A current analysis of behavioral problems in patients with idiopathic Parkinson's disease

Abstract

Parkinson's disease (PD) is a progressive disabling neurological disorder resulting from degeneration of dopamine-containing cells in the substantia nigra (1). Tremor, rigidity, bradykinesia, diminished hand and foot dexterity, and postural instability are the characteristic motor manifestations. Dementia, various forms of cognitive impairment, and depressive disorders are also present in PD (2). Although postmortem studies indicate that motor signs develop when 80% of the cells in the substantia nigra are lost, the pathophysiology of the nonmotor features, in particular, dementia and depression, is only partially understood. For example, the course of the motor disability parallels the degenerative process in the nigra, and biochemical and pharmacological studies implicate that this results from the loss of dopamine (1). Behavioral manifestations of PD, on the other hand, are linked to degenerative changes in other neurotransmitter systems. Although levodopa and related agents alleviate most of the motor manifestations, they are ineffective or of limited value in patients with nonmotor behavioral manifestations. Because behavioral problems have a significant impact on the management of PD, the purpose of this review is to highlight current understanding of these manifestations of the idiopathic form of PD. EPIDEMIOLOGY OF IDIOPATHIC PDBecause the age of onset of the motor manifestations may increase the risk of developing a behavioral change, it is important to first consider the epidemiology of this degenerative disorder. The prevalence of PD in the general population varies from -100 to 200 per 100,000 (3,4). Idiopathic PD (IPD) is the most common form, accounting for >85% of patients with PD (5). Age-specific prevalence of IPD dramatically increases in each decade; after age 65 the prevalence is twice that for all lower age ranges and the prevalence again doubles after age 75. At age 65 and older the prevalence of IPD is approximately 1,000 per 100,000 (3,4). S48 BEHAVIOR PROBLEMS IN IDIOPATHIC PD s49Recent investigations indicate that prevalence for blacks and women is similar to those for whites and men (4).The incidence of IPD is -20 per 100,000 in the general population, but the incidence also rises dramatically with age (5). Rajput and associates ( 5 ) found the rate to be 113.4 per 100,000 person-years between the ages of 65 and 74 and 254.4 per 100,000 person-years at ages 75-84. Sex and race differences in incidence were not apparent. Survival after diagnosis of PD is similar to that in healthy aged adults when levodopa is used (5). However, the mortality rates for untreated or partially treated patients with PD, as might be expected with dementia, is higher. EPIDEMIOLOGY OF DEPRESSION IN IPDDepression is probably the most common mental disturbance in IPD (2). In a review of 14 recent studies that included >1,500 patients, Gotham et al. (6) estimated the mean prevalence to be 46%. Prevalence ranged from 20% to as high as 90% in these studies. In our own investigations (7,8), depression was present in...

The association of incident dementia with mortality in PD

“…To explore the possibility that the association of dementia with mortality was related to withdrawal of levodopa (due to increased psychiatric side effects) 24 or to a hypothetical protective effect of selegiline on disease progression, 25,26 which might both delay the development of dementia and increase survival, we repeated the analysis controlling for use of levodopa and use of selegiline as time-dependent covariates in different models. We performed supplementary analyses designed to evaluate other possible confounders in the association of incident dementia with mortality in PD.…”

An Estimate of the Incidence of Depression in Idiopathic Parkinson's Disease

“…We used criteria for depression modified from the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition.3 A unified Parkinson's disease rating scale4 score of 3 or more on the depression item was accepted as diagnostic. According to this scale, 0 indicates no depression; 1, periods of sadness or guilt, never sustained for days or weeks; 2, sustained depression (1 week or longer); 3, sustained depression with vegetative symp¬ toms (insomnia, anorexia, weight loss, loss of interest); and 4, sustained depression with vegetative symptoms and suicidal thoughts or intent. Otherwise, depression was defined as a per¬ sistently depressed mood (not a grief reaction, eg, following the death of a spouse) or a feeling of sadness or being "down-inthe-dumps" associated with a loss of interest in usual activities and with vegetative signs and symptoms.…”

Combined effect of age and severity on the risk of dementia in Parkinson's disease

“…Dementia complicates the course of idiopathic Parkinson's disease (PD) in many patients. The development of dementia in patients with PD limits standard pharmacotherapy of PD,1 affects quality of life,2 contributes to caregiver distress,3 and has been associated with nursing home placement 4. The development of dementia also has been associated with reduced survival in patients with PD 5–7.…”