Dados do Trabalho

Título

Orthostatic tremor plus associated with parkinsonism: a case report

RESUMO

Case Presentation
Female patient, 79 years old, hypertensive, family history of Parkinson's disease. Five years ago, she started presenting tremors in the lower limbs only when in orthostatic position. It progressed until last year, when it evolved to difficulty in standing. Four months ago, she started treatment with Primidone 100mg/day, without significant improvement. She denied symptoms of REM sleep behavior disorder, anosmia, or constipation. On physical examination, high-frequency tremor was observed in orthostatic position in all four limbs, more significant in lower limbs, grade 2 bradykinesia on the upper limbs and 1 on the right lower limb, rigidity grade 1 on the right and 2 on the left, reduced arm swing during ambulation and postural instability. Previous MRI and ENMG were normal. Based on the patient’s clinic, the diagnosis of orthostatic tremor (OT) was defined. The patient showed a good response to the increase of Primidone to 250mg/day and subsequently started treatment with Levodopa 200mg/day for Parkinsonism.
Discussion
In this report, the patient presented a movement disorder characterized by tremor while in an orthostatic position associated with parkinsonism, suggesting a diagnosis of OT-plus. OT is a rare condition of unknown origin that usually occurs in the lower limbs and occasionally involves the trunk and abdomen. The tremor is characterized by its high-frequency and low-amplitude. It begins immediately or a few minutes after assuming orthostatic position and disappears or decreases with ambulation or rest. When associated with another neurological disease, in this case parkinsonism, it is called OT-Plus. Other neurological manifestations reported in the literature are Parkinson's disease, dyskinesias, neuropathies and others.
Final Comments
In order to make the OT diagnosis, muscle recording performed by surface electrodes while standing is essential, since high-frequency tremor 13 to 18 Hz is characteristic. It is important to emphasize that the conventional ENMG of the lower limbs does not present significant changes. Regarding treatment, drugs known to be effective in reducing tremors, such as primidone and propranolol, should be considered. Levodopa has also shown a modest response to OT-Plus associated with parkinsonism, suggesting involvement of the dopaminergic system. Among the differential diagnoses, it is worth mentioning other causes of postural instability, such as Parkinson's disease, ataxias and other types of tremor.

Palavras Chave

orthostatic, tremor, parkinsonism.