Do polio survivors have a higher risk of epilepsy?

We planned this study to investigate the frequency of epilepsy in paralytic polio survivors. We analyzed the clinical data of 91 paralytic polio survivors. Patients who had been diagnosed with epilepsy were examined by electroencephalography and brain magnetic resonance imaging. 11 of the 91 patients had epilepsy (12%). The mean age at which the patients were exposed to acute poliomyelitis was 5.3±3.8 years (age range: 1-13). The mean age of epilepsy onset was 17±5.6 (age range: 4-25) in the epileptic patients. Our findings suggest that paralytic polio survivors may be at a higher risk for epilepsy compared to normal subjects.     

Endovascular management of unruptured intracranial aneurysms: does outcome justify treatment?

OBJECTIVE: The appropriate management of unruptured intracranial aneurysms depends on a complete understanding of their natural history and on the risks and efficacy of treatment options. There is little current data on the risks of endovascular therapy for these aneurysms. The aim of this study was to assess outcome of endovascular treatment of unruptured intracranial aneurysms. METHOD: A retrospective analysis was performed on all unruptured aneurysms treated by Guglielmi detachable (GD) coils at this institution from 1994 to 2000. RESULTS: Seventy three unruptured aneurysms were treated in 62 patients. There were 52 female and 10 male patients, with a median age of 55.7 years. Clinical background was: subarachnoid haemorrhage due to rupture of an additional aneurysm (40), headache (4), third nerve palsy (four), familial (four), and incidental (10). There were 14 technical failures with no clinical sequelae. Four procedural complications occurred (5.5%, 95% confidence interval (95% CI) 0.3% to 10.9%). One patient had temporary clinical sequelae (1.4%, 95% CI 0% to 2.7%); 79% of treated aneurysms had stable occlusions at follow up, 10.5% showed improved occlusion grade, 10.5% showed some recurrence, and three patients have required retreatment. Follow up modified Glasgow outcome scores were grade 1, 71%; grade 2, 18%; grade 3, 3%; grade 4, 3%. There were no deaths or haemorrhages during the follow up period. Two patients died as a result of complications from subarachnoid haemorrhage. CONCLUSION: The endovascular treatment of patients with unruptured aneurysms is safe with few clinical or procedural complications. Poor outcomes were only seen in those patients who presented with subarachnoid haemorrhage due to rupture of an aneurysm at another site.     

Is cardiovascular disease a risk factor in the development of axonal polyneuropathy?

OBJECTIVES: To determine if cardiovascular disease may be a risk factor in the development of chronic idiopathic axonal polyneuropathy (CIAP). METHODS: In this incidence case-control study, the prevalence of cardiovascular disease and risk factors in 97 patients with CIAP (mean age 67.5 (SD 7.9) years) and the prevalence of neuropathic features in 97 patients with peripheral arterial disease (PAD) (mean age 67.1 (SD 7.3) years) were investigated. The results were compared with those for 96 age and sex matched controls without diagnosed PAD or polyneuropathy (mean age 67.5 (SD 9.1) years). In a randomly chosen subgroup of 23 patients with CIAP, 42 patients with PAD, and 48 controls, an electrodiagnostic investigation was performed. RESULTS: Patients with CIAP more often had manifest cardiovascular disease and cardiovascular risk factors than controls (stroke 18% v 6% of patients, odds ratio (OR) 3.2 (95% confidence interval (CI) 1.8 to 5.9); heart disease 29% v 15%, OR 2.4 (95% CI 1.2 to 4.9); family history of cardiovascular disease 42% v 21%, OR 2.8 (95% CI (1.5 to 5.2); hypertension 56% v 39%, OR 2.0 (95% CI 1.1 to 3.6); hypercholesterolaemia 46% v 21%, OR 3.3 (95% CI 1.5 to 7.3); current smoking 38% v 23%, OR 2.1 (95% CI 1.1 to 3.9)). The prevalence of cardiovascular disease and cardiovascular risk factors was lower than in patients with PAD. Patients with PAD more often had polyneuropathy than controls (15% v 5%, OR 3.3 (95% CI 1.1 to 10.0)). There was a trend towards lower nerve conduction velocities and lower amplitudes on electrodiagnostic investigation compared with controls. CONCLUSION: This study shows that cardiovascular disease and CIAP often coexist, and therefore cardiovascular disease may be a cofactor in the development of CIAP.     

Is Alzheimer’s disease amyloidosis the result of a repair mechanism gone astray?

Here, we synthesize several lines of evidence supporting the hypothesis that at least one function of amyloid-β is to serve as a part of the acute response to brain hemodynamic disturbances intended to seal vascular leakage. Given the resilient and adhesive physicochemical properties of amyloid, an abluminal hemostatic repair system might be highly advantageous, if deployed on a limited and short-term basis, in young individuals. However, in the aged, inevitable cardiovascular dysfunction combined with brain microvascular lesions may yield global chronic hypoperfusion that may lead to continuous amyloid deposition and consequential negative effects on neuronal viability. A large body of experimental evidence supports the hypothesis of an amyloid-β rescue function gone astray. Preventing or inducing the removal of amyloid in Alzheimer's disease (AD) has been simultaneously successful and disappointing. Amyloid deposits clearly play major roles in AD, but they may not represent the preeminent factor in dementia pathogenesis. Successful application of AD preventative approaches may hinge on an accurate and comprehensive view of comorbidities, including cardiovascular disease, diabetes, and head trauma.     

Is retinal photography useful in the measurement of stroke risk?

BACKGROUND: The retinal microcirculation can be viewed non-invasively to give a unique perspective of the cerebral microcirculation in vivo. Studying pathological changes of retinal blood vessels (microaneurysms, retinal haemorrhages, and retinal arteriolar narrowing) may help to understand the causes of various cerebrovascular disorders. Retinal photography provides such an opportunity. RECENT DEVELOPMENTS: Several recent studies have shown that retinal microvascular changes are reliably documented by retinal photographs. These retinopathy changes seem to be fairly common in the general population, even in people without hypertension or diabetes. Retinopathy is related to incident clinical stroke and stroke mortality and to MRI-defined subclinical cerebral white-matter lesions and cerebral atrophy, independent of blood pressure, diabetes, and other cerebrovascular risk factors. WHERE NEXT?: Retinal microvascular abnormalities seem to be markers of concomitant cerebral microangiopathy, and retinal photography may be useful for the investigation of microvascular disorders of the brain in clinical and epidemiological settings. Future research should be aimed at the development of standardised photographic methods for the assessment of retinal microvascular changes, the replication of these findings in other populations and in people with other cerebrovascular disorders, and the examination of the increased accuracy of stoke-risk stratification given by retinal photography     

Is a fetal origin of the posterior cerebral artery a risk factor for TIA or ischemic stroke?

Background and purpose Fetal origin of the posterior cerebral artery (PCA) is not uncommon. Whether patients with this anomaly have a higher risk of ischemic stroke in the territory of the PCA is not known. The clinical benefit of screening for a fetal origin in patients with TIA or stroke in the territory of the PCA and an ipsilateral atherosclerotic carotid stenosis is not clear. This study assessed the frequency of a fetal origin of the PCA in patients with a TIA or infarct in the territory of the PCA with 16-multidetector-row CT angiography (CTA). Methods 82 patients (52 male; mean age = 64; range 19 to 90 years) with isolated homonymous hemianopia and/or a PCA infarct underwent CTA of the carotid artery and circle of Willis. Results A fetal origin of the PCA at the symptomatic side was present in 14 patients (17 %) and at the asymptomatic side in 18 patients (22%) (OR: 0.7; 95 % CI: 0.3 to 1.7). Severity of stenosis (NASCET criteria) of the ICA at the symptomatic side was < 30%, 30–49% and ≥ 50% in 72, 2 and 8 patients, respectively. Number and frequency of a fetal origin in these groups were 12 (17 %), 0 (0%) and 2 (25 %), respectively. There was no association between a severe carotid stenosis and a fetal origin of the PCA at the symptomatic side. Conclusion This study does not provide arguments for an increased risk of ischemic stroke in the territory of the PCA in patients with a fetal origin of the PCA. A few patients with a TIA or infarct in the territory of the PCA have a fetal origin of the PCA in combination with a high-grade stenosis of the ipsilateral ICA, but not more often than one would expect from chance. Nevertheless, these patients may benefit from carotid endarterectomy.     

Is migraine a risk factor for the occurrence of eating disorders? Prevalence and biochemical evidences

The eating disorders (ED), anorexia nervosa (AN) and bulimia nervosa (BN), are severe psychiatric and somatic conditions occurring mainly in young woman. Although the aetiology is largely unknown, same evidences suggest that biological and psychological factors play a relevant role in the pathogenesis, along with monoamine, indole and same hypothalamic hormonal dysfunctions. Migraine is characterized by similar metabolic and psychological anomalies suggesting that a possible relationship exists between the two pathological conditions. To understand the possible relationship between migraine and ED, we have investigated the prevalence of migraine and the other primary headaches in a large group of AN and BN patients. In addition, we have studied the role of tyrosine metabolism in the same group of AN and BN young woman sufferers. In particular, we measured plasma levels of elusive amines: tyramine (Tyr) and octopamine (Oct) and catecholamines: noradrenalin (NE), dopamine (DA). The results of this study show that the prevalence of migraine in the woman affected by ED is very high (<75?%). The levels of Tyr and DA were higher and levels of NE were lower in the ED patients in respect to the control subjects. These biochemical findings suggest that abnormalities of limbic and hypothalamic circuitries play a role in the pathogenesis of ED. The very high prevalence of migraine in our group of ED sufferers and the biochemical profile of migraine, similar to that of ED patients shown in this study, suggest that migraine may constitute a risk factor for the occurrence of ED in young females. This hypothesis is supported by the onset of migraine attacks that initiated, in the majority of the patients, before the occurrence of ED symptoms.     

Is migraine a risk factor for the occurrence of eating disorders? Prevalence and biochemical evidences

The eating disorders (ED), anorexia nervosa (AN) and bulimia nervosa (BN), are severe psychiatric and somatic conditions occurring mainly in young woman. Although the aetiology is largely unknown, same evidences suggest that biological and psychological factors play a relevant role in the pathogenesis, along with monoamine, indole and same hypothalamic hormonal dysfunctions. Migraine is characterized by similar metabolic and psychological anomalies suggesting that a possible relationship exists between the two pathological conditions. To understand the possible relationship between migraine and ED, we have investigated the prevalence of migraine and the other primary headaches in a large group of AN and BN patients. In addition, we have studied the role of tyrosine metabolism in the same group of AN and BN young woman sufferers. In particular, we measured plasma levels of elusive amines: tyramine (Tyr) and octopamine (Oct) and catecholamines: noradrenalin (NE), dopamine (DA). The results of this study show that the prevalence of migraine in the woman affected by ED is very high (<75 %). The levels of Tyr and DA were higher and levels of NE were lower in the ED patients in respect to the control subjects. These biochemical findings suggest that abnormalities of limbic and hypothalamic circuitries play a role in the pathogenesis of ED. The very high prevalence of migraine in our group of ED sufferers and the biochemical profile of migraine, similar to that of ED patients shown in this study, suggest that migraine may constitute a risk factor for the occurrence of ED in young females. This hypothesis is supported by the onset of migraine attacks that initiated, in the majority of the patients, before the occurrence of ED symptoms.     

School refusal behaviour: Are children and adolescents with autism spectrum disorder at a higher risk?

School refusal behaviour in students with autism spectrum disorder (ASD) is poorly studied despite being considered a serious problem. This study assessed the frequency, duration, and expression of school refusal behaviour in students with ASD, aged 9–16 years, without intellectual disability. Further, the associations between school refusal behaviour and sociodemographic factors were explored. Teachers and parents assessed this behaviour over 20 days in a cross-sectional study of 216 students, including 78 students with ASD and 138 typically developing (TD) students. School refusal behaviour was significantly higher in students with ASD as compared to TD students. Significant associations were found between school refusal behaviour and illness of other family members. The study concludes that school refusal behaviour is pervasive in students with ASD.     

Is forebrain neurogenesis a potential repair mechanism after stroke?

The use of adult subventricular zone (SVZ) neurogenesis as brain repair strategy after stroke represents a hot topic in neurologic research. Recent radiocarbon-14 dating has revealed a lack of poststroke neurogenesis in the adult human neocortex; however, adult neurogenesis has been shown to occur, even under physiologic conditions, in the human striatum. Here, these results are contrasted with experimental poststroke neurogenesis in the murine brain. Both in humans and in rodents, the SVZ generates predominantly calretinin (CR)-expressing GABAergic interneurons, which cannot replace the broad spectrum of neuronal subtypes damaged by stroke. Therefore, SVZ neurogenesis may represent a repair mechanism only after genetic manipulation redirecting its differentiation.     

Is the risk of multiple sclerosis related to the ‘biography’ of the immune system?

Multiple sclerosis (MS) with onset in childhood offers a unique opportunity to study the infectious background of this disease but the immune reactions against infectious agents in such children have only recently been investigated. These and other epidemiological studies strongly implicate involvement of one or more infectious agents in the aetiology of MS, with Epstein-Barr virus (EBV) being the prime candidate. Rather than being the actual cause of MS, it is more probable that these agents are involved in the development of immunoregulatory pathways. These pathways, if disturbed by hygiene-related factors including an altered sequence of infections, may generate and maintain a deficit within the immunological network that facilitates, to particular early events in the development of MS, preceding the onset of MS disease by years or a decade. A framework that can serve as a guide for further epidemiological, immunologic and molecular biologic investigations is formulated. This approach may shed light on the complex natural history of MS and may lead to rational preventive and therapeutic strategies. It is possible that, in the future, MS could be prevented by vaccination against EBV in early childhood; the framework is of relevance to the design of an appropriate type of vaccine.     

Is the hippocampus of the rat part of a specialized navigational system?

The spatial mapping theory of hippocampal function proposes that the rat hippocampus is specialized for navigational computations, computations that allow the animal to solve difficult spatial problems. In this paper, we review evidence obtained by recording place cells and other "spatially tuned" cells from freely moving rats. Our main conclusion is that the nature of the signals carried by these cells and the ways in which the signals transform after changing the environment imply that the hippocampus and associated structures are able to represent aspects of the geometry of the environment.