As a result of this enlightened appreciation of its pathology and clinical manifestations, there has been recognized a need for a broader view of PD than the previous focused emphasis on DA-related motor symptoms in the therapeutic interaction. The American Academy of Neurology (AAN) has issued 10 Quality Measures for Care of PD.14 Demonstrated adherence to these guidelines will qualify participating physicians for increased reimbursement under pay-for-performance provisions of Medicare, but more importantly, the increased awareness of the diversity of problems caused by PD will likely of itself improve the provision of care to this population. The 10 quality measures and some of the features pertaining to them will follow.
Is this really PD? Symptoms of PD can be caused by neuroleptic (D2 blocking) medications. These include most antipsychotic agents as well the antiemetics – metaclopramide and prochlorperazine. Parkinsonian features can be seen with multiple strokes and normal pressure hydrocephalus (NPH). The atypical Parkinsonian syndromes such as Progressive Supranuclear Palsy (PSP), Corticobasal Syndrome or Degeneration (CBD) and Multiple Systems Atrophy (MSA) can sometimes be difficult to distinguish from PD. The clinical phenotype may only become clear as it unfolds over time. The best predictors of pathologically proven “idiopathic” PD are asymmetric onset, typical resting tremor and sustained response to L-Dopa.15
Parkinson's disease is associated with a wide range of neuropsychiatric features16. Depression occurs in 34-40% of patients with PD, anxiety 40% (generalized, panic or OCD) and can be an off phenomenon. Psychosis occurs in 15-40% of patients with PD on long-term follow-up, increasing with age and cognitive impairment. Routine antipsychotic drugs block D2 receptors which causes worsening of Parkinsonian symptoms. Only Quietapine and clozaril can currently be used to manage PD psychosis without worsening Parkinsonism,17 the later requiring appropriate monitoring of blood due to risk of agranulocytosis. Impulse control disorders are reported by up to 17% of patients on dopamine agonists.
At a 15-year follow-up ~50% of PD patients are demented by DSMIV criteria. Executive dysfunction and cognitive impairment can be found with formal testing even in 24% of patients with early disease. Rivastigmine has been shown to modestly improve cognitive function in PD Dementia.18
As noted above there is widespread involvement of the autonomic nervous system in Parkinson's disease resulting in many symptoms that adversely impact the quality of life.19 PD patients suffer from orthostatic hypotension (OH) 45%, constipation 70%, bladder dysfunction 40%, and erectile dysfunction 55%. PD itself, as well as the medications we use to treat it (L-dopa, DA agonists) and many medications for comorbid conditions e.g. beta blockers, Ca-channel blockers, diuretics, cause OH. Treatment can consist of compression hose, salt, florinef, and pro-amtine. Bladder dysfunction which results in nocturia in many patients is difficult to treat and does not respond readily to manipulation of dopamine agents. Evaluation of the prostate is worthwhile and if management with fluid restriction, anticholinergics, DDAVP fail treatment with botox, recently approved by the FDA, may be considered.
Patients with PD are sleepy for many reasons including perhaps a significant loss of orexin (the neurotransmitter necessary for alertness and absent in narcoleptics) in the lateral hypothalamus.20 Excessive daytime somnolence (EDS) is a complaint in 50% of PD patients and is contributed to by medications, restless leg syndrome (RLS), discomfort from wearing off, nocturia, and obstructive sleep apnea (OSA). Sleep fragmentation is present in 80% of patients with PD, RLS occurs in 20% (10% general population). RSBD, present in >40% of PD patients, may antedate onset of motor signs by up to 20 years.21 A loss of REM atonia results in the enactment of typically violent dreams with patients fighting off attacking animals or people and consequently being at risk of injury to themselves and bed partners. Successful treatment can usually be effected with klonopin 0.5 to 1mg hs or melatonin 3 to 6 mg hs.
We stage PD with Hoehn and Yahr stages:
Stage 1: unilateral signs
Stage 2: bilateral
Stage 3: appearance of postural instability
Stage 4-5-6: increasing debility
Stage 3 thus marks the appearance of imbalance and increased risk of falls and represents a significant threshold of increased risk and morbidity. After eight years 46% of PD patients have fallen, 33% recurrently. Twenty-five percent of falls result in major injury.22 Eighty percent of falls are due to freezing of gait and postural instability. Orthostatic hypotension may contribute. Treatment consists preferably of prevention – adjustment of medication, physical therapy, use of cane, walker, U Step Walker©.