Excessive Sweating Can Affect Patients With Dyskinesia, Anxiety
Excessive sweating, known as hyperhidrosis, is fairly common among people with Parkinson’s and can worsen as the disease progresses, a three-year study of patients in early disease stages reported.
Researchers also observed that hyperhidrosis was associated with motor symptoms like dyskinesia (uncontrollable movements) and often accompanied non-motor symptoms like sexual dysfunction and anxiety.
These findings add evidence to “the importance of clinical recognition of hyperhidrosis,” the researchers wrote.
While hyperhidrosis is reported to affect about 28% of all with Parkinson’s, it is one of the least studied non-motor symptoms associated with the disease, the researchers noted.
Excessive sweating often occurs in the hands and feet, even after little or no exercise, and can appear in the prodromal (before symptoms are evident) stage of Parkinson’s.
It is not yet clear what might cause hyperhidrosis, and how it develops over time. The scientists suggested that it might be due to “denervation [nerve loss] hypersensitivity of the sweating pathways due to the neural impairment” caused by the disease.
A team of researchers in China looked at the frequency of hyperhidrosis and how it relates to other symptoms in 224 people with early-stage Parkinson’s, being treated at the neurology department of their Sichuan University hospital between February 2014 and May 2016.
To assess hyperhidrosis, researchers used a specific question about hyperhidrosis on the Non-Motor Symptoms Scale (NMSS) that addresses both its frequency and severity. They then followed these people annually for three years.
The study’s 121 men and 103 women had a mean age of 57.6 and a mean disease duration of 1.5 years. Of them, 195 (87%) continued with examinations through to the three-year visit.
In total, 54 of 224 people (24.1%) had hyperhidrosis at the study’s start, rising to 67 of 195 (34.4%) after three years. In patients with hyperhidrosis, however, the condition was not continuously evident from one visit to the next.
Of the 54 people who started with hyperhidrosis, only 15 showed consistent excessive sweating at three years. “Despite an increased frequency of hyperhidrosis … it was not always persistent,” the researchers wrote.
Evaluations of patients’ mental health, measured using the Hamilton Depression Rating Scale (HDRS) and the Hamilton Anxiety Rating Scale (HARS), found higher scores — indicating greater depression and anxiety levels — among patients with hyperhidrosis at the study’s start relative to those without it. These people also scored worse (higher scores) on the sleep and fatigue domains of the NMSS.
HARS scores for anxiety in further analyses also “significantly associated with the severity of hyperhidrosis” over the study’s three years, the researchers reported.
The relative risk of developing hyperhidrosis was also seen to more than double in patients with dyskinesia than in other patients over the study’s years. Likewise, “the changing pattern of hyperhidrosis frequency was similar with that of dyskinesia,” the researchers wrote.
The presence of hyperhidrosis was also linked to sexual dysfunction, anxiety, and motor symptoms as assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS) part III.
Noted study limitations were the lack of a healthy control group for comparison and the use of a single NMSS item to assess hyperhidrosis.
Still, the researchers concluded that “hyperhidrosis is common … and its frequency increases along with disease duration.”
Hyperhidrosis in Parkinson’s, they added, “is not only associated with motor severity and motor [complications] such as dyskinesia, but … also with non-motor symptoms such as sexual dysfunction and anxiety.”