Diffusion-tensor MR imaging of optic pathway in idiopathic intracranial hypertension.

PURPOSE: To investigate the role of diffusion tensor imaging (DTI) of optic pathway in patients with idiopathic intracranial hypertension (IIH). PATIENTS AND METHODS: This study included 41 IIH patients and 22 controls. They underwent DTI of the optic nerve (ON) and optic radiation (OR). Their fractional anostrophy (FA) and mean diffusivity (MD) were calculated by two reviewers and correlated with papilledema grade. RESULTS: The optic nerve mean FA and MD of patients for reviewer-1 were 0.21 ± 0.047 and 2.189 ± 0.52 ×10-3 mm2/s and for reviewer-2 were 0.216 ± 0.047 and 2.17 ± 0.54 ×10-3 mm2/s. The mean ON FA and MD of controls for reviewer-1 were 0.33 ± 0.048 and 1.29 ± 0.26 ×10-3 mm2/s and for reviewer-2 were 0.34 ± 0.05 and 1.3 ± 0.26 ×10-3 mm2/s. There was significant difference in FA and MD between patients and controls (p < 0.00001). The OR mean FA and MD of patients for reviewer-1 were 0.61 ± 0.03 and 2.26 ± 0.55 ×10-3 mm2/s and for reviewer-2 were 0.6 ± 0.03 and 2.24 ± 0.57 ×10-3 mm2/s The mean OR FA and MD of controls for reviewer-1 were 0.6 ± 0.03 and 2.19 ± 0.49 ×10-3 mm2/s and for reviewer-2 were 0.6 ± 0.03 and 2.18 ± 0.49 ×10-3 mm2/s. There was no significant difference in FA and MD obtained in patients and controls. Both the FA and the MD of the ON showed strong correlation with the papilledema grade (r = -0.8 and 0.951, respectively). CONCLUSION: Our findings suggest that, IIH is associated mainly with pre-chiasmatic or ON involvement rather than post-chiasmatic parenchymal or OR involvement. DTI MD and FA parameters of the ON may be a reliable imaging biomarker for diagnosis of IIH and well correlated with papilledema grades.

Proposal of multimodal computed tomography-based scoring system in prediction of hemorrhagic transformation in acute ischemic stroke.

INTRODUCTION: The routinely used computed tomography (CT)-based workup in the setting of acute ischemic stroke (AIS) includes non-contrast brain CT, CT angiography (CTA), and CT perfusion. Several CT, CTA, CTP-based radiological biomarkers of hemorrhagic transformation (HT) were reported. AIM OF THE STUDY: To assess the predictive value of the combined multimodal CT parameters for HT after AIS and proposal of predictive scoring scale. METHODS: The source images of the NCCT, CTA and CTP of 282 AIS patients involving the anterior circulation (HT = 91, non-HT = 191) were retrospectively reviewed and the following biomarkers were recorded and analyzed: Early subtle ischemic signs, hyperdense middle cerebral artery sign (HMCAS) and Alberta Stroke Program Early CT Score (ASPECTS) < 7 in NCCT, large-vessel occlusion (LVO), clot burden score (CBS) < 6, large-vessel occlusion, poor collateral score (CS) and Tmax > 6 s ≥ 56.5 ml. A scoring system to predict HT based on these biomarkers was developed. Each biomarker counts for a single point with the total score ranging from 0 to 7. RESULTS: All the aforementioned multimodal CT biomarkers and the selected cut offs were significantly associated with higher HT risk. The calculated scores were statistically significant different between the HT and the non-HT groups with AUC 0.761 (95% CI 0.703-0.819, P < 0.0000001). Rates of HT were approximately five times higher in patients with score ≥ 3. CONCLUSION: Multimodal CT-based scoring system may provide highly reliable predictive model of hemorrhagic transformation in acute ischemic stroke.

Combined Conduit Score in Contrast-Enhanced Magnetic Resonance Venography in Patients with Idiopathic Intracranial Hypertension : Neuro-interventionalists' vs. Radiologists' Assessment.

BACKGROUND: Based on increased understanding of the idiopathic intracranial hypertension (IIH) pathophysiology, venous sinus stenting (VSS) has emerged as an effective treatment for patients with transverse sinus stenosis (TSS). The presence of a reliable TSS screening tool is warranted. The combined conduit score (CCS) is the most widely used score for evaluation of the cerebral sinovenous stenosis in contrast-enhanced magnetic resonance venography (CE-MRV). PURPOSE OF THE STUDY: To evaluate the interobserver agreement between neuro-interventionalists and radiologists with respect to the CCS in evaluation of transverse sinus stenosis in patients with idiopathic intracranial hypertension using CE-MRV. METHODS: A retrospective study was conducted on 26 consecutive patients diagnosed with IIH and underwent CE-MRV. The 2 neuro-interventionalists and 2 radiologists separately evaluated the cerebral venous sinuses using the CCS. RESULTS: The mean CCS was significantly different between the neuro-interventionalists and radiologists (p < 0.001), higher for the radiologists. The inter-rater reliability was excellent (ICC = 0.954, 95% CI: 0.898-0.979) between the 2 neuro-interventionalists, good between the 2 radiologists (ICC = 0.805, 95% CI: 0.418-0.921), but was not acceptable between the neuro-interventionalists and the radiologists (ICC 0.47 95% CI:-2.2-0.782). CONCLUSION: Despite the excellent agreement between the neuro-interventionists and the good agreement between the radiologists, there was no agreement between the neuro-interventionists and the radiologists. Our finding suggests that there is a gap between the 2 specialties but does not favor any of them. Factors related to the observers, the venous sinus system, the MRV or the CCS score may have resulted in this discrepancy. Automatic or semi-automatic feature extractions to produce quantifiable biomarkers for IIH are warranted. The clinical decisions should not depend only on strongly observer-dependent scores with training and/or experience-dependent influences.

The role of automated computed topography perfusion in prediction of hemorrhagic transformation after acute ischemic stroke.

INTRODUCTION: The role of computed tomography perfusion (CTP) in prediction of hemorrhagic transformation (HT) has been evolving. We aimed to study the role of automated perfusion post-processing software in prediction of HT using the commercially available RAPID software. METHODS: Two hundred eighty-two patients with anterior circulation ischemic stroke, who underwent CTP with RAPID automated post-processing, were retrospectively enrolled and divided into HT (n = 91) and non-HT groups (n = 191). The automated RAPID-generated perfusion maps were reviewed. Mismatch volume and ratio, time to maximum (Tmax) > 4-10s volumes, hypoperfusion index, cerebral blood flow (CBF) < 20-38% volumes, cerebral blood volume (CBV) < 34%-42% volumes, and CBV index were recorded and analyzed. RESULTS: The volumes of brain tissues suffering from reduction of cerebral blood flow (CBF < 20%-38%), reduction in cerebral blood volumes (CBV < 34-42%), and delayed contrast arrival times (Tmax > 4-10s) were significantly higher in the HT group. The mismatch volumes were also higher in the HT group (p = .001). Among these parameters, the Tmax > 6s volume was the most reliable and sensitive predictor of HT (p = .001, AUC = 0.667). However, the combination of the perfusion parameters can slightly improve the diagnostic efficiency (AUC = 0.703). There was no statistically significant difference between the non-HT group and either the parenchymal or the symptomatic subtypes. CONCLUSION: The RAPID automated CTP parameters can provide a reliable predictor of HT overall but not the parenchymal or the symptomatic subtypes. The infarct area involving the penumbra and core represented by the Tmax > 6s threshold is the most sensitive predictor; however, the combination of the perfusion parameters can slightly improve the diagnostic efficiency.

Evaluation of stroke prognostication using age and NIH Stroke Scale index (SPAN-100 index) in delayed intravenous thrombolysis patients (beyond 4.5 hours).

OBJECTIVES: the efficacy of delayed intravenous tissue plasminogen activator (tPA), beyond the 4.5 h window, is evolving. Advanced age and high admission National Institutes of Health Stroke Scale (NIHSS) score are proposed to adversely affect the outcome of delayed thrombolysis and limit the inclusion criteria. The summation of patient age and admission NIHSS score was introduced as the SPAN-100 index as a tool of prediction of the clinical outcome after acute ischemic stroke (AIS). We aimed to assess the SPAN-100 index in AIS thrombolysed patients after 4.5 h. MATERIALS AND METHODS: The SPAN-100 index was applied to AIS patients receiving delayed IV thrombolysis (IVT) after 4.5 h. Patients demographics, risk factors, clinical, laboratory and radiological data, mismatch evidence, treatment onset and modality, NIHSS score at baseline and at discharge, and 3 months follow-up modified Rankin Scale (mRS) were reviewed. SPAN-100 score ≥ 100 is classified as SPAN-100 positive while score < 100 is SPAN-100 negative. Clinical outcomes, death and intracerebral hemorrhage (ICH) incidences were compared between SPAN-100 positive and negative groups. RESULTS: SPAN-100-positive delayed IVT-patients (11/136) had a 6-fold increased risk for unfavorable outcome compared to SPAN-negative patients (OR 6.34; 95% CI 1.59-25.24 p=0.004), however there was no relation between the SPAN-100 positivity and mortality or ICH. CONCLUSION: SPAN-100-positive patients are more likely to achieve non-favorable outcome with delayed IVT in comparison to the SPAN-100-negative patients. SPAN-100 index may influence the eligibility criteria of delayed thrombolysis.

Combined accuracy of optic nerve sheath diameter, strain ratio, and shear wave elastography of the optic nerve in patients with idiopathic intracranial hypertension.

PURPOSE: This study assessed the combined accuracy of optic nerve sheath diameter (ONSD), strain ratio (SR), and shear wave elastography (SWE) of the optic nerve (ON) in patients with idiopathic intracranial hypertension (IIH). METHODS: This prospective study was carried out on both ONs of 34 consecutive patients diagnosed with IIH and 16 age- and sex-matched healthy volunteers. All of the study participants were women. The ONSD, SR, and SWE of the ON were measured. The severity of papilledema of IIH patients was sub-classified into mild papilledema and moderate/severe papilledema. RESULTS: The mean ONSD (5.6±1.1 mm), SR (0.7±0.1), and SWE (30.1±16.7 kPa) of the IIH patients were significantly different (P=0.001) from the ONSD (4.1±0.5 mm), SR (0.9±0.1), and SWE (8.2±3.4 kPa) of controls. The cutoff values of ONSD, SR, and SWE of the ON for differentiating IIH patients from controls were 5.45 mm, 0.8, and 10.3 kPa with areas under the curve (AUCs) of 0.91, 0.86, and 0.96 and accuracy values of 91%, 81%, and 93%, respectively. Combined SWE and ONSD and combined SWE, ONSD, and SR for differentiating IIH patients from controls revealed AUCs of 0.98 and 0.99 and accuracy values of 96% and 96%, respectively. ONSD, SR, and SWE showed significant differences between mild and moderate/severe papilledema (P=0.001). Papilledema was correlated with SWE (r=0.8, P=0.001), ONSD (r=0.4, P=0.001), and SR (r=-0.4, P=0.001). CONCLUSION: The combination of ONSD, SR, and SWE may be helpful for diagnosing IIH, and a good indicator of the degree of papilledema.

Effect of changes in optic nerve elasticity on central retinal artery blood flow in patients with idiopathic intracranial hypertension.

PURPOSE: To assess changes in central retinal artery (CRA) blood flow by orbital color-coded Doppler ultrasonography in patients with idiopathic intracranial hypertension (IIH) and their relation with optic nerve (ON) elasticity assessed by shear wave elastography (SWE). METHODS: This study was carried out on 68 eyes of patients diagnosed with IIH and 32 eyes of healthy controls. The severity of papilledema in IIH patients was sub-classified into mild and moderate/severe groups. Color-coded Doppler was used to measure peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (Vmean) and pulsatility index (PI) of the CRA. RESULTS: PSV, Vmean, and SWE were significantly higher in patients with IIH than in controls (p = 0.001). The optimal cut-off values of PSV and Vmean for differentiating IIH patients from controls were 11.25 and 6.75 cm/s with AUC 0.81 and 0.785 respectively. AUC was 0.92 and accuracy 91% for combined PSV, Vmean and SWE differentiation between IIH patients and controls. PSV, Vmean and SWE were significantly different between mild versus moderate/severe papilledema (p = 0.001). PSV and Vmean were correlated with papilledema (r = 0.790 and 0.722 respectively) and SWE (r = 0.818 and 0.761 respectively). CONCLUSION: IIH is associated with decreased ON elasticity and reduced CRA blood flow. Individual and combined color-coded Doppler of the CRA and SWE help in diagnosis of IIH. CRA hemodynamic changes are correlated with papilledema severity and with the extent of biomechanical changes in the ON represented by SWE.

Impact of stress and hypertension on the cerebrovasculature.

OBJECTIVES: Both stress and hypertension (HTN) are considered major health problems that negatively impact the cerebral vasculature. In this article we summarize the possible relationship between stress and HTN. METHODS: We conducted a systematic review of the literature using a database search of MEDLINE, PubMed, Scopus, and Web of Science. RESULTS: Psychological stress is known to be an important risk factor for essential hypertension. Acute stress can induce transient elevations of blood pressure in the context of the fight-or-flight response. With increased intensity and duration of a perceived harmful event, the normal physiological response is altered, resulting in a failure to return to the resting levels. These changes are responsible for the development of HTN. Genetic and behavioral factors are also very important for the pathogenesis of hypertension under chronic stress situation. In addition, HTN and chronic stress may lead to impaired auto-regulation, regional vascular remodeling, and breakdown of the blood brain barrier (BBB). The effects of both HTN and chronic stress on the cerebral blood vessels shows that both have common structural and functional effects including endothelial damage with subsequent increased wall thickness, vessel resistance, stiffness, arterial atherosclerosis, and altered hemodynamics. CONCLUSION: Most of the above mentioned vascular effects of stress were primarily reported in animal models. Further in-vivo standardization of pathological vascular indices and imaging modalities is warranted. Radiological quantification of these cerebrovascular changes is therefore essential for in depth understanding of the healthy and diseased cerebral arteries functions, identification and stratification of patients at risk of cardiovascular and neurological adverse events, enactment of preventive measures prior to the onset of systemic HTN, and the initiation of personalized medical management.

Pathogenesis and Evaluation of the Effects of Idiopathic Intracranial Hypertension on the Optic Nerves.

Idiopathic intracranial hypertension (IIH) is a clinical syndrome of raised intracranial pressure of unknown aetiology. Although papilloedema and visual alterations are among the most important manifestations of the disease, their pathophysiological mechanisms are not fully understood. We aim to review the up-to-date evidence regarding how the optic nerves are affected, the possible pathophysiology and the methods of their assessment.

Factors Affecting the Degree of Angular Remodeling in Stent-Assisted Coiling of Bifurcation Aneurysms.

BACKGROUND: Stent-assisted coiling (SAC) leads to significant changes in the vascular angle altering the bifurcation geometry and the hemodynamics at the bifurcation apex. It is believed that the stent alone exerts this effect, but other possible factors have not been studied. PURPOSE: To study the factors contributing to angular remodeling following SAC of bifurcation aneurysms including the anatomical, stent-related, and coil-related factors. MATERIALS AND METHODS: We reviewed 43 basilar and carotid bifurcation aneurysms treated by SAC using Neuroform EZ (n = 28), Enterprise (n = 8), and Lvis Jr. (n = 7) stents. The bifurcation angle between the mother and stented daughter vessel was measured in 4 settings: pretreatment, poststenting, postcoiling, and at delayed follow-up (6-12 months). The degree of stent-induced angular remodeling was calculated by subtracting the poststenting bifurcation angle from the pretreatment one, while the coil-induced angular remodeling was calculated as the difference between the postcoiling and poststenting bifurcation angle. The immediate postprocedural degree of angular remodeling is the sum of the stent- and coil-induced angular remodeling. We studied the effect of several factors including the pretreatment bifurcation angle, aneurysm site, diameter of parent vessel, stent type, stent length in the daughter vessel, postoperative actual in situ coil size, and packing density. RESULTS: The mean degree of stent-induced and coil-induced angular remodeling was 10.2 (0-47) and 4.53 (-7 to 30), respectively. The immediate postprocedural and delayed angular remodeling was 14.8 (-4 to 47) and 4.75 (-12 to 40), respectively. The degree of immediate remodeling was significantly affected by the actual in situ coil size (p = 0.017), and the pretreatment bifurcation angle (p = 0.024). Linear regression was carried out and the pretreatment bifurcation angle was defined as a predictor. The degree of delayed remodeling is significantly affected only by the pretreatment bifurcation angle (p = 0.011). CONCLUSION: Immediate angular remodeling following SAC of bifurcation aneurysms can happen after stenting or coiling or both. This is the first study reporting the role of the coils as an additional factor beside the stent in inducing immediate angular changes; this effect is correlated to the size of the coils. The pretreatment bifurcation angle is the most consistent factor affecting the degree of both immediate and delayed angular remodeling.

The Relation Between Aortic Arch Branching Types and the Laterality of Cardio-Embolic Stroke.

BACKGROUND AND PURPOSE: The trajectory of cardiogenic emboli could be affected by anatomical and flow characteristics of the aortic arch. We aimed to study the relation between the different aortic arch patterns and the laterality of cardiogenic emboli. METHODS: 192 cardioembolic strokes were classified into 3 groups according to the type of the aortic arch; type 1 (n = 69), type 2 (n = 49), type 3 (n = 74). The side and site of the cerebral vessels occlusion were divided into anterior and posterior circulation strokes, and anterior strokes were further subdivided into right or left internal carotid, middle or anterior cerebral arteries occlusion. RESULTS: Overall, the anterior circulation embolic occlusions were more common than the posterior, and middle cerebral artery more commonly affected than internal carotid artery. The left side propensity was higher either in the total patients' pool or after segregation into atrial fibrillation (AF) and non AF cardio-embolic cases in all types of aortic arch except for type 1 aortic arch in the non AF cases. This propensity tended to get higher with advancement of the aortic arch types but failed to show statistically significant difference between the 3 arch types, however combination of type 2 and 3 arches into a single group showed statistically significant rise in the left side propensity in the total cardioembolic cases (P = 0.039) and in the non AF cardioembolic cases (P = 0.029). The bovine arch also showed increased left side propensity. CONCLUSION: Cardioemboli tends to have left anterior cerebrovascular predilection especially with AF. Different geometrical patterns of aortic arch branching seem to affect the laterality of cardioemboli and increase its left side predilection.

Radiological predictors of hemorrhagic transformation after acute ischemic stroke: An evidence-based analysis.

Hemorrhagic transformation (HT) is one of the most common adverse events related to acute ischemic stroke (AIS) that affects the treatment plan and clinical outcome. Identification of a sensitive radiological marker may influence the controversial thrombolytic decision in the setting of AIS and may at a minimum indicate more intensive monitoring or further prophylactic interventions. In this article we summarize possible radiological biomarkers and the role of different radiological modalities including computed tomography (CT), magnetic resonance imaging, angiography, and ultrasound in predicting HT. Different radiological indices of early ischemic changes, large ischemic lesion volume, severe blood flow restriction, blood-brain barrier disruption, poor collaterals and high blood flow velocities have been reported to be associated with higher risk of HT. The current levels of evidence of the available studies highlight the role of the different CT perfusion parameters in predicting HT. Further large standardized studies are recommended to compare the sensitivity and specificity of the different radiological markers combined and delineate the most reliable predictor.

Long term effects of corticosteroids in multiple sclerosis in terms of the "no evidence of disease activity" (NEDA) domains.

BACKGROUND: Multiple sclerosis (MS) is a chronic immune-mediated inflammatory disease of the central nervous system (CNS) that usually is clinically characterized by multiple subacute relapses and remissions. The established therapeutic strategies include intravenous methylprednisolone (IV-MP) for treatment of relapses and immunomodulatory or immunosuppressive treatment to prevent new relapses and progression of disability. Despite not being one of the recommended immunomodulatory or immunosuppressive treatments, monthly IV-MP is frequently seen in clinical practice especially in the low income developing countries. OBJECTIVES: To review the evidences for the possible disease modifying potential of corticosteroids in the treatment of MS in terms of the NEDA 3 domains. MATERIALS & METHODS: Available literature from PubMed search and personal experiences on corticosteroid treatment in multiple sclerosis were reviewed. RESULTS: There is some evidence that pulsed treatment with methylprednisolone have beneficial long-term effects on relapse rate, MRI findings and disability progression. CONCLUSION: More data is needed to determine long-term disease modifying effects of corticosteroids. The findings of this study suggest that, perhaps, regular pulse glucocorticoid treatment may have important long-term consequences (beneficial) for patients with MS and it may achieve the NEDA target. Certainly, the magnitude of the reported effects deserves further investigation in both relapsing and progressive MS populations.

Objective Assessment of Arterial Steal Phenomenon in Direct Carotid Cavernous Fistula Using 2D Parametric Parenchymal Blood Flow Analysis.

The aim of the study is to evaluate the hemodynamic changes and the parenchymal perfusion associated with carotid cavernous fistulas before and after embolization using two-dimensional (2D) parenchymal blood flow analysis. A 15-year-old boy presented with 2-month history of progressive right eye proptosis, chemosis, and diplopia after a motor vehicle accident. Intracranial liquid embolization using Onyx-18 through the inferior petrosal approach was done with balloon protection at the opening of the fistula in the internal carotid artery, resulting in complete occlusion of the fistula. Parenchymal blood flow analysis was done before and immediately after embolization. 2D parametric parenchymal blood flow analysis is newly introduced software that can provide data cannot be conveyed by conventional digital subtraction angiography alone. The software allows for objective assessment of the arterial steal and the parenchymal perfusion both pre, and post-embolization. Pre-embolization assessment may influence the therapeutic decision, while post-embolization assessment can evaluate the treatment efficacy.

Software-based simulation for preprocedural assessment of braided stent sizing: a validation study.

OBJECTIVEThe authors sought to validate the use of a software-based simulation for preassessment of braided self-expanding stents in the treatment of wide-necked intracranial aneurysms.METHODSThis was a retrospective, observational, single-center study of 13 unruptured and ruptured intracranial aneurysms treated with braided self-expanding stents. Pre- and postprocedural angiographic studies were analyzed. ANKYRAS software was used to compare the following 3 variables: the manufacturer-given nominal length (NL), software-calculated simulated length (SL), and the actual measured length (ML) of the stent. Appropriate statistical methods were used to draw correlations among the 3 lengths.RESULTSIn this study, data obtained in 13 patients treated with braided self-expanding stents were analyzed. Data for the 3 lengths were collected for all patients. Error discrepancy was calculated by mean squared error (NL to ML -22.2; SL to ML -6.14, p < 0.05), mean absolute error (NL to ML 3.88; SL to ML -1.84, p < 0.05), and mean error (NL to ML -3.81; SL to ML -1.22, p < 0.05).CONCLUSIONSThe ML was usually less than the NL given by the manufacturer, indicating significant change in length in most cases. Computational software-based simulation for preassessment of the braided self-expanding stents is a safe and effective way for accurately calculating the change in length to aid in choosing the right-sized stent for optimal placement in complex intracranial vasculature.

2D Parametric Parenchymal Blood Flow as a Predictor of the Hemorrhagic Events after Endovascular Treatment of Acute Ischemic Stroke: A Single-Center Retrospective Study.

BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is one of the major adverse events related to the endovascular management of acute ischemic stroke. It is important to evaluate the risk of ICH as it may result in clinical deterioration of the patients. Development of tools which can predict the risk of ICH after thrombectomy can reduce the procedure-related morbidity and mortality. 2D parenchymal blood flow could potentially act as an indicator for ICH. METHODS: 2D parenchymal blood flow was used to evaluate pre- and postthrombectomy digital subtraction angiography series of patients with acute ischemic stroke in the anterior circulation. A recently developed software allows the separation of the vascular filling and parenchymal blush signals using band-pass and band-reject filtering to allow for greater visibility of the parenchyma offering a better visual indicator of the effect of treatment. The "wash-in rate" was selected as the parameter of interest to predict ICH. RESULTS: According to the presence or absence of signs of intracranial parenchymal hemorrhage in the follow-up dual-energy CT brain scans, the patients were classified into a hemorrhagic and nonhemorrhagic group (15 patients each). The only significant difference between the groups is the calculated wash-in rate after thrombectomy (p = 0.024). The cutoff value of the wash-in rate after thrombectomy was suggested to be 11,925.0, with 60% sensitivity to predict the hemorrhage and 93.3% specificity. CONCLUSIONS: Elevated parametric parenchymal blood flow wash-in rates after thrombectomy may be associated with increased risk of hemorrhagic events.

Enterobiasis-related inflammatory caecal polyp masquerading as a malignancy.

A 55 -year-old Asian man was seen in the emergency department with bleeding per rectum. He was a teetotaller and had no previous abdominal surgery. He did, however, report a change in bowel habit towards constipation. He underwent colonoscopy which revealed a lesion, highly suspicious of malignancy, in the caecum. On review by two consultants, a decision to completely resect this lesion was made. Histological analysis of the polypoidal growth showed it to be a consequence of chronic infection with the helminth Enterobius vermicularis. Importantly, there was no evidence of dysplastic or malignant cells. The patient was subsequently discharged with a 3-day course of antihelminthic mebendazole and reassured that his per rectal bleeding was most likely due to haemorrhoids discovered at rectal examination.