[Transient monocular vision loss]. / Tijdelijke stoornissen van het zien met één oog.

Transient monocular vision loss (TMVL) caused by temporary disturbance of blood flow to the retina is a harbinger of future vascular complications. The diagnosis may be difficult, not only because it is solely dependent on history taking, but also because the range of monocular visual symptoms a patient may experience is wide. The classic pattern of a sudden black or grey visual field, or a curtain that is drooping in front of one eye, easily fits in the diagnosis of TMVL; however, coloured vision or flashes should not always be considered as benign. The distinction between visual symptoms of one or both eyes should receive attention during history taking. It is the professional expertise of the neurologist and ophthalmologist which should make it possible to establish the correct diagnosis. A patient suspected of a retinal TIA should be evaluated and treated with the same urgency as someone with a cerebral TIA.

Transient monocular blindness.

An attack of abrupt loss of vision in one eye that recovers completely after a short period is called "transient monocular blindness" (TMB) or amaurosis fugax. The most common cause of TMB is atherothromboembolism from the origin of the internal carotid artery (ICA), whereas atrial fibrillation is quite uncommon. TMB also can be caused by anterior optic nerve ischemia, that is usually caused by thrombosis in the posterior ciliary artery. Thrombosis in the central retinal vein may be another cause. Dissection of the ICA, vascular malformations, or fibromuscular dysplasia are other potential etiologies. Blurring of vision as compared with blackened vision or positive phenomena such as flashing is probably associated with a higher risk of future cardiovascular events, whereas involvement of the partial monocular field is associated with a relative benign prognosis. In patients with atherosclerosis, antiplatelet therapy is indicated and treatment of vascular risk factors should have high priority. Carotid endarterectomy should be performed only in case of an ICA stenosis of more than 70% in the presence of at least one other risk factor for stroke.

Type of stroke after transient monocular blindness or retinal infarction of presumed arterial origin.

BACKGROUND: Retinal infarction and transient monocular blindness (TMB) are associated with an increased risk of future ischaemic stroke. Little information is available on the type of subsequent ischaemic strokes that may occur (anterior or posterior circulation and small vessel or large vessel). AIM: To analyse the type of stroke after TMB. METHODS: Patients with transient or permanent retinal ischaemia were selected from three prospective studies: the Dutch TIA Trial, the Dutch Amaurosis Fugax Study and the European/Australian Stroke Prevention in Reversible Ischaemia Trial. On follow-up the type of stroke was classified according to the supply territory and the type of vessel involved. RESULTS: 654 patients were included. During a mean follow-up of 5.2 years, 42 patients were found to have had a cerebral or retinal infarct, of which 27 occurred in the carotid territory ipsilateral to the symptomatic eye, 9 in the territory of the contralateral carotid artery and 6 were infratentorial strokes. Thirty patients had a large-vessel infarct, four had a small-vessel infarct and eight had a retinal infarct. Characteristics associated with a notable increased risk for subsequent stroke or retinal infarction were age > or = 65 years, a history of stroke, a history of intermittent claudication, diabetes mellitus, Rankin score > or = 3, more than three attacks of retinal ischaemia and any degree of ipsilateral carotid stenosis on duplex ultrasonography observation. CONCLUSION: Ischaemic strokes after TMB or retinal infarction were found to be mainly large-vessel infarcts in the territory of the ipsilateral carotid artery. TMB and retinal infarction are probably manifestations of large-vessel disease.

Clinical features of transient monocular blindness and the likelihood of atherosclerotic lesions of the internal carotid artery.

To assess which features of transient monocular blindness (TMB) are associated with atherosclerotic changes in the ipsilateral internal carotid artery (ICA), 337 patients with sudden, transient monocular loss of vision were prospectively studied. History characteristics of the attack were compared with the presence of atherosclerotic lesions of the ipsilateral ICA. All patients were directly interviewed by a single investigator. Of all patients, 159 had a normal ICA on the relevant side, 33 had a stenosis between 0%-69%, 100 had a stenosis of 70%-99%, and 45 had an ICA occlusion. An altitudinal onset or disappearance of symptoms was associated with atherosclerotic lesions of the ipsilateral ICA. A severe (70%-99%) stenosis was also associated with a duration between 1 and 10 minutes, and with a speed of onset in seconds. An ICA occlusion was associated with attacks being provoked by bright light, an altitudinal onset, and the occurrence of more than 10 attacks. Patients who could not remember details about the mode of onset, disappearance, or duration of the attack were likely to have a normal ICA. Our findings may facilitate the clinical decision whether or not to perform ancillary investigations in these patients.

A comparison of cerebral hemodynamic parameters between transient monocular blindness patients, transient ischemic attack patients and control subjects.

PURPOSE: To assess whether patients with transient monocular blindness (TMB) and patients with hemispheric transient ischemic attacks (hTIA) differ from each other with respect to cerebral hemodynamic parameters. METHODS: Seventeen TMB patients and 23 hTIA patients with a moderate to severe stenosis or an occlusion of the internal carotid artery (ICA) underwent magnetic resonance (MR) angiography, (1)H MR spectroscopy and transcranial Doppler sonography. Thirty-one control subjects were investigated to obtain reference values for the MR investigations. Quantitative flow was measured in the ICAs, the basilar artery and the middle cerebral arteries (MCA). Metabolic changes in the MCA territory were studied by assessing N-acetyl-aspartate (NAA)/choline ratios and prevalences of lactate. The prevalence of collateral flow was assessed in the circle of Willis and the ophthalmic arteries. The vasomotor reactivity was studied by measuring the CO(2) reactivity of the MCA territories. RESULTS: Quantitative flow in the cerebropetal arteries and the MCAs did not differ between TMB patients and hTIA patients. Also patterns of collateral flow, prevalence of lactate and CO(2) reactivity were similar. The mean ipsilateral NAA/choline ratio was lower in hTIA patients compared with TMB patients (p < 0.01), and was predominantly correlated with symptomatology (p < 0.01), i.e. whether patients had TMB or hTIA, and not with ipsilateral MCA flow (p = 0.2) or ipsilateral CO(2) reactivity (p = 0.7). CONCLUSION: The results of this study indicate that there are no cerebral hemodynamic differences between TMB patients and hTIA patients. It is therefore unlikely that hemodynamic factors account for differences in clinical characteristics between the two patient groups.

Evidence of a chronic systemic cause of instability of atherosclerotic plaques.

BACKGROUND: Major thrombotic and embolic complications of atherosclerosis are closely associated with irregularity and rupture of atheromatous plaques in both the carotid and coronary arteries. Plaque instability is partly determined by local factors, but systemic factors, such as infection, autoimmunity, or genes, may also be important. If plaque stability is influenced by systemic factors that are present in only a proportion of patients, some individuals should be more prone to rupture of plaques than others--ie, irregular plaques should occur in multiple vascular beds in some individuals more frequently than would be expected by chance alone. METHODS: We studied 5393 carotid bifurcation angiograms from 3007 patients with a recently symptomatic carotid stenosis. We assessed the extent to which plaque-surface irregularity at the symptomatic carotid artery was associated with irregularity at a distant site, the contralateral carotid artery, and the extent to which plaque irregularity at these sites was associated with previous myocardial infarction or subsequent non-stroke vascular death (due mainly to coronary-artery disease). FINDINGS: Patients with plaque-surface irregularity (n=1897) in the symptomatic carotid artery were more likely than those with smooth plaque (n=110) to have irregularity in the contralateral carotid artery (odds ratio 2.21 [95% CI 1.62-3.01], p<0.001). Patients with irregular plaques in both arteries were more likely to have had a previous myocardial infarction than patients with smooth plaques (hazard ratio 1.82 [1.23-2.64], p<0.001), and were more likely to have a non-stroke vascular death on follow-up (hazard ratio 1.67 [1.15-2.44], p=0.007). However, there was no difference in the risk of non-vascular death (hazard ratio 0.92 [0.57-1.45], p=0.5). These associations were not explicable on the basis of differences in traditional vascular risk factors. INTERPRETATION: These data suggest that some individuals have a systemic predisposition to irregularity and rupture of atherosclerotic plaques that is independent of traditional vascular risk factors. This finding supports the hypothesis that other systemic factors are important in the cause of plaque instability.

How do general practitioners diagnose and manage patients with transient monocular loss of vision of sudden onset?

Symptoms of transient loss of vision in one eye differ widely. They may have different causes and therefore carry a different prognosis. We studied the influence of differences between characteristics of transient monocular blindness on the diagnosis and management by general practitioners (GPs). A postal questionnaire, was sent to 1600 GPs in The Netherlands along with four case vignettes describing a case history of a 56-year-old man with transient monocular disturbances of vision of sudden onset. We introduced random permutations in the following four elements of the history: partial or complete visual field involved, blurring or blacking out of vision, attacks lasting minutes or hours, and patients having covered either eye during the attack or not. Respondents were asked about the probable diagnosis and the preferred management. For each of the 16 permutations about 50 responses were obtained (overall response rate 54%). Ischemic transient monocular blindness (ITMB) was chosen as the most likely diagnosis in 49%. In 12% primary ocular disease was suspected. Involvement of the complete visual field, blacking out of vision, and short attacks were identified as independent predictors of a diagnosis of ITMB. A diagnosis of ITMB would have resulted in referral to a specialist in 72% of patients. Antithrombotic treatment would have been initiated in only 36% of ITMB patients. GPs consider brief attacks with complete blacking out of vision most typical for retinal ischemia. They refer only three-quarters of patients with probable ITMB to a specialist and start antithrombotic medication in only one-third of these patients. Therefore further education with regard to transient monocular blindness is needed.

Transient monocular blindness and antiphospholipid antibodies in systemic lupus erythematosus.

BACKGROUND AND OBJECTIVE: Among patients with systemic lupus erythematosus (SLE), the presence of antiphospholipid antibodies (APA), notably the lupus anticoagulant, and anticardiolipin antibodies (aCL) characterizes a subset of patients with a thrombotic tendency. During the regular follow-up care of patients with SLE, we noticed that many described transient visual disturbances. Because a hypercoagulable state may cause transient monocular blindness (TMB), we determined the frequency of TMB and studied its relation to the presence of APA in patients with SLE. METHODS: We asked 175 unselected patients with SLE whether they had transient visual disturbances and reviewed their medical charts. All patients were examined with specific attention to the presence of livedo reticularis. Blood was examined for APA. RESULTS: Visual disturbances were recorded for 136 (78%) patients. According to predefined criteria, the symptoms were diagnosed as TMB for 10 (6%) patients and as visual disturbances associated with migraine for 18 (10%) patients. Five of the 10 patients with TMB had attacks in either eye. The 175 patients with SLE accrued a maximum total of 6,349 patient years in their lifetime. From this, the incidence of TMB can be calculated to be at least 158 per 100,000 per year. Lupus anticoagulant was detected in 3 of 10 patients with TMB and 41 of 165 patients without TMB (odds ratio, 1.3; 95% CI, 0.2 to 6.0). aCLs were found in 5 of 10 patients with TMB and 91 of 165 patients without TMB (odds ratio, 0.8; 95% CI, 0.2 to 3.7). CONCLUSIONS: The frequency of TMB among patients with SLE is at least 158 per 100,000 compared with the normal population (14 per 100,000 per year). However, among patients with SLE, no significant relation could be shown between TMB and the presence of APA or livedo reticularis.

[Referral of patients with polyneuropathy by the family physician: influence of type of symptoms but not of age]. / Verwijzing van patiënten met een polyneuropathie door de huisarts: geen invloed van de leeftijd, maar wel van de aard van de klachten.

OBJECTIVE: To investigate the influence of the age of the patient and the nature of a polyneuropathy on the referral behaviour of general practitioners (GPs). DESIGN: Written questionnaire sent to GPs regarding paper case records of polyneuropathy. SETTING: University Hospital Utrecht, the Netherlands. METHODS: 1590 GPs were asked about their differential diagnosis regarding a paper case record of a patient with polyneuropathy. There were six case records, differing in age (53, 64 and 73 years) and nature of the disease (sensory or sensorimotor polyneuropathy). The GPs were divided into six groups with similar demographic characteristics and type of practice. To avoid focus on polyneuropathy, all GPs also received questions about three other neurological cases (amaurosis fugax, radicular syndrome and vasovagal collapse). RESULTS: The mean response of the questionnaire was 54% (n = 844). Most GPs diagnosed the polyneuropathy (analysis of variance; p < 0.0001). The age of the patient did not influence the diagnosis nor the referral behaviour. At least 73% of the patients with a sensory and 81% of the patients with a sensorimotor polyneuropathy were referred to neurologists for further investigations (chi(2)-test; p < 0.05). CONCLUSION: At least 73% of the GPs referred a patient with polyneuropathy to a neurologist; patients with muscle weakness were referred more often than patients with only sensory disturbances. Referral was not influenced by the age of the patient.

Lupus anticoagulant is the strongest risk factor for both venous and arterial thrombosis in patients with systemic lupus erythematosus. Comparison between different assays for the detection of antiphospholipid antibodies.

Antiphospholipid antibodies (aPL) characterize patients at risk for both arterial and venous thrombotic complications. Recently it has been recognized that the presence of plasma proteins such as beta 2-glycoprotein I(beta 2 GPI) and prothrombin are essential for the binding of aPL to phospholipids and that these proteins are probably the real target of aPL. The discovery of these new antigens for aPL introduces the possibility of new assays to detect the presence of aPL. However, it is not known whether these assays improve the identification of patients at risk for thrombosis. In this retrospective study we compared the value of the classic assays LAC (lupus anticoagulant) and ACA (anticardiolipin antibodies) to detect aPL associated with thrombotic complications, with new assays which are based on the binding of aPL to the plasma proteins prothrombin and beta 2GPI. To do so, we have used these assays in a group of 175 SLE patients and correlated the positivity of the different assays with the presence of a history of venous and arterial thrombosis. Control groups were patients without SLE but with LAC and/or ACA and thrombosis (n = 23), patients with thrombosis without LAC and ACA (n = 40) and 42 healthy controls. In the univariate analysis, in which no distinction has been made between high and low antibody levels, we confirmed LAC and ACA to be related to both arterial and venous thrombosis. Anti-beta 2GPI- and anti-prothrombin-antibodies, both IgG and IgM correlate with venous thrombosis and anti-beta 2GPI-IgM with arterial thrombosis. Multivariate analysis showed that LAC is the strongest risk factor (OR 9.77; 95% CI 1.74-31.15) for arterial thrombosis. None of the other factors is a significant additional risk factor. For venous thrombosis LAC is the strongest risk factor (OR 6.55; 95% CI 2.36-18.17), but ACA-IgM above 20 MPL units also appeared to be a significant (p = 0.0159) risk factor (OR 3.90; 95% CI 1.29-11.80). Furthermore, the presence of anti-beta 2GPI- and/or anti-prothrombin-antibodies in LAC positive patients (n = 60) does not increase the risk for thrombosis. The results showed that (i) the LAC assay correlates best with a history of both arterial and venous thrombosis and (ii) neither the anti-beta 2GPI ELISA nor the anti-prothrombin ELISA gives additional information for a thrombotic risk in SLE patients.

Factor V Leiden, antiphospholipid antibodies and thrombosis in systemic lupus erythematosus.

Thromboembolic complications are frequently observed in patients with systemic lupus erythematosus (SLE). Significant associations have been reported between these complications and the presence of antiphospholipid antibodies, notably the lupus anticoagulant and anticardiolipin antibodies. Factor V Leiden is a genetic disorder associated with an increased risk of venous thrombosis. We studied these factors in 173 patients with SLE in relation to both arterial and venous thrombosis. The frequency of factor V Leiden in SLE patients in comparable to that in the Dutch population (5%) and a risk factor for venous thrombosis (odds ratio 4.9; CI 1.2-19.6), but not for arterial thrombosis. The lupus anticoagulant is a risk factor for both arterial thrombosis (odds ratio 7.1: CI 2.9-17.4) and venous thrombosis (odds ratio 6.4; CI 2.7-15.4). From multivariate analysis, both the lupus anticoagulant and factor V Leiden appeared independent risk factors for venous thrombosis.