Differential expression of group I metabotropic glutamate receptors in rat spinal cord somatic and autonomic motoneurons: possible implications for the pathogenesis of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of somatic, but not autonomic, motoneurons. The reason for this selective vulnerability is unknown. The pathogenesis of ALS is thought to involve glutamatergic excitotoxic mechanisms. While overactivation of ionotropic glutamate receptors may trigger excitotoxicity, we have previously shown that stimulation of group I metabotropic glutamate receptors (mGluRs) can exert neuroprotective effects on cultured motoneurons. Using in situ hybridization, we found a differential expression of group I mGluRs (mGluR1 and 5) in rat spinal cord. Autonomic motoneurons from the sacral parasympathetic Onuf's nucleus and thoracic sympathetic neurons, which are spared in ALS, express high levels of mGluR5, while somatic motoneurons do not. In addition, mGluR1 mRNA is found only in smaller somatic motoneurons, which seem to be less vulnerable in ALS. Thus, differential mGluR expression might provide a possible clue to the selective vulnerability of different motoneuronal subpopulations in ALS.

[Noninvasive intermittent self-ventilation as a palliative measure in amyotrophic lateral sclerosis]

Almost all patients with amyotrophic lateral sclerosis (ALS) experience symptoms of nocturnal hypoventilation during the course of the illness. These symptoms can develop years before death and may severely affect quality of life. Non-invasive intermittent home mechanical ventilation (HMV) via mask is a possible palliative measure for these symptoms, which is not often used in Germany. We report on our experience with HMV in 24 patients with ALS. Our data show a good palliative effect in 17 of 24 treated patients. Severe complications did not occur. The mean ventilation time at present is 14 months. Available options and their consequences need to be discussed in detail with patients and relatives before HMV is initiated.

Discontinuation of mechanical ventilation in patients with amyotrophic lateral sclerosis

Mechanical ventilation, both invasive and non-invasive, may be an effective means of improving the quality of life and prolonging the survival of patients suffering from amyotrophic lateral sclerosis (ALS). However, the attitude towards this palliative measure varies greatly between different centres and countries. One of the arguments cited against this procedure is the fear that a patient might request the physician to discontinue life support. We believe that the question of withdrawal of mechanical ventilation can only be meaningfully addressed in the general context of palliative care. Here, we review possible modes of action in response to a patient's request for life support withdrawal and their medical, legal and ethical implications. We propose that the following goals should be pursued: (1) prevention of unwanted ventilation by early, open discussion with patient and relatives, (2) delivery of optimal palliative care by the caring team, (3) recognition of the patient's right to withdraw his/her consent to an invasive medical procedure. If these goals have been met, it may be medically, legally and ethically justified for the physician to take all necessary steps to ensure a peaceful death after discontinuation of life support.

Breaking the news in amyotrophic lateral sclerosis

Telling the diagnosis to patients with amyotrophic lateral sclerosis (ALS) is a daunting task for any neurologist. Obviously, breaking the news in ALS is not a standardizable procedure. However, proven techniques exist to reduce the trauma to the patient and ease the burden on the doctor, thus reducing the risk of burnout and the tendency to 'pull away' from the patient. Such communication skills are of fundamental importance to clinical practice and should be more prominent in medical teaching. The way the patient is told the diagnosis is now recognized to be the first and one of the most delicate steps in palliative care. Information is best offered in a stepwise fashion at the patient's pace with an emphasis on positive aspects, and in the presence of the patient's family. Reviewing available therapeutic options and current research efforts may foster hope for the future, while pointing out that almost all symptoms of ALS can be alleviated by palliative therapy may help to reduce fears. Encouraging patients to ask questions and disclose anxieties is important for their psychological wellbeing. Available options for mechanical ventilation should be reviewed early enough to allow for unhurried decision-making. We believe that the terminal phase of the disease should be discussed at the latest when dyspneic symptoms appear, in order to prevent unwarranted fears of 'choking to death'.

Mechanical ventilation in amyotrophic lateral sclerosis: a cross-cultural perspective

Mechanical ventilation is known to be an effective means of relieving symptoms of chronic hypoventilation and prolonging life in patients with amyotrophic lateral sclerosis (ALS). Various methods of mechanical ventilation are available to patients with ALS. However, attitudes towards mechanical ventilation in ALS vary widely across different cultures, and even within a given medical system. This article describes differences and similarities between a North American, a European and a Japanese approach, based on the respective medical and cultural traditions. The common goal is to provide optimal palliative care to patients with ALS.

A placebo-controlled trial of insulin-like growth factor-I in amyotrophic lateral sclerosis. European ALS/IGF-I Study Group

To test the safety and efficacy of recombinant human insulin-like growth factor-I (rhIGF-I) in ALS, 183 patients from eight European centers were randomized to receive double-blind placebo (n = 59) or rhIGF-I 0.1 mg/kg/day (n = 124) subcutaneously for 9 months. At study completion, the primary efficacy outcome measure (change in disease progression as assessed by the Appel ALS rating scale) showed no significant difference between treatment groups. RhIGF-I appeared to be safe and well-tolerated.

Dopaminergic deficit in amyotrophic lateral sclerosis assessed with [I-123] IPT single photon emission computed tomography

Dopamine transporter imaging was performed in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 11 age matched controls with [I-123] IPT (N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta(4-chlorophen yl)-tropane), a new cocaine analogue that selectively binds to the dopamine transporter located on dopaminergic nerve terminals. Image analysis showed that striatal IPT binding was moderately but significantly reduced in the ALS group compared with controls (p<0.01). The reduction of IPT binding was similar for patients with bulbar onset compared with those with limb onset. There was no correlation between values for uptake of striatal IPT and the age of the patients or the duration of the disease. These data indicate that nigrostriatal dopaminergic neurons are subclinically affected in a subset of patients with sporadic ALS.

Activation of metabotropic glutamate receptors delays apoptosis of chick embryonic motor neurons in vitro

Glutamatergic excitotoxicity has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, activation of metabotropic glutamate receptors (mGluRs) is neuroprotective in several paradigms. We therefore tested the effect of selective mGluR agonists on cultured chick embryonic motor neurons. Activation of group I mGluRs with (s)-3,5-dihydroxyphenylglycine (DHPG) and group III mGluRs with L-2-amino-4-phosphono-butanoate (L-AP4) promoted a modest but significant, dose-dependent delay of apoptosis, which could be blocked by specific mGluR antagonists. Group II or selective mGluR5 stimulations were ineffective. Correspondingly, in situ hybridization experiments showed only expression of mGluR1 (group I) and mGluR4 and 7 (group III) in human motor neurons. Dissection of the pathways involved in this survival effect may help to elucidate the pathogenesis of ALS.

Inhibitors of p38 mitogen-activated protein kinase promote neuronal survival in vitro

Mammalian mitogen-activated protein kinases include the extracellular signal-regulated protein kinase, the c-Jun amino-terminal kinase, and the p38 subgroups. Sustained activation of Jun kinase and p38 have been shown to precede apoptosis of PC12 pheochromocytoma cells induced by withdrawal of trophic factors. To investigate the possible role of p38 in neuronal apoptosis, we tested the effect of two selective p38 inhibitors, the pyridinyl imidazole compounds SB203580 and SB202190, on different populations of chick embryonic neurons in vitro. Both substances promoted the in vitro survival of sensory, sympathetic, ciliary and motor neurons in a dose-dependent fashion. When assayed in nerve growth factor-stimulated PC12 cells, SB203580 pretreatment inhibited the activation of both ribosomal S6 kinases-1 and -2 with the same IC50 (approximately 30 microM) that inhibited apoptosis in primary neurons. Thus, p38 inhibitor-sensitive pathways may be involved in apoptosis of neurotrophic factor-deprived primary neurons, and in activation of ribosomal S6 kinases.

CEP-1347/KT7515, a JNK pathway inhibitor, supports the in vitro survival of chick embryonic neurons

Developing neurons depend on target-derived trophic factors for survival in vivo and in vitro, which also decrease the activity of c-Jun N-terminal kinase (JNK). We have recently described a survival-promoting effect of inhibitors of cyclin-dependent kinases and JNK on chick peripheral embryonic neurons. Here, we report that the small trophic molecule CEP-1347/KT7515, which has been shown to inhibit the JNK signalling pathway, can promote long term-survival of cultured chick embryonic dorsal root ganglion, sympathetic, ciliary and motor neurons. Because of their pharmacological properties, small trophic molecules such as CEP-1347/KT7515 might be of interest for the treatment of neurodegenerative disorders.

Apoptosis of central and peripheral neurons can be prevented with cyclin-dependent kinase/mitogen-activated protein kinase inhibitors

Previous studies have indicated that certain members of the cyclin-dependent kinase/mitogen-activated protein kinase superfamily are involved in apoptosis of neuronal cells. Here, we have examined programmed cell death induced by withdrawal of neurotrophic support from CNS (rat retinal) and PNS (chick sympathetic, sensory, and ciliary) neurons. All four neuron types were equally rescued by the purine analogues olomoucine and roscovitine. Olomoucine inhibits multiple cyclin-dependent and mitogen-activated protein kinases with similar potency. Roscovitine is a more selective cyclin-dependent kinase inhibitor; but, so is butyrolactone I, which did not prevent retinal ganglion cell death. The specific p38MAPK inhibitor SB-203580 did not prevent apoptosis in retinal ganglion cells. Death of these cells in the absence of neurotrophic factors was accompanied by morphological changes indicative of apoptosis, including nuclear condensation and fragmentation. Treatment with olomoucine or roscovitine not only prevented these apoptotic changes in retinal ganglion cells but also blocked neurite outgrowth. The survival-promoting activity of olomoucine correlated with its in vitro IC50 for c-Jun N-terminal kinase-1 and its potency to repress c-jun induction in live PC12 cells. Roscovitine was more potent in rescuing neurons than in inhibiting Jun kinase. Thus, the antiapoptotic action of roscovitine might be due to inhibition of additional kinases.

[Considerations in patient education in amyotrophic lateral sclerosis (ALS)]

Given the relentless progression of amytrophic lateral sclerosis (ALS) and the lack of causative therapy, breaking the news to ALS patients and their families is a daunting task for any physician. Obviously, such a task cannot be standardized. However, it is now recognized to be the first and one of the most sensitive and important steps in palliative care. Information should be offered in a stepwise fashion, in the presence of the patient's family. All questions from the patient should be discussed openly, with emphasis on the positive aspects. Available therapeutic options should be reviewed, pointing out the fact that all symptoms of ALS can be alleviated by palliative therapy. At the onset of dyspneic symptoms, the terminal phase of the disease and the option of mechanical ventilation should be discussed.

Survival-promoting activity of inhibitors of cyclin-dependent kinases on primary neurons correlates with inhibition of c-Jun kinase-1

Cyclin-dependent kinases and mitogen-activated protein kinases have been implicated in the regulation of cellular survival and apoptosis. We tested the effect of two mitogen-activated/cyclin-dependent kinase inhibitors, olomoucine and butyrolactone I, on the in vitro survival of chick embryonic neurons. Sensory, sympathetic, and ciliary neurons, when prepared at their respective time point of programmed cell death, could be rescued from apoptosis by both inhibitors in a dose-dependent fashion. In contrast, dividing sympathetic precursors underwent apoptosis when treated with olomoucine, but not butyrolactone I, at the same range of concentration. With similar potency, olomoucine and butyrolactone I inhibited immunocomplex c-Jun kinase activity. Both substances inhibited neurite outgrowth in a dose-dependent manner; developmentally younger neurons were more sensitive to this effect than older ones. These results suggest that certain mitogen-activated/cyclin-dependent kinases associated with cell division in neuronal precursors (i) may become essential components of the apoptotic machinery by the time neurons reach their phase of naturally occurring cell death and (ii) may be necessary for neurite outgrowth during development.

Palliative therapy in the terminal stage of neurological disease

As recently pointed out by the American Academy of Neurology, providing adequate palliative care to dying patients is the duty of every neurologist. Because of a lack of relevant articles in the neurological literature, we have compiled current treatment recommendations for the most important symptoms arising in the endstage of neurological diseases. These recommendations include treatment of dyspnea, death rattle, restlessness, pain, thirst, depression, and others. A discussion of difficult decisions is included, e.g., the appropriate extent of fluid substitution or the ethical implications of sedation in the terminal phase. It is hoped that this compilation may provide a basis for future research in palliative therapy in neurology.

Palliative care in amyotrophic lateral sclerosis

The poor prognosis of amyotrophic lateral sclerosis (ALS) makes palliative care a challenge for the neurologist. Most disabilities associated with progressive disease can be ameliorated by symptomatic treatment. Prognosis and treatment options should be openly discussed with the patient and his/her relatives. Nutritional deficiency due to pronounced dysphagia can be efficiently relieved by a percutaneous enterogastrostomy. Respiratory insufficiency can be treated by non-invasive ventilation at home, provided the familial environment is supportive. Adequate assistance and palliative treatment in the terminal phase is of paramount importance.

Amyotrophic lateral sclerosis: lessons in trial design from recent trials

The recent history of clinical trials in ALS is marked by a great diversity in trial design. This has limited the comparability of the trial results, and has resulted in intense discussions about which parameters should or should not be evaluated when testing a new drug for ALS. This article discusses, without any claim to completeness, some aspects of trial design in relation to past, ongoing and future ALS trials, including: choice of endpoints, measurement of disease progression, assessment of quality of life, placebo-controlled trials, open-label trials, collaboration with the industry, and methods for investigating mechanisms of action of experimental drugs.

[Recommendations of Bavarian Muscle Centers of the German Neuromuscular Disease Society for home ventilation of neuromuscular diseases of adult patients]

During recent years home ventilation has been shown to be useful for a growing number of patients with neuromuscular diseases and respiratory insufficiency caused by weakness of the respiratory muscles. Despite its technical simplicity, home ventilation leads to a number of social, ethical, medical and infrastructural problems. This consensus paper discusses the special situation of patients with neuromuscular diseases in home ventilation and describes the current thinking in the following topics: (1) definition of home ventilation; (2) aims of home ventilation; (3) indications and preconditions of home ventilation; (4) techniques and forms of home ventilatory support; (5) preparation for and practical questions of home ventilation; (6) stopping home ventilation.

A novel SOD1 mutation in an Austrian family with amyotrophic lateral sclerosis

We report on an Austrian pedigree with autosomal dominant amyotrophic lateral sclerosis (ALS), diagnosed in six patients from two generations. The only surviving clinically affected family member was examined in our ALS clinic. Historical information on other affected individuals was obtained from knowledgeable family members. The mean +/- S.D. age of onset of the disease was 54 +/- 6.9 years, with a range of 43-66 years. The duration of the index patient's disease until death was 8 months. Using single strand conformational polymorphism (SSCP) analysis, we studied the index patient's exons 1, 2 and 4 of the Cu/Zn superoxide dismutase gene (SOD1) on chromosome 21. A variant banding pattern was observed for exon 1. Sequencing studies showed a previously undescribed T to A missense mutation at position 8 in exon 1 of the SOD1 gene. This mutation results in the elimination of an Eco57I restriction site. Whereas the index patient was heterozygous for this restriction site, 50 unrelated healthy controls and an unaffected brother were not. The mutation lies in a region involved in dimer contact in the three-dimensional structure of the SOD1 protein. This region comprises other known sites for ALS-causing mutations.

[X chromosomal bulbospinal neuropathy (X-BSN, Kennedy syndrome): an illness with repetitive triplet sequences. Case report, differential diagnosis and molecular genetics aspects]

X-chromosomal recessive bulbospinal neuronopathy (X-BNS, Kennedy's disease) is an important differential diagnosis of amyotrophic lateral sclerosis. We present the data of ten own patients along with a review of the literature on this uncommon disease which is caused by an expanded CAG-repeat in the androgen receptor gene. This mutation probably affects the transcription regulating activity of the androgen receptor in neurons. Signs and symptoms of X-BSN can be derived from partial insensitivity for androgens and a mixed, mainly motor neuronopathy. The clinical diagnosis is based on: 1. lower motor neuron weakness of bulbar and proximal limb muscles with onset in the third to fifth decade, 2. cramps and pronounced fasciculations, particularly of facial muscles, 3. postural tremor, 4. diminished or absent sensory action potentials inspite of only minor sensory impairment, 5. gynecomastia, and 6. infertility, diabetes mellitus and hyperlipoproteinemia in a minority of cases. Unlike amyotrophic lateral sclerosis, disease progression is slow with barely shortened life expectancy, which should be stressed in patient counselling. Causal treatment is as yet unavailable but several aspects of palliative medicine should be considered.

Ras p21 protein promotes survival and differentiation of human embryonic neural crest-derived cells

We have previously shown that the oncogene product p21 Ras is essential for the survival and neurite outgrowth-promoting activity of nerve growth factor on cultured chick embryonic sensory, but not sympathetic neurons. In order to extend our observations to the human system and to non-neuronal cells, we introduced the oncogenic form of p21 Ras into the cytoplasm of three different types of cultured human embryonic neural crest derivatives (8th-11th gestational week): dorsal root ganglion neurons, sympathetic neurons, and adrenal chromaffin cells. These cells are dependent on nerve growth factor for survival and/or fibre outgrowth in vitro. In dorsal root ganglion neurons, p21 Ras promoted survival and fibre outgrowth which was quantitatively and qualitatively comparable to the nerve growth factor effect (84% vs. 95%, control 18%). Sympathetic neurons showed a similar effect, albeit with a higher background survival (91% vs. 93%, control 58%). On chromaffin cells, which respond to nerve growth factor with pronounced fibre outgrowth in culture, the effect of p21 Ras was again comparable to that of nerve growth factor (35% vs. 30%, control 5%). The survival and fibre outgrowth-promoting effects of p21 Ras on human embryonic dorsal root ganglion neurons, sympathetic neurons and chromaffin cells suggest an involvement of p21 Ras in the intracellular signal transduction of nerve growth factor in human neural crest-derived cell populations.

p21ras supports the survival of chick embryonic motor neurones

Various trophic factors present in muscle extract can promote the survival of cultured motor neurones. However, little is known about the signal transduction pathways used in these cells. The proto-oncogene product p21ras has been shown to play an important role in proliferative and differentiative signalling pathways. We report here that cytoplasmic introduction of its oncogenic form, p21ras(G12V), fully supports the in vitro survival of chick embryonic motor neurones. The proto-oncogenic form of p21ras also showed a dose-dependent survival effect, while a C-terminally truncated counterpart of p21ras(G12V) was ineffective. These results suggest an involvement of p21ras in signal transduction pathways leading to motor neurone survival and may be of relevance for the development of therapeutic strategies for motor neurone disease.

Postoperative neuropsychological dysfunction and cerebral oxygenation during cardiac surgery

In 41 patients undergoing cardiac operations with extracorporeal circulation, oxidized cytochrome a,a3(CtO2), deoxygenated hemoglobin (Hb), and oxygenated hemoglobin (HbO2) were measured in brain tissue by near-infrared spectrophotometry (NIRS) intraoperatively. Monitoring also included electroencephalography (EEG) and jugular-bulb venous saturation (SBJO2). All operations were performed using membrane oxygenators, moderate hypothermia (26-28 degrees C) and pH alpha-stat management. During cardiopulmonary bypass (CPB) CtO2 and HbO2) were reduced, reaching minimal values when rewarming was instituted. At the end of the operation CtO2 and HbO2 had regained initial levels. During CPB, arterial PCO2, pH, and temperature were closely related to CtO2 (r = 1000, r = -0.964 and 0.929 respectively; p < 0.001, p < 0.001, and p < 0.003 respectively). Neuropsychological testing by the Mini-Mental-State Test indicated reversible postoperative neuropsychological deficits in four patients. There patients had a lower CtO2 minimum compared to those without these deficits (-4.5 mumol/L v. -0.7 mumol/L; p = 0.036). These findings support the hypothesis that neuropsychological deficits in patients after cardiac surgery can be caused by intraoperative cerebral hypoxia.

NGF-response of EGF-dependent progenitor cells obtained from human sympathetic ganglia

Signalling molecules are thought to play a significant role in determining the fate of neural crest progenitor cells. The human sympathetic chain was identified at 6.5, 7.5, 8.2, 10.2 and 11.4 postconception (PC) weeks demonstrating low affinity nerve growth factor (NGF) receptors, and was processed for tissue culture. In the presence of epidermal growth factor (EGF), floating spheres of proliferating progenitor cells were developed in vitro. In the absence of EGF progenitor cells differentiated into tyrosine hydroxylase (TH)-immunoreactive neuronal and TH-negative flat cells. NGF treatment significantly increased neurite outgrowth and survival of TH-immunoreactive cells. The multipotent cells we isolated differ from previously reported sympathoadrenal progenitors in that they give rise to TH immunoreactive neurones precociously sensitive to NGF.