Detecting Apathy in Individuals with Parkinson's Disease: A Systematic Review

Anatomical correlates of apathy and impulsivity co-occurrence in early Parkinson's disease

BACKGROUND

Although apathy and impulse control disorders (ICDs) are considered to represent opposite extremes of a continuum of motivated behavior (i.e., hypo- and hyperdopaminergic behaviors), they may also co-occur in Parkinson's disease (PD).

OBJECTIVES

We aimed to explore the co-occurrence of ICDs and apathy and its neural correlates analyzing gray matter (GM) changes in early untreated PD patients. Moreover, we aimed to investigate the possible longitudinal relationship between ICDs and apathy and their putative impact on cognition during the first five years of PD.

METHODS

We used the Parkinson's Progression Markers Initiative (PPMI) database to identify the co-occurrence of apathy and ICDs in 423 early drug-naïve PD patients at baseline and at 5-year follow-up. Baseline MRI volumes and gray matter changes were analyzed between groups using voxel-based morphometry. Multi-level models assessed the longitudinal relationship (across five years) between apathy and ICDs and cognitive functioning.

RESULTS

At baseline, co-occurrence of apathy and ICDs was observed in 23 patients (5.4%). This finding was related to anatomical GM reduction along the cortical regions involved in the limbic circuit and cognitive control systems. Longitudinal analyses indicated that apathy and ICDs were related to each other as well as to the combined use of levodopa and dopamine agonists. Worse apathetic and ICDs states were associated with poorer executive functions.

CONCLUSIONS

Apathy and ICDs are joint non-exclusive neuropsychiatric disorders also in the early stages of PD and their co-occurrence was associated with GM decrease in several cortical regions of the limbic circuit and cognitive control systems.

Clinical features and neurobiochemical mechanisms of olfactory dysfunction in patients with Parkinson disease

This study aimed to investigate clinical features, influencing factors and neurobiochemical mechanisms of olfactory dysfunction (OD) in Parkinson disease (PD). Total 39 patients were divided into the PD with OD (PD-OD) and PD with no OD (PD-nOD) groups according to overall olfactory function, including threshold, discrimination and identification, assessed by Sniffin' Sticks test. Motor function and non-motor symptoms were rated by multiple scales. Dopamine, acetylcholine, norepinephrine and 5-hydroxytryptamine levels in cerebrospinal fluid (CSF) were measured. We found that the PD-OD group showed significantly lower score of Montreal Cognitive Assessment Scale, higher scores of rapid eye movement sleep behavior disorder (RBD) Screening Questionnaire and Epworth Sleepiness Scale than the PD-nOD group (p < 0.05). RBD Screening Questionnaire score was independently associated with the scores of overall olfactory function and discrimination (p < 0.05). Dopamine and acetylcholine levels in CSF from the PD-OD group was significantly lower than that from the PD-nOD group (p < 0.05). Dopamine and acetylcholine levels in CSF were significantly and positively correlated with the scores of overall olfactory function, threshold, discrimination and identification in PD patients (p < 0.05). RBD Screening Questionnaire score was significantly and negatively correlated with acetylcholine level in CSF in PD patients with poor olfactory detection (p < 0.05). This investigation reveals that PD-OD is associated with cognitive impairment, probable RBD and excessive daytime sleepiness. PD-OD is correlated with the decreased levels of dopamine and acetylcholine in CSF. RBD is an independent influencing factor of overall olfactory function and discrimination, and the decreased acetylcholine level in CSF may be the common neurobiochemical basis of RBD and OD in PD patients.

Screening for non-motor symptoms in Egyptian patients with Parkinson’s disease

Background

Most of the patients with Parkinson’s disease (PD) suffer from non-motor symptoms (NMS). Despite their marked effect on patients’ quality of life, NMS remain under-estimated by physicians, patients and caregivers. The aim of this study was to suggest a battery to screen for the presence of NMS in PD patients in the setting of an outpatient clinic and to assess the NMS of PD in Egyptian patients and factors affecting them.

Results

This study was conducted on 50 patients with PD, 35 males (70%) and 15 females (30%) whom their age ranged from 36 to 80 years with a mean of 62.88 ± 8.74 years. All patients were assessed using the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Apathy Scale (AS), Montreal Cognitive Assessment (MOCA), Hamilton Depression Rating Scale (HDRS) and Parkinson’s Disease Sleep Scale (PDSS). The mean age at disease onset was 59.10 ± 9.34 years and the mean disease duration was 3.76 ± 3.16 years. 98% of patients (49 out of 50) had at least one non-motor symptom. The mean MDS-UPDRS scores were 15.74 ± 7.93 for part I, 17.94 ± 11.61 for part II and 42.32 ± 22.74 for part III. The mean score for AS was 9.90 ± 10.66 with 70% of patients considered apathetic. The mean MOCA score was 21.12 ± 4.73 with 38 patients (76%) found to be cognitively impaired. The mean HDRS score was 12.26 ± 8.52 with 34 patients (68%) found to be depressed. The mean PDSS score was 92.22 ± 32.53 with sleep disturbances found in 38 patients (76%). A statistically significant negative correlation was found between the HDRS and PDSS scores (P value < 0.001). Age of patients, age at disease onset and disease duration were not correlated to MDS-UPDRS, AS, MOCA, HDRS and PDSS scores.

Conclusions

Most of the patients with PD were found to suffer from NMS including apathy, cognitive impairment, depression and sleep disturbances. Physicians need to screen their PD patients for NMS on regular basis using the appropriate tools. Self-administered questionnaires could function as reliable screening tools for NMS in PD patients.

Apathy in Parkinson's Disease: A Retrospective Study of Its Prevalence and Relationship With Mood, Anxiety, and Cognitive Function

Apathy is thought to be an important clinical feature of Parkinson's disease (PD). However, its prevalence ranges greatly across studies because of differing definitions, assessment tools, and patient inclusion criteria. Furthermore, it remains unclear how the presentation of apathy in PD is related to mood disorder and/or cognitive impairment. This study sought to examine the prevalence of a pure apathy syndrome in PD, distinct from both depression and anxiety, and reveal its associated cognitive profile. A retrospective study was performed on 177 PD patients who had completed measures of apathy [Apathy Evaluation Scale (AES)] and mood functioning [Hospital Anxiety and Depression Scale (HADS)] and had undergone extensive neuropsychological assessment, using measures of intellectual functioning, memory, executive function, attention, language, visual processing, and cognitive speed; 14.7% of the sample indicated clinically significant levels of apathy, but this nearly always co-presented with depression and/or anxiety, with cases of "pure" apathy very rare (2.8%). On extensive cognitive assessment, patients with mood disorder performed worse on a measure of non-verbal intellectual functioning, but patients with additional apathy or apathy only demonstrated no further losses. The syndrome of apathy in PD greatly overlaps with that of depression and anxiety, suggesting that apathy in PD may be in large an epiphenomenon of mood disorder, with no specific neuropsychological features.