Associations between antipsychotics exposure and dementia risk: A prospective cohort study of 415,100 participants

BACKGROUND

Antipsychotics (APs) are among the most widely prescribed medications, and have been shown to cause cognitive decline. But previous studies on their effects on dementia risk are controversial and scarce. We aimed to examine the relationships of APs exposure with the risk of dementia.

METHODS

Data were obtained from a prospective cohort of 415,100 UK Biobank (UKB) participants. We investigated the effects of APs exposure and their various classes on dementia risk by using multivariable Cox proportional hazard models and further the dose-response effects of oral APs.

RESULTS

After a mean follow-up of 8.64 years, 5235 (1.3 %) participants developed all-cause dementia (ACD), among whom 2313 (0.6 %) developed Alzheimer's disease (AD), and 1213 (0.3 %) developed vascular dementia (VaD). Exposure to any APs conferred increased risks of ACD (HR: 1.33, 95 % CI = 1.17-1.51, P < 0.001) and VaD (HR: 1.90, 95 % CI = 1.51-2.40, P < 0.001), but not AD (HR: 1.22, 95 % CI = 1.00-1.48, P = 0.051). Cumulative dose-response relationships of oral APs with the risks of ACD and VaD were observed (P for trend, P < 0.05).

LIMITATIONS

Our study is observational and does not show evidence of causality. Since there are relatively few cases of dementia in the UKB, APs exposure may be higher than estimated in our study.

CONCLUSIONS

APs exposure increased the risk of developing dementia. Dose-response relationships were found between oral APs and dementia risk. Efforts to raise awareness of doctors and patients about this potential drug-related risk are critical to reducing APs use.

Risk of Incident Atrial Fibrillation and Subsequent Use of Oral Anticoagulants in Patients with Dementia

BACKGROUND

 Dementia and atrial fibrillation (AF) have many shared risk factors. Besides, patients with dementia are under-represented in randomized trials, and even if AF is present, oral anticoagulants (OACs) are not prescribed frequently. This study aimed to report the incidence of newly diagnosed AF in dementia patients, and the impacts of use of vitamin K antagonist (VKA; e.g., warfarin) and non-VKA OAC (NOACs) on stroke and bleeding outcomes.

METHODS

 Our study utilized the Taiwan National Health Insurance Research Database. A total of 554,074 patients with dementia were compared with 554,074 age- and sex-matched patients without dementia regarding the risk of incident AF. Among patients with dementia who experienced incident AF, the risks of clinical events of patients treated with warfarin or NOACs were compared with those without OACs (reference group).

RESULTS

 The risk of incident AF was greater for patients with dementia compared with those without (adjusted hazard ratio [aHR]: 1.054; 95% confidence interval [CI]: 1.040-1.068 for all types of dementia, aHR: 1.035; 95% CI: 1.020-1.051 for presenile/senile dementia, and aHR: 1.125; 95% CI: 1.091-1.159 for vascular dementia). Among patients with dementia and experienced incident AF, warfarin use was associated with a higher risk of ischemic stroke (aHR: 1.290; 95% CI: 1.156-1.440), intracranial hemorrhage (ICH; aHR: 1.678; 95% CI: 1.346-2.090), and major bleeding (aHR: 1.192; 95% CI: 1.073-1.323) compared with non-OACs. NOAC use was associated with a lower risk of ischemic stroke (aHR: 0.421; 95% CI: 0.352-0.503) and composite risk of ischemic stroke or major bleeding (aHR: 0.544; 95% CI: 0.487-0.608) compared with non-OACs. These results were consistent among the patients after the propensity matching.

CONCLUSION

 In this large nationwide cohort, the risk of newly diagnosed AF was higher in patients with dementia (all dementia, presenile/senile dementia, and vascular dementia) compared with those without dementia. For patients with dementia who experienced incident AF, NOAC use was associated with a better clinical outcome compared with non-OAC. Patients with dementia require a holistic approach to their care and management, including the use of NOACs to reduce the risks of clinical events.

Direct oral anticoagulants are associated with lower risk of dementia in patients with atrial fibrillation

BACKGROUND AND AIM

Atrial fibrillation (AF) is associated with increased risk of dementia. Whether direct oral anticoagulation (DOAC) reduce this risk compared to vitamin-K antagonist (VKA) is unclear. The aim of this study was to assess the risk of new all-cause dementia and vascular dementia in AF patients, treated with either DOAC or VKAs.

METHODS

Anonymized electronic medical records from the TriNetX federated research network were used. AF patients treated with DOACs within 1 month of AF diagnosis, were 1:1 propensity score-matched with those treated with a VKA. The analysis included patients who completed 5 and 10 years of follow-up and were assessed for all-cause dementia and vascular dementia. Cox proportional hazard models were used to hazard ratios (HR), respectively with 95% confidence intervals (CIs).

RESULTS

Among patients who completed 5 years of follow-up, after propensity score matching the final cohort consisted of 215,404 well-matched AF patients. All-cause dementia was diagnosed in 4,153 (3.9%) patients among those treated with DOACs and 4,150 (3.9%) among the VKA-treated patients (HR: 1.01, 95%CI: 0.96-1.05). Among patients 65-74 years old who were followed, DOAC treatment was associated with lower risk of dementia compared to VKAs (HR: 0.72; 95%CI: 0.59-0.86). Among patients who completed 10 years of follow-up, after propensity score matching the final cohort consisted of 19,208 well-matched AF patients. All-cause dementia was diagnosed in 314 (3.3%) patients among those treated with DOACs and 451 (4.7%) among the VKA-treated patients. DOAC treatment was associated with significantly lower risk of all-cause dementia during a follow-up period of 10 years compared to VKA treatment (HR: 0.72, 95%CI: 0.62-0.83), which remained consistent in patiens ≥65 years old.

CONCLUSION

This propensity-score matched analysis showed that among AF patients, treatment with a DOACs for a period of 10 years was associated with lower risk of all-cause dementia and vascular dementia compared to VKA treatment, an effect which was not apparent in those treated for shorter duration. This finding requires confirmation in ongoing randomised controlled trials.

Association of regular use of ibuprofen and paracetamol, genetic susceptibility, and new-onset dementia in the older population

OBJECTIVE

Although the possible efficacy and adverse effects of paracetamol and ibuprofen on dementia are of global clinical and public health importance, to date, the relationship of the use of paracetamol and ibuprofen with incident dementia remains uncertain. We aimed to assess the prospective association of regular use of ibuprofen and paracetamol with new-onset dementia in an older population.

METHODS

This study included 212,968 participants from the UK Biobank, aged ≥60 years, with available data of ibuprofen, paracetamol use and without dementia at baseline. The primary outcome was new-onset all-cause dementia. The secondary outcomes included new-onset Alzheimer's disease and new-onset vascular dementia.

RESULTS

During a median follow-up of 12.3 years, 6407 (3.0%) participants developed new-onset all-cause dementia. Participants who regularly used paracetamol had a significantly higher risk of new-onset all-cause dementia (adjusted HR, 1.18; 95%CI: 1.10-1.26), compared with non-users. However, there was no significant association between regular use of ibuprofen and new-onset all-cause dementia (users vs. non-users; adjusted HR, 1.06; 95%CI: 0.97-1.16). Furthermore, APOE ε4 dosage and genetic risk scores (GRS) of Alzheimer's disease calculated by 25 single nucleotide polymorphisms did not significantly modify the relationship of regular use of paracetamol and ibuprofen with new-onset all-cause dementia (Both P-interactions >0.05). Similar results were found in the propensity score analysis. Similar findings were also observed for new-onset Alzheimer's disease and new-onset vascular dementia.

CONCLUSIONS

Regular use of paracetamol, but not ibuprofen, was associated with a significantly higher risk of new-onset dementia in the old population, regardless of genetic risks of dementia.

Ambient air pollution and risk of incident dementia in older men living in a region with relatively low concentrations of pollutants: The Health in Men Study

BACKGROUND

In areas with moderate to severe air pollution, pollutant concentrations are associated with dementia risk. It is unclear whether the same relationship is present in regions with lower ambient air pollution.

OBJECTIVE

To determine whether exposure to air pollution is associated with risk of incident dementia in general, and Alzheimer's disease and vascular dementia in particular, in older men living in a relatively low ambient air pollution region.

METHODS

The cohort comprised 11,243 men residing in Perth, Australia. Participants were aged ≥65 years and free of a dementia diagnosis at time of recruitment in 1996-1999. Incident dementia was identified from recruitment to 2018 via ICD diagnosis codes and subsequent study waves. Concentrations for three air pollutants, nitrogen dioxide (NO₂), fine particulate matter less than 2.5 μm in diameter (PM_2.5), and black carbon (BC) were estimated at participants' home addresses using land-use regression models. We used Cox proportional hazards regression models adjusting for smoking status, physical activity, BMI, education, and socio-economic status.

RESULTS

Of 3053 (27.2%) incident cases of dementia, 1670 (54.7%) and 355 (11.6%) had documented Alzheimer's disease and vascular dementia. The average concentration of NO₂ was 13.5 (SD 4.4) μg/m³, of PM_2.5 was 4.54 (SD 1.6) μg/m³ and of BC was 0.97 (SD 0.29) ×10^-5 m^-1. None of the air pollutants were associated with incident dementia or Alzheimer's disease. In the unadjusted model, increased exposure to PM_2.5 was associated with an increased risk of vascular dementia (for a 5 μg/m³ increase: HR 1.62, 95% CI 1.13, 2.31). However, this association was attenuated following adjustment for confounders (HR 1.39, 95% CI 0.93, 2.08). NO₂ and BC were not associated with vascular dementia incidence.

DISCUSSION

Exposure to air pollution is not associated with increased risk of incident dementia in older men living in a region with relatively low ambient air pollution.

Association of 5α-Reductase Inhibitors With Dementia, Depression, and Suicide

Importance

In recent decades, there has been increased interest in the possible adverse neurological effects of 5α-reductase inhibitors (5-ARIs), which have been used mainly for benign prostatic hyperplasia and androgenic alopecia. Numerous studies and reports have indicated associations of 5-ARIs with depression and suicide. However, most of these studies had methodological shortcomings, and very little is known about the potential association of 5-ARIs with dementia.

Objective

To investigate the association of 5-ARI use with all-cause dementia, Alzheimer disease, vascular dementia, depression, and suicide.

Design, Setting, and Participants

This Swedish register-based cohort study included 2 236 876 men aged 50 to 90 years between July 1, 2005, and December 31, 2018. Statistical analyses were performed from September 15, 2021, to May 25, 2022.

Main Outcomes and Measures

A diagnosis of all-cause dementia, Alzheimer disease, vascular dementia, depression, or completed suicide.

Exposures

A recorded prescription in the Swedish national prescription register of finasteride or dutasteride and duration of use.

Results

Of 2 236 876 men (median age at the start of follow-up, 55 years [IQR, 50-65 years] and at treatment initiation, 73 years [IQR, 66-80 years]), 70 645 (3.2%) started finasteride treatment, and 8774 (0.4%) started dutasteride treatment. Men taking finasteride or dutasteride were at increased risk of all-cause dementia (finasteride: hazard ratio [HR], 1.22 [95% CI, 1.17-1.28]; dutasteride: HR, 1.10 [95% CI, 1.01-1.20]), Alzheimer disease (finasteride: HR, 1.20 [95% CI, 1.10-1.31]; dutasteride: HR, 1.28 [95% CI, 1.09-1.50]), vascular dementia (finasteride: HR, 1.44 [95% CI, 1.30-1.58]; dutasteride: HR, 1.31 [95% CI, 1.08-1.59]), and depression (finasteride: HR, 1.61 [95% CI, 1.48-1.75]; dutasteride: HR, 1.68 [95% CI, 1.43-1.96]). However, the magnitude of the association decreased over time, and the findings became statistically nonsignificant with continuous exposures over 4 years, except for depression, which showed a constant risk over time, with no differences between finasteride and dutasteride. In contrast, 5-ARIs were not associated with suicide (finasteride: HR, 1.22 [95% CI, 0.99-1.49]; dutasteride: HR, 0.98 [95% CI, 0.62-1.54]).

Conclusions and Relevance

This cohort study found that, while men receiving 5-ARI treatment showed a higher risk for dementia in the initial periods after starting treatment, the decreasing magnitude of the association over time suggested that the risk may be, entirely or in part, due to increased dementia detection among patients with benign prostate enlargement. Both finasteride and dutasteride were similarly associated with depression with a constant risk over time, while neither drug was associated with suicide. Prescribing clinicians and potential users should be aware of the possible risks for depression associated with 5-ARI use.

Sitagliptin Attenuates the Cognitive Deficits in L-Methionine-Induced Vascular Dementia in Rats

Vascular dementia (VaD) is the second most prevalent type of dementia characterized by progressive cognitive deficits and is a major risk factor for the development of Alzheimer's disease and other neurodegenerative disorders. This study is aimed at determining the potential neuroprotective effect of sitagliptin (STG) on cognitive deficits in L-methionine-induced VaD in rats and the possible underlying mechanisms. 30 adult male Wistar albino rats were divided equally (n = 10) into three groups: control, VaD, and VaD + STG groups. The cognitive performance of the animals was conducted by open field, elevated plus maze, Y-maze, novel object recognition, and Morris water maze tests. Serum homocysteine, TNF-α, IL-6, IL-10, total cholesterol, and triglycerides levels were assessed together with hippocampal MDA, SOD, and BDNF. Histopathological and immunohistochemical assessments of the thoracic aorta and hippocampus (CA1 region) were also performed. Chronic L-methionine administration impaired memory and learning and induced anxiety. On the other hand, STG protected against cognitive deficits through improving oxidative stress biomarkers, inflammatory mediators, lipid profiles, and hippocampus level of BDNF as well as decreasing caspase-3 and GFAP and increasing Ki-67 immunoreactions in the hippocampus. Also, STG improved the endothelial dysfunction via upregulation of aortic eNOS immunoreaction. STG improved the cognitive deficits of L-methionine-induced VaD by its antioxidant, anti-inflammatory, antiapoptotic, and neurotrophic effects. These findings suggest that STG may be a promising future agent for protection against VaD.

Ameliorative role of rolipram, PDE-4 inhibitor, against sodium arsenite-induced vascular dementia in rats

Arsenic exposure to the population leads to serious health problems like neurotoxicity, nephrotoxicity, and cardiovascular abnormality. In the present study, the work has been commenced to discover the prospect of rolipram a phosphodiestrase-4 (PDE-4) inhibitor against sodium arsenite (SA)-induced vascular endothelial dysfunction (EnDF) leading to dementia in rats. Wistar rats were treated with SA (5 mg/kg body weight/day orally) for 44 days for induction of vascular EnDF and dementia. Learning and memory were evaluated using Morris water maze (MWM) test. Vascular EnDF was evaluated using aortic ring preparation. Various biochemical parameters were also evaluated like brain oxidative stress (viz. reduced glutathione and thiobarbituric acid reactive substances level), serum nitrite/nitrate activity, acetylcholinesterase activity, and inflammatory markers (viz. neutrophil infiltration in brain and myeloperoxidase). SA-treated rats showed poor performance in water maze trials indicating attenuated memory and ability to learn with significant rise (p < 0.05) in brain acetylcholinesterase activity, brain oxidative stress, neutrophil count, and significant decrease (p < 0.05) in serum nitrite/nitrate levels and vascular endothelial functions. Rolipram (PDE-4 inhibitor) treatment (0.03 mg/kg and 0.06 mg/kg body weight, intraperitoneally daily for 14 days) significantly improved memory and learning abilities, and restored various biochemical parameters and EnDF. It is concluded that PDE-4 modulator may be considered the prospective target for the treatment of SA-induced vascular EnDF and related dementia.

Carnosine as a Possible Drug for Zinc-Induced Neurotoxicity and Vascular Dementia

Increasing evidence suggests that the metal homeostasis is involved in the pathogenesis of various neurodegenerative diseases including senile type of dementia such as Alzheimer’s disease, dementia with Lewy bodies, and vascular dementia. In particular, synaptic Zn²⁺ is known to play critical roles in the pathogenesis of vascular dementia. In this article, we review the molecular pathways of Zn²⁺-induced neurotoxicity based on our and numerous other findings, and demonstrated the implications of the energy production pathway, the disruption of calcium homeostasis, the production of reactive oxygen species (ROS), the endoplasmic reticulum (ER)-stress pathway, and the stress-activated protein kinases/c-Jun amino-terminal kinases (SAPK/JNK) pathway. Furthermore, we have searched for substances that protect neurons from Zn²⁺-induced neurotoxicity among various agricultural products and determined carnosine (β-alanyl histidine) as a possible therapeutic agent for vascular dementia.

Association between air pollution and risk of vascular dementia: A multipollutant analysis in Taiwan

Evidence regarding the association of specific air pollutants with vascular dementia (VaD) risk is limited. In this nested case-control study, we enrolled 831 adults aged >65 years with VaD (International Classification of Diseases, Ninth Revision, Clinical Modification code 290.4x) newly diagnosed during 2005-2013; 3324 controls were age-, sex-, and VaD diagnosis year-matched with the study patients. Both patients with VaD and controls were selected from among a cohort of one million beneficiaries of Taiwan's National Health Insurance program, all of whom were registered in 2005. Exposure to the mean daily air pollutant concentration, derived from 76 fixed air quality monitoring stations, in 3, 5, and 7 years before VaD diagnosis was assessed using the spatial analysis method (i.e., ordinary kriging) on ArcGIS. A logistic regression model was used to calculate covariate-adjusted odds ratios (ORs) of VaD in relation to specific air pollutants. After potential confounders and other air pollutants were controlled for, high concentrations of coarse particulate matter (10 µm or less in diameter) and carbon monoxide (CO) were sporadically associated with higher OR of VaD. The most prominent association was observed for nitrogen dioxide (NO₂) exposure within 5 and 7 years before diagnosis. Compared with the <25th percentile of NO₂ exposure, the 25th-50th, 50th-75th, and >75th percentiles of NO₂ exposure significantly increased ORs (95% confidence intervals): 1.62 (1.28-2.23), 1.61 (1.11-2.33), and 2.22 (1.35-3.65) within 5 years before diagnosis, respectively, and 1.59 (1.20-2.11), 1.65 (1.15-2.37), and 2.05 (1.28-3.28) within 7 years before diagnosis, respectively. We found that higher NO₂ exposure in the past was significantly associated with an elevated risk of VaD. Although less consistent, higher exposure to CO was also associated with a higher risk of VaD. Most NO₂ in cities originates from motor vehicle exhaust; other sources of NO₂ are petrol and metal refining, electricity generation from coal-fired power stations, other manufacturing industries, and food processing. Future studies should investigate associations of VaD with specific sources of NO₂.

Ameliorative role of Atorvastatin and Pitavastatin in L-Methionine induced vascular dementia in rats

BACKGROUND

Statins, HMG-CoA reductase inhibitors, are widely prescribed drugs for dyslipidemias. Recent studies have indicated number of cholesterol independent actions of statins including their beneficial effects on vascular endothelial dysfunction and memory deficits associated with dementia of Alzheimer's type. However the potential of statins in dementia of vascular origin still remains to be explored. Therefore, the present study has been designed to investigate the effect of Atorvastatin & Pitavastatin on vascular endothelial dysfunction associated memory deficits in rats. In this study L-Methionine induced vascular dementia was assessed by Morris water-maze (MWM) test. Biochemical analysis was also performed to unfold possible mechanism of statins mediated modulation of vascular dementia.

RESULTS

L-Methionine produced endothelial dysfunction as reflected by significant decrease in serum nitrite concentration. L-Methionine treated rats performed poorly on MWM indicating impairment of memory as well. These rats also showed a significant rise in brain oxidative stress, acetylcholinesterase (AChE) activity and serum total cholesterol levels. Both Atorvastatin as well as Pitavastatin attenuated L-Methionine induced endothelial dysfunction associated memory deficits. Statins also reversed L-Methionine induced rise in brain oxidative stress, AChE activity and serum cholesterol.

CONCLUSION

The beneficial effects of statins may be attributed to their multiple effects and the study highlights the potential of these drugs in vascular dementia.

Delayed leukoencephalopathy with stroke-like presentation in chemotherapy recipients

BACKGROUND

A transient leukoencephalopathy mimicking cerebrovascular accident has been described as a complication of chemotherapy, most commonly in recipients of intrathecal methotrexate for childhood leukaemia. Recently published neuroimaging data suggest a common pathophysiology associated with a variety of chemotherapy agents and modes of administration.

METHODS

We reviewed the medical literature for single reports and case series of patients presenting with stroke-like episodes while receiving systemic or intrathecal chemotherapy. We only included studies providing detailed neuroimaging data. Patients with cerebrovascular accidents were excluded.

RESULTS

We identified 27 reports of toxic leukoencephalopathy in patients treated with methotrexate (intrathecal, systemic), 5-fluorouracil and its derivative carmofur, and capecitabine. Diffusion weighted imaging (DWI) of all patients revealed well demarcated hyperintense lesions within the subcortical white matter of the cerebral hemispheres and the corpus callosum, corresponding to areas of decreased proton diffusion on apparent diffusion coefficient (ADC) maps (available in 21/27 patients). Lesions exceeded the confines of adjacent vascular territories. Complete resolution of symptoms within 1-4 days was accompanied by normalisation of ADC abnormalities. However, fluid attenuated inversion recovery (FLAIR) sequences frequently revealed persistent white matter abnormalities.

CONCLUSIONS

Several pathophysiological models of delayed leukoencephalopathy after exposure to intrathecal or systemic chemotherapy have been proposed. DWI findings in this cohort are indicative of cytotoxic oedema within cerebral white matter and lend support to an at least partially reversible metabolic derangement as the basis for this syndrome.

Reversible posterior leukoencephalopathy syndrome after bevacizumab/FOLFIRI regimen for metastatic colon cancer

OBJECTIVE

To describe a patient with reversible posterior leukoencephalopathy syndrome following the administration of bevacizumab (Avastin), a monoclonal antibody against vascular endothelial growth factor.

DESIGN

Case report/literature review.

SETTING

University hospital.

PATIENT

A 52-year-old man receiving chemotherapy for stage IV rectal carcinoma.

RESULTS

Clinical and radiographic evidence consistent with reversible posterior leukoencephalopathy syndrome was found following the administration of irinotecan hydrochloride, leucovorin calcium, and fluorouracil (FOLFIRI) regimen chemotherapy and bevacizumab.

CONCLUSIONS

Reversible posterior leukoencephalopathy syndrome following treatment with angiogenesis modulators can occur. In addition to raising clinical suspicion in appropriate patients, this report may yield clues to the pathophysiologic underpinnings of reversible posterior leukoencephalopathy syndrome.

Reversible Impairment of Auditory Callosal Pathway in 5-Fluorouracil-Induced Leukoencephalopathy

OBJECTIVE

To report the course of functional and imaging recovery of the auditory callosal pathway in a patient with 5-fluorouracil-induced leukoencephalopathy.

DESIGN

Case study.

SETTING

University hospital.

PATIENT

A 58-year-old man with hypopharyngeal cancer who developed 5-fluorouracil-induced leukoencephalopathy.

MAIN OUTCOME MEASURES

Imaging (magnetic resonance imaging) and functional (dichotic listening test) evaluation on the auditory callosal pathway.

RESULTS

The patient underwent systemic chemotherapy with pirarubicin, cisplatin, and 5-fluorouracil. On the last day of the regimen, the patient suddenly became restless and convulsive. On diffusion-weighted magnetic resonance images, the signal intensity at the splenium of the corpus callosum was very high. Fluid-attenuated inversion recovery images showed no abnormal findings at this time. Intravenous methylprednisolone sodium succinate and glycerin 10% was started immediately. On the ninth day after onset, the patient was free of neurologic symptoms. Although pure-tone audiograms and speech discrimination scores were normal, dichotic listening tests revealed significant left ear suppression, indicating severe injury of the auditory callosal pathway. On fluid-attenuated inversion recovery images, the signal intensity at the splenium was high, whereas the posterior trunk was normal. At 6 weeks after onset, dichotic listening test results returned to normal and hyperintensity at the splenium was much less marked on fluid-attenuated inversion recovery images.

CONCLUSION

By using both functional and imaging modalities, this case study demonstrated, for the first time in a reversible manner, that the auditory callosal pathway runs through the most posterior part of the corpus callosum including the splenium. Diffusion-weighted magnetic resonance imaging was considered useful for early diagnosis of 5-fluorouracil-induced leukoencephalopathy.

Soluble semicarbazide-sensitive amine oxidase (SSAO) activity is related to oxidative stress and subchronic inflammation in streptozotocin-induced diabetic rats

Diabetes is known to increase the risk of Alzheimer's disease (AD) and vascular dementia via oxidative stress and inflammation. There are speculations that SSAO activity might be related to the development of AD. Our aim was to investigate whether changes of soluble SSAO activity, oxidative stress and inflammation markers are related to each other in diabetes. Soluble and tissue-bound SSAO activities (from serum and aorta, respectively) were determined in streptozotocin (STZ)-induced diabetic rats without insulin treatment, receiving insulin once, or twice daily compared to control animals. After three weeks of treatment soluble and tissue-bound SSAO activities (seSSAO and aoSSAO, respectively), serum total antioxidant status (TAS), high sensitivity C-reactive protein (hsCRP), fructose amine levels and routine laboratory parameters were determined. SeSSAO activity significantly increased in the diabetic groups without treatment and receiving insulin once daily, and a marked decrease in aoSSAO activity was seen in all diabetic groups. Increased oxidative stress was correlated with hsCRP elevation, while hsCRP and seSSAO activity were also significantly correlated. In all groups seSSAO and aoSSAO activities were in negative correlation with each other. Our results support the view that poor metabolic control leads to increased oxidative stress, which in turn may cause the elevation of hsCRP levels. Soluble SSAO on the one hand acts as an adhesion molecule--thus possibly being a factor responsible for the late complications of diabetes--and on the other hand, it may contribute to oxidative stress. Our parsimonious conclusion is that there is a relation between the risk factors of AD and vascular dementia (diabetes, oxidative stress and chronic inflammation) and SSAO activity, which may originate from the vessel wall.

[Partial occipital seizures as main symptom of posterior encephalopathy secondary to immunosuppresants]

INTRODUCTION

Reversible posterior leukoencephalopathy syndrome (RPLS) affects patients who are following immunosupressive treatment. It can affect children too, it can be irreversible and occipital seizures can be the main manifestation. We describe the EEG of five children who presented occipital seizures due to posterior leukoencephalopathy syndrome secondary to treatment with immunosupressives. They had different clinico- electrical evolutions.

CASES REPORTS

Five children aged from 18 months to 11 years who had been treated with bone marrow, liver or kidney transplantation and one or two immunosupressive drugs: cyclosporine, tacrolimus. 4-50 days after the transplantation they presented arterial hypertension and low conscience. Occipital seizures or status were registered in EEG. Neuroimaging showed edema lesions in posterior regions. They were treated with antihipertensives, antiepileptics and substitution or reduction of immunosupressive drugs doses. Two patients presented further episodes and three of them had persistent abnormal EEG. Two patients had more than one status even though Cys A had been replaced by Tacrolimus or because the drug dose had not been modified. The Immunosupressive drugs are necessary for the transplantation's good outcome and they cannot be easily stopped.

CONCLUSIONS

Low conscience level and oculoclonic movements may form part of the subtle clinic of the occipital seizures, that may be the main manifestation of PLS in children who are following immunosupressor treatment. The realization of an EEG is indispensable for a quick diagnose and in order to achieve the reversibility of the syndrome. If we cannot get it, EEG will be useful for the evolution follow-up too.

Increased white matter hyperintensities in male methamphetamine abusers

BACKGROUND

The current study was conducted to compare the prevalence, severity, and location of white matter signal hyperintensities (WMH) on brain magnetic resonance (MR) imaging in methamphetamine (MA) abusers.

METHODS

Thirty-three MA abusers and 32 age- and gender-matched healthy comparison subjects were studied. Axial T-2 weighted images and fluid attenuated inversion recovery axial images were obtained using 3.0 T MR scanner. The severity of WMH was assessed separately for deep and periventricular WMH. Ordinal logistic regression models were used to assess the odds ratio for WMH.

RESULTS

MA abusers had greater severity of WMH than the healthy comparison subjects (odds ratio: 7.06, 8.46, and 4.56 for all, deep, and periventricular WMH, respectively). Severity of deep WMH correlated with total cumulative dose of MA (p = 0.027). Male MA abusers had greater severity of WMH than female MA abusers (odds ratio = 10.00). While male MA abusers had greater severity of WMH than male comparison subjects (odds ratio = 18.86), there was no significant difference in WMH severity between female MA abusers and female comparison subjects.

CONCLUSIONS

The current study reports increased WMH in MA abusers, which may be related to MA-induced cerebral perfusion deficits. In addition, female MA abusers had less severe WMH than male MA abusers, possibly due to estrogen's protective effect against ischemic or neurotoxic effects of MA.

Does Lithium Therapy Protect Against the Onset of Dementia?

Lithium compounds might theoretically play a role in preventing dementia by inhibiting formation both of beta amyloid and hyper phosphorylated tau protein. We carried out a case-control study to assess any possible clinical effects of lithium therapy on the diagnosis of dementia, using data from the General Practice Research Database, which collects routine data from primary care patients in the UK. Patients who received lithium had a higher risk of a diagnosis of dementia compared with those who did not (adjusted odds ratio 1.8, 95% CI 1.1-2.8). There was a trend toward increasing risk with increasing numbers of lithium prescriptions. This evidence does not support the use of lithium for preventing dementia.

Chemotherapy-induced toxic leukoencephalopathy causes a wide range of symptoms: a series of four autopsies

We have observed an increasing number of autopsies on patients with chemotherapy-related complications. One complication is toxic leukoencephalopathy, which is due to a direct toxic effect of chemotherapeutic agents on the central nervous system white matter. Autopsies of four cases of toxic leukoencephalopathy were performed following standard protocols. The brain and spinal cord were examined routinely, and histological sections were taken for evaluation. We report here three patients with hematologic malignancies and one patient with metastatic carcinoma with chemotherapy-induced leukoencephalopathy. The first was a 56-year-old male treated with multiple chemotherapeutics for multiple myeloma. He presented with confusion and focal seizures with a rapid progression to coma and decerebrate posturing. The second was a 36-year-old male who developed mental status changes, ataxia and dysarthria following treatment for lymphoma. The third was a 16-year-old male who developed a profound peripheral and central neuropathy after chemotherapy treatment for T-cell acute lymphoblastic leukemia. The fourth was a 49-year-old female patient who was treated with multiple chemotherapeutics for Stage II breast carcinoma and subsequently developed visual acuity and field defects. The neuropathologic findings in these cases, although similar, varied in severity and distribution. The white matter was affected by severe myelin pallor, edema, and a prominent macrophage infiltrate in each of the cases. The location and extent of the central nervous system pathology correlated with the type and severity of clinical symptoms. These four cases, with their varied presenting symptoms, clinical courses, and degree of pathology, emphasize the importance of considering toxic leukoencephalopathy as an etiology of acute neurologic deterioration following high-dose chemotherapy.

Acute leukoencephalopathy after inhalation of a single dose of heroin

We describe extended and repeat magnetic resonance (MR) examinations in the case of a 16-year-old male who developed acute left-sided sensorimotor hemiplegia after a single dose of inhaled heroin. MRI revealed symmetrical hyperintense signals in T 2 -weighted images and massive diffusion disorders in the diffusion weighted images predominantly in parieto-occipital subcortical white matter and both ventral globi pallidi with preservation of U fibers and no brain oedema. MR spectroscopy data were compatible with combined hypoxic and mitochondrial damage resulting in axonal injury without demyelination. Normal values and variations had been obtained from spectra of five age-matched subjects. This is the first reported MR follow-up study of leukoencephalopathy occurring acutely after a first inhaled dose of heroin. We postulate that toxic spongiform leukoencephalopathy in heroin addicts may be the outcome of a complex mechanism directly triggered by heroin and causing mitochondrial as well as hypoxic injury in specific and limited areas of white matter.

Neurologic complications of chemotherapy for children with cancer

Survival rates for children with cancer have increased dramatically over the past few decades. Development of new chemotherapeutic agents and the expanded use of older agents have had a major impact on this celebrated improvement. Chemotherapy can have, however, significant toxicity on the nervous system. The most common neurologic complications involve acute alterations in consciousness, leukoencephalopathy, seizures, cerebral infarctions, paralysis, neuropathy, and ototoxicity. Most of the information on toxicity comes from prospective reports and the adult patient population. Methotrexate, cyclosporin, and platinum compounds are the most frequently cited. No prospective studies have been done to evaluate chemotherapy-induced neurotoxicity in the pediatric population, and the exact incidence of such complications is unknown. Such investigation is greatly needed, as it may lead to a better understanding of how chemotherapy affects the nervous system and ultimately help develop more strategies to prevent drug-related neurotoxicity in pediatric cancer patients.

Diffusion-weighted magnetic resonance imaging in early stage of 5-fluorouracil-induced leukoencephalopathy

We report a case of 5-fluorouracil (5-FU)-induced leukoencephalopathy in which magnetic resonance imaging (MRI) of the brain, including diffusion-weighted imaging (DWI), was performed serially. The initial T2-weighted and FLAIR images showed diffuse mild hyperintensity in bilateral deep cerebral white matter and corpus callosum, which on T1WI appeared as non-enhanced faint hypointensity. Isotropic DWI disclosed the abnormality as well-conspicuous diffuse hyperintensity with decreased ADC. Serial studies revealed that majority of the abnormal signal intensity on these sequences resolved, and the decreased ADC values approached normal. Some hyperintensity remained in the deep cerebral white matter and the splenium, but no further significant ADC change after normalization was noted. Measurement of ADC along the three orthogonal directions showed the presence of directional dependence of diffusion throughout the length of study. These findings suggest that early stage of 5-FU-induced leukoencephalopathy is associated with reversible restricted diffusion and preservation of anisotropy. Diffusion-weighted imaging may be useful for the diagnosis.

L-asparaginase-induced reversible posterior leukoencephalopathy syndrome in a child with acute lymphoblastic leukemia

Reversible posterior leukoencephalopathy syndrome (RPLS) is being increasingly described with various etiologies even in the absence of hypertension. We present an 11-year-old patient with acute lymphoblastic leukemia who presented with seizures while on treatment with L-asparaginase. MRI showed bilaterally symmetrical nonenhancing occipital lesions characteristic of RPLS. L-Asparaginase-induced RPLS is a rare cause of neurological symptoms in patients on induction chemotherapy.

Methotrexate-induced toxic leukoencephalopathy

Drug-induced leukoencephalopathy is a devastating adverse event that can cause significant morbidity and mortality. Risk factors include advanced age, administration of certain chemotherapies, presence of an Ommaya device, central nervous system malignancy, and most important, exposure to cranial radiation. A 73-year-old woman developed leukoencephalopathy 2 months after her last dose of intraventricular methotrexate. Although leukoencephalopathy is a severe adverse effect of the agent, her case is different because it occurred without prior exposure to cranial radiation.

[Acute encephalitis complicating acute polyradiculoneuritis]

We report the case of a 43-year-old man who developed an acute encephalopathy after IVIg therapy for AIDP. Imaging studies showed predominantly posterior leukoencephalopathy. The signs and symptoms of the encephalopathy completely resolved by steroids. Two patients with acute encephalopathy, following IVIg therapy, were reported previously in the literature. However, our observation differed from them by the presence of a marked pleiocytosis of cephalospinal fluid before beginning of IgIV. Two hypothesis may be made: a post-infectious meningo-encephalo-AIDP or a complication of IgIV. This side effect, even rare, has not to be underestimated.

Transient ischemic attack in heavy cannabis smokers--how 'safe' is it?

Drugs are lately considered high-risk factors for cerebrovascular disease. Three male patients (mean age 24.6 years) who were heavy cannabis smokers presented with transient ischemic attacks (TIA) shortly after cannabis abuse. The complete examination of all 3 consisted of: EEG, brain CT scan, brain MRI, cerebral vessel angiography (digital subtraction and magnetic resonance angiography); also a full cerebrospinal fluid, urine and blood analysis (immunological, biochemical and hormonal tests were included). Urine was further examined for drug metabolites. An extensive cardiological investigation was carried out. Small vessel leukoencephalopathy was revealed by the brain CT and MRI. EEG recordings of the first patient showed paroxysmal sharp waves with left hemispheric dominance. The other 2 patients had diffuse delta and theta activity in their EEG tracings. The urine analysis was positive for cannabis metabolites. There were no other abnormal findings in the rest of the meticulous and thorough study of all 3 patients, which leads to the conclusion that cannabis was the only risk factor responsible for the observed TIA, contradictory to other studies, which support that cannabis is a 'safe' drug. More research is required in order for this issue to be completely elucidated.

FK506-induced intractable leukoencephalopathy following allogeneic bone marrow transplantation

FK506-related leukoencephalopathy has been reported to be reversible and readily treated by discontinuation or reduction of FK506. We describe two pediatric cases of FK506-related leukoencephalopathy following allogeneic bone marrow transplantation, which could not be readily controlled. These cases show that FK506-related leukoencephalopathy is not always reversible, and patients may develop epilepsy. Bone Marrow Transplantation (2000) 25, 331-334.