Prospective studies conducted during the last decade have shown that the majority of patients wit... more Prospective studies conducted during the last decade have shown that the majority of patients with Parkinson’s disease (PD) develop dementia. In addition, using a variety of definitions and methods, more recent research suggests that approximately a quarter of PD patients without dementia have mild cognitive impairment (PD-MCI). Furthermore, several studies have shown that approximately 20% have MCI even at time
A growing body of literature supports the view that essential tremor (ET) involves alteration of ... more A growing body of literature supports the view that essential tremor (ET) involves alteration of cerebellar-thalamo-cortical networks which can result in working memory and executive deficits. In this study, we tested the hypothesis that individuals with ET would exhibit worse performance on memory tasks requiring more intrinsic organization and structuring (i.e., word lists) relative to those with fewer 'executive' demands (i.e., stories), similar to that previously observed in individuals with Parkinson's disease (PD). Participants included a convenience sample of 68 ET patients and 68 idiopathic PD patients, retrospectively matched based on age, education, and sex. All patients underwent routine neuropsychological evaluation assessing recent memory, auditory attention/working memory, language, and executive function. Memory measures included the Hopkins Verbal Learning Test-R and WMS-III Logical Memory. Both ET and PD patients performed significantly worse on word lis...
The subjects were six 8-to 11-year-old boys with attention deficits enrolled in their school&... more The subjects were six 8-to 11-year-old boys with attention deficits enrolled in their school's resource specialist program for learning disabled children. The effects of baseline conditions, teacher-administered reinforcers, and self-administered reinforcers were evaluated ...
Five patients with left hemispatial neglect and five aphasic control subjects were given a hemisp... more Five patients with left hemispatial neglect and five aphasic control subjects were given a hemispatial pointing task. They were instructed to point to an imaginary point in space perpendicular to the midline of the chest. Right hemisphere-damaged subjects with neglect deviated more into the hemispace ipsilateral to the lesion than left hemisphere-damaged controls. This task did not require sensory input from left hemispace, and the defective performance cannot be attributed to sensory inattention or to impaired gaze or memory. The finding is compatible with hemispatial akinesia.
Patients with hemispatial neglect perform activities poorly in the hemispace contralateral to the... more Patients with hemispatial neglect perform activities poorly in the hemispace contralateral to the lesion. We postulate that hemispatial neglect induced by right hemisphere lesions may be associated with a directional hypokinesia: initiation of movements toward the hemispace contralateral to the lesion is affected more than movements toward the lesion. We tested 6 patients with hemispatial neglect caused by right hemisphere damage, 7 with left hemisphere damage and no neglect, and 12 controls. Patients with left hemispatial neglect initiated responses to left hemispace more slowly than toward right hemispace.
Objective: Parkinson&... more Objective: Parkinson's disease (PD) is a neurodegenerative disorder resulting in a wide variety of symptoms. The current study examined the influence of apathy, depression and motor symptoms on quality of life (QoL) in PD patients. Information was drawn from an 18-month period. Method: Participants (N = 397) were assessed for apathy (Apathy Scale; Starkstein et al., 1992), depression (Beck Depression Inventory-II; Beck, Steer, Ball & Ranieri, 1996), motor severity (Unified Parkinson's Disease Rating Scale, Part III; UPDRS; Fahn, Elton & Committee, 1987), and QoL (Parkinson's Disease Questionnaire-39; Jenkinson, Fitzpatrick, Peto, Greenhall, & Hyman,1997) at 3 time points: an initial clinical evaluation (baseline), a 6-month follow-up, and an 18-month follow-up. Latent growth-curve models were used to determine the influence of apathy, depression, and motor symptoms on QoL trajectories. Results: Greater difficulties with QoL at baseline showed the strongest relationship to more severe depression symptoms, followed by more severe motor symptoms, younger age, and less education (all p values < .001). Worsening of QoL over the 18-month period was only predicted by a worsening of depression (p = .003). The relationship between QoL and depression symptoms remained significant in a subsample of nondepressed PD patients. Conclusion: Overall, findings from the current study suggest that self-reported QoL among PD patients is primarily related to depression. Future efforts to improving clinical care of PD patients may benefit by focusing on improving psychosocial adjustment or treatments targeting depression. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shap... more Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shape. To determine whether linear registration methods (image transformation to 6, 9, and 12° of freedom) alter structural volume and cognitive associations, we examined transformation alterations to the caudate nucleus within individuals diagnosed with Parkinson's disease (PD) and demographically matched non-PD peers. Volumes from native and six were expected be significantly different from 9 and 12° of freedom methods. Caudate nucleus volumes were expected to be associated with measures of processing speed and mental flexibility, but the strength of the association based on transformation approach was unknown. MRI brain scans from individuals with Parkinson's disease (n = 40) and age-matched controls (n = 40) were transformed using 6, 9, and 12° of freedom to an average brain template. Correlations controlling for total intracranial volume assessed expected structural-behavioral a...
The Parkinson&amp... more The Parkinson's disease questionnaire-39 (PDQ-39) is a common measure of health related quality of life (HRQoL) that is widely used with Parkinson disease (PD) patients. Previous evidence suggests that the PDQ-39 reflects at least 8 dimensions (i.e., Emotion, Cognitions, Mobility, etc). To date, little research has examined the external/convergent validity of the Cognitions and Emotional Well-being domains of the PDQ-39. A convenience sample of 303 PD patients underwent a comprehensive multi-domain neuropsychological evaluation, including tests of execution function, episodic verbal memory, processing speed, language and working memory, as well as completing measures of depression, apathy, state and trait anxiety and HRQoL (PDQ-39). Hierarchical regressions were conducted in order to examine the relationship between scores on neuropsychological tests and the Cognitions index, as well as mood measures and the Emotional Well-being index of the PDQ-39. Neuropsychological test performance did not account for a significant amount of variance in the PDQ-39 Cognitions index scores. Instead, it was depression that significantly contributed to the Cognitions index, above and beyond neuropsychological performance. The PDQ-39 Emotional Well-being index was also related to mood measures, primarily depression and trait anxiety. The PDQ-39 Cognition index may be more related to mood functioning, as opposed to cognitive functioning, and should not be considered a "proxy" for cognitive functioning. Future studies are needed to better explain the construct of this index.
We reviewed our deep brain stimulation patient database to describe hardware complications which ... more We reviewed our deep brain stimulation patient database to describe hardware complications which resulted from implantable pulse generator mobility, a phenomenon referred to as Twiddler's syndrome. A prospectively collected database of adverse events for all patients operated on at the University of Florida was queried searching for hardware malfunctions. Of 362 total leads implanted in 226 patients since 2002, there were 17 hardware malfunctions. Three of them were due to Twiddler's syndrome, representing 1.3% of patients (3 of 226 patients) and 1.4% of leads (5 of 362 leads). The subjects had characteristic presentations including re-emergence of symptoms, pain along the path of the hardware, abnormal impedances/current drain and radiographic signs of twisting/fracture. In all cases securing the implantable pulse generator within the chest pocket resolved the issue. Twiddler's syndrome in the population of movement disorder patients treated with deep brain stimulation is an uncommon but important adverse event. It possesses a characteristic presentation and with appropriate diagnostic evaluation it is treatable and future occurrences are preventable.
To collect the information necessary to design the methods and outcome variables for a larger tri... more To collect the information necessary to design the methods and outcome variables for a larger trial of scheduled deep brain stimulation (DBS) for Tourette syndrome. We performed a small National Institutes of Health-sponsored clinical trials planning study of the safety and preliminary efficacy of implanted DBS in the bilateral centromedian thalamic region. The study used a cranially contained constant-current device and a scheduled, rather than the classic continuous, DBS paradigm. Baseline vs 6-month outcomes were collected and analyzed. In addition, we compared acute scheduled vs acute continuous vs off DBS. A university movement disorders center. Five patients with implanted DBS. A 50% improvement in the Yale Global Tic Severity Scale (YGTSS) total score. RESULTS Participating subjects had a mean age of 34.4 (range, 28-39) years and a mean disease duration of 28.8 years. No significant adverse events or hardware-related issues occurred. Baseline vs 6-month data revealed that reductions in the YGTSS total score did not achieve the prestudy criterion of a 50% improvement in the YGTSS total score on scheduled stimulation settings. However, statistically significant improvements were observed in the YGTSS total score (mean [SD] change, -17.8 [9.4]; P=.01), impairment score (-11.3 [5.0]; P=.007), and motor score (-2.8 [2.2]; P=.045); the Modified Rush Tic Rating Scale Score total score (-5.8 [2.9]; P=.01); and the phonic tic severity score (-2.2 [2.6]; P=.04). Continuous, off, and scheduled stimulation conditions were assessed blindly in an acute experiment at 6 months after implantation. The scores in all 3 conditions showed a trend for improvement. Trends for improvement also occurred with continuous and scheduled conditions performing better than the off condition. Tic suppression was commonly seen at ventral (deep) contacts, and programming settings resulting in tic suppression were commonly associated with a subjective feeling of calmness. This study provides safety and proof of concept that a scheduled DBS approach could improve motor and vocal tics in Tourette syndrome. Refinements in neurostimulator battery life, outcome measure selection, and flexibility in programming settings can be used to enhance outcomes in a future larger study. Scheduled stimulation holds promise as a potential first step for shifting movement and neuropsychiatric disorders toward more responsive neuromodulation approaches. clinicaltrials.gov Identifier: NCT01329198.
A masked facial expression, one of the hallmark features of Parkinson disease (PD), can form the ... more A masked facial expression, one of the hallmark features of Parkinson disease (PD), can form the basis for misattributions by others about a patient's mood or interest levels. Reports of preserved intensity of internal emotional experience in PD participants raise the question of whether patients are aware of their outward expressivity levels. The aim of the present study was to determine whether PD participants exhibit deficits in overall emotional expressivity, and if so, whether they are aware of these deficits. We evaluated 37 non-demented PD participants and 21 comparison participants using the Berkeley Expressivity Questionnaire (BEQ). To examine awareness of emotional expressivity, we compared participant self-ratings of their own expressivity to ratings made by family members or close friends. Participants also completed questionnaires regarding depression and apathy and underwent motor examination and cognitive screening. PD participants' self-ratings of emotional expressivity were significantly lower than comparison participants' self-ratings. Even so, the PD participants viewed themselves as experiencing equivalent levels of emotional intensity to comparison participants, based on analysis of the BEQ subscales. Informant and PD participant self-ratings did not differ, indicating that PD participants accurately appraise the extent of their reduced expressivity. These findings suggest that anosognosia for emotional expressivity is not a prominent feature of nondemented Parkinson disease. Importantly, PD participants are aware of their reduced expressivity and report experiencing emotions as intensely as comparison participants. These findings highlight the view that diminished emotional expressivity in PD should not be mistaken for decreased subjective emotional experience.
Prospective studies conducted during the last decade have shown that the majority of patients wit... more Prospective studies conducted during the last decade have shown that the majority of patients with Parkinson’s disease (PD) develop dementia. In addition, using a variety of definitions and methods, more recent research suggests that approximately a quarter of PD patients without dementia have mild cognitive impairment (PD-MCI). Furthermore, several studies have shown that approximately 20% have MCI even at time
A growing body of literature supports the view that essential tremor (ET) involves alteration of ... more A growing body of literature supports the view that essential tremor (ET) involves alteration of cerebellar-thalamo-cortical networks which can result in working memory and executive deficits. In this study, we tested the hypothesis that individuals with ET would exhibit worse performance on memory tasks requiring more intrinsic organization and structuring (i.e., word lists) relative to those with fewer 'executive' demands (i.e., stories), similar to that previously observed in individuals with Parkinson's disease (PD). Participants included a convenience sample of 68 ET patients and 68 idiopathic PD patients, retrospectively matched based on age, education, and sex. All patients underwent routine neuropsychological evaluation assessing recent memory, auditory attention/working memory, language, and executive function. Memory measures included the Hopkins Verbal Learning Test-R and WMS-III Logical Memory. Both ET and PD patients performed significantly worse on word lis...
The subjects were six 8-to 11-year-old boys with attention deficits enrolled in their school&... more The subjects were six 8-to 11-year-old boys with attention deficits enrolled in their school's resource specialist program for learning disabled children. The effects of baseline conditions, teacher-administered reinforcers, and self-administered reinforcers were evaluated ...
Five patients with left hemispatial neglect and five aphasic control subjects were given a hemisp... more Five patients with left hemispatial neglect and five aphasic control subjects were given a hemispatial pointing task. They were instructed to point to an imaginary point in space perpendicular to the midline of the chest. Right hemisphere-damaged subjects with neglect deviated more into the hemispace ipsilateral to the lesion than left hemisphere-damaged controls. This task did not require sensory input from left hemispace, and the defective performance cannot be attributed to sensory inattention or to impaired gaze or memory. The finding is compatible with hemispatial akinesia.
Patients with hemispatial neglect perform activities poorly in the hemispace contralateral to the... more Patients with hemispatial neglect perform activities poorly in the hemispace contralateral to the lesion. We postulate that hemispatial neglect induced by right hemisphere lesions may be associated with a directional hypokinesia: initiation of movements toward the hemispace contralateral to the lesion is affected more than movements toward the lesion. We tested 6 patients with hemispatial neglect caused by right hemisphere damage, 7 with left hemisphere damage and no neglect, and 12 controls. Patients with left hemispatial neglect initiated responses to left hemispace more slowly than toward right hemispace.
Objective: Parkinson&... more Objective: Parkinson's disease (PD) is a neurodegenerative disorder resulting in a wide variety of symptoms. The current study examined the influence of apathy, depression and motor symptoms on quality of life (QoL) in PD patients. Information was drawn from an 18-month period. Method: Participants (N = 397) were assessed for apathy (Apathy Scale; Starkstein et al., 1992), depression (Beck Depression Inventory-II; Beck, Steer, Ball & Ranieri, 1996), motor severity (Unified Parkinson's Disease Rating Scale, Part III; UPDRS; Fahn, Elton & Committee, 1987), and QoL (Parkinson's Disease Questionnaire-39; Jenkinson, Fitzpatrick, Peto, Greenhall, & Hyman,1997) at 3 time points: an initial clinical evaluation (baseline), a 6-month follow-up, and an 18-month follow-up. Latent growth-curve models were used to determine the influence of apathy, depression, and motor symptoms on QoL trajectories. Results: Greater difficulties with QoL at baseline showed the strongest relationship to more severe depression symptoms, followed by more severe motor symptoms, younger age, and less education (all p values < .001). Worsening of QoL over the 18-month period was only predicted by a worsening of depression (p = .003). The relationship between QoL and depression symptoms remained significant in a subsample of nondepressed PD patients. Conclusion: Overall, findings from the current study suggest that self-reported QoL among PD patients is primarily related to depression. Future efforts to improving clinical care of PD patients may benefit by focusing on improving psychosocial adjustment or treatments targeting depression. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shap... more Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shape. To determine whether linear registration methods (image transformation to 6, 9, and 12° of freedom) alter structural volume and cognitive associations, we examined transformation alterations to the caudate nucleus within individuals diagnosed with Parkinson's disease (PD) and demographically matched non-PD peers. Volumes from native and six were expected be significantly different from 9 and 12° of freedom methods. Caudate nucleus volumes were expected to be associated with measures of processing speed and mental flexibility, but the strength of the association based on transformation approach was unknown. MRI brain scans from individuals with Parkinson's disease (n = 40) and age-matched controls (n = 40) were transformed using 6, 9, and 12° of freedom to an average brain template. Correlations controlling for total intracranial volume assessed expected structural-behavioral a...
The Parkinson&amp... more The Parkinson's disease questionnaire-39 (PDQ-39) is a common measure of health related quality of life (HRQoL) that is widely used with Parkinson disease (PD) patients. Previous evidence suggests that the PDQ-39 reflects at least 8 dimensions (i.e., Emotion, Cognitions, Mobility, etc). To date, little research has examined the external/convergent validity of the Cognitions and Emotional Well-being domains of the PDQ-39. A convenience sample of 303 PD patients underwent a comprehensive multi-domain neuropsychological evaluation, including tests of execution function, episodic verbal memory, processing speed, language and working memory, as well as completing measures of depression, apathy, state and trait anxiety and HRQoL (PDQ-39). Hierarchical regressions were conducted in order to examine the relationship between scores on neuropsychological tests and the Cognitions index, as well as mood measures and the Emotional Well-being index of the PDQ-39. Neuropsychological test performance did not account for a significant amount of variance in the PDQ-39 Cognitions index scores. Instead, it was depression that significantly contributed to the Cognitions index, above and beyond neuropsychological performance. The PDQ-39 Emotional Well-being index was also related to mood measures, primarily depression and trait anxiety. The PDQ-39 Cognition index may be more related to mood functioning, as opposed to cognitive functioning, and should not be considered a "proxy" for cognitive functioning. Future studies are needed to better explain the construct of this index.
We reviewed our deep brain stimulation patient database to describe hardware complications which ... more We reviewed our deep brain stimulation patient database to describe hardware complications which resulted from implantable pulse generator mobility, a phenomenon referred to as Twiddler's syndrome. A prospectively collected database of adverse events for all patients operated on at the University of Florida was queried searching for hardware malfunctions. Of 362 total leads implanted in 226 patients since 2002, there were 17 hardware malfunctions. Three of them were due to Twiddler's syndrome, representing 1.3% of patients (3 of 226 patients) and 1.4% of leads (5 of 362 leads). The subjects had characteristic presentations including re-emergence of symptoms, pain along the path of the hardware, abnormal impedances/current drain and radiographic signs of twisting/fracture. In all cases securing the implantable pulse generator within the chest pocket resolved the issue. Twiddler's syndrome in the population of movement disorder patients treated with deep brain stimulation is an uncommon but important adverse event. It possesses a characteristic presentation and with appropriate diagnostic evaluation it is treatable and future occurrences are preventable.
To collect the information necessary to design the methods and outcome variables for a larger tri... more To collect the information necessary to design the methods and outcome variables for a larger trial of scheduled deep brain stimulation (DBS) for Tourette syndrome. We performed a small National Institutes of Health-sponsored clinical trials planning study of the safety and preliminary efficacy of implanted DBS in the bilateral centromedian thalamic region. The study used a cranially contained constant-current device and a scheduled, rather than the classic continuous, DBS paradigm. Baseline vs 6-month outcomes were collected and analyzed. In addition, we compared acute scheduled vs acute continuous vs off DBS. A university movement disorders center. Five patients with implanted DBS. A 50% improvement in the Yale Global Tic Severity Scale (YGTSS) total score. RESULTS Participating subjects had a mean age of 34.4 (range, 28-39) years and a mean disease duration of 28.8 years. No significant adverse events or hardware-related issues occurred. Baseline vs 6-month data revealed that reductions in the YGTSS total score did not achieve the prestudy criterion of a 50% improvement in the YGTSS total score on scheduled stimulation settings. However, statistically significant improvements were observed in the YGTSS total score (mean [SD] change, -17.8 [9.4]; P=.01), impairment score (-11.3 [5.0]; P=.007), and motor score (-2.8 [2.2]; P=.045); the Modified Rush Tic Rating Scale Score total score (-5.8 [2.9]; P=.01); and the phonic tic severity score (-2.2 [2.6]; P=.04). Continuous, off, and scheduled stimulation conditions were assessed blindly in an acute experiment at 6 months after implantation. The scores in all 3 conditions showed a trend for improvement. Trends for improvement also occurred with continuous and scheduled conditions performing better than the off condition. Tic suppression was commonly seen at ventral (deep) contacts, and programming settings resulting in tic suppression were commonly associated with a subjective feeling of calmness. This study provides safety and proof of concept that a scheduled DBS approach could improve motor and vocal tics in Tourette syndrome. Refinements in neurostimulator battery life, outcome measure selection, and flexibility in programming settings can be used to enhance outcomes in a future larger study. Scheduled stimulation holds promise as a potential first step for shifting movement and neuropsychiatric disorders toward more responsive neuromodulation approaches. clinicaltrials.gov Identifier: NCT01329198.
A masked facial expression, one of the hallmark features of Parkinson disease (PD), can form the ... more A masked facial expression, one of the hallmark features of Parkinson disease (PD), can form the basis for misattributions by others about a patient's mood or interest levels. Reports of preserved intensity of internal emotional experience in PD participants raise the question of whether patients are aware of their outward expressivity levels. The aim of the present study was to determine whether PD participants exhibit deficits in overall emotional expressivity, and if so, whether they are aware of these deficits. We evaluated 37 non-demented PD participants and 21 comparison participants using the Berkeley Expressivity Questionnaire (BEQ). To examine awareness of emotional expressivity, we compared participant self-ratings of their own expressivity to ratings made by family members or close friends. Participants also completed questionnaires regarding depression and apathy and underwent motor examination and cognitive screening. PD participants' self-ratings of emotional expressivity were significantly lower than comparison participants' self-ratings. Even so, the PD participants viewed themselves as experiencing equivalent levels of emotional intensity to comparison participants, based on analysis of the BEQ subscales. Informant and PD participant self-ratings did not differ, indicating that PD participants accurately appraise the extent of their reduced expressivity. These findings suggest that anosognosia for emotional expressivity is not a prominent feature of nondemented Parkinson disease. Importantly, PD participants are aware of their reduced expressivity and report experiencing emotions as intensely as comparison participants. These findings highlight the view that diminished emotional expressivity in PD should not be mistaken for decreased subjective emotional experience.
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