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The saccadic and neurological deficits in type 3 Gaucher disease.

Benko W, Ries M, Wiggs EA, Brady RO, Schiffmann R, Fitzgibbon EJ - PLoS ONE (2011)

Bottom Line: We found that patients with type 3 Gaucher disease had a significantly higher regression slope of duration vs amplitude and peak duration vs amplitude compared to healthy controls for both horizontal and vertical saccades.Saccadic latency was significantly increased for horizontal saccades only.Vertical saccade peak duration vs amplitude slope significantly correlated with IQ and with the performance on the Purdue Pegboard but not with the brainstem and somatosensory evoked potentials.

View Article: PubMed Central - PubMed

Affiliation: Developmental and Metabolic Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.

ABSTRACT

Unlabelled: Our objective was to characterize the saccadic eye movements in patients with type 3 Gaucher disease (chronic neuronopathic) in relationship to neurological and neurophysiological abnormalities. For approximately 4 years, we prospectively followed a cohort of 15 patients with Gaucher type 3, ages 8-28 years, by measuring saccadic eye movements using the scleral search coil method. We found that patients with type 3 Gaucher disease had a significantly higher regression slope of duration vs amplitude and peak duration vs amplitude compared to healthy controls for both horizontal and vertical saccades. Saccadic latency was significantly increased for horizontal saccades only. Downward saccades were more affected than upward saccades. Saccade abnormalities increased over time in some patients reflecting the slowly progressive nature of the disease. Phase plane plots showed individually characteristic patterns of abnormal saccade trajectories. Oculo-manual dexterity scores on the Purdue Pegboard test were low in virtually all patients, even in those with normal cognitive function. Vertical saccade peak duration vs amplitude slope significantly correlated with IQ and with the performance on the Purdue Pegboard but not with the brainstem and somatosensory evoked potentials. We conclude that, in patients with Gaucher disease type 3, saccadic eye movements and oculo-manual dexterity are representative neurological functions for longitudinal studies and can probably be used as endpoints for therapeutic clinical trials.

Trial registration: ClinicalTrials.gov NCT00001289.

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Saccadic eye movement parameters.
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pone-0022410-g002: Saccadic eye movement parameters.

Mentions: Patients had a general ophthalmologic assessment before assessment of saccadic eye movements, to identify visual impairment. Horizontal and vertical saccadic eye movements were recorded using a scleral search coil technique and were sampled at 1 kHz using Realtime (EXperimentation) (REX) [18]. The subjects sat with their head in a chin cup and their forehead against a headrest and faced a screen 1 meter away on which a red laser spot was back projected (the spot subtended about 0.5 deg). A mirror galvanometer moved the target spot in a pseudorandom sequence from -15 deg to +15 deg with target jumps of 2.5, 5, 7.5, 10, 12.5, 15, 20, 25, 30 deg in each direction. The target jumped approximately every 3 seconds with about 0.5 sec variability. Subjects were instructed to follow the target with their eyes. A minimum of 100 target jumps was recorded for a sequence of vertical saccades and then a minimum of 100 target jumps for horizontal saccades. The eye position data was then filtered and differentiated to obtain eye velocity. Saccades were detected using a velocity criterion, and their characteristics (latency, amplitude, duration, and peak velocity) were determined (Figure 2). Saccade latency is defined as the time from target onset to the time of eye motion onset using velocity criteria (Figure 2). Saccade gain is defined as the amplitude of the first saccade made to a target divided by the target's distance from fixation (Figure 2). Saccade peak duration is defined as saccade amplitude divided by saccade peak velocity and was used to linearize the graph of saccade velocity vs amplitude, often referred to as the main sequence [18], [19], [20]. The graph of saccade duration vs amplitude tended to be linear and further manipulations were not necessary [18], [20]. Regression lines were fitted to the data of saccade peak duration vs amplitude and saccade duration vs amplitude as a method to summarize saccade performance for any particular recording session. Slower, more abnormal saccades yielded regression slopes that were larger for duration vs amplitude graphs and larger for peak duration vs amplitude graphs.


The saccadic and neurological deficits in type 3 Gaucher disease.

Benko W, Ries M, Wiggs EA, Brady RO, Schiffmann R, Fitzgibbon EJ - PLoS ONE (2011)

Saccadic eye movement parameters.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3140522&req=5

pone-0022410-g002: Saccadic eye movement parameters.
Mentions: Patients had a general ophthalmologic assessment before assessment of saccadic eye movements, to identify visual impairment. Horizontal and vertical saccadic eye movements were recorded using a scleral search coil technique and were sampled at 1 kHz using Realtime (EXperimentation) (REX) [18]. The subjects sat with their head in a chin cup and their forehead against a headrest and faced a screen 1 meter away on which a red laser spot was back projected (the spot subtended about 0.5 deg). A mirror galvanometer moved the target spot in a pseudorandom sequence from -15 deg to +15 deg with target jumps of 2.5, 5, 7.5, 10, 12.5, 15, 20, 25, 30 deg in each direction. The target jumped approximately every 3 seconds with about 0.5 sec variability. Subjects were instructed to follow the target with their eyes. A minimum of 100 target jumps was recorded for a sequence of vertical saccades and then a minimum of 100 target jumps for horizontal saccades. The eye position data was then filtered and differentiated to obtain eye velocity. Saccades were detected using a velocity criterion, and their characteristics (latency, amplitude, duration, and peak velocity) were determined (Figure 2). Saccade latency is defined as the time from target onset to the time of eye motion onset using velocity criteria (Figure 2). Saccade gain is defined as the amplitude of the first saccade made to a target divided by the target's distance from fixation (Figure 2). Saccade peak duration is defined as saccade amplitude divided by saccade peak velocity and was used to linearize the graph of saccade velocity vs amplitude, often referred to as the main sequence [18], [19], [20]. The graph of saccade duration vs amplitude tended to be linear and further manipulations were not necessary [18], [20]. Regression lines were fitted to the data of saccade peak duration vs amplitude and saccade duration vs amplitude as a method to summarize saccade performance for any particular recording session. Slower, more abnormal saccades yielded regression slopes that were larger for duration vs amplitude graphs and larger for peak duration vs amplitude graphs.

Bottom Line: We found that patients with type 3 Gaucher disease had a significantly higher regression slope of duration vs amplitude and peak duration vs amplitude compared to healthy controls for both horizontal and vertical saccades.Saccadic latency was significantly increased for horizontal saccades only.Vertical saccade peak duration vs amplitude slope significantly correlated with IQ and with the performance on the Purdue Pegboard but not with the brainstem and somatosensory evoked potentials.

View Article: PubMed Central - PubMed

Affiliation: Developmental and Metabolic Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.

ABSTRACT

Unlabelled: Our objective was to characterize the saccadic eye movements in patients with type 3 Gaucher disease (chronic neuronopathic) in relationship to neurological and neurophysiological abnormalities. For approximately 4 years, we prospectively followed a cohort of 15 patients with Gaucher type 3, ages 8-28 years, by measuring saccadic eye movements using the scleral search coil method. We found that patients with type 3 Gaucher disease had a significantly higher regression slope of duration vs amplitude and peak duration vs amplitude compared to healthy controls for both horizontal and vertical saccades. Saccadic latency was significantly increased for horizontal saccades only. Downward saccades were more affected than upward saccades. Saccade abnormalities increased over time in some patients reflecting the slowly progressive nature of the disease. Phase plane plots showed individually characteristic patterns of abnormal saccade trajectories. Oculo-manual dexterity scores on the Purdue Pegboard test were low in virtually all patients, even in those with normal cognitive function. Vertical saccade peak duration vs amplitude slope significantly correlated with IQ and with the performance on the Purdue Pegboard but not with the brainstem and somatosensory evoked potentials. We conclude that, in patients with Gaucher disease type 3, saccadic eye movements and oculo-manual dexterity are representative neurological functions for longitudinal studies and can probably be used as endpoints for therapeutic clinical trials.

Trial registration: ClinicalTrials.gov NCT00001289.

Show MeSH
Related in: MedlinePlus