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Biomedical subjects

M R Lemke

Publications and source records attributed to M R Lemke.

At least 19 recordsLinked to original sources
PubMed2007

[Antidepressant effects of dopamine agonists. Experimental and clinical findings].

Results of preclinical and clinical studies implicate that, in addition to serotonin and norepinephrin, dopaminergic mechanisms play a role in the pathogenesis and treatment of depression. Newer antidepressants such as bupropion, sertraline, and venlafaxine act as partial inhibitors of presynaptic dopamine reuptake. Experimental studies show that dopaminergic effects contribute to the development of anxiety, depression, and anhedonia. These studies revealed, among the new nonergot dopamine agonists, anxiolytic properties for ropinirole and anxiolytic, antidepressive, and antianhedonic effects of pramipexole which seem to relate to its specific action on D(2) and D(3) receptors in the mesolimbic system and prefrontal cortex. In addition, affective disorders may be associated with impairments of neuronal plasticity, and pramipexole seems to exert neurotrophic properties. Controlled and open studies in depressed patients with Parkinson's disease show therapeutic effects of dopamine agonists on motor deficits, anhedonia, and depression. Various dopamine agonists have been tested in open studies in patients with depression and may add to the spectrum of treatment options in mood disorders. Recently published placebo-controlled trials in small patient groups implicate that pramipexole is effective as additional treatment to mood stabilizers in I and II bipolar depression.

Animals↗
PubMed2006

Kinetic tremor in Parkinson's disease--an underrated symptom.

Since the first description of the disorder which we now call "Parkinson's Disease" (PD) much has changed not only because of new therapeutic possibilities. Initially only the rest tremor was described. Today it is generally accepted that PD can be accompanied by different forms of tremor. Nevertheless the kinetic tremor is hardly examined and no attention is paid to it in clinical rating scales although it can already be found in old published drawings of PD-patients. To date instrumented investigations do not capture the most common kinetic tremor of PD that seems to be frequent under everyday life conditions. In order to assess the significance of kinetic tremor in PD, tremor during a spiral drawing task was investigated in an open study involving 870 patients. The results indicate that a combination of rest, postural and kinetic tremors constitute the most frequent tremor constellation in PD.

Adolescent↗
PubMed2006

[Long-term effects of traumatic experiences on somatic and psychic complaints of German World War Two refugees].

The effects of expulsion from German territories following World War Two have not been studied systematically, and little is known about long-term effects of this potentially traumatic experience. Via mail, 600 refugees from former German territories due to World War Two were asked to complete questionnaires about biographic data, somatic and psychic health (SCL-90-R questionnaire), and specific aspects related to traumatic experiences (post-traumatic stress disorder questionnaire). Of those contacted, 25% participated in the investigation. Of them, 9.8% fulfilled diagnostic criteria of post-traumatic stress disorder according to DSM IV. Only 1.8% of an age-matched control group met these criteria. Analysis of the SCL-90-R questionnaire showed higher scores for former refugees in somatic and psychic complaints than the control group. We show that expulsion following war may lead to symptoms of post-traumatic stress disorder and somatic and psychic complaints after more than 50 years. Our investigation supports the necessity of adequate care for subjects expelled from their home countries and the psychologically traumatised.

Aged↗
PubMed2002

[Pramipexole in Parkinson disease. Results of a treatment observation].

Pramipexole is a novel, internationally available selective nonergot D2 dopamine agonist. The effectiveness, tolerability, and safety of pramipexole have been extensively proven in controlled trials in patients in the early and advanced stage of Parkinson's disease as monotherapy and in combination with L dopa. These trials indicated specific activity against tremor, anhedonia, and depression. Therefore, the present prospective, multicenter postmarketing surveillance study evaluated for the first time to what extent the results from the controlled pramipexole trials could be replicated under routine conditions in neurological practice and clinics. Modern scales were applied for the assessment of tremor and mood, i.e., the Short Parkinson's Evaluation Scale (SPES), the Tremor Impact Scale (TIS), and the German version of the Snaith-Hamilton Pleasure Scale (SHAPS-D). In 298 German Centers, 657 Parkinson's patients (365 men, 292 women) in advanced disease stages were treated with pramipexole in combination with levodopa. The average ages (+/- SD) were 67 (+/- 8.9) years for men and 69 (+/- 9.4) years for females. Motor functioning, especially tremor, motor complications, depression, and activities of daily living improved highly significantly (P < 0.0005), including self-rating by the patients. The dosage of levodopa could be reduced on average by 8% (P < 0.0001). This might contribute to a slowing of the disease progression in the long run. Dropouts due to side effects were observed only in 3.5% of the patients. Using new assessment scales suitable for routine application allowed confirmation of the results from controlled clinical trials with regard to tremor, anhedonia, and depression. The average daily dosage of pramipexole prescribed was 1.05 mg and thus was definitely lower than the average daily dosages of 2.35-2.66 mg used in controlled trials. This signifies that the option to adjust dosage according to effectiveness and tolerability under routine conditions yields a considerably lower incidence of adverse effects.

Aged↗
PubMed2002

[Locomotion and depression. Clinical and physiological aspects of gait alterations in Parkinson's disease and major depression].

BACKGROUND: Behavioral disturbances of patients with major depression manifest in various motor domains and are relevant for differential diagnosis, therapeutic interventions, as residual symptoms and possibly early manifestation of Parkinson's disease. Alterations of gait as the main component of locomotion are a clinically well-known motor phenomenon of depressed patients. Therefore, pathophysiology of gait disturbances, different methods to analyze gait and empirical findings in patients with major depression are summarized. METHODS: The current literature was examined including information of manufacturers, Medline, PubMed, PsychLIT and Excerpta Medica. Findings in healthy subjects, in Parkinson's disease, and in major depression are discussed in detail regarding specificity and clinical relevance. RESULTS: Kinematic analysis of gait regulation by videography, ultrasound, opto-electronic measures reveals information about disturbances in central nervous motor programming. Only few studies exist about quantitative data of gait alterations in patients with major depression. Results indicate disturbances in functions of the basal ganglia. CONCLUSIONS: Analysis of gait using modern technology yields information about cortical and subcortical dysfunctions. Empirical findings in major depression need further investigation regarding their relevance as residual symptoms, as response predictors, and as risk factors for manifestation of Parkinson's disease.

Basal Ganglia↗
PubMed2001

[Disordered behavioral control in psychiatric illnesses. Neurophysiological aspects of impulsive behavior].

OBJECTIVE: Dysfunction of behavioral control represents a central component of many psychiatric disorders and may be connected with self-mutilating and antisocial behavior. However, only a few studies have investigated objective assessment and quantification of impulsive behavior, which is relevant for psychiatric practice and research. Because new techniques enable objective assessment of behavior generation and execution, the current knowledge about neurophysiological aspects of behavioral control is summarized. METHOD: The contemporary literature on neuronal mechanisms of initiation and execution of behavior and movements and new neurophysiological methods and findings are discussed in respect to their application in psychiatry. RESULTS: Behavior, defined as movements of a body in time and space, is the result of cortical and subcortical processes. These consist of two general components: (1) perception and selection of a stimulus and (2) execution of a movement, including decision and planning phases. Planning and execution, modulated by cognition and emotions, are dependent on the balance of inhibitory and excitatory aspects of behavior control. Combined detection of electrical brain activity and kinematic analysis of peripheral movements enables the analysis of control mechanisms. CONCLUSION: Impulsiveness and inhibition of behavior depend on neuronal control mechanisms which can be analyzed by neurophysiological methods. Objective assessment of impulsive behavior related to psychiatric disturbances including eating disorders, substance abuse, and personality disorders may clarify underlying neurobiological mechanisms and enable rational pharmaco- and psychotherapeutic interventions.

Brain↗
PubMed2001

[Motor behavior in depression: applications and limitations of actigraphic analyses].

OBJECTIVE: Alterations of motor behavior in depression play a key role in psychosocial activities and interpersonal communication and are relevant for differential diagnosis and treatment. Functions and application of actigraphy and empirical findings in depression will be summarised and discussed. METHODS: The current knowledge retrieved from information of manufacturers, Medline, PsycLIT, and PSYNDEX regarding features of actigraphic equipment and clinical aspects of gross motor analysis in depression was examined. RESULTS: Actigraphy is a practical method to monitor and quantify gross motor activity, but setting variables including sensitivity or epoch length vary among commercially available instruments. Measures of motor activity in depressed patients are used for diagnosis, evaluation of sleep, and prediction of treatment response. CONCLUSIONS: Measurements of motor behavior by actigraphy can be used in depression for diagnostic procedures and treatment evaluation. The role of actigraphic setting variables needs further clarification. Actigraphy may be used for behavioral analysis including individual regulation of motor activity as an objective parameter for evaluation of depression and other psychiatric disorders.

Activities of Daily Living↗
PubMed2001

Amitriptyline enhances the central component of physiological tremor.

OBJECTIVES: Postural tremor is a regularly encountered side effect of amitriptyline which can be strong enough to cause discontinuation of therapy. The aim was to characterise amitriptyline induced tremor and to assess if the central or reflex component of physiological tremor was modulated by this drug. METHODS: The postural hand tremor was measured in 15 patients on a clinical rating scale, by power spectral analysis of accelerometer, forearm flexor, and extensor EMG before and after the beginning of amitriptyline treatment for major depression or chronic pain syndrome. A coherence analysis between flexor and extensor muscles on the same side was performed. RESULTS: There was a clinically visible increase in postural tremor in a third of these patients. The tremor amplitude measured by accelerometer total power increased in every patient under amitriptyline. The EMG synchronisation as reflected by significant peaks in the flexor or extensor spectrum generally occurring at higher frequencies (8-18 Hz) than the accelerometric tremor frequencies (6-11 Hz) did not change. The number of patients with a significant flexor-extensor coherence in the 7-15 Hz range increased significantly under amitriptyline, the frequency bands of significant coherence corresponded with the EMG frequencies, and both were independent of changes to the hand's resonant frequency by added inertia. CONCLUSIONS: An enhancement of postural tremor under amitriptyline is a common phenomenon although not always clinically apparent. The increase in EMG-EMG coherence indicates an increased common central drive to the motor units as its frequency is not influenced by peripheral resonance or reflex mechanisms. This is the first account of a drug induced enhancement of the central component of physiological tremor.

Amitriptyline↗
PubMed1999

Antimicroglia antibodies in sera of Alzheimer's disease patients.

BACKGROUND: Immune mechanisms seem to contribute to the degenerative process in Alzheimer's disease. Antibodies directed against animal brain tissue were found in sera of Alzheimer's patients. METHODS: Antibodies were measured in sera of 25 Alzheimer's patients and a comparison group of 25 age- and sex-matched controls. Sera were tested for their immunological response to various brain structures of postmortem human brain tissue. RESULTS: In 8 patients with Alzheimer's disease perinuclear antibodies directed against microglia were found in amygdala and frontal cortex. In the control group 1 subject showed antibody binding to microglia. CONCLUSIONS: Perinuclear antibodies to microglia may play a role in tissue destruction of Alzheimer's disease. These data add to the evidence that immune mechanisms play a role in the pathophysiology of Alzheimer's disease.

Aged↗
PubMed1999

Temporal segmentation of human short-term behavior in everyday activities and interview sessions.

Human behavior is structured by serial order and timing of functionally related groups of movements with a duration of a few seconds. These elementary action units have been described in ethological studies during unstaged everyday behavior, but not during interview sessions. Psychomotor alterations are relevant for differential diagnosis and treatment, and psychiatric patients are generally evaluated during interview sessions. Therefore the time structure of upper limb movements (n = 764) of healthy subjects (n = 22) were studied using videotaped interviews and frame-by-frame analysis and compared to movements (n = 530) of unstaged human everyday behavior (n = 154). The number of action units, but not their duration, was correlated inversely with self-reported impairment of mood and pleasure experience in healthy persons. The temporal distribution of movements in interview sessions did not differ from the time patterns of everyday behavior. This method could be a promising tool to investigate time patterns of movements and psychomotor alterations in psychiatric patients during interview sessions.

Adult↗
PubMed1999

[Motor signs of depression].

OBJECTIVE: Alterations of motor phenomena are observable clinical phenomena of depressed patients. In addition to cognitive and emotional disturbances, motor dysfunctions are frequent psychopathological features which relate to neurobiological mechanisms of depression. Specific functions of various motor domains, pathophysiological concepts, and relevance of motor functions for diagnosis and prognosis of depression are summarized. METHODS: The contemporary literature regarding clinical and research aspects of differential diagnosis, treatment response and pathophysiology as well as the current knowledge regarding objective measures of motor signs in depression are reviewed. RESULTS: Alterations in motility (gross motor activity), locomotion, gestures, mimic, speech characteristics, and tremor are relevant for diagnosis, therapy and prognosis of depression. A large body of literature exists regarding qualitative, indirect measures of motor phenomena and quantitative analysis of motility. Only few unidimensional studies exist in respect to locomotion, gait and tremor in depression. The low correlation between physiological and clinical features may be due to methodological issues. Whereas most publications investigate motor functions indirectly using different functional coding and classification systems, only few studies report direct, physical, characteristics (kinematics) of motor phenomena in depression. CONCLUSIONS: Existing concepts do not clarify the relation of psychological and somatic components of motor signs. Agitation and retardation should be analyzed as multidimensional and independent variables. New psychometric instruments for documentation of motor phenomena in depression need further evaluation. Application of current technology and quantitative movement analysis may yield further insights in pathophysiological mechanisms and therapeutic strategies and represent important aspects of neurobiological research of depression.

Circadian Rhythm↗
PubMed1999

Timing of movements in depressed patients and healthy controls.

BACKGROUND: Psychomotor disturbances are fundamental psychopathological features of major depression and observable components of behaviour. Human behaviour is segmented into action units with duration of a few seconds due to central nervous motor processing. Timing may depend on cognitive and emotional functions which are affected in depression. Therefore, time structure of action units in depressed patients was compared to healthy controls. METHODS: Included were patients with major depression and melancholic features. Upper limb movements (total n = 566) of depressed patients and matched controls were evaluated using videotaped interviews and frame-by-frame analysis with a temporal resolution of 40 ms. RESULTS: Behaviour of depressed patients in interview sessions was organised in action units with a narrow time span of only a few seconds. Single, non-repetitive action units were significantly shorter (median = 1.20 s) and repetitive units longer (median = 4.92 s) in patients compared to controls (median = 2.08 and 2.96, respectively). LIMITATIONS: Behaviour in interview sessions might differ from activities of daily living. DISCUSSION: Altered temporal segmentation of movements appears to be an observable, measurable sign of melancholic depression and may allow further insights in pathophysiological dysfunctions of the disease. Clinical implications of these motor changes for differential diagnosis, course and treatment of depression are discussed and need further evaluation.

Adult↗
PubMed1999

Psychomotor retardation and anhedonia in depression.

Anhedonia, the inability to experience pleasure, and observed changes in psychomotor performance are frequent psychopathological phenomena in major depression with possible common neurobiological mechanisms. Interest, pleasure and reactivity to pleasurable stimuli contribute to movement generation and observable behaviour. Therefore the relationship between anhedonia and psychomotor retardation was studied in 48 depressed patients. Subjectively experienced anhedonia correlated with self-rated but not with observer-rated global severity of depression. There was a significant correlation between anhedonia and psychomotor retardation assessed with the Widöcher Retardation Scale. The results suggest the existence of an empirical relationship between reduced ability to experience pleasure and observable psychomotor retardation in depression. Specific measures of psychomotor phenomena may provide further insights into the relationship between observable behaviour and self-experienced symptoms in depression.

Adult↗
PubMed1998

[Motor activity and subjective findings in depressive patients].

Intensity of symptoms including mood and psychomotor activity has been shown to vary according to the time of the day in a group of depressed patients. This pattern represents one diagnostic criterion for the melancholic type of depression. The variation of intensity is experienced by the patient and can be observed as a behavioral symptom. However, the relation of circadian alterations in psychomotor activity and depressed mood remains unclear. Therefore, spontaneous motor activity and experienced intensity of symptoms were measured in 21 depressed patients who showed daily variations of subjective symptoms. Patients felt significantly less active, awake, and more depressed in the morning compared to the evening. However, corresponding activity levels, which were measured by actigraphy, appeared significantly higher in the morning compared to the evening. Increased motor activity could represent the observable behavioral equivalent of self-experienced psychomotor retardation and depressed mood.

Adult↗
PubMed1998

[German version of the Snaith-Hamilton-Pleasure Scale (SHAPS-D). Anhedonia in schizophrenic and depressive patients].

The Snaith-Hamilton-Pleasure-Scale (SHAPS), introduced in English in 1995, assesses self-reported anhedonia in psychiatric patients. It has proven psychometric properties and advantages in applicability compared to other instruments assessing anhedonia. This study presents results of a systematic transcultural protocol translating the SHAPS into German (SHAPS-D). Quality of translation was confirmed on the one hand by bilingual reviewers with regard to equivalence in content and tone. On the other hand stable results were found in a test-retest-design crossing the English and German version with bilingual persons. SHAPS-D was obtained from schizophrenic (n = 50) and depressive (n = 33) patients and from healthy controls (n = 67). Results on applicability, internal consistency and relationship to depression, subjective quality of life, well-being as well as psychopathology indicate that the SHAPS-D is a useful and promising instrument in assessing anhedonia.

Adult↗
PubMed1997

Motor activity and daily variation of symptom intensity in depressed patients.

Spontaneous motor activity measured by actigraphy and subjectively experienced intensity of symptoms were investigated in 16 unipolar depressed inpatients with melancholic features. Patients felt significantly less active, awake, and more depressed in the morning compared to the evening. However, morning activity levels appeared significantly higher compared to evening levels. Diurnal variations of symptoms were reflected by actigraphically measured motor activity, which was negatively correlated with subjectively experienced symptom intensity. Increased motor activity may represent an observable, psychobiological, behavioral equivalent of self-experienced depressive symptoms in major depression with melancholic features.

Adult↗