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Biomedical subjects

G J Hankey

Publications and source records attributed to G J Hankey.

At least 91 records · Page 5Linked to original sources

Lacunar transient ischaemic attacks: a clinically useful concept?

Lacunar ischaemic stroke syndromes are clinically, pathophysiologically, and prognostically distinguishable from cortical ischaemic stroke syndromes. Could cerebrovascular transient ischaemic attacks (TIAs) share similar heterogeneity? 130 patients with TIAs were prospectively studied, 71 of whom underwent carotid angiography. Symptoms were associated with a 50% or greater stenosis of the ipsilateral internal carotid artery in 36 (67%) of 54 patients with presumed cortical TIAs, but in only 1 (6%) of 17 patients with presumed lacunar TIAs (p less than 0.0001). These findings support the view that cortical TIAs are associated with ipsilateral extracranial internal carotid artery atheromatous disease, whereas patients with lacunar TIAs may have absent or insignificant large-vessel disease, and probable intracranial small-vessel disease. Accurate distinction between lacunar and cortical events may have implications for investigation and treatment of patients with TIAs.

Aged↗

The role of imaging in the management of cerebral and ocular ischaemia.

The last decade has seen several major technological advances in vascular neuroradiology, the most clinically significant of which have been the facility to image the brain and the extracranial carotid bifurcation noninvasively with accuracy and safety. Another major advance has been unequivocal evidence from formal statistical overviews that antiplatelet therapy, particularly aspirin, reduces the risk of serious vascular events by about 25%. These advances have changed clinical practice such that most patients presenting with symptoms suggestive of cerebral ischaemia should now have cranial CT to exclude intracerebral hemorrhage, not only because the causes and prognosis of cerebral ischaemia differ from those of intracerebral hemorrhage, but because many patients with cerebral ischaemia should be considered for antiplatelet therapy. Besides the use of long term antiplatelet therapy and control of vascular risk factors, other acute treatment options are limited with the possible exception of anticoagulation, thrombolysis, cytoprotective agents and carotid endarterectomy. If, as seems likely, the current clinical trials show that carotid endarterectomy plus medical therapy improve upon the stroke-free survival of patients treated medically, at least in symptomatic patients with severe stenosis, the number of carotid endarterectomies performed will increase considerably because carotid bifurcation disease is the most common cause of cerebral and ocular ischemic events. It will then be even more important to be able to obtain accurate anatomical and physiological information about the extracranial and intracranial circulations with utmost safety. Duplex ultrasound is currently the noninvasive screening method of choice for carotid bifurcation disease because it is available, relatively cheap, and reasonably accurate. It not only images the vessel lumen and degree of stenosis, but also the morphology of the vessel wall and associated plaque, the relevance of which is still uncertain in the pathogenesis of cerebral and ocular ischaemia. A major limitation of duplex sonography is that it cannot reliably distinguish tight stenosis from occlusion and it does not image the proximal or distal carotid circulation. The aim of newer techniques will be to distinguish tight extracranial carotid stenosis from occlusion and to provide anatomical, physiological and pathological information about the intracranial circulation and ischemic lesions (in view of potential for thrombolytic therapy of major intracranial vessel occlusion) with safety and reproducible accuracy.

Brain Ischemia↗

The prognosis of hospital-referred transient ischaemic attacks.

A cohort of 469 hospital-referred patients with transient ischaemic attacks (TIA) of the brain (66%) or eye (34%) due to presumed atheromatous thromboembolism, lipohyalinosis or cardiogenic embolism, without prior stroke, was assembled between 1976-86. Follow up was prospective and complete until the patients death or the end of 1986. During a mean period of follow up of 4.1 years there were 82 deaths (58 vascular, 24 non-vascular), 63 first-ever strokes and 58 patients with coronary events. A coronary event accounted for 51% of deaths whilst stroke was the cause in 12%. The average risk of death over the first five years after TIA was 4.5% per year. The risk of stroke was 6.6% in the first year and 3.4% per year on average over the first five years. Stroke occurred in the same vascular territory as the initial TIA in about two-thirds of cases, and was of lacunar type in one fifth of these strokes. The average risk of a coronary event over the first five years after TIA was 3.1% per year, similar to that of stroke. However, the risk of a coronary event, and also death, was fairly constant each year after a TIA, in contrast to the risk of stroke which was highest in the first year. The average risk of stroke, myocardial infarction or vascular death over the first five years after TIA was 6.5% per year and the average risk of stroke, myocardial infarction or death from any cause was 7.5% per year. The prognosis of this cohort of hospital-referred TIA patients was better than that of TIA patients in the same community who presented to the Oxfordshire Community Stroke Project (OCSP), and reflected the impact of referral bias. The hospital-referred patients were younger, assessed at a later date after their last TIA, and comprised a greater proportion of patients who had had a TIA of the eye (amaurosis fugax), which had a better prognosis than TIA of the brain. Knowledge of the prognosis of different populations of TIA patients not only enhances understanding and interpretation of previous studies but is also required for optimal patient management and the planning of treatment trials.

Carotid Artery, Internal↗

Future directions in stroke management.

The management of stroke patients continues to evolve, with recent advances in vascular neuroradiology and the secondary prevention of stroke. This article reviews these findings and the potential impact of new investigations and treatments that are being evaluated in research institutions.

Cerebrovascular Disorders↗

Symptomatic carotid ischaemic events: safest and most cost effective way of selecting patients for angiography, before carotid endarterectomy.

OBJECTIVE: To determine the safest, least costly, and most effective way to select patients with symptomatic carotid ischaemic events for carotid angiography before carotid endarterectomy. DESIGN: Prospective cohort study. SETTING: University departments of clinical neurosciences and clinical neurology. PATIENTS: 485 Patients with carotid territory transient ischaemic attacks of the brain (n = 224) or eye (n = 162) or retinal infarction (n = 99) were referred to a single neurologist between 1976 and 1986. INTERVENTIONS: Clinical examination by auscultation over the precordium, supraclavicular fossae, and neck vessels (all patients). Cerebral angiography of patients suitable for carotid endarterectomy. MAIN OUTCOME MEASURES: Financial cost and number of disabling strokes after angiography. RESULTS: 296 Patients were investigated by cerebral angiography. Ischaemic symptoms had occurred in the distribution of 298 internal carotid arteries (symptomatic) that were imaged, two patients having bilateral symptoms. The presence or absence of a carotid bruit and the maximum percentage diameter stenosis of the origin of the symptomatic internal carotid artery were correlated. The prevalence of mild disease (diameter stenosis greater than or equal to 25%) of the symptomatic internal carotid artery was 57%, and if an ipsilateral carotid bruit was heard the probability of mild stenosis rose to 92%. The prevalence of moderate disease of the symptomatic internal carotid artery (stenosis greater than or equal to 50%) was 39%, and if a bruit was heard the probability doubled to 78%. The prevalence of severe internal carotid disease (stenosis greater than or equal to 75%) was 22%, and if a bruit was heard the probability was more than double, at 49%. The direct cost to both the NHS and the private health sector of investigating patients with symptomatic carotid ischaemia was estimated for several strategies of carotid artery imaging and expressed in terms of financial cost and number of strokes after angiography incurred in detecting all patients with diameter stenosis of the symptomatic internal carotid artery of greater than or equal to 25%, 50%, or 75%. To detect diameter stenosis of the internal carotid artery of greater than or equal to 25% it is most cost effective to proceed directly to cerebral angiography in patients with a carotid bruit over the symptomatic carotid bifurcation and to screen patients without a carotid bruit by duplex carotid ultrasonography; patients in whom duplex ultrasonography discloses stenosis of greater than or equal to 25% are then referred for cerebral angiography. To detect only more severe internal carotid disease (stenosis of greater than or equal to 50%) the same policy applies, unless the local duplex ultrasonographic service is particularly efficient and reliable, when it is probably most cost effective and safer to screen all patients by this method irrespective of the findings on cervical auscultation. To detect stenosis of 75% or greater it is most cost effective to screen all patients with duplex ultrasonography, whether a carotid bruit is present or not, because this approach reduces the number of angiograms required, is the least expensive, and results in the least number of strokes after angiography. CONCLUSIONS: Patients selection for cerebral angiography before carotid endarterectomy needs to be appropriate and cost effective. Sound clinical evaluation and duplex carotid ultrasound are required. The findings of this study should not be applied to other medical centres without first considering possible differences in the prevalence of carotid artery disease, the efficiency and reliability of duplex ultrasonography, the local complication rates of cerebral angiography, and the local costs of the imaging procedures.

Adult↗

Benign recurrent unilateral abducens nerve palsy.

The recurrence of an isolated unilateral left abducens nerve palsy on five occasions over five years is described in an adult. No evidence of any systemic or intracranial disorder has been identified. The aetiology remains uncertain and the clinical course is benign. The diagnosis of 'benign' abducens nerve palsy is one of exclusion and is made retrospectively after an adequate period of serial evaluations.

Abducens Nerve↗

Complications of cerebral angiography for patients with mild carotid territory ischaemia being considered for carotid endarterectomy.

It is essential to image the carotid bifurcation adequately in patients with symptomatic carotid territory ischaemia if they are being considered for carotid endarterectomy. Optimal resolution is achieved by selective intraarterial contrast angiography which is an invasive procedure carrying some risk. The overall risk-benefit of carotid endarterectomy is currently being investigated in several large randomised trials in Europe and North America. Because cerebral angiography is a prerequisite for carotid endarterectomy, the risks of cerebral angiography will need to be added to those of surgery when considering whether carotid endarterectomy is effective in the management of these patients. This study evaluated prospectively 382 patients with symptomatically mild carotid ischaemia who had cerebral angiography to visualise a potentially resectable lesion at the carotid bifurcation. Complications followed 14 cerebral angiograms in 13 patients (3.4%); two complications were local (0.5%), two systemic (0.5%) and 10 were neurological (2.6%). The neurological complications were transient (TIA 1, generalised seizure 1) in two patients (0.5%), reversible (stroke) in three (0.8%) and permanent (stroke) in five patients (1.3%). There were no deaths. The significant risk factors for post angiographic stroke were (1) stroke before angiography compared with transient ischaemic attacks of the eye or brain and (2) the presence of greater than or equal to 50% diameter stenosis of the symptomatic internal carotid artery; unfortunately it may be the latter patients who are most at risk of stroke as part of the natural history of their disease and therefore most in need of prophylactic carotid endarterectomy (which requires cerebral angiography). The absolute risk of post-angiographic stroke of patients for cerebral angiography using clinical evaluation and Duplex carotid ultrasound screening.

Adolescent↗

Cerebral angiographic risk in mild cerebrovascular disease.

We review the eight prospective and seven retrospective studies from which it is possible to derive the complication rate of conventional cerebral angiography for patients with mild ischemic cerebrovascular disease who are potential candidates for carotid endarterectomy. Three studies of intravenous and one of intra-arterial digital subtraction angiography are also examined. An overview of the results suggests that the risk of a neurological complication (TIA or stroke) is about 4% and that a permanent neurological deficit (disabling stroke) occurs in about 1%. The mortality rate is very low (less than 0.1%). Systemic complications are not infrequent, particularly with intravenous digital subtraction angiography. The complication rate of cerebral angiography must be considered when evaluating the risks of carotid endarterectomy in patients with ischemic cerebrovascular disease.

Brain Ischemia↗

Mitochondrial encephalomyopathy with corticosteroid dependence.

A 12-year-old boy with corticosteroid-responsive mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) is described. His mother proved to have an asymptomatic mitochondrial myopathy on examination of a muscle biopsy specimen. Three weeks after the onset of vomiting, headache, ataxia and visual and speech impairment, he presented with a background of somatic growth retardation, deafness and school failure. Examination revealed disorientation, dysphasia, dyspraxia, optic atrophy, hemianopia, hemiparesis and sensory inattention. A cranial computed tomographic scan disclosed a large, low-density area, which was consistent with infarction, in the left posterior hemisphere and marked calcification of the basal ganglia bilaterally. Within two weeks of the commencement of corticosteroid treatment, the neurological dysfunction resolved. Attempts to decrease the dosage of dexamethasone caused an exacerbation of symptoms repeatedly. Two weeks after ceasing corticosteroid therapy, the patient developed a serious neurological relapse and a new, large, low-density area, which resembled an infarction, in the right posterior hemisphere on a computed tomographic scan. The reintroduction of corticosteroid therapy again resulted in the rapid resolution of all symptoms. It became evident that the patient had an exquisitely sensitive corticosteroid dependency, whereby a reduction in the dexamethasone dosage of even 0.25 mg a day caused confusion, headaches and increasing lactic acidaemia. Although it is difficult to assess the impact of various therapies in MELAS because of the episodic natural course of the disease, this remarkable corticosteroid responsiveness also has been noted in four previously reported patients with MELAS syndrome; therefore, it would seem reasonable to suggest that corticosteroid therapy now should be considered as standard treatment for this condition. However, corticosteroid therapy in other forms of mitochondrial disorders still awaits careful evaluation.

Acidosis, Lactic↗

Familial periodic ataxia.

A teen-age girl presented with recurrent stereotyped episodes of vertigo and ataxia and manifested constant horizontal gaze-evoked nystagmus. Cranial computed tomographic scans and metabolic biochemical screens gave normal results. The diagnosis of familial periodic ataxia was made from the family history and examination of the family members. Familial periodic ataxia is a rare disorder of cerebellar function which is inherited dominantly and has a benign prognosis. The underlying pathophysiology remains uncertain but a therapeutic response frequently is achieved with acetazolamide.

Acetazolamide↗

Late-onset post-hemiplegic hemidystonia: CT and angiographic findings.

A 27-year-old woman is described who suffered an acute left hemiplegia at the age of three years and 20 years later she noted the onset of unilateral left limb dystonic movements. Her cranial CT scan showed an area of low density, consistent with longstanding infarction, in the right lentiform nucleus. Cerebral angiography demonstrated aneurysmal dilatation of the terminal portion of the right internal carotid artery, minor irregularity of the lenticulostriate branches of the right middle cerebral artery (suggestive of Moya Moya disease) and occlusion of the right anterior cerebral artery. The dystonic movements improved with levodopa therapy. Clinico-radiological correlation in this case supports recent evidence for a disruption of pathways between the caudate nucleus, lentiform nucleus and thalamus in the pathophysiology of hemidystonia.

Adult↗

Angiographically demonstrated arterial spasm in a case of benign sexual headache and benign exertional headache.

Benign headaches related to sexual activity and exertion are being recognised with increasing frequency. We wish to report a case of benign sexual headache (Type 2) and benign exertional headache, occurring sequentially in the same patient. Multiple areas of cerebral arterial spasm were demonstrable on angiography. This observation would support the concept that benign sexual headache (Type 2) and benign exertional headache may have a similar pathophysiology.

Adult↗

The utility of testing tactile perception of direction of scratch as a sensitive clinical sign of posterior column dysfunction in spinal cord disorders.

Classical beliefs about the functions of the dorsal columns of the spinal cord have been attacked following recent evidence that position and vibration sensations may be carried in the dorsal spinocerebellar tracts. There is evidence that the one specific function of the dorsal columns is for the transmission of information concerning the direction of tactile cutaneous movement. Thirty normal controls, 43 patients with spinal cord disorders and 10 patients with functional disorders were examined prospectively using an easily administered "direction of scratch" protocol. Interpretation of the direction of a 2 cm vertical tactile cutaneous movement over the lower limbs was found to be accurate in normal controls and grossly inaccurate in patients with functional disorders, exceeding the error rate of guessing. Detection of direction of 2 cm scratch was moderately impaired in 11 of 13 patients with spastic paraparesis and preserved sensation to all other modalities and 23 of 24 patients with spastic paraparesis and impaired proprioception and/or vibration sensations. Direction of 2 cm scratch, proprioception and vibration sensations were preserved in the three cases with anterior spinal cord syndromes. It is proposed that tactile perception of direction of 2 cm scratch over the lower limbs is a sensitive sign of posterior column function which can be usefully incorporated into the clinical sensory examination in the evaluation of spinal cord disorders.

Adolescent↗

Long term survival with early childhood intracerebral tumours.

Three young adults are described who presented during early childhood with a seizure disorder due to an underlying intracerebral tumour. The tumours were excised incompletely 14-19 years later. The histological findings were those of a temporal lobe benign capillary haemangioblastoma (Case 1), parietal lobe subependymoma (Case 2), and parietal lobe ganglioglioma (Case 3). After a mean period of follow-up of 22 years (range 18-26), only mild residual physical disabilities exist in each patient. These three cases illustrate (1) the need promptly to investigate children who present with focal seizures or whose EEG shows definite focal abnormalities, (2) the relevant investigations should include cranial CT or MRI in such cases and (3) that certain supratentorial tumours have a favourable outcome due to their benign biological behaviour rather than their location.

Adolescent↗

Detection of basilar artery thrombosis by computed tomography.

Thrombosis of the basilar artery is not uncommon and occurs in the elderly as well as in younger patients. The clinical diagnosis may be supported by the appearance on computed tomography enabling appropriate investigations and therapeutic measures to be taken which may lead to a favourable outcome. Four cases of basilar artery thrombosis are described in which the clinical diagnosis was assisted by computed tomography. The basilar artery, which is normally isodense in unenhanced studies, was seen as a hyperdense structure. Follow-up scans demonstrated a decrease in the density and size of the vessel consistent with resolution of a thrombus.

Adult↗