Classifying sensory patterns and their effects on locomotion and tremor

1981 ◽  
Vol 59 (7) ◽  
pp. 645-655 ◽  
Author(s):  
R. B. Stein ◽  
T. Gordon ◽  
M. N. Oğuztöreli ◽  
R. G. Lee
Keyword(s):  
Essential Tremor ◽  
Peripheral Nerves ◽  
Sensory Input ◽  
Neural Oscillations ◽  
Neuromuscular System ◽  
Step Cycle ◽  
Parkinsonian Tremor ◽  
Reflex Effect ◽  
Sensory Activity

Methods are described for analyzing the patterns of sensory activity in peripheral nerves during unrestrained behaviour. In locomotion, nerves supplying ankle extensors and flexors typically show two bursts of sensory activity per step cycle. Variations in sensory input may be important in modulating the ongoing oscillation. Altered sensory input may also change the phase of an ongoing oscillation (as in human essential tremor) or may only have a transient reflex effect (as in Parkinsonian tremor). Various types of interactions can be analyzed using a model of the peripheral neuromuscular system and its central connections. In general, the following categories are suggested for sensory actions on neural oscillations: (1) modulation of (a) the amplitude or (b) the frequency; (2) resetting (i.e., a maintained change in the timing of an oscillation without changes in frequency); (3) repatterning an oscillation (a) over several cycles (e.g., gait changes in locomotion) or (b) within a cycle or two (e.g., the stumble corrective reaction); and (4) gating an oscillation on or off.

Contralateral voluntary hand movement inhibits human parkinsonian tremor and variably influences essential tremor

2004 ◽  
Vol 357 (3) ◽  
pp. 187-190 ◽  
Author(s):  
Gertrúd Tamás ◽  
László Pálvölgyi ◽  
Annamária Takáts ◽  
Imre Szirmai ◽  
Anita Kamondi
Keyword(s):  
Essential Tremor ◽  
Hand Movement ◽  
Parkinsonian Tremor

Discharge Patterns of Coxal Levator and Depressor Motoneurones of the Cockroach, Periplaneta Americana

1970 ◽  
Vol 52 (1) ◽  
pp. 139-165
Author(s):  
K. G. PEARSON ◽  
J. F. ILES
Keyword(s):  
Peripheral Nerves ◽  
Sensory Input ◽  
Periplaneta Americana ◽  
Motor Axon ◽  
Extracellular Recordings ◽  
Before And After ◽  
Collateral Pathways ◽  
Discharge Patterns ◽  
Flexion And Extension ◽  
Leg Movements

1. Observation of movements of the metathoracic legs of the cockroach before and after section of peripheral nerves allowed identification of muscles involved in flexion and extension of the femur. 2. Extracellular recordings from the nerves to these coxal muscles show that during rhythmic leg movements bursts of activity in a number of levator motor axons were strongly reciprocal and generally non-overlapping with those of a slow depressor motor axon. 3. These reciprocal patterns persisted after removal of all sensory input from the legs. 4. The durations of levator bursts were relatively constant compared to those of the depressor, corresponding to the behavioural observations on leg protraction time. The pattern was asymmetric: levator bursts could be generated without depressor activity, but never the reverse. 5. No evidence was found for inhibitory collateral pathways between antagonist motoneurones. 6. It is proposed that levator motoneurones are driven by a group of bursting interneurones which simultaneously inhibit the ongoing depressor activity.

Some effects of de-afferentation on the developing amphibian nervous system

Development ◽  
1965 ◽  
Vol 14 (1) ◽  
pp. 75-87
Author(s):  
Arthur Hughes
Keyword(s):  
Nervous System ◽  
Quantitative Study ◽  
Peripheral Nerves ◽  
Hind Limb ◽  
Sensory Input ◽  
Bufo Marinus ◽  
Degenerative Changes ◽  
Normal Embryo

An adult anuran can still walk or swim if the nerves supplying one or even two limbs are de-afferentated (Gray, 1950). However, in a developing amphibian, a limb at motile stages becomes paralysed when deprived of its sensory input. A sequence of degenerative changes then follow in the cord and in peripheral nerves. Tadpoles of Bufo marinus and late embryos of Eleutherodactylus martinicensis have been submitted to this experiment; in these tropical forms the subsequent events follow rapidly. Most attention has been paid to Eleutherodactylus, on which a quantitative study of the numbers of fibres in nerves to the hind limb during development has recently been published (Hughes, 1965a). This work, together with a study of the behaviour of the normal embryo (Hughes, 1965b) has been used as a basis for the present experimental observations. The source of the embryos of E. martinicensis and the methods of culturing and observing them remain the same as in previous studies (Hughes, 1962,1964a & b, 1965a & b).

scholarly journals Local Vibrational Therapy for Essential Tremor Reduction: A Clinical Study

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 552
Author(s):  
Silvijus Abramavičius ◽  
Mantas Venslauskas ◽  
Antanas Vaitkus ◽  
Vaidotas Gudžiūnas ◽  
Ovidijus Laucius ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Essential Tremor ◽  
Medical Device ◽  
The Body ◽  
Rank Test ◽  
Main Study ◽  
Safety Study ◽  
Serious Adverse Events ◽  
Parkinsonian Tremor ◽  
Device Use

Background and objectives: tremor is an unintentional and rhythmic movement of any part of the body that is a typical symptom of Essential Tremor (ET). ET impairs the quality of life of patients and is treated with pharmacotherapy. We investigated the tremor reduction efficacy of an innovative vibrational medical device (IMD) in ET patients. Materials and Methods: we conducted a prospective, single-center, single-arm, pragmatic study in ET patients with an extended safety study to evaluate the efficacy and safety of the Vilim Ball—a local hand-arm vibration device that produces vibrations in the frequency range of 8–18 Hz and amplitude from 0 to 2 mm. The primary endpoint was the decrease in the power spectrum after device use. The secondary endpoints were safety outcomes. Results: In total, 17 patients with ET were included in the main study, and no patients withdrew from the main study. The tremor power spectrum (m2/s3 Hz) was lower after the device use, represented as the mean (standard deviation): 0.106 (0.221); median (Md) 0.009 with the interquartile range; IQR, 0.087 vs. 0.042 (0.078); Md = 0.009 with the IQR 0.012; Wilcoxon signed-rank test V = 123; and p = 0.027. Seven patients reported that vibrational therapy was not effective. Two patients reported an increase in tremor after using the device. In the extended safety study, we included 51 patients: 31 patients with ET and 20 with Parkinsonian tremor, where 48 patients reported an improvement in tremor symptoms and 49 in function. No serious adverse events were reported, while two patients in the Parkinsonian tremor group reported a lack of efficacy of the proposed medical device. Conclusions: the device reduces essential tremor in some patients and is safe to use in ET.

Tremor is attenuated during walking in essential tremor with resting tremor but not parkinsonian tremor

2011 ◽  
Vol 18 (9) ◽  
pp. 1224-1228 ◽  
Author(s):  
Kei Uchida ◽  
Masaaki Hirayama ◽  
Fumitada Yamashita ◽  
Norio Hori ◽  
Tomohiko Nakamura ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Parkinsonian Tremor ◽  
Resting Tremor

scholarly journals Clinical and Electromyographic Examinations of Patients with Essential Tremor

2000 ◽  
Vol 27 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Ivan Milanov
Keyword(s):  
Essential Tremor ◽  
Neurological Examination ◽  
Lower Limbs ◽  
Electromyographic Activity ◽  
Parkinsonian Tremor ◽  
Historical Aspects ◽  
Rest Tremor ◽  
Different Types ◽  
Antagonistic Muscles ◽  
Alt Activity

ABSTRACT:Background:It is believed that no clinical differences exist among essential, familial and senile tremor, or between the tremor with synchronous or alternating electromyographic activity. The aim of this study was to evaluate the clinical and electromyographic findings in a large group of patients with different types of essential tremor.Methods:Two hundred and twenty patients with sporadic, familial or senile variants of essential tremor were examined. According to the electromyographic activity recorded from the antagonistic muscles, the patients were subdivided into a group with synchronous (SYN) and a group with alternating (ALT) activity. The historical aspects of the disease were noted, and a detailed neurological examination was performed.Results:A widespread tremor involving upper and lower limbs and 3-4 different anatomical regions was typical for familial tremor. It also had higher amplitude than the sporadic and senile tremor. ALT tremor had a higher amplitude and longer burst duration than SYN and more often involved lower limbs. Rest tremor was common in the ALT group. Overall, ALT tremor was more common than previously supposed.Conclusion:The familial and ALT tremors are more disabling than other types of essential tremor. Since electromyographic ALT activity is common in essential tremor, its presence does not reliably distinguish essential and Parkinsonian tremor.

Tremors

2016 ◽  
Author(s):  
Alfonso Fasano ◽  
Günther Deuschl
Keyword(s):  
Movement Disorder ◽  
Essential Tremor ◽  
Involuntary Movement ◽  
The Body ◽  
Drug Induced ◽  
Parkinsonian Tremor ◽  
Dystonic Tremor ◽  
Physiologic Tremor ◽  
Disease Definition ◽  
Holmes Tremor

Tremor is the most common movement disorder and denotes a rhythmic and involuntary movement of one or several regions of the body. This review covers disease definition, essential tremor, enhanced physiologic tremor, parkinsonian tremor, dystonic tremor, orthostatic tremor, cerebellar tremor, Holmes tremor, neuropathic tremor, palatal tremor, drug-induced and toxic tremors, functional tremor, rare tremor syndromes, tremorlike conditions, and treatment of tremor. Figures show action tremor assessment, the central nervous system circuits of tremor, magnetic resonance imaging findings in specific tremor conditions, general management of tremor patients, an algorithm for the treatment of parkinsonian tremor, and an algorithm for the treatment of dystonic tremor and primary writing tremor. Tables list types of tremor according to the condition of activation, tremor conditions in newborns and during childhood, clinical features of the most common tremor syndromes, motor signs other than tremor and nonmotor features of essential tremor patients, Movement Disorder Society consensus criteria for the diagnosis of essential tremor, genetic and environmental causes of essential tremor, causes of enhanced physiologic tremor, drugs and toxins known to cause tremor, paroxysmal tremors, pseudorhythmic myoclonus in the differential diagnosis of tremor, and pharmacologic management of essential tremor. Key words: essential tremor, movement disorder, pathologic tremor, physiologic tremor, tremor This review contains 6 highly rendered figures, 7 videos, 11 tables, and 163 references.

Different effects of essential tremor and Parkinsonian tremor on multiscale dynamics of hand tremor

2021 ◽  
Author(s):  
Dongning Su ◽  
Fangzhao Zhang ◽  
Zhu Liu ◽  
Shuo Yang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Hand Tremor ◽  
Parkinsonian Tremor ◽  
Multiscale Dynamics

Control of Locomotor Cycle Durations

2005 ◽  
Vol 94 (2) ◽  
pp. 1057-1065 ◽  
Author(s):  
S. Yakovenko ◽  
D. A. McCrea ◽  
K. Stecina ◽  
A. Prochazka
Keyword(s):  
Sensory Input ◽  
Cycle Duration ◽  
Fictive Locomotion ◽  
Experimental Phase ◽  
Step Cycle ◽  
Phase Duration ◽  
Two Parameters ◽  
Lower Background ◽  
Sensitivity Gain ◽  
Stimulation Of

In intact animals and humans, increases in locomotor speed are usually associated with decreases in step cycle duration. Most data indicate that the locomotor central pattern generator (CPG) shortens cycle duration mainly by shortening the durations of extensor rather than flexor phases of the step cycle. Here we report that in fictive locomotion elicited by electrical stimulation of the midbrain locomotor region (MLR) in the cat, spontaneous variations in cycle duration were due more to changes in flexor rather than extensor phase durations in 22 of 31 experiments. The locomotor CPG is therefore not inherently extensor- or flexor-biased. We coined the term “dominant” to designate the phase (flexion or extension) showing the larger variation. In a simple half-center oscillator model, experimental phase duration plots were fitted well by adjusting two parameters that corresponded to background drive (“bias”) and sensitivity (“gain”) of the oscillator's timing elements. By analogy we argue that variations in background drive to the neural timing elements of the CPG could produce larger variations in phase duration in the half-center receiving the lower background drive, i.e., background drive may determine which half-center is dominant. The fact that data from normal cats were also fitted well by the model indicates that sensory input and central drive combine to determine locomotor phase durations. We conclude that there is a considerable flexibility in the control of phase durations in MLR-induced fictive locomotion. We posit that this may be explained by changes in background excitation of neural timing elements in the locomotor CPG.

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