haematoma was found which communicated with an orbital subperiosteal haematoma through a shelved orbital roof fracture. The haematomas were drained and the patient made an uneventful postoperative recovery. Although rare, an extradural haemorrhage should be considered in any patient presenting to an ophthalmologist with progressive proptosis and headache following a head injury.

Adolescent↗
PubMed1993

Post-traumatic chiasmatic disruption.

Ten patients with traumatic disruption of the optic chiasm are presented. The clinical sequence of fronto-facial trauma and CSF rhinorrhoea, followed days later by diabetes insipidus and discovery of a bi-temporal visual field loss constitute a characteristic syndrome which should be recognized by the attending medical staff. Magnetic resonance imaging, not previously reported, and post-mortem evidence point to a physical disruption of the chiasm and infundibulum as the cause of the visual and hypothalamic signs. The resulting field defect is permanent but the diabetes insipidus is transient in 50% of patients and can be adequately managed with manipulation of the patient's fluid intake.

Adolescent↗
PubMed1989

Intracranial tuberculomas. An assessment of a therapeutic 4-drug trial in 35 children.

35 children with suspected tuberculomas of the brain were given a therapeutic 4-drug trial of isoniazid, rifampicin, pyrazinamide and ethambutol. Their clinical and computed tomographic (CT) appearances were analysed retrospectively: 32 responded well to treatment with recognizable improvement on CT after 6 weeks. Three patients did not respond. One of these non-responders had a surgically removed temporal cystic astrocytoma. The majority presented with focal seizures and had a single hemispheral lesion. 14% had multiple lesions, 6% were in the cerebellum. Only 2 patients had raised intracranial pressure and required ventriculoperitoneal shunting.

Adolescent↗