Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

A probabilistic atlas and reference system for the human brain: International Consortium for Brain Mapping (ICBM)

Motivated by the vast amount of information that is rapidly accumulating about the human brain in digital form, we embarked upon a program in 1992 to develop a four-dimensional probabilistic atlas and reference system for the human brain. Through an International Consortium for Brain Mapping (ICBM) a dataset is being collected that includes 7000 subjects between the ages of eighteen and ninety years and including 342 mono- and dizygotic twins. Data on each subject includes detailed demographic, clinical, behavioural and imaging information. DNA has been collected for genotyping from 5800 subjects. A component of the programme uses post-mortem tissue to determine the probabilistic distribution of microscopic cyto- and chemoarchitectural regions in the human brain. This, combined with macroscopic information about structure and function derived from subjects in vivo, provides the first large scale opportunity to gain meaningful insights into the concordance or discordance in micro- and macroscopic structure and function. The philosophy, strategy, algorithm development, data acquisition techniques and validation methods are described in this report along with database structures. Examples of results are described for the normal adult human brain as well as examples in patients with Alzheimer's disease and multiple sclerosis. The ability to quantify the variance of the human brain as a function of age in a large population of subjects for whom data is also available about their genetic composition and behaviour will allow for the first assessment of cerebral genotype-phenotype-behavioural correlations in humans to take place in a population this large. This approach and its application should provide new insights and opportunities for investigators interested in basic neuroscience, clinical diagnostics and the evaluation of neuropsychiatric disorders in patients.

Systemic inflammation and disease progression in Alzheimer disease

BACKGROUND

Acute and chronic systemic inflammation are characterized by the systemic production of the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) that plays a role in immune to brain communication. Previous preclinical research shows that acute systemic inflammation contributes to an exacerbation of neurodegeneration by activation of primed microglial cells.

OBJECTIVE

To determine whether acute episodes of systemic inflammation associated with increased TNF-alpha would be associated with long-term cognitive decline in a prospective cohort study of subjects with Alzheimer disease.

METHODS

Three hundred community-dwelling subjects with mild to severe Alzheimer disease were cognitively assessed, and a blood sample was taken for systemic inflammatory markers. Each subject's main caregiver was interviewed to assess the presence of incident systemic inflammatory events. Assessments of both patient and caregiver were repeated at 2, 4, and 6 months.

RESULTS

Acute systemic inflammatory events, found in around half of all subjects, were associated with an increase in the serum levels of proinflammatory cytokine TNF-alpha and a 2-fold increase in the rate of cognitive decline over a 6-month period. High baseline levels of TNF-alpha were associated with a 4-fold increase in the rate of cognitive decline. Subjects who had low levels of serum TNF-alpha throughout the study showed no cognitive decline over the 6-month period.

CONCLUSIONS

Both acute and chronic systemic inflammation, associated with increases in serum tumor necrosis factor alpha, is associated with an increase in cognitive decline in Alzheimer disease.

Germline mutations affecting the proofreading domains of POLE and POLD1 predispose to colorectal adenomas and carcinomas

Many individuals with multiple or large colorectal adenomas or early-onset colorectal cancer (CRC) have no detectable germline mutations in the known cancer predisposition genes. Using whole-genome sequencing, supplemented by linkage and association analysis, we identified specific heterozygous POLE or POLD1 germline variants in several multiple-adenoma and/or CRC cases but in no controls. The variants associated with susceptibility, POLE p.Leu424Val and POLD1 p.Ser478Asn, have high penetrance, and POLD1 mutation was also associated with endometrial cancer predisposition. The mutations map to equivalent sites in the proofreading (exonuclease) domain of DNA polymerases ɛ and δ and are predicted to cause a defect in the correction of mispaired bases inserted during DNA replication. In agreement with this prediction, the tumors from mutation carriers were microsatellite stable but tended to acquire base substitution mutations, as confirmed by yeast functional assays. Further analysis of published data showed that the recently described group of hypermutant, microsatellite-stable CRCs is likely to be caused by somatic POLE mutations affecting the exonuclease domain.

Three-dimensional MRI atlas of the human cerebellum in proportional stereotaxic space

We have prepared an atlas of the human cerebellum using high-resolution magnetic resonance-derived images warped into the proportional stereotaxic space of Talairach and Tournoux. Software that permits simultaneous visualization of the three cardinal planes facilitated the identification of the cerebellar fissures and lobules. A revised version of the Larsell nomenclature facilitated a simple description of the cerebellum. This atlas derived from a single individual was instrumental in addressing longstanding debates about the gross morphologic organization of the cerebellum. It may serve as the template for more precise identification of cerebellar topography in functional imaging studies in normals, for investigating clinical-pathologic correlations in patients, and for the development of future probabilistic maps of the human cerebellum.

The epidemiology of DSM-III-R bipolar I disorder in a general population survey

BACKGROUND

Data are presented on the general population epidemiology of DSM-III-R bipolar I disorder in the United States.

METHODS

Data come from the US National Comorbidity Survey (NCS), a general population survey of DSM-III-R disorders. A modified version of the Composite International Diagnostic Interview was used to make diagnoses.

RESULTS

A small (N = 59) clinical reappraisal study showed that the only manic symptom profile that could validly be assessed with the CIDI is characterized by euphoria, grandiosity and the ability to maintain energy without sleep, which described approximately half of all clinically validated bipolar I cases in the NCS. Further analysis focused on this symptom profile, which involved N = 29 cases in the total sample. Lifetime prevalence was estimated to be 0.4% and 12-month prevalence only slightly lower. Caseness was negatively related to income, education and age, positively related to urbanicity, and elevated among the previously married, never married and non-whites. All cases reported at least one other NCS/DSM-III-R disorder and 59.3% reported that their episode of bipolar disorder (either mania or depression) occurred at a later age than at least one other NCS/DSM-III-R disorder. Although 93.2% of lifetime cases reported some lifetime treatment, only 44.7% of recent cases were in treatment.

CONCLUSIONS

The type of bipolar disorder examined here is highly chronic, co-morbid and impairing. Increased efforts are required to attract current cases into appropriate treatment. Methodological research is needed to develop more accurate measures of other bipolar symptom profiles for use in general population epidemiological studies.

A four-dimensional probabilistic atlas of the human brain

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons between the ages of 18 and 90 years. Given the presumed large but previously unquantified degree of structural and functional variance among normal persons in the human population, the basis for this atlas and reference system is probabilistic. Through the efforts of the International Consortium for Brain Mapping (ICBM), 7,000 subjects will be included in the initial phase of database and atlas development. For each subject, detailed demographic, clinical, behavioral, and imaging information is being collected. In addition, 5,800 subjects will contribute DNA for the purpose of determining genotype- phenotype-behavioral correlations. The process of developing the strategies, algorithms, data collection methods, validation approaches, database structures, and distribution of results is described in this report. Examples of applications of the approach are described for the normal brain in both adults and children as well as in patients with schizophrenia. This project should provide new insights into the relationship between microscopic and macroscopic structure and function in the human brain and should have important implications in basic neuroscience, clinical diagnostics, and cerebral disorders.

Cardiac sympathetic denervation in Parkinson disease

BACKGROUND

In Parkinson disease, orthostatic hypotension can result from L-dopa treatment or from sympathetic neurocirculatory failure. The latter is detected by abnormal blood pressure responses to the Valsalva maneuver and can be associated with loss of functional cardiac sympathetic nerve terminals.

OBJECTIVE

To determine the frequency of cardiac sympathetic denervation in Parkinson disease, with or without sympathetic neurocirculatory failure, and its association with disease duration, severity, and L-dopa treatment

DESIGN

Intergroup comparisons in resting patients.

SETTING

National Institutes of Health Clinical Center, Bethesda, Maryland.

PATIENTS

29 patients with Parkinson disease (9 with sympathetic neurocirculatory failure, 10 who had stopped receiving or had never been treated with L-dopa), 24 patients with multiple-system atrophy (17 with sympathetic neurocirculatory failure, 8 receiving L-dopa), 7 patients with pure autonomic failure, 33 controls with episodic or persistent orthostatic intolerance without sympathetic neurocirculatory failure, and 19 normal volunteers.

MEASUREMENTS

Beat-to-beat blood pressure responses to the Valsalva maneuver, interventricular septal 6-[18F]fluorodopamine-derived radioactivity, cardiac extraction fraction of [3H]norepinephrine, appearance rate of norepinephrine in coronary sinus plasma (cardiac norepinephrine spillover) and venous-arterial differences in levels of dihydroxyphenylglycol (DHPG) and endogenous L-dopa.

RESULTS

Of the 29 patients with Parkinson disease, 9 with sympathetic neurocirculatory failure and 11 without had low septal 6-[18F]fluorodopamine-derived radioactivity (2861 +/- 453 Bq/mL per MBq/kg and 5217 +/- 525 Bq/mL per MBq/kg, respectively). All 6 patients with Parkinson disease and decreased 6-[18F]fluorodopamine-derived radioactivity who underwent right-heart catheterization had a decreased cardiac extraction fraction of [3H]norepinephrine and virtually no cardiac norepinephrine spillover or venous-arterial increments in plasma levels of DHPG and L-dopa. Sympathetic neurocirculatory failure and decreased 6-[18F]fluorodopamine-derived radioactivity were unrelated to disease duration, disease severity, or L-dopa treatment

CONCLUSIONS

Many patients with Parkinson disease-including all those with sympathetic neurocirculatory failure-have evidence of cardiac sympathetic denervation. This suggests that loss of catecholamine innervation in Parkinson disease occurs in the nigrostriatal system in the brain and in the sympathetic nervous system in the heart

Consequence of Abeta immunization on the vasculature of human Alzheimer's disease brain

A major feature of Alzheimer's disease is the accumulation of amyloid-beta peptide (Abeta) in the brain both in the form of plaques in the cerebral cortex and in blood vessel as cerebral amyloid angiopathy (CAA). Experimental models and human clinical trials have shown that accumulation of Abeta plaques can be reversed by immunotherapy. In this study, we hypothesized that Abeta in plaques is solubilized by antibodies generated by immunization and drains via the perivascular pathway, detectable as an increase in cerebrovascular Abeta. We have performed a follow up study of Alzheimer's disease patients immunized against Abeta42. Neuropathological examination was performed on nine patients who died between four months and five years after their first immunization. Immunostaining for Abeta40 and Abeta42 was quantified and compared with that in unimmunized Alzheimer's disease controls (n = 11). Overall, compared with these controls, the group of immunized patients had approximately 14 times as many blood vessels containing Abeta42 in the cerebral cortex (P<0.001) and seven times more in the leptomeninges (P = 0.013); among the affected blood vessels in the immunized cases, most of them had full thickness and full circumference involvement of the vessel wall in the cortex (P = 0.001), and in the leptomeninges (P = 0.015). There was also a significantly higher level of cerebrovascular Abeta40 in the immunized cases than in the unimmunized cases (cortex: P = 0.009 and leptomeninges: P = 0.002). In addition, the immunized patients showed a higher density of cortical microhaemorrhages and microvascular lesions than the unimmunized controls, though none had major CAA-related intracerebral haemorrhages. The changes in cerebral vascular Abeta load did not appear to substantially influence the structural proteins of the blood vessels. Unlike most of the immunized patients, two of the longest survivors, four to five years after first immunization, had virtually complete absence of both plaques and CAA, raising the possibility that, given time, Abeta is eventually cleared from the cerebral vasculature. The findings are consistent with the hypothesis that Abeta immunization results in solubilization of plaque Abeta42 which, at least in part, exits the brain via the perivascular pathway, causing a transient increase in the severity of CAA. The extent to which these vascular alterations following Abeta immunization in Alzheimer's disease are reflected in changes in cognitive function remains to be determined.

Systemic infection, interleukin 1beta, and cognitive decline in Alzheimer's disease

Activated microglia, the resident macrophages of the brain, are a feature of Alzheimer's disease. Animal models suggest that when activated microglia are further activated by a subsequent systemic infection this results in significantly raised levels of interleukin 1beta within the CNS, which may in turn potentiate neurodegeneration. This prospective pilot study in Alzheimer's disease subjects showed that cognitive function can be impaired for at least two months after the resolution of a systemic infection and that cognitive impairment is preceded by raised serum levels of interleukin 1beta. These relations were not confounded by the presence of any subsequent systemic infection or by baseline cognitive scores. Further research is needed to determine whether recurrent systemic infections drive cognitive decline in Alzheimer's disease subjects through a cytokine mediated pathway.

Synovial sarcoma. Uniform response of metastases to high dose ifosfamide

BACKGROUND

This report describes the unusually high response rate of metastatic synovial sarcoma to high dose ifosfamide (14-18 g/m2) when that drug was used to treat 13 consecutive patients with recurrent metastatic synovial sarcoma before surgery (or thoracotomies) to provide optimal salvage therapy for these patients.

PATIENTS AND METHODS

Thirteen patients with recurrent or pulmonary metastatic synovial sarcoma seen at the Cedars-Sinai Comprehensive Cancer Center (Los Angeles, CA) from April, 1989 through January, 1993 were treated with high dose ifosfamide (14-18 g/m2). Ifosfamide was infused at the dose of 2 g/m2 over a 4-hour bolus infusion, followed by 2-g/m2 24-hour continuous infusions of ifosfamide, for a total of 14 or 18 g/m2 (6-8 days). Mesna (Mesnex, Bristol-Myers Oncology, Princeton, NJ) was infused with the ifosfamide at equimolar doses. Supplemental sodium bicarbonate (180 mEq) was given daily to prevent severe acidosis. Nine of the thirteen patients were treated with prior chemotherapy for their primary tumors. Prior chemotherapy consisted of doxorubicin (Adriamycin, Adria Labs, Dublin, OH) in all patients and doxorubicin combined with cisplatin in eight of them.

RESULTS

All 13 patients had objective responses to high dose ifosfamide chemotherapy. There were nine partial responses and four complete responses. Five of the patients died of disease at 20-40 months (median, 27 months) from initial therapy. Eight patients have survived from 2 to 43 months (median, 20 months) from initial therapy, and three of these patients are disease free. Those patients surviving disease free had successful surgical removal of their residual metastatic disease after chemotherapy.

CONCLUSION

Metastatic synovial sarcoma appears to be particularly sensitive to high dose ifosfamide chemotherapy. This experience suggests that there is a role for high dose ifosfamide chemotherapy in preoperative and postoperative adjuvant chemotherapy for primary synovial sarcoma, which is usually always a high grade malignant lesion with a poor prognosis after surgery alone.

Sympathetic cardioneuropathy in dysautonomias

BACKGROUND

The classification of dysautonomias has been confusing, and the pathophysiology obscure. We examined sympathetic innervation of the heart in patients with acquired, idiopathic dysautonomias using thoracic positron-emission tomography and assessments of the entry rate of the sympathetic neurotransmitter norepinephrine into the cardiac venous drainage (cardiac norepinephrine spillover). We related the laboratory findings to signs of sympathetic neurocirculatory failure (orthostatic hypotension and abnormal blood-pressure responses associated with the Valsalva maneuver), central neural degeneration, and responsiveness to treatment with levodopa-carbidopa (Sinemet).

METHODS

Cardiac scans were obtained after intravenous administration of 6-[18F]fluorodopamine in 26 patients with dysautonomia. Fourteen had sympathetic neurocirculatory failure--three with no signs of central neurodegeneration (pure autonomic failure), two with parkinsonism responsive to treatment with levodopa-carbidopa, and nine with central neurodegeneration unresponsive to treatment with levodopa-carbidopa (the Shy-Drager syndrome). The rates of cardiac norepinephrine spillover were estimated on the basis of concentrations of intravenously infused [3H]norepinephrine during catheterization of the right side of the heart.

RESULTS

Patients with pure autonomic failure or parkinsonism and sympathetic neurocirculatory failure had no myocardial 6-[18F]fluorodopamine-derived radioactivity or cardiac norepinephrine spillover, indicating loss of myocardial sympathetic-nerve terminals, whereas patients with the Shy-Drager syndrome had increased levels of 6-[18F]fluorodopamine-derived radioactivity, indicating intact sympathetic terminals and absent nerve traffic. Patients with dysautonomia who did not have sympathetic neurocirculatory failure had normal levels of 6-[18F]fluorodopamine-derived radioactivity in myocardium and normal rates of cardiac norepinephrine spillover.

CONCLUSIONS

The results of 6-[18F]fluorodopamine positron-emission tomography and neurochemical analyses support a new clinical pathophysiologic classification of dysautonomias, based on the occurrence of sympathetic neurocirculatory failure, signs of central neurodegeneration, and responsiveness to levodopa-carbidopa.

The efficacy of donepezil in the treatment of neuropsychiatric symptoms in Alzheimer disease

OBJECTIVE

To determine the efficacy of donepezil in the treatment of neuropsychiatric symptoms in patients with Alzheimer disease (AD) in a randomized withdrawal study.

METHOD

Patients with mild to moderate AD with marked neuropsychiatric symptoms at baseline (Neuropsychiatric Inventory [NPI] > 11 points) were treated openly with donepezil 5 mg daily for 6 weeks followed by 10 mg daily for a further 6 weeks. Patients were then randomized (60:40) to either placebo or 10 mg donepezil daily. All patients were assessed at 6 weeks and provided there was no marked cognitive deterioration their blinded treatment was continued for a further 6 weeks. NPI and carer distress were assessed at 6 weekly intervals throughout the study.

RESULTS

A total of 134 patients participated. Following randomization patients who continued on donepezil 10 mg for 12 weeks had improvements in NPI compared with the placebo group (mean change -2.9 vs 3.3 points; ITT-LOCF p = 0.02) and in NPI-Distress scores (median change -2.0 vs 1.0 points; ITT-LOCF p = 0.01). During the open-label phase the total NPI and NPI-Distress scores were lower after 12 weeks treatment with open label donepezil compared with baseline (total NPI 22 points vs13 points; ITT-LOCF p < 0.0001; NPI-Distress 13.5 vs 7.9 points; ITT-LOCF p < 0.0001). In the open-label phase all domains of the NPI (with the exception of elation) were improved (all p < 0.05 after Bonferroni correction).

CONCLUSIONS

Donepezil has significant efficacy in the treatment of neuropsychiatric symptoms in patients with mild to moderate AD.

Improved assay for plasma dihydroxyphenylacetic acid and other catechols using high-performance liquid chromatography with electrochemical detection

Several modifications of an HPLC-electrochemical assay method for plasma levels of norepinephrine (NE), epinephrine (EPI), dopamine (DA), dihydroxyphenylglycol (DHPG), dihydroxyphenylalanine (DOPA) and dihydroxyphenylacetic acid (DOPAC) that improve the accuracy and reliability of DHPG, DOPA, and DOPAC measurements are described. In batch alumina extractions, increasing the amount of alumina decreased analytical recoveries of DHPG, DOPA, and especially DOPAC, and increasing the strength of the eluting acid increased recoveries of these catechols, without affecting recoveries of the amines NE, EPI and DA. Refrigeration (4 degrees C) until injection stabilized DOPAC in aqueous solution and therefore improved the reproducibility of plasma DOPAC measurements. Circulation of chilled water (15 degrees C) around the column using a water jacket decreased variability in retention times of the catechols and thereby facilitated identification of peaks, while enhancing separation of DHPG from the solvent front. Use of 6-fluoro-DOPA and 6-fluoro-DOPAC as internal standards did not improve inter-assay reliability. We recommend that in assays of plasma catechols including DOPAC, small (5 mg), precisely measured amounts of alumina be used, with a relatively strong eluting solution (e.g. 0.04 M phosphoric acid-0.2 M acetic acid, 20:80, v/v), and that the samples be refrigerated until injection, with column temperature held constant at less than 20 degrees C.

Validity of current clinical criteria for Alzheimer's disease, vascular dementia and dementia with Lewy bodies

BACKGROUND

Following the success of the NINCDS-ADRDA criteria for Alzheimer's disease, groups interested in vascular dementia and dementia with Lewy bodies have now adopted similar criteria.

AIMS

To assess whether the validity of these criteria are influenced by the prevalence of mixed pathologies or by the prevalence rate.

METHOD

A community based post-mortem study.

RESULTS

Mixed pathologies were common (33.8%). The high specificities obtained for the CDLB and NINDS-AIREN criteria (1.00 and 0.95, respectively) were associated with low sensitivities (0.22 and 0.43, respectively). Low prevalence and the presence of mixed pathologies had a deleterious effect on positive predictive values.

CONCLUSIONS

Current clinical diagnostic criteria are good at detecting pathology per se but not at detecting pure pathology. A large proportion of subjects from the general population fulfilling probable CDLB, probable NINCDS-ADRDA or probable NINDS-AIREN will have mixed pathologies.

In vivo morphometry of the intrasulcal gray matter in the human cingulate, paracingulate, and superior-rostral sulci: hemispheric asymmetries, gender differences and probability maps

Volumes of the intrasulcal gray matter were measured in three cerebral sulci located on the medial wall of the human frontal lobe: cingulate sulcus (CS), paracingulate sulcus (PCS), and superior-rostral sulcus (SRS). The measurements were carried out on T1-weighted 3-D high-resolution magnetic-resonance (MR) images acquired in 105 young right-handed volunteers (42 female and 63 male). Before the measurement, the images were transformed into a standardized stereotaxic space (Talairach and Tournoux [1988] Human Brain: 3-Dimensional Proportional System. An Approach to Cerebral Imaging. Stuttgart, New York: Georg Thieme Verlag), thus removing inter-individual differences in brain size. The intrasulcal gray matter was segmented in a semi-automatic manner. Significant gender differences were found in the volume of the CS (female > male) and the PCS (male > female). Hemispheric asymmetries were observed between the left and right volumes of the intrasulcal gray matter in the anterior (right > left) and posterior (left > right) segments of the CS, as well as between the left and right volumes of the PCS (left > right). There was no interaction between the asymmetries and gender. In addition, significant positive correlations were found between the left and right gray-matter volumes in the anterior (r = 0.43) and posterior (r = 0.66) segments of the CS, whereas significant negative correlations were observed between the gray-matter volumes of the anterior segment of the CS and those of the PCS (left hemisphere: r = -0.48; right hemisphere: r = -0.42). The observed hemispheric asymmetries in the CS and PCS gray-matter volumes are consistent with the proposed role of these structures in the integration of emotions with cognition (CS) and in the control of speech/vocalization (PCS). The pattern of inter-hemispheric correlations in the sulcal gray-matter points to an increasing asynchrony in the foetal development of primary (CS), secondary (SRS), and tertiary (PCS) sulci, respectively. The presence of negative correlations between the two neighbouring sulci (CS and PCS) suggests that a process of compensation could underlie interactions between adjacent primary and tertiary sulci. Besides the above volumetric analysis, we also provide average (probability) maps of the three sulci; the use of such maps for the parcellation of the medial frontal lobe and localization of "peaks" obtained in blood-flow activation studies is discussed.

Proinflammatory cytokines, sickness behavior, and Alzheimer disease

BACKGROUND

In Alzheimer disease (AD), systemic inflammation is known to give rise to a delirium. However, systemic inflammation also gives rise to other centrally mediated symptoms in the absence of a delirium, a concept known as sickness behavior. Systemic inflammation is characterized by the systemic production of the proinflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) that mediate immune to brain communication and the development of sickness behavior.

OBJECTIVE

To determine if raised serum TNFα or IL-6 are associated with the presence of sickness behavior symptoms, independent of the development of delirium, in a prospective cohort study of subjects with AD.

METHODS

A total of 300 subjects with mild to severe AD were cognitively assessed at baseline and a blood sample taken for inflammatory markers. Cognitive assessments, including assessments to detect the development of a delirium, and blood samples were repeated at 2, 4, and 6 months. The development of neuropsychiatric symptoms in the subject with AD over the 6-month follow-up period was assessed independently by carer interview at 2, 4, and 6 months.

RESULTS

Raised serum TNFα and IL-6, but not CRP, were associated with an approximately 2-fold increased frequency of neuropsychiatric symptoms characteristic of sickness behavior. These relationships are independent of the development of delirium.

CONCLUSIONS

Increased serum proinflammatory cytokines are associated with the presence of symptoms characteristic of sickness behavior, which are common neuropsychiatric features found in AD. This association was independent of the presence of delirium.

Hippocampal tissue of patients with refractory temporal lobe epilepsy is associated with astrocyte activation, inflammation, and altered expression of channels and receptors

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Previous research has demonstrated several trends in human tissue that, undoubtedly, contribute to the development and progression of TLE. In this study we examined resected human hippocampus tissue for a variety of changes including gliosis that might contribute to the development and presentation of TLE. The study subjects consisted of six TLE patients and three sudden-death controls. Clinicopathological characteristics were evaluated by H&E staining. Immunohistological staining and Western blotting methods were used to analyze the samples. Neuronal hypertrophy was observed in resected epileptic tissue. Immunohistological staining demonstrated that activation of astrocytes was significantly increased in epileptic tissue as compared to corresponding regions of the control group. The Western blot data also showed increased CX43 and AQP4 in the hippocampus and downregulation of Kir4.1, α-syntrophin, and dystrophin, the key constituents of AQP4 multi-molecular complex. These tissues also demonstrated changes in inflammatory factors (COX-2, TGF-β, NF-κB) suggesting that these molecules may play an important role in TLE pathogenesis. In addition we detected increases in metabotropic glutamate receptor (mGluR) 2/3, mGluR5 and kainic acid receptor subunits KA1 (Grik4) and KA2 (Grik5) in patients' hippocampi. We noted increased expression of the α1c subunit comprising class C L-type Ca(2+) channels and calpain expression in these tissues, suggesting that these subunits might have an integral role in TLE pathogenesis. These changes found in the resected tissue suggest that they may contribute to TLE and that the kainic acid receptor (KAR) and deregulation of GluR2 receptor may play an important role in TLE development and disease course. This study identifies alterations in number of commonly studied molecular targets associated with astrogliosis, cellular hypertrophy, water homeostasis, inflammation, and modulation of excitatory neurotransmission in hippocampal tissues from TLE patients.

5-HT2A and 5-HT2C receptor polymorphisms and psychopathology in late onset Alzheimer's disease

The psychopathology of Alzheimer's disease (AD) is varied and includes both behavioural and psychological symptoms. Behavioural and psychological symptoms are common and contribute to the difficulties experienced by carers. However, the mechanism whereby these symptoms occur in some individuals with AD is not understood. We hypothesized that common genetic polymorphisms in neurotransmitter systems are risk factors for these symptoms in the course of AD. A total of 211 subjects from a population-based prospective study of psychopathology within late-onset AD were genotyped for the 5-HT2A receptor polymorphism 102-T/C and the 5-HT2C receptor polymorphism Cys23Ser. Associations were found between the presence of the C102 allele and the presence of visual (Fisher's exact test, one-tailed, P = 0.003) and auditory hallucinations (Fisher's exact test, one-tailed, P = 0.004) and between the presence of the Ser23 allele and visual hallucinations (chi2 = 7.5, df = 1, P = 0.006) (P = 0.03, 0.04 and 0.06, respectively, after Bonferroni correction). In addition, there was an association between the Cys23Ser polymorphism and hyperphagia (chi2 = 6.7, df = 2, P = 0.03) (P = 0.3 after Bonferroni correction). We conclude that common 5-HT2A and 5-HT2C genetic polymorphisms previously showing only weak associations with psychotic illness are associated with psychotic symptoms in AD but are clinically silent until the onset of the neurodegenerative process.

Catechols in post-mortem brain of patients with Parkinson disease

BACKGROUND

Dihydroxyphenylacetaldehyde (DOPAL), a cytotoxic metabolite of dopamine, is the focus of the 'catecholaldehyde hypothesis' about the pathogenesis of Parkinson disease. This study explored whether DOPAL is detectable in human striatum - especially in the putamen (Pu), the main site of dopamine depletion in Parkinson disease - and is related to other neurochemical indices of catecholamine stores and metabolism in Parkinson disease.

METHODS

Putamen, caudate (Cd), and frontal cortex (Ctx) catechols were measured in tissue from patients with pathologically proven end-stage Parkinson disease (N=15) and control subjects (N=14) of similar age with similar post-mortem intervals.

RESULTS

Putamen DOPAL (3% of dopamine in controls) correlated with dopamine and dihydroxyphenylacetic acid both across all subjects and within the Parkinson disease and control groups. Pu dopamine was decreased by 93% and dihydroxyphenylacetic acid 95% in Parkinson disease vs. controls, with smaller decreases of DOPAL (83%) and norepinephrine (73%) in Pu and of dopamine (74%) and dihydroxyphenylacetic acid (82%) in Cd. In Parkinson disease, Pu DOPAL:dihydroxyphenylacetic acid averaged 3.4 times and DOPAL:dopamine 4.4 times control (P=0.03 each). The main catecholamine in Ctx was norepinephrine, which was decreased by 51% in Parkinson disease patients.

CONCLUSIONS

Correlated decreases of DOPAL, dopamine, and dihydroxyphenylacetic acid in Parkinson disease reflect severe loss of Pu dopamine stores, which seems more extensive than loss of Pu norepinephrine or Cd dopamine stores. Increased Pu DOPAL:dihydroxyphenylacetic acid ratios in Parkinson disease suggest decreased detoxification of DOPAL by aldehyde dehydrogenase. Elevated levels of cytosolic DOPAL might contribute to loss of dopaminergic neurons in Parkinson disease.

Alzheimer's disease: differences in technetium-99m HMPAO SPECT scan findings between early onset and late onset dementia

OBJECTIVE

To compare the HMPAO SPECT cerebral perfusion patterns in early and late onset Alzheimer's disease.

METHODS

Twenty patients with early onset disease (<65 years) and 44 patients with late onset disease (>65 years) were studied. All patients fulfilled NINCDS-ADRDA clinical criteria and had details of disease severity and length of history at the time of imaging. Technetium-99m HMPAO SPECT brain scans were acquired on a multi-detector gammacamera and analysed visually and with statistical parametric mapping (SPM99).

RESULTS

Patients with early onset disease had significantly greater posterior cortical association area involvement whereas those with late onset disease had significantly greater medial temporal hypoperfusion. These findings were unchanged after controlling for disease severity and length of illness.

DISCUSSION

These functional imaging findings of the differences between early and late onset Alzheimer's disease are supported by published findings that include histopathological and clinical evidence; namely late onset patients tend to present with the characteristic involvement of the medial temporal lobes producing marked memory loss whereas early onset patients present with predominant posterior cortical association area involvement. These age related findings should be borne in mind when clinically diagnosing, and interpreting functional brain imaging studies in, patients with suspected Alzheimer's disease.

Plasma levels of catechols and metanephrines in neurogenic orthostatic hypotension

BACKGROUND

Neurogenic orthostatic hypotension (NOH) usually results from deficient release of the sympathetic neurotransmitter norepinephrine (NE) when the patient stands up. In pure autonomic failure (PAF) and PD with NOH, sympathetic denervation can explain this deficiency, whereas in multiple-system atrophy (MSA), deficient baroreflex regulation of sympathetic traffic to intact terminals probably causes the NOH. From the concept of a unitary sympathoadrenomedullary system, one might predict parallel sympathoneural and adrenomedullary abnormalities in NOH.

OBJECTIVE

To test the concept of parallel sympathoneural and adrenomedullary abnormalities in NOH by simultaneous measurements of plasma levels of catechols and metanephrines.

METHODS

Antecubital venous blood drawn via an indwelling cannula with the subject supine was assayed for catecholamines (NE, epinephrine [EPI]), dihydroxyphenylglycol (DHPG), and metanephrines (normetanephrine [NMN] and metanephrine [MN]) in patients with PAF, PD + NOH, or MSA + NOH. Control subjects had PD lacking NOH or were normal volunteers at least 35 years old. Cardiac sympathetic innervation was assessed by 6-[18F]fluorodopamine PET scanning.

RESULTS

The three NOH groups differed clearly in patterns of plasma catechols and metanephrines. The PAF group had low NE, DHPG, NMN, EPI, and MN levels, the group with MSA + NOH had generally normal levels, and the PD + NOH group low NMN levels and low DHPG levels for given NE levels but normal mean NE, EPI, and MN levels. All patients with PAF or PD + NOH had markedly decreased 6-[18F]fluorodopamine-derived radioactivity throughout the left ventricular myocardium; all patients with MSA + NOH had normal radioactivity.

CONCLUSIONS

PAF involves generalized loss of sympathoadrenomedullary cells, MSA + NOH intact sympathoadrenomedullary cells, and PD + NOH intact adrenomedullary cells but organ-selective sympathetic denervation, especially in the heart.