Impaired compensation for mechanical loads in a patient with hemiballismus following stroke.

Flexion movements of the wrist were studied in a patient who showed signs of hemiballismus following a unilateral infarction, which damaged the region neighboring the subthalamic nucleus. The experiments were designed to test whether a lesion of this nature impairs load compensation and, specifically, whether antagonist activity can be appropriately suppressed when initiating a movement. The latency between movement onset and agonist EMG onset changed from the normal relationship where agonist onset precedes movement to one where agonist onset followed movement when an extensor load was placed on the affected limb.

Comparison of the standard and structured interview guide for the Hamilton Depression Rating Scale in depressed geriatric inpatients.

The interrater reliability of the standard Hamilton Depression Rating Scale (Ham-D) and a structured interview guide for the Ham-D (the SIGH-D) were compared in a sample of 20 elderly inpatients with major depression. Each patient was independently interviewed by four raters; two used the standard 24-item Ham-D, and the other two used a 24-item modified version of the Structured Interview Guide for the Ham-D. Systematic counterbalancing of raters and scales and a stringent evaluation schedule were used to counter position effects, spontaneous symptom change, or diurnal variation.

Are there deficits in anticipatory postural adjustments in Parkinson's disease?

We studied anticipatory postural adjustments in patients with Parkinson's disease who dropped a load from extended arms while standing. Anticipatory postural adjustments were seen when load dropping was induced by a fast, bilateral shoulder abduction but not when it was induced by pressing a trigger with the right thumb. We conclude that anticipatory postural adjustments in patients with Parkinson's disease can change with the magnitude of an action which is used to trigger a predictable postural perturbation.

Feedforward postural adjustments in a simple two-joint synergy in patients with Parkinson's disease.

Patients with Parkinson's disease, age-matched controls and young control subjects performed discrete elbow or wrist movements in a sagittal plane under the instruction to move one of the joints "as fast as possible." Relative stability of the other, postural joint was comparable in all 3 groups, while movement time was the highest in the patients and the lowest in young controls. Typically, EMG patterns in both muscle pairs acting at the joints demonstrated a commonly observed "tri-phasic" pattern.