# Long term (TEN YEARS) follow-up in a trembling patient with parkinsonian signs without dopaminergic denervation

## TL;DR

A patient with tremor and parkinsonian signs but no dopaminergic denervation was followed for ten years, showing how symptoms can progress without dopamine system involvement.

## Contribution

This case report provides a long-term clinical and neuroimaging follow-up of an atypical tremor syndrome without dopaminergic denervation.

## Key findings

- Parkinsonian features like re-emergent tremor and sequence effect bradykinesia can occur without dopaminergic denervation.
- Dopaminergic therapy was ineffective, while beta-blockers and benzodiazepines provided partial relief.
- DaT-SPECT remained negative despite progressive motor symptoms, highlighting the need for alternative diagnostic approaches.

## Abstract

Some patients presenting with Parkinson’s disease (PD)-like features do not exhibit dopaminergic denervation, complicating clinical categorization. This case report describes a patient with a long-standing upper limb action tremor accompanied by parkinsonian signs, but without evidence of dopaminergic denervation, followed over an extended period of ten years. The case highlights the diagnostic challenges and underscores the importance of longitudinal observation in such atypical presentations.

A 76-year-old man with tremor and parkinsonian features was followed for ten years with clinical observation, video recordings, kinematic movement analysis, and structural and functional neuroimaging, including DaT-SPECT.

Clinical and kinematic evaluations revealed asymmetric upper limb action tremor, inconstant rest tremor, bradykinesia with sequence effect, re-emergent tremor, and progressive motor symptoms. Over time, tremor extended to cranial regions, and mild dystonic postures emerged. Structural neuroimaging ruled out secondary causes, and DaT-SPECT remained negative despite symptom progression. Dopaminergic therapy was ineffective, while propranolol and clonazepam provided partial relief.

This case highlights that parkinsonian motor features − such as re-emergent tremor and bradykinesia with sequence effect − can manifest and progress over time in patients with tremor, even in the absence of dopaminergic denervation. These findings underscore the need for further research into the role of the dopaminergic system in trembling patients. Moreover, they emphasize the importance of long-term follow-up and the integration of biomarkers to enhance the characterization and diagnostic accuracy of tremor syndromes.