Medical cannabis doesn't appear to exacerbate disease or neuropsychiatric symptoms in patients with movement disorders, two Israeli research teams reported.
The practice calls for careful monitoring of patients and additional study, said the researchers, who presented their findings at the International Congress of Parkinson's Disease and Movement Disorders.
Cannabis for Parkinson's Disease
One retrospective study focused on Parkinson's disease, evaluating the safety and effects of long-term treatment with medical cannabis, which has become a widely available treatment for controlling symptoms in Parkinson's disease and other pain disorders. Studies have demonstrated its efficacy in patients with Parkinson's disease, but long-term safety has never been examined in Parkinson's disease compared with untreated patients.
Their study included 152 patients with idiopathic Parkinson's disease (mean age at diagnosis: 55.6 plus or minus 9.5 years) from the Sheba Medical Center Movement Disorders Institute who had been issued a license for medical cannabis. Seventy-six patients treated with cannabis were compared with 76 patients with similar characteristics who were not treated with cannabis.
Investigators collected data on patients who were followed at the institute between 2008 and 2022. Average follow-up period was 3.6 years.
Specifically, they collected data on levodopa equivalent daily dose (LEDD), Hoehn and Yahr scale progression, and patient-reported outcome measures on cognitive impairment, depressive, and psychotic symptoms, at baseline and at follow-up.
The Hoehn and Yahr scale allows for the quantification of different disease stages and LEDD provides a summary of the total daily medication a patient is receiving, explained Tomer Goldberg, BSc, the study's lead author. Both are widely accepted motor severity and progression measures for Parkinson's disease. "We wanted to check whether cannabis treatment influences these two motor parameters," said Mr. Goldberg, who is affiliated with Tel Aviv University and the Movement Disorders Institute at Sheba Medical Center.
The medical cannabis–treated group and the untreated group had no significant differences in the mean annual change in LEDD or Hoehn and Yahr score. At 1, 2, and 3 years of follow-up, the treated group showed no signs of psychotic, depressive, or cognitive deterioration (P = .10-.68). The groups in Kaplan-Meier analyses also exhibited no differences in these nonmotor symptoms over time (P = .27-.93).
The findings suggest that cannabis treatment appears to be safe and has no negative effect on disease progression, said Mr. Goldberg. "It is important to note that we did not investigate all of the potential side effects of this treatment, and that prescribing medical cannabis for patients with Parkinson's disease should be done with careful monitoring of each patient's individual response to the treatment," he added.
Cannabis for Huntington's Disease
Another study, targeting Huntington's disease, drew similar conclusions. Psychiatric symptoms and cognitive decline are often present in Huntington's disease patients, who have few treatment options. "An overall improvement in chorea and in neuropsychiatric symptoms was reported following cannabis treatment in several studies both in humans and in murine models," wrote the study authors.
In this study, a certified Huntington's disease specialist reviewed the medical records of 150 patients who were being followed in an Huntington's disease clinic. Study metrics included the Unified Huntington's Disease Rating Scale and Montreal Cognitive Assessment scores, indications for treatment, and adverse events related to treatment. Among the 150 patients, 19 had received cannabis treatment for indications such as sleep disorders, behavioral anomalies, and chorea. All but one patient reported an improvement in symptoms (94%). No adverse events were recorded, although one patient died from a COVID-19 infection.
Overall, medical cannabis appeared to safely relieve symptoms in patients with Huntington's disease. A double-blind randomized controlled trial should further examine efficacy of these findings, the study authors recommended.
Mr. Goldberg had no disclosures or conflicts of interest in reporting his research.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
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Cite this: Medical Cannabis Safe for Huntington's, Parkinson's Disease? - Medscape - Sep 23, 2022.