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A Clifton

Publications and source records attributed to A Clifton.

At least 19 recordsLinked to original sources
PubMed2006

The use of intraoperative monitoring and treatment of symptomatic microemboli in carotid artery stenting: case report and discussion.

Carotid artery stenting is a recently introduced treatment in symptomatic atherosclerotic carotid artery disease with acceptable complication rates. The major risk is perioperative embolic stroke. Transcranial Doppler ultrasonography (TCD) can be used to identify embolic signals and guide therapy. We present a case of symptomatic embolization in a 72-year-old female following carotid stent deployment complicated by haemodynamic changes. Despite concurrent dual antiplatelet medication significant symptomatic embolization occurred even after restoration of the blood pressure, and modulation of the rate of embolization was achieved using dextran-40 guided by TCD monitoring. The patient recovered from an initially profound hemiparesis and dysphasia to minor sensory changes. Microemboli are common following carotid artery stenting and there appears to be a threshold phenomenon associated with prolonged embolization and progression to cerebral infarction. TCD can be used to detect particulate microemboli and therefore may be useful in guiding antithrombotic therapy in this setting. Dextran-40 has been shown to reduce the embolic load following carotid endarterectomy and was used to good effect in this patient in terms of both embolic load and clinical outcome. This is the first case of embolization following carotid stenting successfully treated with dextran-40, and offers a further option for therapeutic intervention in microembolism detected by TCD and stresses the importance of perioperative monitoring of embolic load for postoperative stroke risk.

Aged↗
PubMed2004

Spontaneous regression of supratentorial intracerebral Langerhans' cell histiocytosis.

Langerhans' cell histiocytosis (LCH) describes a group of conditions affecting the reticuloendothelial system. It includes the subtypes of Letterer-Siwe disease, Hand-Schuller-Christian disease and eosinophilic granuloma and most often presents in childhood. Intracranial involvement in LCH is usually restricted to the hypothalamic-pituitary axis or involves extra-axial extension from skull vault lesions. Supratentorial intracerebral lesions with mass effect and enhancement have rarely been described and are not included in the magnetic resonance based classification system of neurological LCH. We present the MRI of a patient with multisystem LCH with spontaneous resolution of enhancing temporal lobe lesions.

Adult↗
PubMed2003

Vertebral artery origin angioplasty and primary stenting: safety and restenosis rates in a prospective series.

OBJECTIVES: To report a single centre ongoing experience of endovascular treatment for atherosclerotic vertebral artery origin stenosis in a series of symptomatic patients, with follow up imaging to determine the incidence of restenosis. METHODS: 14 patients with vertebral artery origin stenosis on catheter angiography were treated. Angioplasty without stenting was undertaken in the first four patients, all of whom had follow up catheter angiography at one year. Subsequently, patients were treated by primary stenting and followed up with colour Doppler ultrasound examination. RESULTS: The procedure was technically successful in all treated arteries, with no immediate complications. The degree of stenosis was reduced from (mean (SD)) 73 (18)% before treatment to 21 (26)% immediately after treatment in the angioplasty alone group (p = 0.059). In the primary stenting patients, the severity of stenosis was reduced from 82 (8)% to 13 (13)% immediately after treatment (p < 0.001). Restenosis to 70% or greater occurred at one year in all four patients initially treated by angioplasty without stenting. One patient subsequently developed further symptoms and was retreated by stenting. One of the 10 patients treated by primary stenting developed restenosis. None of the remaining patients had further posterior circulation ischaemic symptoms during a mean follow up period of 33.6 months (range 1 to 72 months). CONCLUSIONS: Restenosis occurs often after vertebral artery origin balloon angioplasty without stenting but is uncommon after stenting. Primary stenting is therefore recommended to maintain patency at this site, and had a low complication rate in this series.

Adult↗
PubMed2001

Radiation protection in interventional radiology.

There is growing concern regarding the radiation dose delivered during interventional procedures, particularly in view of the increasing frequency and complexity of these techniques. This paper reviews the radiation dose levels currently encountered in interventional procedures, the consequent risks to operators and patients and the dose reduction that may be achieved by employing a rigorous approach to radiation protection.

Fluoroscopy↗
PubMed2000

Hydrocephalus: comparison of clipping and embolization in aneurysm treatment.

OBJECT: In this retrospective study conducted at Atkinson Morley's Hospital and Middlesbrough General Hospital, the authors analyzed 100 matched patients who had suffered subarachnoid hemorrhage (SAH) to determine whether the technical procedure by which aneurysms are treated affects the development of chronic hydrocephalus. METHODS: Four hundred seventy-five patients presented with SAH between 1995 and 1998. Exclusion criteria included posterior circulation aneurysms, multiple aneurysms, electively clipped or embolized aneurysms, angiographically undetected SAH, patients who died within 1 month of neurosurgical intervention, and patients with the same aneurysm location but a different Fisher grade. The authors matched 50 patients who underwent embolization of their aneurysms with another 50 who had similar Fisher grades and aneurysm types and underwent clipping of their aneurysms. The maximum incidence of ruptured aneurysms occurred in patients who were between 41 and 60 years of age, with women preponderant in both study groups. In each group, 27 patients had anterior communicating artery aneurysm, 13 had posterior communicating artery aneurysm, seven had middle cerebral artery aneurysm, and three had internal carotid artery aneurysm. The lesions in three patients in each group were Fisher Grade I, in 23 patients they were Fisher Grade II, in 14 they were Fisher Grade III, and 10 patients had Fisher Grade IV SAH. Nine patients among those with clipped aneurysms and eight of the patients who underwent embolization had hydrocephalus for which they needed intervention. These interventions included lumbar puncture, ventricular drainage, and ventriculoperitoneal (VP) shunt placement; three patients in each group needed VP shunt placement. CONCLUSIONS: The technical procedure used to treat aneurysms, whether clipping or embolization, does not significantly affect the development of chronic hydrocephalus. However, a larger sample of patients is needed for accurate comparisons and stronger conclusions.

Adolescent↗
PubMed1999

Fatal cerebral reperfusion hemorrhage after carotid stenting.

BACKGROUND: The hyperperfusion syndrome is a recognized complication of carotid endarterectomy. Reports of cerebral hyperperfusion injury following internal carotid artery (ICA) angioplasty are few, and this complication has never been reported following internal carotid stenting. CASE DESCRIPTION: A 68-year-old normotensive man was referred to our hospital for assessment 5 months after experiencing a left hemispheric ischemic stroke. Angiography confirmed 95% stenosis of the left ICA. Left carotid percutaneous transluminal stenting was performed without any initial complications. Color Doppler ultrasound of the ICA immediately after stenting revealed an elevated peak systolic velocity of 2.3 m/s, in the absence of significant vessel stenosis or spasm on angiography. Seven hours after the procedure, the patient suddenly deteriorated. CT of the brain revealed extensive intracerebral hemorrhage (ICH), and he subsequently died 18 days later. There was no history of headache or seizure activity, and his blood pressure was only mildly elevated at the time of the deterioration. This is the first report of ICH after internal carotid stenting. CONCLUSIONS: ICH may occur as a hyperperfusion phenomenon after internal carotid stenting, in the presence of mild to moderate arterial hypertension, without being heralded by any of the typical symptoms of the hyperperfusion syndrome. Patients with increased velocities on color Doppler ultrasound of the ICA after angioplasty should be monitored closely for features of cerebral hyperperfusion injury. Further studies are warranted to determine whether more aggressive treatment of mild to moderate hypertension after carotid stenting would reduce the likelihood of this potentially fatal complication.

Aged↗
PubMed1999

Should we screen for familial intracranial aneurysm?

BACKGROUND AND PURPOSE: The purpose of this study was to establish whether individuals with a family history of >/=2 first-degree relatives with intracranial aneurysm should be offered screening for aneurysm. METHODS: We derived 3 theoretical models and calculated the outcomes of screening with magnetic resonance angiography (MRA) followed by digital subtraction angiography (DSA) if MRA was positive (model 1), screening with DSA alone (model 2), and not screening (model 3). Screening was repeated at intervals of 10 years, and aneurysms detected were treated surgically. We assumed a prevalence of aneurysm of 9.8% (95% CI, 8.9% to 10.6%) in the population screened, an annual rupture rate of asymptomatic aneurysm of 0.8% (95% CI, 0.4% to 1.5%), and a 75% chance of poor outcome from rupture. We assumed the sensitivity and specificity of MRA were each 90% and the risk of DSA was 0.1%. The risk of surgery was taken as 5.1%. RESULTS: Screening 1000 individuals on 3 occasions with MRA and DSA or with DSA alone followed by surgery resulted in poor outcome in 14 and 18 individuals, respectively, over 30 years. Without screening, poor outcome occurred in 15 individuals over the same period of time. CONCLUSIONS: Screening is not an effective way of reducing morbidity and mortality from ruptured intracranial aneurysm in individuals with a history of >/=2 affected first-degree relatives with ruptured intracranial aneurysm unless the expected incidence of asymptomatic aneurysm is considerably >10%.

Adult↗
PubMed1999

Clozapine and risperidone in chronic schizophrenia: effects on symptoms, parkinsonian side effects, and neuroendocrine response.

OBJECTIVE: Clozapine and risperidone were the first two "second-generation" antipsychotic drugs approved for schizophrenia. There is currently little information about their comparative efficacy from head-to-head clinical trials. The purpose of this study was to examine the comparative efficacy of clozapine and risperidone for positive and negative symptoms, depression, parkinsonian side effects, and indexes of neuroendocrine function in schizophrenic patients who met a priori criteria for partial response to traditional neuroleptic agents. METHOD: After a baseline fluphenazine treatment period, 29 patients participated in a 6-week, double-blind, parallel-group comparison of the effects of these agents. RESULTS: Clozapine was superior to risperidone for positive symptoms and parkinsonian side effects, but there were no significant differences between the drugs on two measures of negative symptoms, Brief Psychiatric Rating Scale total scores, and depression scores. The clozapine patients, but not the risperidone patients, demonstrated significant reductions from the fluphenazine baseline in positive symptoms, total symptoms, and depression. In addition, clozapine produced fewer effects on plasma prolactin than risperidone or fluphenazine. The mean daily doses during week 6 of the trial were 403.6 mg of clozapine and 5.9 mg of risperidone. CONCLUSIONS: The findings from this study indicate that these drugs have both important differences and similarities in their comparative efficacy in chronically ill, partially responsive patients with schizophrenia. Further research on second-generation antipsychotic drugs in this patient population that addresses key methodological issues, such as optimal dose and treatment duration, are needed.

Adult↗
PubMed1999

Dissecting vertebral artery aneurysm: diagnosis and coil embolization.

Dissecting aneurysm of the intradural vertebral artery, a rare cause of stroke and sub-arachnoid haemorrhage, is associated with a poor neurological outcome if the disease is unrecognized and remains untreated. Clinical manifestations may be delayed or overlooked and non-invasive radiological investigations demonstrate little or no abnormality. We describe the diagnosis and successful endovascular occlusion of a dissecting vertebral artery aneurysm using detachable microcoils; a novel technique that has advantages over conventional therapeutic procedures.

Adult↗
PubMed1998

Amyloid angiopathy causing widespread miliary haemorrhages within the brain evident on MRI.

The case of a 70-year-old woman with cerebral amyloid angiopathy (CAA) is presented. MRI of the head showed widespread miliary foci of haemorrhage within the cerebrum and cerebellum, with some additional linear lesions within the cerebral cortex and patchy lesions in the white matter. This is in contrast to the more usual pattern of intracranial haemorrhage in CAA, i.e., a lobar haematoma.

Aged↗
PubMed1998

Giant aneurysm of the petrous internal carotid artery: diagnosis and treatment.

We report the case of a giant fusiform aneurysm of the petrous internal carotid artery in a 15-year-old patient who had presented with headache, hearing loss and Horner's syndrome. Definitive radiological diagnosis was made by non-invasive imaging techniques, including magnetic resonance angiography (MRA). The aneurysm was obliterated by endovascular balloon occlusion following successful tolerance of test occlusion of the internal carotid artery.

Adolescent↗
PubMed1998

The dopamine D3 receptor (DRD3) Ser9Gly polymorphism and schizophrenia: a haplotype relative risk study and association with clozapine response.

Several lines of evidence suggest that the dopamine D3 receptor is involved in the pathophysiology of schizophrenia. The D3 receptor gene (DRD3) contains a polymorphism resulting in a serine-glycine substitution in the N-terminus of the receptor. Shaikh and colleagues have reported a significant association between the DRD3 Ser9 allele and the Ser9/Ser9 genotype with schizophrenia in 133 Caucasians. In a meta-analysis of previous studies, Ser9 and the Ser9/Ser9 genotype were found to be significantly associated with schizophrenia, although these investigators could not confirm reports of excess homozygosity at this locus in schizophrenia. These authors also report that, in an unblinded study, the Ser9/Ser9 genotype was more frequent in patients who did not respond to clozapine. These data represent the most comprehensive examination of DRD3 Ser9Gly in schizophrenia to date. We have therefore determined DRD3 Ser9Gly genotypes in 58 patients with schizophrenia and in their parents. Moreover, we have genotyped 68 schizophrenics participating in double-blind clozapine trials. We do not find that Ser9 is preferentially transmitted in schizophrenia, cannot confirm excess DRD3 homozygosity in schizophrenia, and do not replicate the association between DRD3 and clozapine response. These data suggest that allelic variation in DRD3 may not play a role in the pathophysiology of schizophrenia or in clozapine response.

Alleles↗
PubMed1998

A functional serotonin transporter (5-HTT) polymorphism is associated with psychosis in neuroleptic-free schizophrenics.

The neurotransmitter serotonin has been implicated in the pathophysiology of psychosis. The serotonin transporter (5-HTT) plays a critical role in regulation of serotonergic function. A recently identified polymorphism in the promoter region of the 5-HTT gene (5-HTTLPR) produces significant differences in 5-HTT expression and function and was found to be associated with anxiety-related traits in healthy volunteers. We investigated whether 5-HTTLPR is associated with psychosis in neuroleptic-free schizophrenic or schizoaffective patients. Fifty patients with schizophrenia or schizoaffective disorder by DSM-III-R criteria were genotyped at 5-HTTLPR and underwent double-blind Brief Psychiatric Rating Scale (BPRS) ratings while neuroleptic-free for approximately 4 weeks. Patients with the 5-HTTLPR II genotype (n = 19) had significantly higher BPRS ratings for psychosis than patients with the Is (n = 25) or ss (n = 6) genotypes. Examination of individual items revealed a specific significant increase in intensity of hallucinations in patients with the 5-HTTLPR II genotpe. These data provide preliminary evidence for a role of serotonin in the pathophysiology of hallucinations and may represent the identification of an allelic variant that modifies the complex clinical presentation of schizophrenia.

Adult↗
PubMed1998

Treatable lesions demonstrated on vertebral angiography for posterior circulation ischaemic events.

Angiography after a posterior circulation ischaemic event is often not considered because of the perception that it will not alter patient management. We identified 53 patients investigated with vertebral angiography over a 5 year period. This was significantly abnormal in 32 patients (60%). Five (9%) had vertebral artery dissections, nine (17%) had unilateral vertebral artery occlusion, two had a basilar artery disease. 16 (30%) had vertebral artery stenosis. 12 stenoses were considered suitable for percutaneous transluminal angioplasty (23%). 11 patients were anticoagulated (21%). There was no significant correlation between clinical features, site of infarct or the presence of carotid stenosis that would have allowed the prediction of the findings in the posterior circulation. Our results indicate that using vertebral angiography to investigate posterior circulation ischaemia will identify a significant number of potentially treatable lesions.

Aged↗