[Foundations for the scientific use of extensive health care data in Germany-results of the Data Sharing working group of the Medical Informatics Initiative]

Healthcare data are an important resource in applied medical research. They are available multicentrically. However, it remains a challenge to enable standardized data exchange processes between federal states and their individual laws and regulations. The Medical Informatics Initiative (MII) was founded in 2016 to implement processes that enable cross-clinic access to healthcare data in Germany. Several working groups (WGs) have been set up to coordinate standardized data structures (WG Interoperability), patient information and declarations of consent (WG Consent), and regulations on data exchange (WG Data Sharing). Here we present the most important results of the Data Sharing working group, which include agreed terms of use, legal regulations, and data access processes. They are already being implemented by the established Data Integration Centers (DIZ) and Use and Access Committees (UACs). We describe the services that are necessary to provide researchers with standardized data access. They are implemented with the Research Data Portal for Health, among others. Since the pilot phase, the processes of 385 active researchers have been used on this basis, which, as of April 2024, has resulted in 19 registered projects and 31 submitted research applications.

[Nationally standardized broad consent in practice: initial experiences, current developments, and critical assessment]

BACKGROUND

The digitalization in the healthcare sector promises a secondary use of patient data in the sense of a learning healthcare system. For this, the Medical Informatics Initiative's (MII) Consent Working Group has created an ethical and legal basis with standardized consent documents. This paper describes the systematically monitored introduction of these documents at the MII sites.

METHODS

The monitoring of the introduction included regular online surveys, an in-depth analysis of the introduction processes at selected sites, and an assessment of the documents in use. In addition, inquiries and feedback from a large number of stakeholders were evaluated.

RESULTS

The online surveys showed that 27 of the 32 sites have gradually introduced the consent documents productively, with a current total of 173,289 consents. The analysis of the implementation procedures revealed heterogeneous organizational conditions at the sites. The requirements of various stakeholders were met by developing and providing supplementary versions of the consent documents and additional information materials.

DISCUSSION

The introduction of the MII consent documents at the university hospitals creates a uniform legal basis for the secondary use of patient data. However, the comprehensive implementation within the sites remains challenging. Therefore, minimum requirements for patient information and supplementary recommendations for best practice must be developed. The further development of the national legal framework for research will not render the participation and transparency mechanisms developed here obsolete.

[The way to routine data from 16 emergency departments for cross-sectoral health services research : Experiences, challenges and solution approaches from the extraction of pseudonymous data for the INDEED project]

BACKGROUND

In Germany there is currently no health reporting on cross-sectoral care patterns in the context of an emergency department care treatment. The INDEED project (Utilization and trans-sectoral patterns of care for patients admitted to emergency departments in Germany) collects routine data from 16 emergency departments, which are later merged with outpatient billing data from 2014 to 2017 on an individual level.

AIM

The methodological challenges in planning of the internal merging of routine clinical and administrative data from emergency departments in Germany up to the final data extraction are presented together with possible solution approaches.

METHODS

Data were selected in an iterative process according to the research questions, medical relevance, and assumed data availability. After a preparatory phase to clarify formalities (including data protection, ethics), review test data and correct if necessary, the encrypted and pseudonymous data extraction was performed.

RESULTS

Data from the 16 cooperating emergency departments came mostly from the emergency department and hospital information systems. There was considerable heterogeneity in the data. Not all variables were available in every emergency department because, for example, they were not standardized and digitally available or the extraction effort was judged to be too high.

CONCLUSION

Relevant data from emergency departments are stored in different structures and in several IT systems. Thus, the creation of a harmonized data set requires considerable resources on the part of the hospital as well as the data processing unit. This needs to be generously calculated for future projects.

Data protection-compliant broad consent for secondary use of health care data and human biosamples for (bio)medical research: Towards a new German national standard

BACKGROUND

The secondary use of deidentified but not anonymized patient data is a promising approach for enabling precision medicine and learning health care systems. In most national jurisdictions (e.g., in Europe), this type of secondary use requires patient consent. While various ethical, legal, and technical analyses have stressed the opportunities and challenges for different types of consent over the past decade, no country has yet established a national consent standard accepted by the relevant authorities.

METHODS

A working group of the national Medical Informatics Initiative in Germany conducted a requirements analysis and developed a GDPR-compliant broad consent standard. The development included consensus procedures within the Medical Informatics Initiative, a documented consultation process with all relevant stakeholder groups and authorities, and the ultimate submission for approval via the national data protection authorities.

RESULTS

This paper presents the broad consent text together with a guidance document on mandatory safeguards for broad consent implementation. The mandatory safeguards comprise i) independent review of individual research projects, ii) organizational measures to protect patients from involuntary disclosure of protected information, and iii) comprehensive information for patients and public transparency. This paper further describes the key issues discussed with the relevant authorities, especially the position on additional or alternative consent approaches such as dynamic consent.

DISCUSSION

Both the resulting broad consent text and the national consensus process are relevant for similar activities internationally. A key challenge of aligning consent documents with the various stakeholders was explaining and justifying the decision to use broad consent and the decision against using alternative models such as dynamic consent. Public transparency for all secondary use projects and their results emerged as a key factor in this justification. While currently largely limited to academic medicine in Germany, the first steps for extending this broad consent approach to wider areas of application, including smaller institutions and medical practices, are currently under consideration.

ToolPool Gesundheitsforschung - A Repository for Software and Services Focused on Supporting Clinical and Epidemiological Research

The academic research environment is characterized by self-developed, innovative, customized solutions, which are often free to use for third parties with open-source code and open licenses. On the other hand, they are maintained only to a very limited extent after the end of project funding. The ToolPool Gesundheitsforschung addresses the problem of finding ready to use solutions by building a registry of proven and supported tools, services, concepts and consulting offers. The goal is to provide an up-to-date selection of "relevant" solutions for a given domain that are immediately usable and that are actually used by third parties, rather than aiming at a complete list of all solutions which belong to that domain. Proof of relevance and usage must be provided, for example, by concrete application scenarios, experience reports by uninvolved third parties, references in publications or workshops held. Quality assurance is carried out for new entries by an agreed list of admission criteria, for existing entries at least once a year by a special task force. Currently, 79 solutions are represented, this number is to be significantly expanded by involving of new editors from current national funding initiatives in Germany.

[Secondary Use of Electronic Medical Record Data from Primary Health Care is Feasible: Report from RADAR Project]

Objectives It is difficult to obtain longitudinal 'real world' data from ambulatory medical care in Germany in a systematic way. Our vision is a large German research data repository featuring representative, anonymized patient and outpatient health care data, longitudinal, continuously updated and across different providers, offering a perspective of linking secondary care data or additional data obtained from research cohorts, for example patient reported data or biodata, and will be accessible for other researchers. Here we report specific methods and results from the RADAR project.Methods Survey of legislation, design of technical processes and organisational solutions, with a feasibility study to evaluate technical and content functionality, acceptability and performance fitness for health services research questions.Results In 2016, a multi-disciplinary scientific team initiated the development of a privacy protection and IT security concept for data exported from the electronic medical records (EMR) of physicians' practices in line with the European General Data Protection Regulation. Technical and organisational requirements for lawful research infrastructure were developed and executed for use in a specific case, namely ̒oral anticoagulation'. In 7 Lower Saxonian general practices, 100 patients were selected by their physician and their data - reduced to 40 essential data fields - extracted from EMR via a mandatory software interface after informed consent. Still in the practice, the data were split into identifying or medical data. These were encrypted and transferred either to a trusted third party (TTP) or to a data repository, respectively. 75 patients who met our inclusion criteria (minimum of one year of oral anticoagulation treatment) received a quality-of-life questionnaire via the TTP. Of the 66 returns, 63 responses were then linked to the EMR data in the repository.Conclusion Results from RADAR project proved the technical and organisational feasibility of lawful, pseudonymised data acquisition and the linkage of questionnaires to EMR data. The protecting concepts privacy by design and data minimization (Art. 25 GDPR with Recital 78) were implemented. Without informed consent, secondary use of routine data from ambulatory care which are sufficiently anonymized but still meaningful is all but impossible under current German law.

Good Practice Data Linkage (GPD): A Translation of the German Version

The data linkage of different data sources for research purposes is being increasingly used in recent years. However, generally accepted methodological guidance is missing. The aim of this article is to provide methodological guidelines and recommendations for research projects that have been consented to across different German research societies. Another aim is to endow readers with a checklist for the critical appraisal of research proposals and articles. This Good Practice Data Linkage (GPD) was already published in German in 2019, but the aspects mentioned can easily be transferred to an international context, especially for other European Union (EU) member states. Therefore, it is now also published in English. Since 2016, an expert panel of members of different German scientific societies have worked together and developed seven guidelines with a total of 27 practical recommendations. These recommendations include (1) the research objectives, research questions, data sources, and resources; (2) the data infrastructure and data flow; (3) data protection; (4) ethics; (5) the key variables and linkage methods; (6) data validation/quality assurance; and (7) the long-term use of data for questions still to be determined. The authors provide a rationale for each recommendation. Future revisions will include new developments in science and updates of data privacy regulations.

Designing and piloting a generic research architecture and workflows to unlock German primary care data for secondary use

Background

Medical data from family doctors are of great importance to health care researchers but seem to be locked in German practices and, thus, are underused in research. The RADAR project (Routine Anonymized Data for Advanced Health Services Research) aims at designing, implementing and piloting a generic research architecture, technical software solutions as well as procedures and workflows to unlock data from family doctor’s practices. A long-term medical data repository for research taking legal requirements into account is established. Thereby, RADAR helps closing the gap between the European countries and to contribute data from primary care in Germany.

Methods

The RADAR project comprises three phases: (1) analysis phase, (2) design phase, and (3) pilot. First, interdisciplinary workshops were held to list prerequisites and requirements. Second, an architecture diagram with building blocks and functions, and an ordered list of process steps (workflow) for data capture and storage were designed. Third, technical components and workflows were piloted. The pilot was extended by a data integration workflow using patient-reported outcomes (paper-based questionnaires).

Results

The analysis phase resulted in listing 17 essential prerequisites and guiding requirements for data management compliant with the General Data Protection Regulation (GDPR). Based on this list existing approaches to fulfil the RADAR tasks were evaluated—for example, re-using BDT interface for data exchange and Trusted Third Party-approach for consent management and record linkage. Consented data sets of 100 patients were successfully exported, separated into person-identifying and medical data, pseudonymised and saved. Record linkage and data integration workflows for patient-reported outcomes in the RADAR research database were successfully piloted for 63 responders.

Conclusion

The RADAR project successfully developed a generic architecture together with a technical framework of tools, interfaces, and workflows for a complete infrastructure for practicable and secure processing of patient data from family doctors. All technical components and workflows can be reused for further research projects. Additionally, a Trusted Third Party-approach can be used as core element to implement data privacy protection in such heterogeneous family doctor’s settings. Optimisations identified comprise a fully-electronic consent recording using tablet computers, which is part of the project’s extension phase.

Process Coverage and Use Case Support of Health Registry Software in Germany

Registries usually operate an IT-infrastructure supporting at least data management as one of the business processes. Several activities in Germany between 2007 and 2018 surveyed the market of respective software products. Combining a survey with representatives of software products with a workshop protocol of software demonstrations, a detailed insight into the market of IT-components arose. A comparison between 2015 and 2018 revealed little progress. The focus is still electronic data capture functionality. With the presented activities, rich material is available to assist registry developers in the planning of their IT-infrastructure and the selection of software products.

[Health and primary care surveillance among asylum seekers in reception centres in Germany: concept, development, and implementation]

BACKGROUND

Reliable data on health and primary care among asylum seekers in reception centres are not routinely available, but required to plan needs-based healthcare services.

OBJECTIVES

To present the concept, development, and implementation of a routine surveillance system in reception centres for asylum seekers.

METHODS

In the scope of the project PRICARE, medical records in reception centres were standardized and digitized, and continuous surveillance was enabled by means of suitable IT infrastructure. The core elements of the surveillance system were developed in three project phases using an iterative and participative design.

FUNDING

Federal Ministry of Health (Grant no. 2516FSB415).

RESULTS

Forming the basis for the surveillance, the electronic health record Refugee Care Manager® (RefCare®) was developed and gradually implemented in 13 reception centres in three federal states. For implementing the tool in daily care routines, IT infrastructure was implemented in all sites and a legally required data protection concept was established. An indicator set was developed and agreed upon for the surveillance, comprising a total of 64 indicators in four domains: morbidity, processes of care, quality of care, and syndromic alerts.

CONCLUSIONS

For the first time in Germany, a harmonized infrastructure spanning federal states was implemented in healthcare settings ensuring medical documentation and surveillance of health and healthcare of asylum seekers in conformity with data protection requirements. The surveillance is feasible; the long-term benefits of routine surveillance and research within the network will be assessed in the future.

[Good Practice Data Linkage]

Individual data linkage of different data sources for research purposes is being increasingly used in Germany in recent years. However, generally accepted methodological guidance is missing. The aim of this article is to define such methodological standards for research projects. Another aim is to provide readers with a checklist for critical appraisal of research proposals and articles. Since 2016, an expert panel of members of different German scientific societies have worked together and developed 7 guidelines with a total of 27 practical recommendations. These recommendations include (1) research aims, questions, data sources and resources, (2) infrastructure and data flow, (3) data privacy, (4) ethics, (5) key variables and type of linkage, (6) data validation/quality assurance and (7) long-term use for future research questions. The authors provide a rationale for each recommendation. Future revisions will include any new developments in science and data privacy.

Towards a Software Tool for Planning IHE-Compliant Information Systems

As hospital information systems are complex and the requirements for interoperability grow with the increasing networking in healthcare, careful planning becomes more and more necessary. The use of standards as described in IHE profiles, for example, are an important prerequisite for enabling interoperability. Enterprise Architecture Planning (EAP) methods should support this, but none of the currently available EAP methods offers the option of using IHE profiles. The 3LGM2IHE project wants to close this gap and implement the support of IHE profiles in the 3LGM² tool. This paper describes how requirements for this tool were determined and presents the results.

Integrated Data Repository Toolkit (IDRT)

Background: In recent years, research data warehouses moved increasingly into the focus of interest of medical research. Nevertheless, there are only a few center-independent infrastructure solutions available. They aim to provide a consolidated view on medical data from various sources such as clinical trials, electronic health records, epidemiological registries or longitudinal cohorts. The i2b2 framework is a well-established solution for such repositories, but it lacks support for importing and integrating clinical data and metadata.

Objectives: The goal of this project was to develop a platform for easy integration and administration of data from heterogeneous sources, to provide capabilities for linking them to medical terminologies and to allow for transforming and mapping of data streams for user-specific views.

Methods: A suite of three tools has been developed: the i2b2 Wizard for simplifying administration of i2b2, the IDRT Import and Mapping Tool for loading clinical data from various formats like CSV, SQL, CDISC ODM or biobanks and the IDRT i2b2 Web Client Plugin for advanced export options. The Import and Mapping Tool also includes an ontology editor for rearranging and mapping patient data and structures as well as annotating clinical data with medical terminologies, primarily those used in Germany (ICD-10-GM, OPS, ICD-O, etc.).

Results: With the three tools functional, new i2b2-based research projects can be created, populated and customized to researcher’s needs in a few hours. Amalgamating data and metadata from different databases can be managed easily. With regards to data privacy a pseudonymization service can be plugged in. Using common ontologies and reference terminologies rather than project-specific ones leads to a consistent understanding of the data semantics.

Conclusions: i2b2’s promise is to enable clinical researchers to devise and test new hypothesis even without a deep knowledge in statistical programing. The approach pre -sented here has been tested in a number of scenarios with millions of observations and tens of thousands of patients. Initially mostly observant, trained researchers were able to construct new analyses on their own. Early feedback indicates that timely and extensive access to their “own” data is appreciated most, but it is also lowering the barrier for other tasks, for instance checking data quality and completeness (missing data, wrong coding).

Registers for Networked Medical Research in Germany: Situation and prospects

BACKGROUND

Several disease specific registers are operated by members of the 'TMF - Technology, Methods, and Infrastructure for Networked Medical Research', an umbrella organization of research networks in Germany.

OBJECTIVE

To describe the coverage and the current state as well as financial and organizational issues of registers operated by member networks of the TMF, to identify their requirements and needs, and to recommend best practice models.

METHODS

A survey with a self-completion questionnaire including all 55 TMF member networks was carried out in winter 2007/2008. Interviews focusing on technological issues were conducted and analyzed in summer 2009 with a convenience sample of 10 registers.

RESULTS

From 55 TMF member networks, 11 provided information about 14 registers. Six registers address diseases of the circulatory system with more than 150,000 registered patients. The interviews revealed a typical setting of "research registers". Research registers are an important mean to generate hypotheses for clinical research, to identify eligible patients, and to share data with clinical trials. Concerning technical solutions, we found a remarkable heterogeneity. The analysis of the most efficient registers revealed a structure with five levels as best practice model of register management: executive, operations, IT-management, software, hardware.

CONCLUSION

In the last ten years, the TMF member networks established disease specific registers in Germany mainly to support clinical research. The heterogeneity of organizational and technical solutions as well as deficits in register planning motivated the development of respective recommendations. The TMF will continue to assist the registers in quality improvement.

Foundations of a metadata repository for databases of registers and trials

The planning of case report forms (CRFs) in clinical trials or databases in registers is mostly an informal process starting from scratch involving domain experts, biometricians, and documentation specialists. The Telematikplattform für Medizinische Forschungsnetze, an umbrella organization for medical research in Germany, aims at supporting and improving this process with a metadata repository, covering the variables and value lists used in databases of registers and trials. The use cases for the metadata repository range from a specification of case report forms to the harmonization of variable collections, variables, and value lists through a formal review. The warehouse used for the storage of the metadata should at least fulfill the definition of part 3 "Registry metamodel and basic attributes" of ISO/IEC 11179 Information technology - Metadata registries. An implementation of the metadata repository should offer an import and export of metadata in the Operational Data Model standard of the Clinical Data Interchange Standards Consortium. It will facilitate the creation of CRFs and data models, improve the quality of CRFs and data models, support the harmonization of variables and value lists, and support the mapping of metadata and data.

Use of sequence information in associative learning in control subjects and cerebellar patients

Previous studies of our group have shown that cerebellar patients are impaired in their ability to associate a color and a numeral or two colors with a button push. The aim of the present study was to examine whether control subjects make use of sequence information in visuomotor associative learning tasks and if this ability is impaired in cerebellar patients. A group of eight patients with degenerative cerebellar disease and eight age, sex and IQ matched controls were tested. Subjects had to learn the association between pairs of colored squares and a button push. Two colored squares were shown one after the other in a fixed or random order on a computer screen. Control subjects but not cerebellar patients took advantage of the fixed order information of colored squares in order to improve associative learning. Differences between groups could not be explained by differences in verbal and visuospatial short-term memory, color discrimination, affective state or motor disturbances. Results suggest that impaired sequencing of sensory stimuli may contribute to disorders in visuomotor associative learning in cerebellar patients.

The role of the human cerebellum in short- and long-term habituation of postural responses

The aim of the present study was to investigate the role of the human cerebellum in short-term (STH) and long-term habituation (LTH) of postural responses to repeated platform perturbations. Ten cerebellar patients and ten age- and sex-matched healthy controls participated. Twenty backward platform translations were applied on each of 5 consecutive days. Changes of postural response size within each day were assessed to determine STH and changes across days to determine LTH. Both controls and cerebellar patients showed a significant reduction of postural response size within each day (i.e. STH). No significant reduction of postural response size was observed across days (i.e. no LTH). Both controls and cerebellar patients, however, showed a tendency of response size to increase across days suggesting long-term sensitization. The amount of changes within and across days did not significantly differ between groups. The present findings suggest that changes of postural response size to repeated perturbations do not depend upon the integrity of the cerebellum.

Cerebellar representation of the eyeblink response as revealed by PET

Blink reflex-related areas in the human cerebellum were studied using [15O]H2O PET in eight healthy subjects. Eyeblinks were evoked by airpuff stimulation and recorded via surface electrodes. PET analysis revealed a cerebellar increase of regional cerebral blood flow in vermal lobule VI and a small ipsilateral paravermal extension in the eyeblink condition compared to rest. This activation partly overlapped with areas found in recent fMRI and animal studies investigating the cerebellar involvement in control of the unconditioned and acquisition of the conditioned eyeblink response. In conclusion, vermal lobule VI extending to ipsilateral paravermal areas appears to be involved in control of the unconditioned eyeblink response.

Limb flexion reflex-related areas in human cerebellum

Numerous studies have shown that the cerebellum is involved in classical conditioning of specific aversive reactions. Only few studies, however, have examined the exact localization of cerebellar areas involved in the control of unconditioned reflex responses. The present study investigated cerebellar areas, which are activated during eliciting of the limb flexion reflex in healthy controls using [15O]H2O PET. Limb flexion reflex related areas were found in vermal lobules III-VI with the local maximum in vermal lobule V. Areas of activation were more widespread compared to a voluntary foot movement and a sensory foot stimulation condition. Limb flexion reflex areas probably reflect efferent reflex modulation as well as sensory inputs from the stimulus itself and/or the reflex response.

Differences in trace and delay visuomotor associative learning in cerebellar patients

Recent studies revealed an impairment of patients with cerebellar lesions in cognitive associative learning paradigms, which could not be explained by motor deficits or increased attentional demands during performance of the motor part of the particular task. To further test the role of the cerebellum in cognitive associative learning a visuomotor associative learning paradigm was conducted, which showed some similarities to reflex conditioning. Subjects had to learn the association between a visual stimulus (i.e., a colored square) and a correct motor response (i.e., pressing a left or right target button on a specialized keyboard) in a stimulus-response paradigm. The correct side of the response was always indicated by a growing circle. The stimuli were presented in two forms: (1) the colored square ("conditioned stimulus", "CS") preceded the growing circle ("unconditioned stimulus", "US") and coterminated with the "US" (delay-condition) or (2) the offset of the colored square was separated from the onset of the circle by a short time interval (trace-condition). Eight patients with degenerative cerebellar disorders and eight age-, sex-, IQ-, and education level-matched controls participated. Both control subjects and cerebellar patients showed significant effects of learning based on reduction of decision times during performance of the task. The explicit knowledge of the correct motor response associated with each of the presented colors, however, was significantly better in control subjects. Furthermore, within-group comparisons revealed that control subjects performed significantly better in the trace-condition compared to the delay-condition, whereas no significant difference was obtained in the cerebellar group. Part of the findings in controls was explained by an age-related decline in the delay-condition. In addition, elderly control subjects appeared to benefit from cue-effects and timing-effects (i.e., fixed trace interval) in the trace-condition resulting in reduced decision times. Neither cue- nor timing-related effects fully accounted for differences between cerebellar patients and controls. The lack of a better performance in the trace-condition compared to the delay-condition in cerebellar patients suggests deficits in learning the stimulus-response association.

Effect of functional NMDA-antagonist flupirtine on automatic postural responses in Parkinson's disease

Animal studies have demonstrated potent antiparkinsonian and other motor effects of the functional NMDA-antagonist flupirtine and suggest a therapeutic use in Parkinson's disease (PD). In healthy subjects flupirtine decreases the functionally destabilizing medium latency (ML) response following toe-up rotations of a moving platform. Because ML responses are known to be increased in PD, this study examined s the effects of flupirtine on postural responses in patients with PD. During 22 days 21 patients with PD took 50 mg, 100 mg flupirtine or placebo following a randomized, double-blind design. Clinical impairment was assessed by means of the Unified Parkinson's Disease Rating Scale (UPDRS). No significant difference between the effect of flupirtine and placebo on ML responses was observed. There was an unspecific improvement of overall UPDRS scores in placebo and flupirtine conditions compared with baseline measures which was more marked in the placebo condition. No improvement in the UPDRS motor subscale was observed. As no beneficial effect on the clinical presentation and no effect on postural responses could be demonstrated, flupirtine does not seem to be a therapeutic option in PD.

Motor deficits cannot explain impaired cognitive associative learning in cerebellar patients

There is a strong evidence that the cerebellum is involved in associative motor learning. The exact role of the cerebellum in motor learning, and whether it is involved in cognitive learning processes too, are still controversially discussed topics. A common problem of assessing cognitive capabilities of cerebellar patients is the existence of additional motor demands in all cognitive tests. Even if the patients are able to cope well with the motor requirements of the task, their performance could still involve compensating strategies which cost them more attentional resources than the normal controls. To investigate such interaction effects of cognitive and motor demands in cerebellar patients, we conducted a cognitive associative learning paradigm and varied systematically the motor demands and the cognitive requirements of the task. Nine patients with isolated cerebellar disease and nine matched healthy controls had to learn the association between pairs of color squares, presented centrally on a computer monitor together with a left or right answer button. In the simple motor condition, the answer button had to be pressed once and in the difficult condition three times. We measured the decision times and evaluated the correctly named associations after the test was completed. The cerebellar subjects showed a learning deficit, compared to the normal controls. However, this deficit was independent of the motor difficulty of the task. The cerebellum seems to contribute to motor-independent processes, which are generally involved in associative learning.

Acute migraine headache: possible sensitization of neurons in the spinal trigeminal nucleus?

OBJECTIVE

To investigate trigeminal sensory processing in patients with migraine using a novel "nociception-specific" blink reflex.

METHODS

Seventeen patients with unilateral migraine headache were studied within 6 hours of onset. Blink reflexes were elicited with a standard stimulating electrode (standard blink reflex) and concentric stimulating electrode (nociception-specific blink reflex) during the acute migraine attack, after treatment with IV lysine acetylsalicylate (1,000 mg) or oral zolmitriptan (5 mg) and interictally.

RESULTS

After standard stimulation, no differences were detected for the R1 and R2 onset latencies and areas under the curve (AUC) between the different time points and the headache and nonheadache side. Nociception-specific stimulation revealed a shortening of R2 onset latencies (44.3 +/- 5.4 ms for headache side vs 48.9 +/- 5.8 ms for nonheadache side) during the acute migraine attack compared with the headache-free interval (49.8 +/- 5.3 vs 49.8 +/- 4.5 ms). The AUC of the R2 increased on the headache side by 680% and on the nonheadache side by 230% compared with the headache-free interval. Drug treatment parallel to pain relief increased the onset latencies (zolmitriptan: 48.0 +/- 8.2 ms for headache side vs 52.3 +/- 7.6 ms for nonheadache side; lysine acetylsalicylate: 48.0 +/- 5.0 ms for headache side vs 51.2 +/- 5.6 ms for nonheadache side) and reduced the AUC of R2 (zolmitriptan by 45% and lysine acetylsalicylate by 48%).

CONCLUSION

The data suggest temporary sensitization of central trigeminal neurons during acute migraine attacks.

Fear conditioned changes of heart rate in patients with medial cerebellar lesions

Fear conditioned changes of heart rate and skin conductance responses were investigated in patients with medial cerebellar lesions. A classical conditioning paradigm with a tone as the conditioned stimulus (CS) and an electrical shock as the unconditioned stimulus (US) was tested on five patients with medial cerebellar lesions due to surgery for astrocytoma and five controls. The CS preceded the US by 5900 ms and coterminated with the US. Changes in heart rate and skin conductance responses were obtained as measures for autonomic fear responses. Effects of conditioning were quantified by comparison of the habituation and extinction phases. Controls, but not cerebellar patients, showed a significant decrease of heart rate during fear conditioning. However, there were no significant fear conditioned changes in electrodermal responses in either group. In summary, the medial cerebellum seems to be involved in fear-conditioned bradycardia in humans.

Involvement of the human medial cerebellum in long-term habituation of the acoustic startle response

Animal studies have shown an involvement of the cerebellar vermis in long-term habituation of the acoustic startle response, but not in short-term habituation. The aim of the present study was to investigate whether short-term and long-term habituation of the acoustic startle response are impaired in patients with medial cerebellar lesions. Five patients with midline cerebellar lesions due to surgery for astrocytoma and ten healthy, age- and sex-matched subjects were studied. Subjects received 40 acoustic startle stimuli each day on five successive days. Peak amplitudes of the startle response recorded at the orbicularis oculi and the sternomastoid muscles were obtained. Data were analyzed for response decrement within the training session of one day (short-term habituation) and for a decrease in the startle response across the five training days (long-term habituation). Short- and long-term habituation of the startle response recorded at the sternomastoid muscles could be achieved in controls and in cerebellar patients. However, long-term habituation of the blink component of the acoustic startle response recorded at the orbicularis oculi muscles was significantly impaired in patients with cerebellar lesions compared with control subjects, whereas short-term habituation was preserved in both groups. The present findings suggest that the medial cerebellum is involved in long-term habituation of the blink component of the startle response in humans.

A possible role of the human cerebellum in conditioning of the jaw-opening reflex

The role of the human cerebellum in classical conditioning of the jaw-opening reflex was investigated using positron emission tomography (PET) in healthy subjects. The jaw-opening reflex was elicited by electrical stimulation of the right corner of the mouth (unconditioned stimulus, US). The conditioned stimulus was a tone preceding the US and coterminating with the US. Changes of regional cerebral blood flow (rCBF) were correlated with the rate of conditioning per PET scan. Conditioning effects were present in one third of all subjects. In these subjects, a significant increase of rCBF in the ipsilateral, intermediate cerebellum was shown during ongoing conditioning. Thus, the intermediate cerebellum appears to be involved in classical conditioning of the jaw-opening reflex in humans.

Fear conditioned potentiation of the acoustic blink reflex in patients with cerebellar lesions

OBJECTIVE

To investigate whether the human cerebellum takes part in fear conditioned potentiation of the acoustic blink reflex.

METHODS

A group of 10 cerebellar patients (eight patients with lesions involving the medial cerebellum, two patients with circumscribed lesions of the cerebellar hemispheres) was compared with a group of 16 age and sex matched healthy control subjects. The fear conditioned potentiation paradigm consisted of three phases. During the first, habituation phase subjects received 20 successive acoustic blink stimuli. In the subsequent fear conditioning phase, subjects passed through 20 paired presentations of the unconditioned fear stimulus (US; an electric shock) and the conditioned stimulus (CS; a light). Thereafter, subjects underwent the potentiation phase, which consisted of a pseudorandom order of 12 trials of the acoustic blink stimulus alone, 12 acoustic blink stimuli paired with the conditioned stimulus, and six conditioned stimuli paired with the unconditioned stimulus. The EMG of the acoustic blink reflex was recorded at the orbicularis oculi muscles. The potentiation effect was determined as the difference in normalised peak amplitude of the blink reflex evoked by pairs of CS and acoustic blink stimuli and evoked by the acoustic stimulus alone.

RESULTS

In the habituation phase, short term habituation of the acoustic blink reflex was preserved in all cerebellar patients. However, in the potentiation phase, the potentiation effect of the blink reflex was significantly reduced in patients with medial cerebellar lesions compared with the controls (mean (SD) potentiation effect (%), patients: -6.4 (15.3), controls: 21.6 (35.6)), but was within normal limits in the two patients with lateral lesions.

CONCLUSIONS

The present findings suggest that the human medial cerebellum is involved in associative learning of non-specific aversive reactions-that is, the fear conditioned potentiation of the acoustic blink reflex.

Non-motor associative learning in patients with isolated degenerative cerebellar disease

In recent decades it has become clear that the cerebellum is involved in associative motor learning, but its exact role in motor learning as such is still controversial. Recently, a contribution of the cerebellum to different cognitive abilities has also been considered, but it remains unclear whether the cerebellum contributes to cognitive associative learning. We compared nine patients with an isolated cerebellar degenerative disease in a cognitive associative learning task with 10 controls. Patients and controls were matched for age, sex, handedness, level of education, intelligence and capabilities of visual memory. The subjects were asked to learn the association between six pairs of colours and numerals by trial and error. Additionally, a simple reaction time and a visual scanning test were conducted in order to control for the influence of motor performance deficits in cerebellar patients. In comparison with the controls, it took the patients significantly longer to learn the correct associations between colours and numerals, and they were impaired in recognizing them later on. Two patients showed no associative learning effect at all. Neither the simple reaction time nor the visual scanning time correlated substantially with the results of associative learning. Therefore, motor-associated disabilities are unlikely to be the reason for the learning deficit in cerebellar patients. Our results suggest that the cerebellum might contribute to motor-independent processes that are generally involved in associative learning.