Biomedical subjects

H Hjaltason

Publications and source records attributed to H Hjaltason.

6 recordsLinked to original sources

PubMed1998

A double blind, randomised, parallel group study to investigate the dose equivalence of Dysport and Botox in the treatment of cervical dystonia.

OBJECTIVE: This study was designed to establish whether a ratio of three units of Dysport is equivalent to one unit of Botox for the treatment of cervical dystonia. METHODS: Patients with predominantly rotational cervical dystonia, and a minimum of four previous Botox treatments, were randomised to receive either the clinically indicated dose of Botox or three times that dose in Dysport units. Study botulinum toxin was administered in a double blind fashion, to one or more clinically indicated muscles, at one or more sites per muscle. Patients returned for assessment two, four, eight, and 12 weeks after treatment. RESULTS: A total of 73 patients (Dysport, 38; Botox, 35) were entered. The Dysport group received a mean (SD) dose of 477 (131) (range 240-720) Dysport units, and the Botox group received a mean (SD) dose of 152 (45) (range 70-240) Botox units. The mean (SEM) post-treatment Tsui scores for the Dysport group (4.8 (0.3)) and the Botox group (5.0 (0.3)) were not statistically different (p=0.66). The study had 91% power to detect a clinically significant difference of two points. Both groups showed substantial improvement in Tsui score by week 2 (mean (SD); Dysport, 46 (28)%; Botox, 37 (28)%), with a peak effect at week 4 (mean (SD); Dysport, 49 (29)%; Botox, 44 (28)%). A similar response profile was seen for other assessments of efficacy. The duration of effect, assessed by time to retreatment, was also similar (mean (SD); Dysport, 83.9 (13.6) days; Botox, 80.7 (14.4) days; p=0.85). During the study 22 of 38 (58%) Dysport patients reported 39 adverse events, and 24 of 35 (69%) Botox patients reported 56 adverse events (p=0.35). A global assessment of efficacy and safety considered that 29 of 38 (76%) Dysport patients and 23 of 35 (66%) Botox patients were treatment successes (p=0.32). CONCLUSION: Patients with predominantly rotational cervical dystonia treated with the clinically indicated dose of Botox or three times that dose in Dysport units show similar improvements and do not have significantly different safety profiles.

Adult↗

PubMed1997

Line bisection with a head-mounted pointing device: an investigation of the role of right hand use and bilateral hemisphere activation in left neglect.

Left hand use in left hemispace has been shown to reduce left neglect. Right hand use can theoretically increase neglect by right spatial cueing and left hemisphere activation. The aim of the present study was to investigate the role of right hand use and right hemisphere activation in left neglect by dissociating hemisphere activation from the hemispace in which the motor response is made. Twelve neglect patients performed line bisection by two means: with their right hand and with a lamp mounted centrally on the forehead ('miner's lamp'). Lamp use induces left and right hemisphere activation without hemispace involvement. Bisection with the lamp and the hand were done with right, left and neutral cues. No difference was found in bisection performance between lamp and right hand use, and no interaction between lamp/hand use and cueing. This indicates that right hand use per se does not influence neglect in line bisection. It is suggested that the apparent lack of right hemisphere activation with lamp use is due to the widespread right-sided lesion of the typical neglect patient.

Adult↗

PubMed1996

Sustained attention and awareness of disability in chronic neglect.

The possible causative role of defective sustained attention and awareness of disability on the persistence of neglect was explored. The study included stroke patients who had had moderate or severe neglect 1-5 years before the start of the present examination. Questionnaire responses showed that the patients were aware of their disability. Impaired sustained attention was associated with poor performance in two out of three tests most sensitive in detecting neglect. This, together with indications of compensation on neglect tests, is interpreted as providing support for the hypothesis that chronic neglect is related to an impaired sustained attention.

Aged↗

PubMed1993

Visual and tactile rod bisection in unilateral neglect.

A rod bisection task was performed by 16 RBD patients with visual neglect, 10 RBD and 10 LBD patients without visual neglect, and 10 normal controls. Three different conditions were used: tactile, where they explored the rod blindfolded; visuo-tactile, where they explored the rod manually without blindfold; and visual, where they pointed to the midpoint without prior manual exploration. Only within the RBD group with visual neglect was there a significant difference between the three conditions. These patients made large rightward errors under the visual condition but no significant deviations from actual midpoint under the visuo-tactile or the tactile condition. It is therefore possible that rod exploration, which is an integral part of tactile bisection, reduces neglect to such an extent that it is difficult to identify neglect in the tactile modality on this task.

Aged↗

PubMed1992

Darkness improves line bisection in unilateral spatial neglect.

This study was performed to determine the influence of background illumination on the performance of patients with left visual neglect. We examined six RBD patients with unilateral visual neglect, and as controls six RBD patients and six LBD patients without neglect. A luminous line consisting of LEDs was used in a line bisection task under two conditions, normal illumination and darkness. As expected, neglect patients made large rightward errors under normal illumination. Their performance improved by about 43% in darkness. Our results are discussed with reference to earlier studies of space exploration without visual guidance.

Adult↗

PubMedDate not supplied

Dissociation of ophthalmokinetic and melokinetic attention in unilateral neglect.

A line cancellation task was performed by 36 right brain-damaged patients with unilateral neglect under four different conditions: normal and mirror-reversed view, with and without cueing. Two types of unilateral neglect were distinguished by directing ophthalmo- and melokinetic components of visuomanual scanning to opposite sides of the stimulus array. In ophthalmokinetic neglect, contralesional visual scanning of the stimulus array was defective, while manual scanning was unimpaired. The converse was true of melokinetic neglect. Ophthalmokinetic neglect was predominantly associated with posterior brain damage, while melokinetic neglect was predominantly associated with frontal or subcortical brain damage. In a few instances, cueing visuomanual scanning toward the neglected side of the stimulus array converted ophthalmokinetic into melokinetic neglect, and vice versa. The results are held to be indicative of two components of space representation and to provide further evidence of response-driven modulation of perceptual awareness.

Adult↗