ID #634 Case Series of the Use of Trihexyphenidyl for Tremors in Pediatric Brain Tumors

Abstract

Trihexphenidyl (Artane) is an anticholinergic drug used for adults with Parkinsons to treat stiffness, tremors, and poor muscle control. There is minimal data available for use in pediatrics but has been used for children with cerebral palsy to treat dystonia. Pediatric brain tumors, especially those with midline gliomas or with thalamic involvement, can cause tremors that greatly affect activities of daily living (ADL) and impair quality of life.

21-year-old male with a pineal germinoma and growing mature teratoma developed tremors that significantly impaired ADLs after a second surgery. Initially trialed a benzodiazepine, symptoms did not improve. Prescribed a dopaminergic antiparkisonism agent that provided some benefit but developed disinhibited behaviors after 2 months of use so discontinued. Began Trihexphenidyl and tremors occurred significantly less often. Tremors overtly noticeable when a dose was missed.

Six-year-old female with a thalamic diffuse midline glioma and presented with a bilateral upper extremity tremor, worse on the left than right, that substantively impaired quality of life. Tremors initially improved with use of steroids and Avastin. However, the response was not maintained. Patient began on a low dose of Trihexphenidyl and tremors significantly improved. However, whenever increased tumor edema or growth were noted, tremors would worsen. Trihexphenidyl dosage would increase and tremors would decrease in frequency and severity.

Tremors in patients with pediatric brain tumors especially those with midline gliomas or with thalamic involvement can be debilitating and distressing. Use of benzodiazepines, beta blockers, and dopaminergic antiparkisonism agents have been historically prescribed for management of symptoms but have intolerable side effects. As reported above, Trihexphenidyl has been successfully used to treat tremors in one patient and a mixed response in the other based on tumor edema and growth. Trihexphenidyl is an anticholinergic drug that should be considered in managing tremors of patients with pediatric brain tumors.