Michael Sabolek

Parkinson’s disease risk score: moving to a premotor diagnosis

Early pre-motor symptoms (also frequently termed “non-motor” symptoms) in Parkinson’s disease (PD), which precede the onset of motor symptoms, are being increasingly recognized by clinicians. Non-motor symptoms in the pre-motor phase of PD include impaired olfaction (hyposmia), sleep disturbances (i.e., radid eye movement sleep behavior disorder, daytime sleepiness), behavioral/emotional dysfunction (i.e., change of personality or change of core personal characteristics), dysautonomia (i.e., constipation, urinary dysfunction, orthostatic hypotension), depressive symptoms (i.e., fatigue, apathy, anxiety), and chronic pain (joint and muscle). The pre-motor phase of PD is based on current pathophysiological concepts that relate these symptoms to early structural changes within lower brainstem nuclei and the peripheral nervous system including the autonomic and enteric ganglia. The perspective to identify these symptoms as early as possible will enable neurologists to make a diagnosis at the pre-motor stage of PD. Thus, the development of a PD risk score will be the first means to identify individuals at risk who are most likely to develop the prototypical motor symptoms of PD later in life. More importantly, these individuals at risk will be the first to benefit from disease-modifying strategies. In this workshop report, the elements of a PD risk score are proposed, including the stepwise sequence of escalating diagnostic measures to diagnose the pre-motor stage in PD.

Cerebrospinal fluid promotes survival and astroglial differentiation of adult human neural progenitor cells but inhibits proliferation and neuronal differentiation.

BackgroundNeural stem cells (NSCs) are a promising source for cell replacement therapies for neurological diseases. Growing evidence suggests an important role of cerebrospinal fluid (CSF) not only on neuroectodermal cells during brain development but also on the survival, proliferation and fate specification of NSCs in the adult brain. Existing in vitro studies focused on embryonic cell lines and embryonic CSF. We therefore studied the effects of adult human leptomeningeal CSF on the behaviour of adult human NSCs (ahNSCs).ResultsAdult CSF increased the survival rate of adult human NSCs compared to standard serum free culture media during both stem cell maintenance and differentiation. The presence of CSF promoted differentiation of NSCs leading to a faster loss of their self-renewal capacity as it is measured by the proliferation markers Ki67 and BrdU and stronger cell extension outgrowth with longer and more cell extensions per cell. After differentiation in CSF, we found a larger number of GFAP+ astroglial cells compared to differentiation in standard culture media and a lower number of β-tubulin III+ neuronal cells.ConclusionsOur data demonstrate that adult human leptomeningeal CSF creates a beneficial environment for the survival and differentiation of adult human NSCs. Adult CSF is in vitro a strong glial differentiation stimulus and leads to a rapid loss of stem cell potential.

Thrombocytopenia during levetiracetam therapy

A 64-year-old patient with symptomatic epilepsy developed thrombocytopenia during treatment with levetiracetam (LEV). As no other medical reason could be evaluated, a medication side effect was postulated. The only new drugs were valproic acid (since 3 weeks) and levetiracetam (since 3 days). After valproic acid medication was ended, thrombocytopenia did not improve and even worsened further. Finally levetiracetam administration was ended and trombocytopenia resolved rapidly and completely within few days.

Adult cerebrospinal fluid inhibits neurogenesis but facilitates gliogenesis from fetal rat neural stem cells

Neural stem cells (NSCs) are a promising source for cell replacement therapies for neurological diseases. Administration of NSCs into the cerebrospinal fluid (CSF) offers a nontraumatic transplantation method into the brain. However, cell survival and intraparenchymal migration of the transplants are limited. Furthermore, CSF was recently reported to be an important milieu for controlling stem cell processes in the brain. We studied the effects of adult human leptomeningeal CSF on the behavior of fetal rat NSCs. CSF increased survival of NSCs compared with standard culture media during stem cell maintenance and differentiation. The presence of CSF enhanced NSC differentiation, leading to a faster loss of self‐renewal capacity and faster and stronger neurite outgrowth. Some of these effects (mainly cell survival, neurite brancing) were blocked by addition of the bone morphogenic protein (BMP) inhibitor noggin. After differentiation in CSF, significantly fewer MAP2ab+ neurons were found, but there were more GFAP+ astroglia compared with standard media. By RT‐PCR analysis, we determined a decrease of mRNA of the NSC marker gene Nestin but an increase of Gfap mRNA during differentiation up to 72 hr in CSF compared with standard media. Our data demonstrate that adult human leptomeningeal CSF enhances cell survival of fetal rat NSCs during proliferation and differentiation. Furthermore, CSF provides a stimulus for gliogenesis but inhibits neurogenesis from fetal NSCs. Our data suggest that CSF contains factors such as BMPs regulating NSC behavior, and we hypothesize that fast differentiation of NSCs in CSF leads to a rapid loss of migration capacity of intrathecally transplanted NSCs.

Valproic acid in normal therapeutic concentration has no neuroprotective or differentiation influencing effects on long term expanded murine neural stem cells.

The antiepileptic drug valproic acid (VPA) has shown neuroprotective effects in different cell types including mesencephalic neural primary cultures. Furthermore, an influence on neural differentiation and neurite outgrowth has been described. Nevertheless, results in this regard are contradictory and data on long term expanded neural stem cells are missing. This is why we investigated possible neuroprotective effects of VPA on fetal mesencephalic neural stem cells (fmNSCs) in vitro, using the neurotoxic agent 1-methyl-4-phenyl-pyridin (MPP+). We also examined potential VPA effects on cell expansion and differentiation and the underlying signaling pathways. In our study, we could exclude any relevant toxic effects of 100 μg/ml and 200 μg/ml VPA on fmNSCs during expansion and differentiation for up to 96 h. MPP+ treatment in concentrations of 30 and 60 μM MPP+ significantly decreased the survival rate of fmNSCs during expansion and differentiation. In all used concentrations, VPA did neither reverse these MPP+ effects when applied simultaneously with MPP+ nor after pre-treatment with VPA for 24 h. In contrast, MPP+ effects were emphasized by VPA pretreatment for 24h when applied during cell expansion. Concerning the self-renewing capacity of fmNSCs, measured by BrdU and Ki67 staining, we did not find any significant influence of VPA. Additionally there was no significant influence of therapeutic VPA dosages on astroglial (GFAP), oligodendroglial (GalC) and neuronal (MAP2) differentiation, measured by immunostaining after 10 days of differentiation. Summing up, we did not find any neuroprotective effects of VPA on fmNSCs in vitro, neither during expansion nor during cell differentiation. Also the self-renewing and differentiation potential of the used fmNSCs was not altered. These findings have implications for the large community of patients having to take VPA on a chronic base, especially in the light of knowledge that a regular cell replacement out of hippocampal adult stem cells is mandatory for the maintenance of normal cognition through adulthood.

Frühe Liquorentlastung verbessert Gangbild und kognitive Störungen

ZusammenfassungDer idiopathische Normaldruckhydrozephalus wird immer noch häufig als Demenzprozess anderer Genese verkannt. Den Patienten bleibt eine adäquate Behandlung und Besserung der Beschwerden versagt. Zur Diagnostik sollten eine Bildgebung mit Magnetresonanztomografie und ein lumbaler Liquorablasstest (TAP-Test) erfolgen. Therapie der Wahl ist die Implantation eines ventrikulo-peritonealen Shunts mit Ableitung des Liquors in den Bauchraum. Bei einer Anamnesedauer unter einem Jahr und noch nicht weit fortgeschrittenem Demenzprozess sind die besten Therapieergebnisse zu erzielen.