Empirical assessment of biases in cerebrospinal fluid biomarkers of Alzheimer's disease: an umbrella review and re-analysis of data from meta-analyses.

OBJECTIVE: Alzheimer's disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available. MATERIALS AND METHODS: We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval. RESULTS: A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger's test were shown in 28% of CSF biomarkers. CONCLUSIONS: Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution.

Similar autobiographical memory impairment in long-term secondary progressive multiple sclerosis and Alzheimer's disease.

BACKGROUND: Memory disturbance is a common symptom of multiple sclerosis (MS), but little is known about autobiographical memory deficits in the long-term course of different MS subtypes. Inflammatory activity and demyelination is pronounced in relapsing-remitting multiple sclerosis (RRMS) whereas, similar to Alzheimer's disease, neurodegeneration affecting autobiographical memory-associated areas is seen in secondary progressive multiple sclerosis (SPMS). OBJECTIVE: In light of distinct disease mechanisms, we evaluated autobiographical memory in different MS subtypes and hypothesized similarities between elderly patients with SPMS and Alzheimer's disease. METHODS: We used the Autobiographical Memory Interview to assess episodic and semantic autobiographical memory in 112 education- and gender-matched participants, including healthy controls and patients with RRMS, SPMS, amnesic mild cognitive impairment (aMCI) and early Alzheimer's dementia (AD). RESULTS: Patients with SPMS, AD, and aMCI, but not with RRMS, exhibited a pattern of episodic autobiographical memory impairment that followed Ribot's Law; older memories were better preserved than more recent memories. In contrast to aMCI and AD, neither SPMS nor RRMS was associated with semantic autobiographical memory impairment. CONCLUSION: Our neuropsychological findings suggest that episodic autobiographical memory is affected in long-term patients with SPMS, possibly due to neurodegenerative processes in functional relevant brain regions.

Macrophage colony-stimulating factor (M-CSF) in plasma and CSF of patients with mild cognitive impairment and Alzheimer's disease.

Macrophage colony-stimulating factor (M-CSF) is a hematopoietic growth factor that activates microglial cells, involved in phagocytosis of amyloid-beta (Abeta) in the brain. In the present study, we found in 50 patients with Alzheimer's disease (AD) significantly increased M-CSF plasma levels compared to 22 patients with mild cognitive impairment (MCI) and 35 age-matched healthy controls. In contrast, MCI patients showed significantly decreased M-CSF levels in cerebrospinal fluid (CSF) compared to AD patients and 20 patients with other non-inflammatory neurological disease (NIND). Analyzing the impact of Beta-amyloid 1-42 (Abeta 1-42), tau protein and M-CSF for differentiation between the groups we found that M-CSF, but not Abeta 1-42 and tau-protein is a significant parameter for distinction between MCI and NIND patients with 68.8% sensitivity and 75.0% specificity. M-CSF CSF levels < or = 357.8 pg/ml yielded 73.7% sensitivity and 75.0% specificity for diagnosing MCI patients in comparison with control subjects. In conclusion, our data indicate that M-CSF in CSF could be a putative biomarker for MCI.

Increase of BDNF serum concentration during donepezil treatment of patients with early Alzheimer's disease.

Alzheimer's disease (AD) can be treated with inhibitors of the enzyme acetylcholinesterase (AChE). Recent pre-clinical and clinical studies gave evidence that AChE-inhibitors have neuroprotective effects and thereby a disease-modifying potential. The mechanism of this action is still discussed. In an animal model oral administration of an AChE-inhibitor lead to an increase of brain derived neurotrophic factor (BDNF) in hippocampus and cortex. Recent studies have found a decrease of BDNF in the serum and brain of AD patients with potentially consecutive lack of neurotrophic support and contribution to progressive neurodegeneration. BDNF serum concentrations were assessed by ELISA in 19 AD patients and 20 age-matched healthy controls at baseline and in the AD patients after 15 months of treatment with donepezil 10 mg per day (one patient received just 5 mg). Before treatment with donepezil we found in AD significantly decreased BDNF serum concentrations (19.2 +/- 3.7 ng/ml) as compared to healthy controls (23.2 +/- 6.0 ng/ml, P = 0.015). After 15 months of treatment the BDNF serum concentration increased significantly in the AD patients (23.6 +/- 7.0 ng/ml, P = 0.001) showing no more difference to the healthy controls (P = 0.882). The results of the present study confirm data of prior investigations that a down-regulation of BDNF in serum and brain of AD patients seems to begin with the first clinical symptoms and to be persistent. A treatment with the AChE-inhibitor donepezil is accompanied with an increase of BDNF serum concentration in AD patients reaching the level of healthy controls. Thus, up-regulation of BDNF might be part of a neuroprotective effect of AChE-inhibitors. The molecular mechanism of this potentially disease-modifying mechanism of action of donepezil should be clarified.

Stage-dependent BDNF serum concentrations in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by cognitive decline and loss of neurons in specific brain regions. Recent findings have suggested an involvement of brain-derived neurotrophic factor (BDNF) in the pathogenesis of AD. BDNF is an endogenous protein involved in the maintenance of neuronal function, synaptic plasticity and structural integrity in the adult brain. To our knowledge, the present pilot study assessed for the first time BDNF serum and CSF concentrations in 30 patients with different stages of AD in comparison to 10 age-matched non-demendet controls. AD patients were divided in two groups according to their MMSE score: Group 1 (n = 15) in early stages with MMSE scores >or=21 (mean of 25.5) and Group 2 (n = 15) with more severe stages of dementia with MMSE scores <21 (mean of 13.3). As main results, we found in patients with early stages of probable AD significantly increased BDNF serum concentrations as compared to more severe stages of AD (p < 0.0001) and age-matched healthy controls (p = 0.028). BDNF serum values in all AD patients correlated significantly with MMSE scores (r = 0.486; p < 0.0001). Levels of BDNF were below the detection limit of the assay in unconcentrated CSF samples of AD patients and non-demendet controls.In summary, BDNF serum values are increased in early stages of Alzheimer's disease, which may reflect a compensatory repair mechanism in early neurodegeneration and could also contribute to increased degradation of beta-amyloid (Abeta). During the course of the disease, BDNF is decreasing, which correlates with the severity of dementia. The decrease of BDNF may constitute a lack of trophic support with an increase of Abeta accumulation and thus contribute to progressive degeneration of specific regions in the AD-affected brain. BDNF should be further evaluated as a candidate marker for clinical diagnosis and therapeutic monitoring in Alzheimer's disease.

Second primary tumor in anti-Ma1/2-positive paraneoplastic limbic encephalitis.

Memory loss can be a symptom of paraneoplastic limbic encephalitis (PLE) a neuropsychiatric disorder associated mostly with small-cell lung cancer and anti-Hu antibodies or with testicular tumors and anti-Ma2 antibodies. We present the case of a patient with temporal coincidence of beginning cognitive decline and diagnosis of a carcinoma of the prostate in whom we diagnosed anti-Ma1/Ma2-positive PLE. The tumor had been completely resected but memory impairment further deteriorated. As the effective treatment of the cancer is considered as the most efficient treatment of a paraneoplastic neurological syndrome (PNS) a second neoplasia was suspected in the patient. By the aid of whole body positron emission tomography with 18-fluorine fluoro-2-deoxy-glucose (FDG-PET) an adenocarcinoma of the cecum could be detected. Two months after surgery anti-Ma antibodies were negative. We conclude that a second neoplasia should be considered, if effective cancer treatment does not lead to improvement or stabilisation of a PNS. Tumor search should be exhaustive and include PET when conventional imaging fails to show a malignancy.

CADASIL: underdiagnosed in psychiatric patients?

OBJECTIVE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is exclusively related to symptoms of the central nervous system. Retrospectively in up to 15% the initial presentation is psychiatric disturbances. In these cases the diagnosis often is delayed or missed. METHOD: Two cases of CADASIL diagnosed in a psychiatric hospital are presented. RESULTS: Both patients were admitted to the gerontopsychiatric department (one because of a suicidal attempt and a depressive episode, the other because of cognitive decline and progressive personal neglect). Brain magnetic resonance imaging (MRI) showed severe leukoencephalopathy in the absence of cardiovascular risk factors. In both cases, diagnosis of CADASIL was made by the identification of specific granular osmiophilic material in skin biopsies. CONCLUSION: Brain MRI should be performed in all cases of late onset of severe psychiatric symptoms. CADASIL should be considered as a possible differential diagnosis whenever a marked leukoencephalopathy is detectable. Diagnosis can be verified by taking a skin biopsy or by specific genetic testing.

[Depression in Hashimoto's encephalopathy. Successful treatment of a severe depressive episode with a glucocorticoid as an add-on therapy]. / Depression bei Hashimoto-Enzephalopathie. Erfolgreiche Behandlung einer schweren depressiven Episode mit einem Kortikosteroid als Add-on-Therapie.

Characteristic clinical findings of Hashimoto's encephalopathy (HE) are stroke-like episodes, epileptic seizures, myoclonus, psychosis, and progressive cognitive impairment. Diagnosis of HE is supported by elevated antithyroid antibodies, an abnormal EEG, and by good response to steroids. We report on a 74-year-old female patient with a severe depressive episode who showed no treatment response to citalopram 40 mg/day and venlafaxine 150 mg/day. Diagnostic examination revealed an abnormal EEG, elevated thyroid peroxidase antibodies (TPO-Ab), and older postinflammatory changes in thyroidal sonography. We diagnosed a depression in HE and began treatment with prednisolone 70 mg/day with stepwise dose reduction, continuing treatment with venlafaxine 150 mg/day. Within 4 weeks of treatment, the severe depressive episode disappeared as well as abnormal EEG. In addition, serum values of TPO-Ab decreased. In HE, depressive symptoms can possibly be seen in a subgroup of patients or in the early course of the disease. Diagnosis of HE should be included in diagnostic procedures in cases of therapy-refractory depression because of a good response of HE to steroids.

[Dementia as a primary symptom in late onset multiple sclerosis. Case series and review of the literature]. / Demenz als Erstsymptom bei spät beginnender Multipler Sklerose. Fallserie mit Literaturübersicht.

Cognitive impairment is meanwhile accepted as a well-known symptomatology affecting up to 60% of the patients even in the early disease course of multiple sclerosis (MS). After a longer duration the development of dementia is not unusual. However, cognitive dysfunction as the primary or only manifestation of MS is thought to be rare. We report on four elderly patients referred to the memory clinic of our psychiatric university hospital because of beginning dementia. All of them were found to have evidence of a chronic inflammatory CNS process compatible with the diagnosis of MS. At the beginning of their symptomatology all patients were older than 60 years . Just in one case, progressive gait disturbances beginning after cognitive decline contributed to restriction in the activities of daily living. Data of 239 cases of the literature were reviewed and revealed motor disturbances as the main initial symptom and often a primary progressive course with unfavourable prognosis in late onset MS. Until now dementia as the primary symptomatology has not been described in patients older than 60 years. Possibly MS as a differential diagnosis in dementia as well as cognitive impairment as an initial symptom of MS is under-recognized.

[Microdeletion 22q11.2. A too rarely diagnosed genetic change in psychiatric illnesses]. / Mikrodeletion 22q11.2. Eine zu selten diagnostizierte genetische Veränderung bei psychiatrischen Erkrankungen.

Microdeletion 22q11.2 with an estimated incidence of 1:4000 is known to cause the DiGeorge syndrome (DGS) or the velocardiofacial syndrome (VCFS), both usually being diagnosed in the newborn period or childhood. Recent studies have shown that children suffering from VCFS frequently develop psychiatric disorders in late adolescence or adulthood. Here we report the case of a 30-year-old man presenting with slight facial dysmorphisms, hypoparathyreoidism, minor cardiac anomalies, and slight cognitive impairments who had developed a severe personality disorder which eventually led to the diagnosis of microdeletion 22q11.2 with maternal inheritance. Psychiatric patients should be thoroughly examined for typical signs associated with this chromosomal anomaly. Genetic diagnosis is necessary because of the 50% probability of inheritance with possibly severe congenital anomalies. In view of a prevalence of 2% in an unselected group of patients with schizophrenic psychosis, microdeletion 22q11.2 is likely to be underdiagnosed.

Morphologically different biopsy specimens of the human gastric mucosa. II. Adenylate cyclase activity in response to prostaglandin E2 and histamine.

Adenylate cyclase (AC) in response to prostaglandin E2 (PGE2) and histamine was studied in morphologically different biopsy specimens from human gastric mucosa. The activities of the enzyme were log-normally distributed and did not differ between males and females. PGE2 activated AC in a concentration-dependent manner in normal gastric mucosa (n = 57), chronic superficial gastritis (GI, 18), chronic gastritis with beginning atrophy (GII, 10), chronic atrophic gastritis (GIII, 24), gastric ulcer (GU, 39), duodenal ulcer (DU, 32), and biopsies of patients operated according to Billroth II (BII, 20) and was most efficacious in GIII and BII. Histamine, which was studied in normal gastric mucosa (n = 27), DU (n = 20), GU (n = 13), and BII (n = 18), stimulated AC most efficaciously and potently in DU, was less effective in normal gastric mucosa and GU, and had no effect at all in BII. Cimetidine treatment of DU patients did not change the PGE2 action, while the degree of stimulation by histamine was reduced. The data indicate characteristic differences of the PGE2- and histamine-sensitive AC in the mucosal samples of these patients.

Morphologically different biopsy specimens of the human gastric mucosa. I. The use of enzymatic cell isolation for quantitative determination of parietal cells.

Single biopsies of human gastric mucosa from controls and different groups of patients were used for enzymatic cell isolation by pronase and collagenase and subsequent count of parietal and nonparietal cells. This procedure was tested in regard to its validity and delivered the following cell numbers. Total gastric cells/mg wet weight gastric mucosa: normal gastric mucosa [controls (C), n = 95] 31,500 +/- (SEM) 1,490, chronic superficial gastritis (GI; n = 49) 36,300 +/- 2,770, chronic gastritis with beginning atrophy (GII; n = 36) 44,100 +/- 3,050 (p less than 0.025), chronic atrophic gastritis (GIII; n = 12) 40,100 +/- 5,760, duodenal ulcer (DU; n = 26) 29,340 +/- 2,280, gastric ulcer (GU; n = 23) 37,090 +/- 3,000, gastric resection according to Billroth I (BI; n = 7) 57,480 +/- 12,360 (p less than 0.005) and Billroth II (BII; n = 12) 52,560 +/- 6,730 (p less than 0.005). Parietal cells/mg wet weight gastric mucosa: 1,910 +/- 490 (C), 1,980 +/- 140 (GI), 1,700 +/- 200 (GII), 1,170 +/- 220 (GIII, p less than 0.025), 2,580 +/- 240 (DU, p less than 0.05), 1,690 +/- 150 (GU), 1,500 +/- 250 (BI), 1,360 +/- 320 (BII). Parietal cell concentration (density) did not differ in males and females and did not change with age. The method delivers relevant cell numbers, is suitable to detect qualitative differences and can be used for the interpretation of biochemical studies.