Whole brain CT perfusion deficits using 320-detector-row CT scanner in TIA patients are associated with ABCD2 score.

BACKGROUND: Transient ischemic attacks (TIA) are cerebral ischemic events without infarction. The uses of CT perfusion (CTP) techniques such as cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT) and cerebral blood flow (CBF) provide real time data about ischemia. It has been shown that CTP changes occur in less sensitive CTP scanners in patients with TIA. Larger detector row CTP (whole brain perfusion studies) may show that CTP abnormalities are more prevalent than previously noted. It is also unclear if these changes are associated with TIA severity. OBJECTIVE: To demonstrate that TIA patients are associated with perfusion deficits using whole brain 320-detector-row CT perfusion, and to determine an association between ABCD2 score and perfusion deficit using whole brain perfusion. METHODS: We retrospectively reviewed all TIA patients for CTP deficits from 2008-2010. Perfusion imaging was reviewed at admission; and it was determined if a perfusion deficit was present along with vascular territory involved. RESULTS: Of 364 TIA patients, 62 patients had CTP deficits. The largest group of patients had MCA territory involved with 48 of 62 patients (77.42%). The most common perfusion abnormality was increased TTP with 46 patients (74.19%). The ABCD2 score was reviewed in association with perfusion deficit. Increased age >60, severe hypertension (>180/100 mmHg), patients with speech abnormalities, and duration of symptoms >10 min were associated with a perfusion deficit but history of diabetes or minimal/moderate hypertension (140/90-179/99 mmHg) was not. There was no association between motor deficit and perfusion abnormality. CONCLUSION: Perfusion deficits are found in TIA patients using whole brain CTP and associated with components of the ABCD2 score.

Laboratory factors associated with symptomatic hemorrhagic conversion of acute stroke after systemic thrombolysis.

BACKGROUND: Laboratory factors associated with hemorrhagic conversion (HC) after Intravenous thrombolysis with rtPA (IVT) for Acute Ischemic Stroke (AIS) remain nebulous despite advances in our knowledge of AIS. This study aimed to investigate the laboratory factors predisposing to HC in AIS patients receiving IVT. METHODS: We retrospectively reviewed the medical records of patients who received IV tPA for AIS at our comprehensive stroke center over a 9.6-year period. Besides age, gender, NIHSS, history of diabetes mellitus (DM), history of atrial fibrillation (Afib), we gathered their laboratory data including International Normalized Ratio (INR), lipid panel, serum albumin, serum creatinine, hemoglobin A1c (HbA1c), and admission blood glucose. Post-thrombolysis brain imagings were reviewed to evaluate for symptomatic ICH (sICH). The mean values of above mentioned laboratory data were compared between the group with sICH and patients with no sICH. Univariate and multivariate logistic regression were performed to evaluate the association of the laboratory findings with presence of sICH. sICH was defined as ICH causing an increase in NIHSS ≥4. RESULTS: Of the 794 subjects in this study 51 (6.4%) had sICH. In the univariate analysis, patients who developed sICH had significantly higher NIHSS on admission (14.2 ± 5.4 vs 11.2 ± 6.5, p < .001), LDL-cholesterol (113.3 mg/dl ±36.9 vs. 101.8 mg/dl ± 38.2, p = .032), HbA1c (6.9% ± 2.3 vs. 6.1 ± 1.3, p = .003) and lower levels of Albumin (3.5 g/dl ±0.4 vs. 3.9 g/dl ± 0.5, p < .001). Furthermore, a higher prevalence of history of DM (45% vs. 21.6%, p = .020) and Afib (25.4% vs. 10.4%, p = .028) was found in subjects who developed sICH. There were no significant group differences regarding age, sex, total cholesterol, blood glucose on admission, serum creatinine or INR levels (p > .05). After adjusting for multiple covariates, lower Albumin level and and higher HbA1c were significantly associated with an increased risk for sICH development (p < .05). Chances of sICH increased by 33% for every 1 g/dl below a normal albumin level of 4.0 g/dl (p < .05). CONCLUSION: Lower endogenous albumin level and higher HbA1c have shown to predispose to a higher risk of sICH after IVT for AIS and might be good predictors of sICH post IVT.

Effect of Heparin on Recanalization in Acute Stroke Patients with Intra-Arterial Thrombi.

Anticoagulant use, such as heparin, is usually contraindicated in acute stroke patients. We present a study of patients, who were treated with intravenous heparin after a stroke that were also found to have an intraluminal thrombus. Prior studies imply that recanalization is achieved with heparin; however heparin should only prevent thrombus propagation. Therefore it is unclear whether and how IV heparin can achieve recanalization of intraluminal thrombi in acute stroke patients. A retrospective review of all acute stroke patients from a single stroke center who received a therapeutic IV heparin infusion from 5/2006 to 9/2011 were included in the study. We compared patients who had complete/partial recanalization and/or improved flow versus those that did not, with both these groups on a standard intravenous heparin infusion protocol. Demographic data was compared between the groups. Average partial thromboplastin time (PTT) during heparin infusion, time between computed tomography angiographies (CTAs), time from stroke onset to receiving IV heparin, and vessel occluded were also compared between groups. Forty-one patients (19 female, 22 male) were included in the study with a total of 55 vessels (either carotid, middle cerebral artery, anterior cerebral artery, posterior cerebral artery/posterior circulation) having intraluminal thrombi; 31 patients had 41 vessels with either partial or complete recanalization of effected vessels, while 10 patients had 14 vessels that did not have at least one vessel recanalize while on heparin. Using t-test we noted that the average PTT between the vessels that had partial/complete recanalization group (61.74) and nonrecanalization group (66.30) was not statistical significantly different (P=0.37).The average time in days on heparin between vascular imaging studies (CTA/conventional angiogram) in the group of vessels with partial/complete recanalization (7.12 days) and the ones with no change (6.11 days) was not significantly different between the two groups (P=0.59). Patient's vessels receiving heparin for <24 hours versus those >24 hours did not significantly differ either (P=0.17). This study compares patient characteristics associated with recanalization of intraluminal thrombi in acute stroke patients on heparin. Recanalization of intraluminal thrombi are not associated with average PTT or duration on heparin.

Omega-3 Fatty Acid Ethyl Esters do not Improve Clopidogrel Associated P2Y12 Inhibition in Stroke Patients.

The specific action of omega-3 fatty acid ethyl esters (OFA) in preventing cerebrovascular disease remains unknown, but research has demonstrated multiple possible mechanisms. In addition to altering lipid profiles, OFA may inhibit platelet aggregation. Clopidogrel inhibits platelets via the P2Y12 receptor. OFA may alter clopidogrel-associated platelet-inhibition via a possible combined effect on P2Y12 inhibition. To determine if OFA affects clopidogrel associated P2Y12 platelet receptor inhibition by comparing the percentage of responders in patients with cerebrovascular disease who were taking clopidogrel with or without OFA. We retrospectively reviewed data from adult patients with cerebrovascular disease or cerebral aneurysms and taking clopidogrel, who were seen at a single hospital between March 2010 to September 2011. We included 438 subjects in the study. For the 67 subjects who received loading doses of both clopidogrel and OFA, 71.6% had a P2Y12 inhibition response more than 20%, which is considered a positive response. For the 55 subjects who received just clopidogrel load, 67.2% of subjects were responders. There were 70.4% responders in the 274 subjects who were taking 75 mg of clopidogrel alone at home, and 73.8% responders in the 42 subjects who were taking both clopidogrel and OFA at home. However, these percentage differences were not statistically significant. This study did not find additional P2Y12 platelet inhibition when patients were given OFA, either given as a loading dose or taking it daily.

Does the MMR vaccine and secretin or its receptor share an antigenic epitope?

In a subgroup of children with autism-spectrum like conditions symptoms seem to appear as a 'regression' (in normal development). It has been postulated that the onset of such autistic symptoms may involve an autoimmune response against the central nervous system and that the antigenic determinant could possibly be gastrointestinal in origin. It has been suggested that the presence of the measles virus and 'autistic enterocolitis' demonstrates the possibility that the MMR triple vaccine may be mediating the inflammation with possible production of antibodies against the virus containing vaccine. Such an antibody may share antigenic determinant to molecules found in the gut. We propose that this may be secretin or its receptor, found in the gut as well as in the central nervous system. The antibody response to the gut may also conceivably occur in the brain at a critical time in development. The modulation of development by secretin may be a static event possibly occurring at a specific time in early childhood development and if it involves an autoimmune response then a disruption in development may result. These hypothesized events can only occur if the MMR vaccine shares antigenic determinants that resemble secretin or any of its receptor types and remains to be studied.

Vitamin D and multiple sclerosis.

BACKGROUND: Epidemiological data support a potential relationship between vitamin D deficiency and an increased risk of developing multiple sclerosis (MS). In vitro studies have expanded the potential role of vitamin D and its receptor beyond calcium modulation, regulation, and maintenance of bone mineralization, to include immune modulation. REVIEW SUMMARY: Whether vitamin D immunomodulatory effects can be translated into clinical benefits in MS patients is still a matter of debate. A review of the biochemistry of vitamin D and its synthesized derivatives is discussed in the context of treating vitamin D deficiency. Animal studies, which led to some human studies, are also discussed. Future studies are pending and will likely yield conclusive results as to the benefit and possible synergistic effects of vitamin D with other disease-modifying therapies of MS. CONCLUSIONS: Further prospective studies are needed to identify vitamin D levels during the various phases of MS, including relapses, remissions and progression, and to determine whether correcting vitamin D during any or all of these phases may affect the incidence or even the course of the disease.

The nervous system's potential role in multiple sclerosis associated bone loss.

Osteoporosis is a degenerative bone disease that causes significant morbidity and mortality in multiple sclerosis (MS) patients; the pathogenesis of this disease being poorly understood in the context of MS. Osteoporosis is seen more frequently in MS patients than in healthy controls matched for age and sex. Extensively studied factors, including impaired ambulation and the use of steroids, do not appear to completely account for the phenomenon. This review summarizes common risk factors, physiologic and genetic, that may contribute to the etiology and progression of osteoporosis in MS patients as well as providing insight into nervous system control of bone metabolism and homeostasis.

Pseudophakic hyperopia in nanophthalmic eyes managed by a posterior chamber implantable collamer lens.

We report a case of a bilateral posterior chamber implantable collamer lens (ICL) implantation post-clear lens extraction, to reduce the residual hyperopia, in a patient with nanophthalmic eyes. A 30-year-old female patient, keen to reduce her dependency on glasses and contact lenses, came to our refractive surgery department. Her refractive error was +12.0 and +12.5 diopters in the right and left eye, respectively, with steep corneas on keratometry and a shallow anterior chamber depth. She underwent clear lens extraction with implantation of +35.0 D and +40.0 D IOL in the right eye and left eye, respectively. Her post-operative best-corrected visual acuity was 20/30 with +8.5 D in the right eye and +6 D in the left. She underwent bilateral ICL implantation. Postoperatively after 6 months, her unaided visual acuity was 20/30 in both eyes. In conclusion, ICL implantation can be considered to correct residual hypermetropic ametropia in pseudophakic eyes when other options have limitations.

New hypotheses on sunlight and the geographic variability of multiple sclerosis prevalence.

Multiple sclerosis is an autoimmune demyelinating disorder of the central nervous system. Its etiology continues to be elucidated. The debate about the environmental impact on the disease etiology and progression has focused on sun light exposure in the recent past, but mainly as it applies to vitamin D and its derivatives. This paper will discuss how sunlight stimulus may effect neuronal and microglial antigenic presentation based on sunlight-dependent neuronal activity, as well as how sunlight may alter the amount of vitamin A and melatonin levels during immune development in the central nervous system. Changes in the number of antigens presented to lymphocytes by antigen-presenting cells for self-selective removal during immune development could therefore alter the number of circulating self-recognizing B and T-lymphocytes. This situation would increase susceptibility to a significantly greater number of self-antigens, and lead to autoimmune disorders such as multiple sclerosis.