28 research outputs found
Objective Quantification of Neuromotor Symptoms in Parkinson's Disease: Implementation of a Portable, Computerized Measurement Tool
Quantification of neuromotor symptoms with device-based measures provides a useful supplement to clinical evaluation. Research using the CATSYS has established its utility as a computerized measurement system to quantify neuromotor function. The primary objective of this study is to provide technical guidance on the use of the CATSYS in Parkinson's disease (PD). Forty-four patients with idiopathic PD and 28 healthy controls were prospectively recruited and evaluated with CATSYS, a portable, Windows-based system consisting of a data logger and four different sensors (tremor pen, touch recording plate, reaction time handle, and force plate for balance recording) for quantification of neuromotor functions. CATSYS discriminated between PD and controls on measurements of rest/postural tremor, pronation/supination, finger tapping, simple reaction time, and postural sway intensity and velocity. CATSYS measurements using the proposed test battery were associated with relevant clinician-rated Unified Parkinson's disease rating scale (UPDRS) items assessing tremor and bradykinesia. More work is warranted to establish CATSYS as a diagnostic/monitoring instrument in movement disorders using the proposed technical approaches
A questionnaire-based (UM-PDHQ) study of hallucinations in Parkinson's disease
Background: Hallucinations occur in 20-40% of PD patients and have been associated with unfavorable clinical outcomes (i.e., nursing home placement, increased mortality). Hallucinations, like other non-motor features of PD, are not well recognized in routine primary/secondary clinical practice. So far, there has been no instrument for uniform characterization of hallucinations in PD. To this end, we developed the University of Miami Parkinson's disease Hallucinations Questionnaire (UM-PDHQ) that allows comprehensive assessment of hallucinations in clinical or research settings.Methods: The UM-PDHQ is composed of 6 quantitative and 14 qualitative items. For our study PD patients of all ages and in all stages of the disease were recruited over an 18-month period. The UPDRS, MMSE, and Beck Depression and Anxiety Inventories were used for comparisons.Results and Discussion: Seventy consecutive PD patients were included in the analyses. Thirty-one (44.3%) were classified as hallucinators and 39 as non-hallucinators. No significant group differences were observed in terms of demographics, disease characteristics, stage, education, depressive/anxiety scores or cognitive functioning (MMSE) between hallucinators and non-hallucinators. Single mode hallucinations were reported in 20/31 (visual/14, auditory/4, olfactory/2) whereas multiple modalities were reported in 11/31 patients. The most common hallucinatory experience was a whole person followed by small animals, insects and reptiles.Conclusion: Using the UM-PDHQ, we were able to define the key characteristics of hallucinations in PD in our cohort. Future directions include the validation of the quantitative part of the questionnaire than will serve as a rating scale for severity of hallucinations
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The effects of lateralization and type of motor symptom at disease onset on cognition in Parkinson's disease
The effects of lateralization and type of motor symptom at disease onset on cognitive functioning in Parkinson's disease were examined. While previous studies have studied these factors separately, no investigation has considered the effects of these variables simultaneously. The current study proposed that patients with right-sided disease onset would show fewer cognitive changes than patients with left-sided disease onset. In addition, patients with tremor only at disease onset were predicted to have less cognitive decline than patents with bradykinesia and rigidity. Further, it was hypothesized that there would be an additive effect of lateralization and type of motor symptom at disease onset, where patients with right-sided tremor would be free from cognitive decline and patients with left-sided bradykinesia/rigidity would demonstrate the greatest cognitive impairments. Eight cognitive tasks assessing language, visuospatial, memory and executive functioning were administered to 67 patients with idiopathic PD. Patients were categorized by side of disease onset (Right-sided and Left-sided) and symptom type at disease onset (Tremor-only and Bradykinesia/Rigidity). Results indicated that patients with right-sided tremor at disease onset (RSO-T-only) performed significantly better than the other PD subgroups across the entire neuropsychological battery. Further, this PD subgroup demonstrated preservation of cognition as compared to a group of healthy control participants, while patients with right-sided bradykinesia/rigidity, left-sided-tremor, and left-sided-bradykinesia/rigidity at disease onset showed widespread deficits in cognitive functioning. No additive risk of cognitive decline was observed for patients with left-sided bradykinesia/rigidity. In sum, the present study indicates that a preservation of cognition in PD requires both a relative sparing of the tight hemisphere and the frontal subcortical circuitry underlying bradykinesia and rigidity. If either system is disrupted, neuropsychological deficits will be observed.</p
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Side and type of motor symptom influence cognition in Parkinson's disease
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Age of disease onset influences cognition in Parkinson's disease
It is controversial whether age of disease onset
is related to cognitive decline in Parkinson's disease
(PD). We administered 7 cognitive measures assessing visuospatial
skills, memory, and executive functions to 222 patients
with idiopathic PD and 108 normal control participants.
Regression analyses demonstrated that older age of disease
onset consistently predicted cognitive decline above and
beyond normative aging and duration of illness. These findings
suggest that older age of disease onset is a critical determinant
of cognitive deterioration in PD. (JINS, 1998,
4, 285â290.
NMDAR-Dependent Control of Call Duration in Xenopus laevis
Many rhythmic behaviors, such as locomotion and vocalization, involve temporally dynamic patterns. How does the brain generate temporal complexity? Here, we use the vocal central pattern generator (CPG) of Xenopus laevis to address this question. Isolated brains can elicit fictive vocalizations, allowing us to study the CPG in vitro. The X. laevis advertisement call is temporally modulated; calls consist of rhythmic click trills that alternate between fast (âŒ60 Hz) and slow (âŒ30 Hz) rates. We investigated the role of two CPG nucleiâthe laryngeal motor nucleus (n.IXâX) and the dorsal tegmental area of the medulla (DTAM)âin setting rhythm frequency and call durations. We discovered a local field potential wave in DTAM that coincides with fictive fast trills and phasic activity that coincides with fictive clicks. After disrupting n.IXâX connections, the wave persists, whereas phasic activity disappears. Wave duration was temperature dependent and correlated with fictive fast trills. This correlation persisted when wave duration was modified by temperature manipulations. Selectively cooling DTAM, but not n.IXâX, lengthened fictive call and fast trill durations, whereas cooling either nucleus decelerated the fictive click rate. The N-methyl-d-aspartate receptor (NMDAR) antagonist dAPV blocked waves and fictive fast trills, suggesting that the wave controls fast trill activation and, consequently, call duration. We conclude that two functionally distinct CPG circuits exist: 1) a pattern generator in DTAM that determines call duration and 2) a rhythm generator (spanning DTAM and n.IXâX) that determines click rates. The newly identified DTAM pattern generator provides an excellent model for understanding NDMAR-dependent rhythmic circuits