Treatments Inadequate for People With Late-stage Disease, Study Says

Current Parkinson’s treatments are insufficient for people with late-stage disease, inadequately controlling for many notable motor and non-motor symptoms, a study in these patients across Europe reports.

The study, “The late stage of Parkinson’s — results of a large multinational study on motor and non-motor complications,” was published in Parkinsonism & Related Disorders.

Although therapies like levodopa — its most widely prescribed treatment — effectively manage Parkinson’s symptoms, they tend to lose effectiveness over time. Off periods (times during which symptoms are not controlled by medication) are experienced by about 40% of people diagnosed with Parkinson’s within four to six years, and about 90% of those with a disease duration of more than 10 years.

To better understand how the disease is experienced in the long term, researchers evaluated 692 people with Parkinson’s in six European countries. All were diagnosed at least seven years ago (average disease duration, 15.4 years).

Their daily levodopa dose was a mean equivalence of 874.1 mg.

Falls were the most commonly reported symptom, experienced by 82% of those assessed. This included falls related to freezing (16%), falls unrelated to freezing (21%), and falls both related and unrelated to freezing (45%). Falls were reported as “frequent” by about a quarter (26%) of the people assessed.

Off-periods were present in 68% of these patients, and experienced by 13% for at least half of each day.

Many reported moderate-to-severe severe difficulties in turning in bed (51%), speech (43%), swallowing (16%), and tremor (11%). More than half also reported experiencing fatigue, constipation, urinary symptoms and nocturia (waking up to urinate at night), and problems with concentration and memory.

About a third (37%) of these people had dementia, and 63% experienced hallucinations or delusions, which were severe in 15%.

Long-term levodopa use is known to sometimes cause involuntary movements, referred to as levodopa-induced dyskinesia. Of the people assessed, 45% reported such dyskinesia, though most were mild. In 7%, dyskinesia was moderate to severe.

Another motor problem associated with long-term levodopa treatment is early morning dystonia, or involuntarily muscle clenching. This was reported by 35% of those assessed.

Disability as a whole was most strongly associated with falls, posture problems, bradykinesia (slow movements), cognitive scores, and speech problems.

“These data suggest that current treatment of late stage parkinsonism in the community remains insufficiently effective to alleviate disabling symptoms in many patients,” the researchers concluded.