Changes in Nutritional Status after Deep Brain Stimulation of the Nucleus Basalis of Meynert in Alzheimer's Disease--Results of a Phase I Study.

OBJECTIVE: The progression of Alzheimer's disease (AD) is associated with impaired nutritional status. New methods, such as deep brain stimulation (DBS), are currently being tested to decrease the progression of AD. DBS is an approved method in the treatment of Parkinson's disease, and its suitability for the treatment of AD patients is currently under experimental investigation. To evaluate the advantages and disadvantages of this new treatment, it is important to assess potential side effects of DBS regarding the nucleus basalis of Meynert; this new treatment is thought to positively affect cognition and might counteract the deterioration of nutritional status and progressive weight loss observed in AD. This study aims to assess the nutritional status of patients with AD before receiving DBS of the nucleus basalis of Meynert and after 1 year, and to analyze potential associations between changes in cognition and nutritional status. DESIGN: A 1-year phase I proof-of-concept study. SETTING: The Department of Psychiatry and Psychotherapy at the University of Cologne. PARTICIPANTS: We assessed a consecutive sample of patients with mild to moderate AD (n=6) who fulfilled the inclusion criteria and provided written informed consent. INTERVENTION: Bilateral low-frequency DBS of the nucleus basalis of Meynert. MEASUREMENTS: Nutritional status was assessed using a modified Mini Nutritional Assessment, bioelectrical impedance analysis, a completed 3-day food diary, and analysis of serum levels of vitamin B12 and folate. RESULTS: With a normal body mass index (BMI) at baseline (mean 23.75 kg/m²) and after 1 year (mean 24.59 kg/m²), all but one patient gained body weight during the period of the pilot study (mean 2.38 kg, 3.81% of body weight). This was reflected in a mainly stable or improved body composition, assessed by bioelectrical impedance analysis, in five of the six patients. Mean energy intake increased from 1534 kcal/day (min 1037, max 2370) at baseline to 1736 kcal/day (min 1010, max 2663) after 1 year, leading to the improved fulfillment of energy needs in four patients. The only nutritional factors that were associated with changes in cognition were vitamin B12 level at baseline (Spearman's rho = 0.943, p = 0.005) and changes in vitamin B12 level (Spearman's rho = -0.829, p = 0.042). CONCLUSION: Patients with AD that received DBS of the nucleus basalis of Meynert demonstrated a mainly stable nutritional status within a 1-year period. Whether DBS is causative regarding these observations must be investigated in additional studies.

Deep brain stimulation of the nucleus basalis of Meynert in Alzheimer's dementia.

Cholinergic neurons of the medial forebrain are considered important contributors to brain plasticity and neuromodulation. A reduction of cholinergic innervation can lead to pathophysiological changes of neurotransmission and is observed in Alzheimer's disease. Here we report on six patients with mild to moderate Alzheimer's disease (AD) treated with bilateral low-frequency deep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM). During a four-week double-blind sham-controlled phase and a subsequent 11-month follow-up open label period, clinical outcome was assessed by neuropsychological examination using the Alzheimer's Disease Assessment Scale-cognitive subscale as the primary outcome measure. Electroencephalography and [(18)F]-fluoro-desoxyglucose positron emission tomography were, besides others, secondary endpoints. On the basis of stable or improved primary outcome parameters twelve months after surgery, four of the six patients were considered responders. No severe or non-transitional side effects related to the stimulation were observed. Taking into account all limitations of a pilot study, we conclude that DBS of the NBM is both technically feasible and well tolerated.

Management and outcome of pallidal deep brain stimulation in severe Huntington's disease.

Neurodegenerative movement disorders, such as Huntington's disease (HD), have become a promising field for Deep Brain Stimulation (DBS). This study aims to contribute to the establishment of a well-grounded database including both expected and unexpected effects of pallidal DBS in HD, and to discuss the ethical and legal restrictions of DBS in cognitively limited patients. Evaluation of the outcome data indicates that pallidal DBS exerted an independent effect on motor symptoms but probably also on the patient's cognitive and affective state. The cognitive decline, however, that characterizes the late stage of neurodegenerative disorders implicates ethical and legal problems given the patients' inability to give informed consent to DBS.

[Deep brain stimulation in schizophrenia]. / Tiefe Hirnstimulation bei der Schizophrenie.

Deep brain stimulation (DBS) has successfully advanced our treatment options for putative therapy-resistant neuropsychiatric diseases. Building on this strong foundation, more and more mental disorders in the stadium of therapy-resistance are considered as possible indications for DBS. Especially, schizophrenia with its associated severe and difficult to treat symptoms is gaining attention. This attention demands critical questions regarding the assumed mechanisms of DBS and its possible influence on the supposed pathophysiology of schizophrenia. Here, we synoptically compare current approaches and theories of DBS and discuss the feasibility of DBS in schizophrenia as well as the transferability from other psychiatric disorders successfully treated with DBS. For this we consider recent advances in animal models of schizophrenic symptoms, results regarding the influence of DBS on dopaminergic transmission as well as data concerning neural oscillation and synchronisation. In conclusion, the use of DBS for some symptoms of schizophrenia seems to be a promising approach, but the lack of a comprehensive theory of the mechanisms of DBS as well as its impact on schizophrenia might hinder the use of DBS for schizophrenia at this point in time.

Clinical effectiveness of unilateral deep brain stimulation in Tourette syndrome.

Dysfunctional basal ganglia loops are thought to underlie the clinical picture of Tourette syndrome (TS). By altering dopaminergic activity in the affected neural structures, bilateral deep brain stimulation is assumed to have a modulatory effect on dopamine transmission resulting in an amelioration of tics. While the majority of published case reports deals with the application of bilateral stimulation, the present study aims at informing about the high effectiveness of unilateral stimulation of pallidal and nigral thalamic territories in TS. Potential implications and gains of the unilateral approach are discussed.

Observations on unaided smoking cessation after deep brain stimulation of the nucleus accumbens.

AIMS: We explore whether clinical research on deep brain stimulation (DBS) of the nucleus accumbens (NAc) to treat addiction is justified besides theoretical speculation. METHODS: Since 2004, 10 patients who were also smokers were treated at the University of Cologne for Tourette's syndrome (TS), obsessive-compulsive disorders (OCD) or anxiety disorders (AD) by DBS of the NAc. We assessed their smoking behavior after DBS and (in retrospection) before by the Fagerstrom Test for Nicotine Dependence (FTND) and additional items. RESULTS: Three male patients were able to quit smoking after DBS. They were less dependent and higher motivated compared to the rest of the sample. They are stimulated with a higher voltage. During 1-year, 2-year, and 30-month follow-ups, we found a higher rate of successful smoking cessation (20, 30 and 30%) compared to unaided smoking cessation in the general population (13, 19 and 8.7%). CONCLUSIONS: Albeit the results of the study are severely limited by the method of retrospective self-assessment of psychiatric patients, further research of DBS of the NAc to treat addiction seems justified. In addition to biological mediators, psychosocial factors should be assessed in further prospective studies.

Deep-brain stimulation: long-term analysis of complications caused by hardware and surgery--experiences from a single centre.

OBJECTIVE: To determine the surgery-related and hardware-related complications of deep-brain stimulation (DBS) at a single centre. METHODS: 262 consecutive patients (472 electrodes) operated for DBS in our department from February 1996 to March 2003 were retrospectively analysed to document acute adverse events (30 days postoperatively). The data of 180 of these patients were additionally revised to assess long-term complications (352 electrodes, mean follow-up 36.3 (SD 20.8) months). RESULTS: The frequency of minor intraoperative complications was 4.2% (11/262 patients). Transient (0.2%) or permanent (0.4%) neurological deficits, and in one case asymptomatic intracranial haemorrhage (0.2%), were registered as acute severe adverse events caused by surgery. Among minor acute complications were subcutaneous bleeding along the extension wire (1.2%) and haematoma at the pulse generator implantation site (1.2%). Skin infection caused by the implanted material was registered in 15 of 262 patients (5.7%). The infection rate during the first observation period was 1.5% (4/262 patients) and the late infection rate was 6.1% (11/180 patients). Partial or complete removal of the stimulation system was necessitated in 12 of 262 (4.6%) patients because of skin infection. During the long-term observation period, hardware-related problems were registered in 25 of 180 (13.9%) patients. CONCLUSIONS: Stereotactic implantation of electrodes for DBS, if performed with multiplanar three-dimensional imaging and advanced treatment planning software, is a safe procedure with no mortality and low morbidity. The main causes for the patients' prolonged hospital stay and repeated surgery were wound infections and hardware-related complications.

Iris pigment epithelial cells: a possible cell source for the future treatment of neurodegenerative diseases.

For the treatment of neurodegenerative disorders such as Parkinson's disease cell or gene therapeutical options are increasingly verified. For such approaches, neural stem cells or astrocytes are discussed as possible cell candidates. As also fetal retinal pigment epithelial cells have been successfully tested for such therapeutical options, we investigated the potential of iris pigment epithelial cells as an autologous source for future cell replacement therapies. Using the ELISA technique, we looked for the secretion of neurotrophic factors under basal and stimulated conditions by iris pigment epithelial cells (IPE) cells and compared them with the secretion of retinal pigment epithelial cells (RPE) cells. As iron plays a causative role in cell death during Parkinson's disease, the iron-binding capacity by IPE cells was investigated. Furthermore, we checked the integrative capacity of IPE cells after transplantation into the striatum of adult rats. Our data reveal that IPE cells produce and secrete a variety of neurotrophic factors which can be stimulated after treatment with cytokines. Following transplantation, the cells can be easily detected by their pigmentation, survive for at least 8 weeks and as shown by electron microscopy integrate within the host tissue. Moreover, cells can be transduced with high efficiency using a third generation adenoviral vector, making them promising vehicles to locally deliver therapeutic proteins for the treatment of neurodegenerative diseases in a combined cell and gene therapeutical approach.

Neural precursor cells as carriers for a gene therapeutical approach in tumor therapy.

Conventional therapeutical approaches such as surgery, radiotherapy, or chemotherapy have been shown to be rather unsuccessful in the treatment of infiltrative growing tumors such as the malignant glioblastoma multiforme. Thus, new therapeutical strategies have to be developed that are suitable for inducing cell death also in migrating tumor cells. These new therapeutical stategies include cell and/or gene therapeutical approaches. We demonstrate that glial-restricted progenitor cells as well as embryonic stem cell-derived neural stem cells belong to cell populations applicable to such therapeutical concepts. Both cell types can be efficiently transduced using a third-generation high-capacity "gutless" adenoviral vector, and show a tropism for the F98 glioma cells by migrating towards a spheroid of F98 glioma cells with a tendency to form a barrier around the tumor spheroid in an in vitro tumor confrontation model. Moreover, in a migration assay, secretion products of glial-restricted precursor cells have shown a potency to inhibit the migratory activity of glioma cells in vitro. In vivo, F98 glioma cell-derived tumor formation in the right striatum resulted in migration of glial as well as neural precursor cells towards the tumor area when cotransplanted in the corpus callosum of the contralateral hemisphere. After arrival, both cell types surround the tumor mass and even invade the experimentally induced tumor. These data indicate that glial-restricted as well as embryonic stem cell-derived neural precursor cells are good candidates as carriers for an ex vivo gene therapeutical approach in tumor therapy.

Intracerebral transplantation and successful integration of astrocytes following genetic modification with a high-capacity adenoviral vector.

To investigate the ability of genetically modified astrocytes to integrate into adult rat brain, two spontaneously immortalized cell lines and the allogenic nontumorigenic glioma cell line F98 were transduced with a high-capacity adenoviral vector (HC-Adv) expressing the EGFP gene from the hCMV promoter. In organotypic slice cultures the transduced astrocytes were shown to integrate into the brain tissue. Following transplantation of the transduced astrocytes into the striatum of adult rats, the transplanted cells survived at least for 6 weeks, continuously expressed the EGFP transgene, in close neighborhood with cells of the recipient tissue executing their differentiation capacity along the glial lineage. Thus, HC-Adv transduced astrocytes are promising vehicles to locally deliver therapeutic proteins for the treatment of neurodegenerative diseases.

Differentiation of green fluorescent protein-labeled embryonic stem cell-derived neural precursor cells into Thy-1-positive neurons and glia after transplantation into adult rat striatum.

OBJECT: The aim of this investigation was to assess new information concerning the capacity of transplanted embryonic stem cell (ESC)-derived neuronal cells to migrate into host brain and to evaluate these cells as a possible source for cell replacement therapy in neurodegenerative disorders such as Parkinson's disease (PD). METHODS: The authors investigated the ability of ESC-derived neural precursor cells to migrate and differentiate in a host striatum by using a D3-derived ESC clone that was transfected stably with a chicken beta-actin cytomegalovirus enhancer-driven green fluorescent protein (GFP)-labeled construct. This procedure allowed easy monitoring of all transplanted cells because of the green fluorescent labeling of donor cells. This approach also afforded easy estimation of cell integration and simultaneous observation of the entire transplanted cell population in relation to immunocytochemically identified neuronal and glial differentiation. After selection of nestin-positive neural precursor cells in a synthetic medium, they were implanted into the striatum of male adult Wistar rats. Their integration was analyzed on morphological studies performed 3 days to 4 weeks posttransplantation. CONCLUSIONS: The investigators found that after transplantation, a subpopulation of GFP-labeled cells differentiated into various neural morphological types that were positive for the mouse-specific Thy-1 antigen, which is known be expressed on neurons, as well as being positive for the astroglial marker glial fibrillary acidic protein. Moreover, GFP-expressing cells that were negative for either of these markers remained close to the injection site, presumably representing other derivatives of the neural lineage. Together, these findings contribute to basic research regarding future transplantation strategies in neurodegenerative diseases such as PD.

Survival of glioma patients after complementary treatment with galactoside-specific lectin from mistletoe.

Malignant glioma patients were prospectively enrolled into a clinical trial. All the patients were provided with the internationally recommended oncologic standard treatment (neurosurgery, radiation, basic clinical care according to protocol and indication) and randomly divided into a treatment group (receiving complementary immunotherapy with a galactoside-specific lectin from mistletoe, ML-1) and a control group (without additional complementary treatment). Whereas the beneficial effects of ML-1 treatment on immunological rescue and quality of life have been recently shown, evaluation of relapse free/overall survival was performed after a 50 months follow up time. Non-stratified analysis of all the patients revealed non-relevant prolongation of relapse-free intervals/overall survival time for the treatment group. However, analysis of stratified stage III/IV glioma patients demonstrated: 1. a tendency for a prolongation of relapse-free survival for patients of the treatment group (17.43 +/- 8.2 months) vs. the control group (10.45 +/- 3.9 months) 2. a statistically significant (BRESLOW p = 0.035) prolongation of the overall survival for the treatment group (20.05 +/- 3.5 months) as compared to the control group (9.90 +/- 2.1 months). These promising data warrant confirmation in a GCP-based prospectively randomized (multicenter) study, which is currently under consideration.

Comprehensive allelotype and genetic anaysis of 466 human nervous system tumors.

Brain tumors pose a particular challenge to molecular oncology. Many different tumor entities develop in the nervous system and some of them appear to follow distinct pathogenic routes. Molecular genetic alterations have increasingly been reported in nervous system neoplasms. However, a considerable number of affected genes remain to be identified. We present here a comprehensive allelotype analysis of 466 nervous system tumors based on loss of heterozygosity (LOH) studies with 129 microsatellite markers that span the genome. Specific alterations of the EGFR, CDK4, CDKN2A, TP53, DMBT1, NF2, and PTEN genes were analyzed in addition. Our data point to several novel genetic loci associated with brain tumor development, demonstrate relationships between molecular changes and histopathological features, and further expand the concept of molecular tumor variants in neuro-oncology. This catalogue may provide a valuable framework for future studies to delineate molecular pathways in many types of human central nervous system tumors.

Quantitative analysis of NF1 and OMGP gene transcripts in sporadic gliomas, sporadic meningiomas and neurofibromatosis type 1-associated plexiform neurofibromas.

The close association of neurofibromatosis type 1 (NF1) with gliomas raises the question of whether the NF1 gene may be involved in the pathogenesis of sporadic astrocytic brain tumors. However, no frequent mutations within NF1 have been described in these tumors. Recent data on a limited series of gliomas indicate that NF1 expression may even be increased, thereby questioning the role of NF1 as a tumor suppressor in astrocytomas. In the present study, we examined the expression of NF1 in a series of 96 tumors including astrocytomas, meningiomas and plexiform neurofibromas. NF1 RNA transcription levels were compared to those of the reference genes B2M, ACTB and GAPD. The expression of OMGP, which is interposed in the NF1 gene, served as an additional control. NF1 expression did not significantly diverge among different malignancy stages of astrocytomas. As expected, the plexiform neurofibromas showed only very low NF1 expression. A striking finding was the highly variable expression of those genes selected to serve as references. While B2M and ACTB exhibited comparable levels of expression within different grades of astrocytomas and meningiomas, GAPD showed an inverse pattern in these tumors. In conclusion, NF1 expression is strongly reduced in NF1-associated plexiform neurofibromas but not in astrocytic tumors. The significant differences between B2M, ACTB and GAPD transcript levels brings into question the common practice of defining gene expression as a ratio between the transcripts of interest and those of these reference genes.

Efficiency of treatment with galactoside-specific lectin from mistletoe against rat glioma.

The cytotoxic activity of the galactoside-specific lectin from mistletoe (mistletoe lectin-1, ML-1) towards the anaplastic glioma cell line (F98) was investigated in vitro (three dimensional spheroid model) and in vivo (Fischer 344 rats). Both model systems demonstrated the dose dependent cytotoxicity of ML-1. F98 glioma cell spheroid growth was significantly inhibited after incubation with defined ML-1 concentrations of 10 and 100 ng/mL. To investigate the in vivo efficacy Fischer 344 rats were intracerebrally implanted with F98 glioma cells and assigned to local and systemic ML-1 treatment, respectively. Histological and immunohistochemical evaluations proved a reduction of tumor volume for both treatment modalities, most pronounced and statistically significant after systemic (immunomodulating) administration of the optimal ML-1 dosage (1 ng/kg BW, subcutaneously) and after low dose (10 ng ML-1 per application (10 microL) local treatment. High dose ML-1 administration (10 ng/kg BW; systemically; 100 ng/application, locally) was less effective than low (optimal) dose treatment and apparently the systemic/immunomodulating approach gained greater benefit for glioma bearing rats.

Analysis of the PTEN gene in human meningiomas.

Previous observations demonstrated that the neurofibromatosis type 2 gene (NF2) plays an important role in the pathogenesis of the transitional, fibroblastic and malignant variants of human meningiomas. No specific genes have been associated with the pathogenesis of meningothelial meningiomas and with the progression to anaplastic meningiomas. However, allelic losses on chromosomal arms 1p, 10q and 14q have been implicated in the process of malignant progression. Recently, PTEN (phosphatase and tensin homolog deleted on chromosome ten) also termed MMAC1 (mutated in multiple advanced cancers 1) or TEP1 (TGF--regulated and epithelial cell-enriched phosphatase), emerged as a candidate gene on chromosome 10q23.3. Initial studies revealed mutations of PTEN in limited series of glioblastomas, breast, kidney and prostate carcinomas mainly as cell lines. In order to evaluate the involvement of PTEN in the development of meningiomas, we have analysed the entire coding sequence of the gene in a series of 55 meningiomas (WHO grade I). 10 atypical meningiomas (WHO grade II) and 10 anaplastic meningiomas (WHO grade III). No PTEN mutations were seen in the WHO grade I meningiomas. However, one of the anaplastic meningiomas carried a somatic mutation. In addition, all tumours were examined for the presence of homozygous deletions of PTEN but these were not detected in any of the meningiomas. Our data suggest that mutations in PTEN are not involved in the formation of low grade meningiomas, but may contribute to malignant progression in a fraction of anaplastic meningiomas.

Molecular genetic evidence for subtypes of oligoastrocytomas.

The histogenesis of oligoastrocytomas remains controversial, with some data arguing similarity of oligoastrocytomas to astrocytic tumors, and other data suggesting closer relationships with oligodendroglial neoplasms. Since the molecular genetic changes in astrocytomas differ from those of oligodendrogliomas, we characterized 120 astrocytic and oligodendroglial tumors, including 38 oligoastrocytomas, for genetic alterations that occur disproportionately between astrocytomas and oligodendrogliomas, i.e. TP53 gene mutations and allelic loss of chromosomes 1p, 17p and 19q. As previously reported, TP53 mutations were common in astrocytic gliomas, occurring in approximately half of WHO grade II and III astrocytomas, but in only 5% of WHO grades II and III oligodendrogliomas. Allelic losses of chromosomes 1p and 19q, however, were common in oligodendrogliomas (41% and 63%), but less frequent in astrocytomas (9% and 35%). Oligoastrocytomas showed TP53 mutations in 12/38 (32%) cases and allelic losses of chromosomes 1p and 19q in 52% and 70%, respectively. Most importantly, TP53 mutations and allelic losses on chromosomes 1p and 19q were inversely correlated in oligoastrocytomas (p < 0.011 and p < 0.019). These data suggest the existence of two genetic subsets of oligoastrocytomas, one genetically related to astrocytomas and the other genetically related to oligodendrogliomas. Histologically, those oligoastrocytomas with TP53 mutations were more often astrocytoma-predominant, while those with chromosome 19q loss were more often oligodendroglioma-predominant.

Clonality of multiple meningiomas.

A significant number of patients with meningiomas develop multiple tumors without anatomical bridges. To understand the mechanism by which multiple meningiomas arise, the authors analyzed DNA from 39 multiple meningiomas in 12 patients to locate alterations in the neurofibromatosis type 2 (NF2) gene. This gene has been shown to be inactivated in meningiomas. No patient in our series had a family history of meningiomas or NF2. All tumors were investigated by single-strand conformation polymorphism analysis of the entire coding region of the NF2 gene and by direct DNA sequencing of altered fragments. The DNA from meningiomas in 10 patients carried NF2 gene mutations. In six of the 10 patients with NF2 mutations, all tumors in the respective individual exhibited the identical DNA alteration in the NF2 gene, thus indicating clonal origin. All four patients with more than two lesions had clonal meningiomas and four patients with two meningiomas each carried different mutations in their tumors. Analysis of constitutional DNA revealed a wild-type NF2 sequence in all 12 patients, thus excluding a forme fruste of NF2 in these cases. Our data demonstrate that the majority of multiple meningiomas with NF2 gene mutations are of somatic and clonal origin. Spread of tumor cells via the cerebrospinal fluid is the most likely mechanism to account for the development of these multiple meningiomas.