STAGES OF PARKINSON’S DISEASE

Symptoms and the impact of Parkinson’s disease can change over time

Parkinson’s disease is often diagnosed upon appearance of the cardinal symptoms that include bradykinesia, rigidity, tremor and postural instability.¹

Scales such as the Hoehn & Yahr scale² are used to describe the symptom progression of Parkinson’s disease.

• The modified Hoehn & Yahr ranks symptoms on an 8-point scale from 0 = no signs of disease, to 5 = wheelchair bound or bedridden  unless aided.
  

In early Parkinson’s disease, symptoms are usually well controlled by oral medications such as levodopa/carbidopa.³

Levodopa, a precursor of dopamine, is metabolised to dopamine by decarboxylation. Carbidopa inhibits the extracerebral (peripheral) decarboxylation of levodopa, so that a larger amount of levodopa is available to the brain. Without carbidopa, a much higher dose of  levodopa would be needed to compensate for the dopamine deficiency in the brain and improve the patient’s motor symptoms.

There are no treatments to stop or slow the progression of Parkinson’s disease,³  and as the disease advances, control of motor symptoms  relies on regular monitoring and treatment adjustment.

In intermediate Parkinson’s disease, drug-induced dyskinesia may emerge and the management of dyskinesia, motor fluctuations and the  continued presence of the cardinal symptoms usually involves reducing or fractionating the oral levodopa dosage and/or prescribing other  drug classes.³

PARKINSON’S DISEASE PROGRESSION

When symptom control by orally administered therapies gives unsatisfactory results⁴

After more than 40 years of clinical use, levodopa remains the most effective symptomatic treatment for Parkinson’s disease.⁵

However, oral levodopa becomes less effective at controlling symptoms over time, which can have an impact on quality of life.⁶

RECOGNIZING POOR SYMPTOM CONTROL

As Parkinson’s disease progresses, the burden on patients increases⁹

People with advanced Parkinson’s disease experience a higher disease burden in terms of motor symptom severity and a negative impact on daily activities and quality of life, compared with people with earlier stages of the disease.⁹

However, there is no current consensus for the definition of advanced Parkinson’s disease.⁵

Expert opinion has suggested the following are signs of advanced Parkinson’s disease:^4,5,10,11*

• When moderate yet detectable levels of motor fluctuations or dyskinesia interfere with daily life
• When oral therapies are no longer controlling symptoms

Developing screening criteria for timely identification of poor symptom control^11*

To better understand and identify advanced Parkinson’s disease, 17 experts in Parkinson’s disease developed a list of 15 clinical indicators.^11*

From these indicators, the 5-2-1 criteria have been proposed as a screening tool for suspected advanced Parkinson’s disease.^11* This means that patients may have advanced Parkinson’s disease if they meet at least one of the following criteria:

• Taking at least 5 oral levodopa doses per day
• Having at least 2 hours of ‘OFF’ time per waking day
• Having at least 1 hour of troublesome dyskinesia per waking day

References

1. Hughes AJ et al. J Neurol Neurosurg Psychiatry 1992; 55:181-184.
2. Goetz CG et al. Mov Disord 2004; 19(9):1020-1028.
3. Fox SH et al. Mov Disord 2018; 33(8):1248-1266.
4. Varanese S et al. Parkinsons Dis 2011; 2010:480260.
5. Kulisevsky J et al. Neurologia 2013; 28(9):558-583.
6. Olanow CW et al. Lancet Neurol 2014; 13(2):141-149.
7. Nyholm D et al. AAPSJ 2013; 15(2):316-323.
8. Nyhom D. Parkinsonism Relat Disord 2007; 13 (suppl):S13-S17.
9. Fasano A et al. BMC Neurology 2019; 19:50.
10. Giugni JC, Okun MS. Curr Opin Neurol 2014; 27(4):450-460.
11. Antonini A et al. Curr Med Res Opin 2018; 34(12):2063-2073.

* This study and publication were funded by AbbVie.