Dizziness May Be Non-Motor Symptom of Early Parkinson’s, Study Finds
Dizziness — including sensations of fainting, imbalance, and vertigo — is common among Parkinson’s patients and may be a potential non-motor symptom of early-stage disease possibly associated with cognitive decline, a study has found.
Typically, dizziness episodes are short and frequent, lasting seconds to minutes and occurring several times per day or week.
The study, “Dizziness in patients with early stages of Parkinson’s disease: Prevalence, clinical characteristics and implications,” was published in the journal Geriatrics and Gerontology.
Parkinson’s disease is diagnosed when typical motor symptoms occur — including tremor, rigidity, balance, and walking problems — but several other motor and non-motor features that surface before that stage could help detect the disease earlier. Some of these non-motor symptoms include loss of the sense of smell, constipation, sleep disturbances, and depression.
“In real clinical settings, we frequently observe that patients with [Parkinson’s disease] complain of dizziness,” the researchers wrote.
Feelings of dizziness may include faintness, lightheadedness, vertigo, and imbalance, and its prevalence is reportedly between 48%–68% in patients with Parkinson’s.
Dizziness is a well-known side effect of dopaminergic medications used for Parkinson’s such as levodopa and dopamine agonists (substances that mimic the action of dopamine in the brain). These agents can lead to a type of low blood pressure that occurs when a person stands up (orthostatic hypotension), causing lightheadedness.
“However, we have observed that drug-naïve patients [who have never taken antiparkinson medications] (…) sometimes report dizziness,” the researchers noted.
In fact, some researchers propose that dizziness may be an early, or prodromal, symptom of Parkinson’s. Despite this hypothesis, little is known about the clinical features and implications of this potential symptom in Parkinson’s patients.
Therefore, a team of Korean researchers at Seoul National University Hospital set out to gather more information about the characteristics of dizziness, and its risk factors and association with early Parkinson’s.
They conducted a pilot study that analyzed data from 80 patients (mean age of 71.3 years) with early-stage Parkinson’s (disease duration of no more than five years), who had been followed at the hospital.
The characteristics of dizziness episodes, including their prevalence, frequency, duration, and type, were surveyed for each patient. Motor and non-motor symptoms (cognition problems, anxiety, depression, and fatigue) were evaluated using different validated scales, to identify risk factors linked to dizziness.
The results showed that out of a total of 80 patients, 46.3% (37 patients) experienced dizziness. Episodes were typically short and frequent, lasting seconds (40.5% of the patients) to minutes (54.1%), and occurring several times a day (48.6%) or week (35.1%).
The most common type of dizziness was presyncope (40.5%) — a sensation of fainting usually caused by a drop in blood pressure that results in insufficient blood flow to the brain — followed by non-specific type (29.7%), disequilibrium (24.3%), and vertigo (5.4%).
Dizziness had no association with demographics (age, sex, education, body mass index) or general parkinsonian parameters such as motor symptoms, disease duration, or levodopa equivalent daily dose.
Among the many scales for motor and non‐motor symptoms assessed, only a lower Montreal Cognitive Assessment score, representing patients’ cognitive health, was significantly associated with dizziness in those with early Parkinson’s — a mean score of 19.7 in patients with dizziness versus 22.5 in those without it.
In summary, the study showed a significant percentage of patients with early Parkinson’s disease experienced dizziness, suggesting that it could be regarded as one of the non-motor symptoms of the disease, and one that could be “associated with cognitive decline,” the investigators wrote.
The association of dizziness to lower cognitive scores was an unexpected finding for the team. A possible explanation is that a drop in blood pressure during presyncope would reduce blood flow to the brain, resulting in cognitive impairments later on. However, patients also had other forms of dizziness that were unlikely related to this effect, so more studies are needed to clarify this issue in the future.
“We hypothesized that longer disease duration or dopaminergic medication would be more related to the occurrence of dizziness, and that the majority of dizzy [Parkinson’s disease] patients would show the orthostatic type of dizziness. However, our results did not fully support these hypotheses,” the researchers said.