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Papers by nicholas lim

Neurology, 2015

BACKGROUND: Apathy is one manifestation of impaired goal-directed behavior (GDB) and is highly pr... more BACKGROUND: Apathy is one manifestation of impaired goal-directed behavior (GDB) and is highly prevalent in individuals with neurodegenerative diseases (ND). Core GDB processes include initiation, planning and motivation; when any of these processes is compromised, apathy results. We examined impaired GDB in Alzheimer’s disease (AD) and Parkinson’s disease (PD) and compared apathy profiles across these two patient groups. DESIGN/METHODS: Participants included 23 subjects with mild AD, 17 PD subjects, and 20 demographically matched normal controls (NC). Caregivers completed the Neuropsychiatric Inventory (NPI) and all subjects had apathy according to the NPI frequency by severity score >1. Subjects were administered the Philadelphia Apathy Computerized Test (PACT), a novel reaction time test that quantifies three components of GDB: initiation, planning, and motivation. Independent samples t-tests were used to compare PACT latencies for each disease group relative to NC then betwee...

Journal of Clinical and Experimental Neuropsychology, 2016

Introduction-Apathy is a syndrome characterized by a reduction in goal-directed behavior. Neurode... more Introduction-Apathy is a syndrome characterized by a reduction in goal-directed behavior. Neurodegenerative diseases frequently exhibit apathy. However, we lack an objective measure of apathy. The Philadelphia Apathy Computerized Task (PACT) measures impairments in goaldirected behavior that contribute to apathy, including initiation, planning and motivation. We sought to examine these mechanisms in Parkinson's disease (PD) patients. Methods-PD patients and healthy controls with a caregiver were recruited for the study. Participants were administered the PACT, a novel computerized assessment of goal-directed behavior based on reaction times, and the Starkstein Apathy Scale (AS). Care partners completed the Neuropsychiatric Inventory (NPI). T-tests and Wilcoxon rank sum tests were used to compare baseline demographic characteristics of PD and control participants. Linear regressions were used to compare PD patients to controls on each of the three PACT subtasks (initiation, planning and motivation) while controlling for motor slowing. We then compared performance on each PACT subtask between PD subjects defined as apathetic using the NPI and Starkstein Apathy Scale and controls. Results-We included 30 PD and 15 control participants in the analysis. When controlling for motor slowing, both all PD and PD apathetic subjects were significantly slower than controls on the planning task and on the initiation task. There were no significant differences between PD patients and controls on the motivation tasks. Conclusions-PD patients showed specific initiation and planning deficits compared to control participants. After using traditional scales to define apathy, PD apathetic patients still exhibited impaired initiation and planning behaviors. These results suggest that the PACT measures aspects of impaired goal-directed behavior that may contribute to apathy in PD.

Neurology, Apr 6, 2015

OBJECTIVE: To validate the Philadelphia Apathy Computerized Task (PACT) as an apathy measure in P... more OBJECTIVE: To validate the Philadelphia Apathy Computerized Task (PACT) as an apathy measure in Parkinson9s Disease (PD). BACKGROUND: Apathy is a common symptom in neurodegenerative disease. However, we lack an objective apathy measure. The PACT measures mechanisms contributing to apathy, including impaired initiation, planning and motivation. DESIGN/METHODS: PD patients with a caregiver were recruited from the Parkinson’s Disease and Movement Disorder’s Center at the University of Pennsylvania (N=38) and compared to healthy controls (N=15). Subjects were administered the PACT, a computerized reaction time test of initiation, planning and motivation (both reward and penalty). Care partners completed the Neuropsychiatric Inventory (NPI), a cut-off of 蠅 1 was used to define apathy. ANOVAs and Chi-square tests were used to examine clinical and demographic factors that varied between apathetic PD patients, non-apathetic PD patients and healthy controls. We then performed ANCOVAs comparing the average latencies on each PACT subtask while controlling for motor slowing. RESULTS: Of the PD patients 55.3[percnt] (N=21) were apathetic. Apathetic PD, non-apathetic PD, and control participants differed significantly in terms of motor speed, but did not differ significantly in terms of age, education, or gender. In a model controlling for motor speed, apathetic PD patients had significantly slower latencies than non-apathetic PD patients and control patients for the reward task (F=14.63, p<0.001), the penalty task (F=14.19, p<0.001), and the planning task (F=15.4, p<0.001). There were no significant differences between groups in the initiation task (F=2.69, p=0.078). CONCLUSIONS: Slower latencies on the PACT motivation and planning blocks were significantly associated with apathy. This suggests that the PACT may successfully measure apathy in PD. The specific motivation and planning deficits may suggest a distinct apathy profile in PD. Study Supported by: Dr. Massimo is supported by NINR F32 NR014777 and Dr. Dahodwala is supported by K23 AG034236. Disclosure: Dr. Fitts has nothing to disclose. Dr. Massimo has nothing to disclose. Dr. Lim has nothing to disclose. Dr. Grossman has nothing to disclose. Dr. Dahodwala has received research support from Teva.

New England Journal of Medicine, 1964

Original Article from The New England Journal of Medicine Androgenic Adrenal Hyperfunction in A... more Original Article from The New England Journal of Medicine Androgenic Adrenal Hyperfunction in Acromegaly.

New England Journal of Medicine, 1962

Original Article from The New England Journal of Medicine Cushing's Syndrome Due to an ACT... more Original Article from The New England Journal of Medicine Cushing's Syndrome Due to an ACTH-Secreting Chromophobe Adenoma.

The Journal of Clinical Endocrinology & Metabolism, 1965

The Journal of Clinical Endocrinology & Metabolism, 1969

The Journal of Clinical Endocrinology & Metabolism, 1964

Endocrine Society JCEM ...

International Journal of Injury Control and Safety Promotion, 2006

The present study sought to learn about risk perceptions held by parents of preschool firesetters... more The present study sought to learn about risk perceptions held by parents of preschool firesetters. A 41-item survey was distributed to 60 parents whose children, aged 6 years and younger, had previously set fires and who were involved in intervention programmes throughout the US. Most parents did not think their children would play with matches/ lighters, or knew how to use these items, although some had witnessed their children playing with matches/lighters previously. Most parents reported having taken precautions to keep matches/lighters out of reach and also educating their children about fire. Regardless, children not only set fires, but in 40% of cases climbed to access the match/ lighter. Parents' perceptions of their children's proclivity for fire play were not consistent with their actual fire-play behaviour. Parents underestimated the likelihood that their children would play with matches/lighters. Although most reportedly undertook preventative measures aimed at thwarting fire play, these strategies were ineffective. Traditionally relied upon precautionary techniques, such as storing lighters out of reach and discussing the dangers of fire, were not sufficient to stem interest and resultant fire play.