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Background and Purpose— Quality monitoring projects are useful tools to improve the quality and to assess temporal trends of stroke care in larger populations. Methods— In Rhineland-Palatinate, Germany, a statewide, hospital-based, acute stroke care quality monitoring project was started in 2001. Initially, participation was mandatory for all hospitals with dedicated stroke units and from 2006 onward was mandatory for all hospitals. Quality monitoring included a structured data assessment and quality indicators for procedural measures. Results— Between 2001 and 2006, the numbers of patients registered annually (N=6389 vs N=10 610), admission P P P P Conclusions— Although these results reflect high standards of acute stroke care and improvements regarding early admission, thrombolytic therapy, and several secondary preventive measures, there is still the potential for further improvement regarding thrombolysis, use of oral anticoagulation and statins, and admission to stroke units, for example.

ZusammenfassungSchlaganfälle im jungen Erwachsenenalter sind deutlich seltener als bei älteren Erwachsenen. In dieser Arbeit berichten wir über 168 Patienten bis zum 45. Lebensjahr, die auf Grund einer zerebrovaskulären Störung innerhalb eines Zeitraums von 3 Jahren auf der Stroke Unit des Klinikums der Stadt Ludwigshafen behandelt worden waren. Diese Patienten wurden retrospektiv hinsichtlich Art, Häufigkeit, Geschlechtsverteilung, Lokalisation, Ursache und Therapie zerebraler Ischämien und Blutungen analysiert. Die Ergebnisse wurden mit aktuellen Literaturdaten zu diesem Thema verglichen.Der Schlaganfall im jungen Erwachsenenalter stellt eine diagnostische und therapeutische Herausforderung dar. Diese Patienten sollten deshalb im Akutstadium immer auf einer Stroke Unit erster Ordnung aufgenommen werden.

We report a 34 year old male patient presenting with occipital headache and bilateral shoulder and neck pain. Cranial MRT discloses a large arachnoid cyst ventral to the medulla oblongata. The cyst displaces the caudal medulla oblongata dorsally to an angle of almost 90 degrees without causing myelopathy. Physical examination reveals normal neurological findings without any sign of brainstem lesions or lesions of the medulla oblongata. Orthopedic evaluation shows mild functional abnormalities as expected in tension headache. Multiple electrophysiologic investigations such as motor-, somatosensory-, and acoustic-evoked potentials, masseter and brain stem reflexes, and electromyography of the left M. trapezius were performed and reveal normal results. MR-angiography discloses displacement of the left vertebral artery to the right without stenosis.We discuss the possibility of a causal connection between the cystic lesion and the reported symptoms. Considering the findings based on a review of the available literature we conclude that the pain syndrome is very likely unrelated to the arachnoid cyst. The latter is herewith an accidental finding in a patient with tension headache, and underlines the importance of thoroughfull clinical examination to avoid unnecessary diagnostic or therapeutic procedures.

History and clinical findings A 41-year-old man was admitted to the hospital because of a series of seizures. History revealed increasing weakness and generalized myalgia following a severe respiratory tract infection three months previously. The clinical examination was dominated by reduced alertness and cognitive impairment. Investigations Positive ANA titres pointed to an autoimmune disease; further laboratory tests revealed an antiphospholipid syndrome. The clinical diagnosis of systemic lupus erythematosus was supported by renal biopsy. Transcranial Doppler sono-graphy and magnetic resonance imaging with angiography revealed cerebral vasculitis with multiple intracerebral grey and white matter lesions. Treatment and course In addition to an immunosuppressive therapy with corticosteroids and intravenous pulses of high-dose cyclophosphamide, oral anticoagulation was given in order to prevent thromboembolic complications. Seizures were treated with valproate. A follow-up MRI revealed multiple glial cell reactions and reduced vasculitic changes. Conclusions Initial neuropsychiatric symptoms and seizures prompted the diagnosis of systemic lupus erythematosus with cerebral vasculitis in a 41-year-old patient. Approximately 20 % of all lupus patients initially present with neuropsychiatric disorders. Central nervous system involvement and renal complications determine the course and prognosis of the disease as well as therapeutic decisions. Particularly in young patients with neuropsychiatric symptoms systemic lupus erythematosus should be excluded routinely.

Background and purpose Comparable, standardised data on the quality and efficiency of stroke care in Germany are lacking. The Arbeitsgemeinschaft Deutscher Schlaganfall-Register (ADSR--German Stroke Registries Study Group) has defined a "Minimum DataSet" for the evaluation of quality indicators of stroke treatment in Germany. Methods The ADSR is a voluntary network of current regional stroke registries aiming at a standardisation in the use of stroke terminology and methods of data collection for German stroke databases. Currently six regional stroke registries are cooperating in the ADSR, combining data from about 18,000 stroke patients in 110 hospitals annually. Results In the design of the ADSR DataSet a modular approach was chosen. The ADSR "Minimum DataSet" was adapted for a wide use in different health care facilities. In addition to the "Minimum DataSet" an "Advanced DataSet" will be developed to document additional items of stroke care in specialised stroke centres. The ADSR DataSet collection will be completed by special "Extended DataSets", designed for answering centre-specific and research questions. Conclusion The ADSR "Minimum DataSet" allows a standardised assessment of stroke care in Germany. It is the first questionnaire that provides valid and reliable comparisons between different clinical settings as well as regional stroke databases. The ADSR "Minimum DataSet" defines core items for a future National German Health Report on stroke care.

The excitatory transmitters glutamate and aspartate become toxic whenever their extracellular levels are increased because of neuronal, glial and endothelial impairment. Taurine, a volume-regulating amino acid, is released upon excitotoxin-induced cell swelling. Our aim was to investigate if glutamate and aspartate in cerebrospinal fluid (CSF) reveal neuropathology in neurological patients, and if taurine unmasks glutamate-mediated toxicity. Glutamate and aspartate are doubled in viral meningitis, acute multiple sclerosis (MS) and myelopathy compared with control subjects and patients with peripheral facial nerve palsy. These levels do not coincide with a disturbed blood-brain barrier, as estimated by the albumin ratio, are independent of their precursors (glutamine, asparagine) and are not associated with cell lysis. Taurine is significantly increased in meningitis, acute MS, and myelopathy, suggesting glutamate-mediated toxicity. Analysis of transmitters in lumbar CSF can be used to identify patients with cerebral and spinal pathology who might benefit from specific receptor-modulating agents.

Am 13. September 2013 ist Prof. Hanns Christian Hopf im Alter von 78 Jahren nach langer Krankheit verstorben. Er war 1973/74 und 1998/99 Prasident der Deutschen EEG-Gesellschaft, der heutigen DGKN, und war uber viele Jahre Mitglied des Vorstandes. Fur seine Leistungen in der klinischen Neurophysiologie wurde er von der Deutschen EEG-Gesellschaft 1976 mit ihrer hochsten Auszeichnung, dem Hans-Berger-Preis, geehrt.

VEP changes in MS patients are due to the demyelinating process which causes conduction alterations as well as inhibitory mechanisms. The pattern-shift VEP can show a delay of the main positivity, a diminished amplitude or/and an altered shape and duration. Concerning to series from the literature and own observations on more than 500 MS patients 4 different types of VEP alterations can be observed: 1. NPN complex with P2 delay; 2. broadening with loss of N2 and P2 delay; 3. bifid P2, P100-P135 complex; 4. deformation and dissociation with loss of P2, N105 dominance and amplitude reduction.

Recent clinical studies in multiple sclerosis (MS) provide new data on the treatment of clinically isolated syndromes, on secondary progression, on direct comparison of immunomodulatory treatments and on dosing issues. All these studies have important implications for the optimized care of MS patients. The multiple sclerosis therapy consensus group (MSTCG) critically evaluated the available data and provides recommendations for the application of immunoprophylactic therapies. Initiation of treatment after the first relapse may be indicated if there is clear evidence on MRI for subclinical dissemination of disease. Recent trials show that the efficacy of interferon beta treatment is more likely if patients in the secondary progressive phase of the disease still have superimposed bouts or other indicators of inflammatory disease activity than without having them. There are now data available, which suggest a possible dose-effect relation for recombinant beta-interferons. These studies have to be interpreted with caution, as some potentially important issues in the design of these studies (e. g. maintenance of blinding in the clinical part of the study) were not adequately addressed. A meta-analysis of selected interferon trials has been published challenging the value of recombinant IFN beta in MS. The pitfalls of that report are discussed in the present review as are other issues relevant to treatment including the new definition of MS, the problem of treatment failure and the impact of cost-effectiveness analyses. The MSTCG panel recommends that the new diagnostic criteria proposed by McDonald et al. should be applied if immunoprophylactic treatment is being considered. The use of standardized clinical documentation is now generally proposed to facilitate the systematic evaluation of individual patients over time and to allow retrospective evaluations in different patient cohorts. This in turn may help in formulating recommendations for the application of innovative products to patients and to health care providers. Moreover, in long-term treated patients, secondary treatment failure should be identified by pre-planned follow-up examinations, and other treatment options should then be considered.

We report a 34 year old male patient presenting with occipital headache and bilateral shoulder and neck pain. Cranial MRT discloses a large arachnoid cyst ventral to the medulla oblongata. The cyst displaces the caudal medulla oblongata dorsally to an angle of almost 90 degrees without causing myelopathy. Physical examination reveals normal neurological findings without any sign of brainstem lesions or lesions of the medulla oblongata. Orthopedic evaluation shows mild functional abnormalities as expected in tension headache. Multiple electrophysiologic investigations such as motor-, somatosensory-, and acoustic-evoked potentials, masseter and brain stem reflexes, and electromyography of the left M. trapezius were performed and reveal normal results. MR-angiography discloses displacement of the left vertebral artery to the right without stenosis.We discuss the possibility of a causal connection between the cystic lesion and the reported symptoms. Considering the findings based on a review of the available literature we conclude that the pain syndrome is very likely unrelated to the arachnoid cyst. The latter is herewith an accidental finding in a patient with tension headache, and underlines the importance of thoroughfull clinical examination to avoid unnecessary diagnostic or therapeutic procedures.

A 41-year-old man was admitted to the hospital because of a series of seizures. History revealed increasing weakness and generalized myalgia following a severe respiratory tract infection three months previously. The clinical examination was dominated by reduced alertness and cognitive impairment.Positive ANA titres pointed to an autoimmune disease; further laboratory tests revealed an antiphospholipid syndrome. The clinical diagnosis of systemic lupus erythematosus was supported by renal biopsy. Transcranial Doppler sono-graphy and magnetic resonance imaging with angiography revealed cerebral vasculitis with multiple intracerebral grey and white matter lesions.In addition to an immunosuppressive therapy with corticosteroids and intravenous pulses of high-dose cyclophosphamide, oral anticoagulation was given in order to prevent thromboembolic complications. Seizures were treated with valproate. A follow-up MRI revealed multiple glial cell reactions and reduced vasculitic changes.Initial neuropsychiatric symptoms and seizures prompted the diagnosis of systemic lupus erythematosus with cerebral vasculitis in a 41-year-old patient. Approximately 20 % of all lupus patients initially present with neuropsychiatric disorders. Central nervous system involvement and renal complications determine the course and prognosis of the disease as well as therapeutic decisions. Particularly in young patients with neuropsychiatric symptoms systemic lupus erythematosus should be excluded routinely.

Comparable, standardised data on the quality and efficiency of stroke care in Germany are lacking. The Arbeitsgemeinschaft Deutscher Schlaganfall-Register (ADSR--German Stroke Registries Study Group) has defined a "Minimum DataSet" for the evaluation of quality indicators of stroke treatment in Germany.The ADSR is a voluntary network of current regional stroke registries aiming at a standardisation in the use of stroke terminology and methods of data collection for German stroke databases. Currently six regional stroke registries are cooperating in the ADSR, combining data from about 18,000 stroke patients in 110 hospitals annually.In the design of the ADSR DataSet a modular approach was chosen. The ADSR "Minimum DataSet" was adapted for a wide use in different health care facilities. In addition to the "Minimum DataSet" an "Advanced DataSet" will be developed to document additional items of stroke care in specialised stroke centres. The ADSR DataSet collection will be completed by special "Extended DataSets", designed for answering centre-specific and research questions.The ADSR "Minimum DataSet" allows a standardised assessment of stroke care in Germany. It is the first questionnaire that provides valid and reliable comparisons between different clinical settings as well as regional stroke databases. The ADSR "Minimum DataSet" defines core items for a future National German Health Report on stroke care.

Das visuelle System mit Rezeptorapparat und retino-kortikalen Projektionsbahnen stellt ein sehr komplexes Beispiel der zentralnervosen Informantionsverarbeitung dar. Dabei sind die anatomischen Strukturen und die sinnesphysiologischen Mechanismen weitgehend aufgeklart und analysiert. Krankheitsprozesse auf den verschiedensten Ebenen der neuronalen Verarbeitung von Sehreizen fuhren zu Sehstorungen, deren Abklarung zunachst in topographischen Dimensionen erfolgt, ehe atiologische Faktoren eruiert werden.

For differential, therapeutic, and prognostic reasons the recognition of early lesions in glaucoma chronicum simplex is very important. Besides sophisticated ophthalmological investigations optic nerve and retinal functions can be tested by flash and pattern-reversal evoked visual potentials and electroretinograms. 38 glaucomatous eyes were investigated by VEP and ERG applying single and flicker flashes as well as transient pattern-reversal stimuli of different check sizes. The results related to the degree of visual field disturbances show the damage of retinal and neuronal elements in a descending order affecting first of all the macular cones, then the rod system, and later on the elements of the second retinal neuron. The ganglion cells seems to be affected after all.

VEP changes in MS patients are due to the demyelinating process which causes conduction alterations as well as inhibitory mechanisms. The pattern-shift VEP can show a delay of the main positivity, a diminished amplitude or/and an altered shape and duration. Concerning to series from the literature and own observations on more than 500 MS patients 4 different types of VEP alterations can be observed: 1. NPN complex with P2 delay; 2. broadening with loss of N2 and P2 delay; 3. bifid P2, P100-P135 complex; 4. deformation and dissociation with loss of P2, N105 dominance and amplitude reduction.

Der N. opticus und das Chiasma sind bei der MS in hohem Mase beteiligt, worauf bereits vor 100 Jahren Parinaud (1884) und Uhthoff (1890) hinwiesen. Fuhrendes Symptom ist die meist plotzlich auftretende Sehstorung, die naturlich auch andere Ursachen wie etwa eine akute Chorioretinitis, kompressive Lasionen von Opticus und Chiasma oder auch ischamische Ausfalle wie bei der Arteriitis cranialis oder der vorderen ischamischen Opticusneuropathie haben kann.

ContextData are limited regarding the risks and benefits of thrombolytic therapy for acute ischemic stroke outside of clinical trials.ObjectiveTo investigate predictors of in-hospital mortality in patients with ischemic stroke treated with intravenous tissue plasminogen activator (tPA) within a pooled analysis of large German stroke registers.Design and SettingProspective, observational cohort study conducted at 225 community and academic hospitals throughout Germany cooperating within the German Stroke Registers Study Group.PatientsA total of 1658 patients with acute ischemic stroke who were admitted to study hospitals between 2000 and 2002 and were treated with tPA.Main Outcome MeasureIn-hospital mortality.ResultsOne hundred sixty-six patients (10%) who received tPA died during hospitalization, with 67.5% of these deaths occurring within 7 days. Factors predicting in-hospital death after tPA use were older age (for each 10-year increment in age, adjusted odds ratio [OR], 1.6; 95% confidence interval [CI], 1.3-1.9) and altered level of consciousness (adjusted OR, 3.4; 95% CI, 2.4-4.7). The overall rate of symptomatic intracranial hemorrhage was 7.1% and increased with age. One or more serious complications was observed in 27.2% of all patients and in 83.9% of patients who died after tPA treatment. An inverse relation between the number of patients treated with tPA in the respective hospital and the risk of in-hospital death was observed (adjusted OR, 0.97; 95% CI, 0.96-0.99 for each additional patient treated with tPA per year).ConclusionIn patients with ischemic stroke who are treated with tPA, disturbances of consciousness and increasing age are associated with increased in-hospital mortality.

A 67-year-old male patient with Waldenstrom's macroglobulinaemia associated with a sensorimotor polyneuropathy is reported. The progress of the disease was well controlled by Chlorambucil therapy. The sural nerve biopsy showed, in addition to loss of myelinated fibres an amorphous hyalin-like substance in the perineurium, endoneurium and the blood vessel walls which was strongly positive with the periodic acid-Schiff stain. Immunofluorescent study revealed that this substance contained IgM. Electron-microscopically this substance was shown to be osmiophilic and granulated. There was no deposit of amyloid in the sural nerve by Congo red and thioflavin T methods. However, cytoplasmic fibrils of about 80 A in thickness were present in the endothelia and pericytes. The pathogenesis of macroglobulinaemic polyneuropathy is discussed with special emphasis on a possible antibody activity of abnormal monoclonal IgM against the peripheral nervous system.

1. Contraction times and spike propagation velocities were determined in the brachial biceps muscle in man. Long contraction times were correlated to slow conduction velocities and short contraction times to fast conduction velocities.

1. Bei 138 Handen mit Karpaltunnelsyndrom von 118 Patienten wurde neben der distalen motorischen Latenz das sensible Aktionspotential des N. medianus am Handgelenk unter Zuhilfenahme der Average-Technik registriert. Bei 97,8% der Hande war die Latenz der raschesten sensiblen Fasern verlangert. 5mal lies sich ein sensibles NAP trotz Summation nicht nachweisen. Mit einer starkeren Verlangerung der distalen Latenz ging durchweg eine Aufsplitterung des Antwortpotentials in mehrere Gipfel einher, denen Fasergruppen verschiedener Leitungsgeschwindigkeit bis zu 7,8 m/sec herunter entsprechen. Wahrscheinlich sind die extrem langsam leitenden Fasern weitgehend entmarkt. Die Splitterung des sensiblen Antwortpotentials und dessen Amplitudenminderung ist neben der Verlangerung der Latenz ein besonders sicheres Schadigungszeichen. 2. In der uberwiegenden Mehrzahl der Falle ist neben der sensiblen auch die distale motorische Latenz verlangert (91,3% der Hande). Nur bei 10 Handen (7,2%) war allein die sensible Latenz pathologisch. Nicht so sehr wegen dieser Falle, sondern in Anbetracht der engeren physiologischen Schwankungsbreite stellt die sensible Latenz ein scharferes diagnostisches Kriterium dar als die motorische. 3. An 39 Handen, bei denen wegen volliger Atrophie des Thenar eine Messung der motorischen Uberleitung nicht moglich war, lies sich ein sensibles Antwortpotential noch registrieren. Gleichwohl ist eine besondere Anfalligkeit der motorischen Fasern gegenuber der Kompression nicht anzunehmen: Wegen der weit groseren Zahl sensibler Fasern im N. medianus mussen aus statistischen Grunden bei einer prozentual gleichen Destruktion beider Faserarten mehr sensible Fasern uberleben (Buchthal). 4. Zwischen Sensibilitatsstorung und Verlangerung der sensiblen Latenz besteht nur ein statistischer Zusammenhang: Je deutlicher die Hypaesthesie, desto groser die durchschnittliche Verlangerung der sensiblen Latenz. Uberraschenderweise ist auch bei Fallen mit angeblich normaler Sensibilitat (36 Hande) das sensible NAP meistens pathologisch. Hier ist die Objektivierung einer Schadigung der sensiblen Fasern mittels des NAP von besonderem Wert. 5. Auf die Bedeutung des sensiblen NAP fur die Differentialdiagnose gegenuber vasomotorischen Acroparaesthesien, dem C 6/C 7-Wurzelreizsyndrom und arthrogenen Schmerzen im Bereich von Hand und Fingern wird hingewiesen.

The pattern-reversal VEP with different check size and the computerized perimetry in the 10 degrees and 30 degrees radius field were recorded in 22 patients suffering from unilateral optic neuritis diagnosed by historical as well as by clinical findings. During the acute attack 12/22 optic neuritis eyes and 3/22 partner eyes had a diminished visual acuity below 0.7. After the attack the visual acuity remained reduced in 9/22 of the affected and 2/22 of the nonaffected partner eyes. The VEP was prolonged in 19/22 optic neuritis eyes and in 12/22 partner eyes applying 50' checks and in 15/22 resp. applying 15' checks. The computed visual fields showed depressions in 21/22 optic neuritis-eyes and in 15/22 partner eyes within in the 30 degrees radius field. VEP and computerized perimetry, there for, can detect subclinical affections of partner eyes in unilateral optic neuritis in a very high percentage.

An die relative Refraktarperiode schliest sich eine supernormale Phase an und daran wiederum eine spate subnormale Phase. Die Wirkung dieser beiden letzten Phasen auf die Leitgeschwindigkeit wurde an sensiblen Nervenfasern untersucht. 80% der Untersuchten zeigten wahrend der supernormalen Phase (4–10 msec nach der ersten Aktivierung) eine Beschleunigung der Leitgeschwindigkeit auf 106% des Normwertes. Die Beschleunigung ist weniger ausgepragt, wenn die Gewebstemperatur erniedrigt ist. Bei 65% der Versuchspersonen wurde eine Verzogerung der Impulsfortleitung wahrend der subnormalen Phase (10–100 msec nach voraufgegangener Aktivierung) beobachtet. Die Veranderungen der Leitgeschwindigkeit laufen zu den bekannten Veranderungen der Membranerregbarkeit parallel.

Absolute and relative refractory periods and the sensory conduction velocity of the median and ulnar nerves were determined in six patients suffering from hypokalemia of various origins. Nerve impulse conduction and the absolute refractory period remained normal, but the relative refractory period was shortened to 1.7 to 2.6 ms at serum K+ levels from 1.6 to 2.9 mval/l. As compared with normal values this decrease was statistically significant.

In a 5-year follow-up of a case of adult metachromatic leukodystrophy, already diagnosed in the preclinical stage, the development of the symptoms of this disease could be studied in detail: initially, lack of drive, emotional lability and depressive mood. At the same time, pain in the arms and beginning gait disturbance. Later, impairment of memory and concentration, disorientation, inadequate behavior and progression of gait disturbance. Finally spastic atactic gait with small steps and dyspractic components, coordination disturbances with writing dysfunction, fast dysarthric speech, hyperkinetic activity, compulsory emotional outbursts and progressive dementia. Only minor neurological signs such as reflex abnormalities. In the EEG, slight slowing of frequencies compared to earlier tracings. Increasing diminution of nerve conduction velocity in the lower limbs. Only minor increase of CSF protein (51 mg%). In spite of normal vision, evoked visual potentials abnormal, response of optical and electrical blink reflexes delayed. Imperfect filling of gallbladder. No significant quantitative changes of the biochemical parameters compared with the findings made 5 years earlier (excretion of urinary sulfatides, diminished activity of arylfulfatase A in urine and leukocytes).

VEPs were measured after pattern reversal in 135 MS patients and 30 control subjects. Neurological findings were documented in a standard manner. An extensive ophthalmological examination of all subjects was part of the study. The latency of P2 was abnormally delayed in 82% of the "definite", in 60% of the "probable" and in 65% of the "possible" MS groups respectively. The VEP was more often delayed in relation to ophthalmological disturbances. Changes in the MS classification had to be made in more than 10% of the patients, due to delay of VEP latency. These were patients with a "spinal" form of MS, which is known to create diagnostic problems. Optically and electrically evoked blink reflexes were recorded in 107 MS patients. All patients with mesencephalic lesions had delayed responses of the optically evoked reflex. 74% of the patients with caudal brainstem lesions had delayed latencies of the components of the electrically evoked blink reflex. The blink reflex was delayed in 18 additional patients without brainstem signs. The possibility of delineating clinically silent brainstem lesions by investigating blink reflexes is discussed.

In 18 patients suffering from chronic renal failure (being haemodialysed three times weekly for 22.2 +/- 27.9 months), sensory conduction velocity and relative refractory period of the sural nerve were estimated immediately before and after dialysis. Before haemodialysis all but one patient had conduction velocities within the normal range (x +/- 2 SD), but 50% had prolonged refractory periods. After dialysis the refractory period decreased to become normal in all but one patient. Visual evoked potential latencies showed no systematic alterations. A membrane abnormality due to uraemic poisoning is assumed to cause the reversible prolongation of the refractory period.

The motor irradiation to muscles of the contralateral side after movements of the normal and the disabled arm was investigated in controls and in hemiparetic patients. It was found that the latency of

Es wird uber eine Familie berichtet, in der Vater und Sohn, und moglicherweise auch der Grosvater, im Alter von 27 bzw. 10 Jahren mit Gehstorungen erkrankten. Zunehmend entwickelte sich eine cerebellare Symptomatik. Parallel gehend, schlieslich aber dominierend, stellten sich ausgepragte spinale Muskelatrophien ein mit besonderer Betonung im Bereich der Hirnnervenkerne. Auserdem fanden sich leichte Zeichen einer Pyramidenbahnschadigung. Der Vererbungsmodus ist offenbar autosomal dominant. Einige weitere Falle aus der Literatur werden referiert. Es scheint sich um ein besonderes klinisches Syndrom zu handeln.

Counter and crystal motions are coupled to explore the reflection space of a crystal along parallel lines in the reciprocal lattice by utilizing any one of three mechanical linkage mechanisms (counter drive linkage, crystal drive mechanism, and point drive mechanism) which are described. The kinematic relations among the moving elements of each of the mechanisms are derived. These relations are used to evaluate the feasibility of these mechanisms as bases for automatic diffractometers. (auth)

Zusammenfassung An 31 gesunden Versuchspersonen wurde die Impulsfortleitung frequenter Serienreize im gemischten N. ulnaris untersucht. Die Fortleitung des 2. und der weiteren Impulse einer Reizserie hangt bei hochfrequenter Reizung von der Dauer der absoluten Refraktarperiode ab. Die absolute Refraktarperiode betragt fur Fasern mit einer Leitgeschwindigkeit uber 50 m/sec 0.4 bis 0.7 msec. Bei niedrigen Reizfrequenzen bestimmt die relative Refraktarperiode die Art der Impulsubermittlung. Die Latenzverzogerung der nachfolgenden Potentiale setzt signifikant fruher, d.h. bei niedrigeren Reizfrequenzen, ein als die Amplitudenabnahme. Die Grenzfrequenz, bei der die Impulse noch unverandert fortgeleitet werden, liegt bei 350 cps.

The effects of the various geometrical factors of the X-ray optical system on intensity, peak-to-background ratio and resolution are derived and illustrated with experimental data. The arrangement of the specimen with respect to the X-ray tube and the optical system is shown to be a major factor in determining the intensity; and procedures for optimizing this source geometry in terms of the variation of intensity of primary radiation reaching the specimen, and self-absorption effects as a function of angle-of-view are outlined. The Soller collimator geometry is introduced with a discussion of the simple single crystal spectrometer and the effects of the angular and linear apertures in the equatorial and axial planes are explained. Various figures of merit are used to evaluate several geometries including the use of two Soller collimators. The minimum foil thickness, total reflection, the testing of Soller collimators, the elimination of spurious sources of background with antiscatter diaphragms and various other geometrical factors are discussed.

Bei 30 Patienten mit Neuropathien unterschiedlichen Schweregrades („subklinisch“, leicht, mittelschwer und schwer) wurden am N. ulnaris neben den ublichen neurophysiologischen Parametern [distale Latenz, maximale motorische und gemischte Nervenleitgeschwindigkeit (Nlg.)] die Refraktarperioden (Rp.) (absolute Rp. und relative Rp.-„Amplitude“ und -„Latenz“) und die unteren Grenzfrequenzen (u. F.) (u. F.-„Amplitude“ und -„Latenz“) bestimmt. Beim Vergleich mit einem Normalkollektiv (n=31, s. Lowitzsch u. Hopf, (1972a)) war die Nlg. nur in 37% der Falle pathologisch verlangsamt, wahrend die relative Rp.-„Latenz“ in ca. 80% und die u. F.-„Latenz“ in ca. 60% pathologisch verandert waren. In zwei Stichproben (13 Normalfalle und 13 Polyneuropathien) mit einer „normalen“ gemischten Nlg. von 51,0–63,5 m/sec unterschieden sich die Mittelwerte fur die distale Latenz sowie die motorische und gemischte Nlg. statistisch nur auf dem 1%-Niveau, fur die relative Rp.-„Latenz“ und die u. F.-„Latenz“ hingegen auf dem 0,5‰-Niveau. Die Bestimmung der Refraktarperioden, insbesondere der rel. Rp. L., sowie der unteren Grenzfrequenz (u. F. L.), stellt eine im Vergleich mit den ublichen neurophysiologischen Verfahren (Nlg.-Bestimmung) wesentlich empfindlichere Untersuchungsmethode zur Erfassung auch geringer („subklinischer“) Funktionsstorungen des peripheren Nervensystems dar. Die unterschiedliche Beeinflussung der Refraktarperioden und der Grenzfrequenzen durch die Art des zugrundeliegenden pathologischen Prozesses (axonale Degeneration — segmentale Demyelinisierung — Mischtyp) wird an Hand der in 9 Fallen nervenbioptisch (N. suralis) gewonnenen Befunde diskutiert.