Epidemiology

Onset between 45 and 65 years of age

Approximately equal sex and ethnic distribution

Risk factors for development of dementia include increased age, greater severity of neurologic symptoms, and presence of APOE e2 allele

Cardinal features of parkinsonian syndrome

4-6 Hz resting tremor

Rigidity

Bradykinesia

Postural instability

Clinical features

Motor

General

Unilateral onset

Persistent asymmetry affecting side of onset most

Excellent initial response (70%-100%) to levodopa

Bradykinesia

Masked facies

Decreased blinking

Hypophonic speech

Prolonged response latency

Slowed festinating gait with decreased arm swing

Micrographia

Rigidity

Trunk & limb muscles

Cogwheeling

Tremor

Resting

Typically, pill-rolling

Cognitive

Characterized by dementia of the subcortical type (please refer to Chapter 31)

Antiparkinsonian medications frequently exacerbate cognitive impairment

Treatment of comorbid mood disorders may improve cognition

Psychiatric

Mood

˜50% depression

Prominent features include anxiety and increased suicidality

Anxiety

Typically Generalized Anxiety Disorder

Panic disorder, obsessive compulsive disorders, and discrete phobias have also been observed

Psychosis

Characterized by visual hallucinations, delusions, confusion

Fluctuates during day, worse in evening

Often associated with longstanding parkinsonian illness, high doses of antiparkinson medications, and dementia

Sleep disturbances

Increased time to sleep onset with multiple awakenings Vivid, disconcerting dreams

Diagnosis

Clinical diagnosis strongly suggested by history and physical exam

Central nervous system imaging, particularly MRI, is indicated in the presence of remarkably unilateral neurologic findings to rule out mass lesion or in the event of atypical neurologic findings

MRI shows reductions in the size of substantia nigra in advanced cases of Parkinson disease

Management

General considerations

Coordinate care with neurologists and other specialists including physical therapy, dietician, social workers

Psychoeducation for patient, family, caregivers

Assessment of functional limitations, including activities of daily living, gait disturbance, fall risk

Attention to caregiver burden

Hallucinations and delusions typically occur at night and are the chief reason families place patients in nursing homes

Treatment of movement disorder

Therapy often entails slowing the progression of the disease with neuroprotective agents (e.g., selegiline) followed by symptomatic treatment with agents such as dopamine agonists and anticholinergics

Neuroprotective agents such as selegiline can slow the progression of the disorder and thus defer the need for dopaminergic therapy

Despite levodopa therapy, parkinsonian motor symptoms reemerge after 5-10 years

For patients unable to tolerate levodopa, amantadine and dopamine receptor agonists are useful adjuncts in the therapy of Parkinson disease

Surgical procedures include stereotactic ventral pallidotomy, deep brain stimulation, or transplantation

Treatment of comorbid psychiatric symptoms

When possible, simplify/optimize medication regimens

Rule out underlying metabolic and infectious causes for perceptual and mood disturbances

Psychotic symptoms are common adverse effects of antiparkinsonism medications

Consider discontinuation of antiparkinsonism medications in the following order: anticholinergics > amantadine > selegiline > dopaminergic agents

Persistent psychotic symptoms warrant use of antipsychotic agents

Clozapine and quetiapine at low doses are preferred agents due to decreased inherent risk of extrapyramidal symptoms

Mood and anxiety symptoms may respond to dopaminergic agent dose reductions

Rule out parkinsonian drug-associated psychiatric symptoms

Visual hallucinations, typically characterized by human or animal figures, usually at night

Persecutory delusions

Elevated mood

Anxiety

Increased sexual interest

Management includes discontinuation of anticholinergic medications, dosage adjustment of antiparkinsonian medications, and/or addition of neuroleptic agents for persistent psychotic symptoms (consider Clozaril or Seroquel to minimize extrapyramidal symptoms)