Cerebellar hypermetria is larger when the inertial load is artificially increased

  title={Cerebellar hypermetria is larger when the inertial load is artificially increased},
  author={Mario Manto and Emile Godaux and Jean Jacquy},
  journal={Annals of Neurology},
Hypermetria is a classical cerebellar symptom designating the overshoot observed when a patient is asked to make a very fast and accurate movement. The movement studied here was wrist flexion. Hypermetria was found to be increased by artificially increasing the inertia of the moving hand. A normal subject adapted himself to increasing inertia by increasing both his agonist activity (the launching force) and its antagonist activity (the braking force). In the same circumstances, a patient with… 
Detection of silent cerebellar lesions by increasing the inertial load of the moving hand
In patients with an apparently normal neurological examination, in spite of a cerebellar lesion documented by magnetic resonance imaging, the addition of a mass to the moving hand caused the appearance of a hypermetria, and this lack of adaptation of fast and accurate movements to an increased inertia appears as a new diagnostic tool enabling the detection of silent Cerebellar lesions.
Rapid Report
Kinematic, EMG and transcranial Doppler studies are combined to understand the effects of hyperventilation on fast goal‐directed movements in patients presenting a SCA 6 and induced an increase of hypermetria.
Recovery of hypermetria after a cerebellar stroke occurs as a multistage process
In a prospective study, fast goal‐directed wrist movements of 8 patients who had experienced an acute cerebellar hypermetria due to a stroke and who had subsequently recovered clinically were repeatedly recorded.
Cerebellar hypermetria associated with a selective decrease in the rate of rise of antagonist activity
3 patients presenting a late‐onset cerebellar degeneration and exhibiting a hypermetria during their fast and accurate movements in spite of a normal onset latency of the antagonist activity are described.
Cerebellar hypermetria: Reduction in the early component of the antagonist electromyogram
  • B. Wild, D. Corcos
  • Biology, Psychology
    Movement disorders : official journal of the Movement Disorder Society
  • 1997
A reanalysis of one published data set that had previously identified only one antagonist component was performed and suggests that hypermetria can be caused by an absence of an early antagonist EMG component, a delayed late component, or both.
Temporal disruption of upper-limb anticipatory postural adjustments in cerebellar ataxic patients
The observed disruption of the intra-limb APA organization confirms that the cerebellum is involved in APA control and supports the view that a proper APA chain may play a crucial role in refining movement metria.
Effects of hyperventilation on fast goal‐directed limb movements in spinocerebellar ataxia type 6
  • M. Manto
  • Biology, Medicine
    European journal of neurology
  • 2001
It is suggested that hyperventilation enhances the defective calcium transfers in SCA‐6, resulting in an impairment of the calcium influx in particular into Purkinje cells involved in the control of fast goal‐directed voluntary movements.
Patients with Cerebellar Ataxia Do Not Benefit from Limb Weights
Cerebellar patients with cerebellar ataxia were challenged with making a single-joint, single degree of freedom reaching movement while various limb masses were tested, and it was predicted that addition of mass would only be effective in reducing dysmetria in hypometric patients.


Physiological analysis of simple rapid movements in patients with cerebellar deficits.
In patients with cerebellar deficits, the first agonist burst of the biceps was frequently prolonged regardless of the distance or speed of the movement, and the most striking kinematic abnormality was prolonged acceleration time.
EMG analysis of patients with cerebellar deficits.
EMGs from biceps and triceps were recorded during stereotyped elbow flexion tasks performed by 20 patients fulfilling clinical criteria for 'cerebellar deficits' and the data were compared with
Cerebellar dysmetria at the elbow, wrist, and fingers.
Cerebellar patients with dysmetria showed hypermetria followed by tremor at all three joints when movements were made with the manipulanda, and an asymmetry with decreased peak accelerations and increased peak decelerations compared to normal movements could be used clinically as sensitive indicators of cerebellar dysfunction.
Movement and electromyographic disorders associated with cerebellar dysmetria.
It is concluded that normal function of the cerebellum is necessary for the generation of agonist and antagonist muscle activity that is both of the appropriate magnitude and timing to control the dynamic phase of arm movements.
Modification of Intention Tremor in Man
T HE tremor observed in patients with Parkinson's disease is present at rest, and may be markedly attenuated during voluntary movement, and whether the sensory feedback of patients with abnormalities of motor control is different from that of normal subjects is attempted.
Ballistic flexion movements of the human thumb.
It is concluded that the individual components of a ballistic movement are relatively fixed in duration and the amount of e.m. activity is altered within this time interval to produce the different forces required for fast movements of different amplitude.
The trajectory of human wrist movements.
It is concluded that minimization of jerk is not a general principle used by the nervous system in organizing voluntary movements, although movements may approach the predicted form, particularly under inertial loading conditions.
Effects of dentate cooling on rapid alternating arm movements.