In clinical practice, it is sometimes difficult to establish whether a patient's tremor is due to Parkinson's disease or essential tremor. The distinction is crucial as the health implications differ significantly between the two conditions. Therefore, the present study aims to develop a diagnostic method based on machine learning techniques to help differentiate whether a patient's tremor is due to one condition or the other. To achieve this, 110 patients with tremor, correctly diagnosed with either Parkinson's disease or essential tremor, will participate. They will undergo two diagnostic tests (tapping test and Archimedean spiral) to capture data that can be processed using machine learning techniques.

Inclusion Criteria:

• Possibility to collaborate in the necessary evaluations.
• Follow-up in the specialized consultation of Movement Disorders at the Neurology Service of Hospital Sant Camil-Consorci Sanitari Alt Penedes i Garraf.
• Legal capacity to provide informed consent.
• Signature of informed consent for study inclusion, either by the participant themselves or by their legal representative.
• Participant with criteria from Group 1 or 2:

Group 1:

• Confirmed diagnosis of tremor due to Parkinson's disease, clinically established, based on the diagnostic criteria of the Movement Disorders Society, and additionally:
• Tremor associated with bradykinesia of any duration.
• Confirmatory clinical diagnosis of tremor due to Parkinson's disease (stages 1 to 2 of Hoehn and Yahr) by the neurologist responsible for the participant's follow-up.

Group 2:

• Confirmed diagnosis of essential tremor, based on the criteria of the Movement Disorders Society, and additionally:
• Positional tremor plus kinetic and/or resting tremor with follow-up in outpatient neurology consultations for at least 3 years without a change in diagnosis.
• Absence of bradykinesia.

Exclusion Criteria:

• Patients undergoing treatment with antipsychotics or antidepressants.
• Patients with Parkinson's disease and dyskinesias.
• Patients undergoing treatment with dopaminergic agonists or primidone.
• Tremor of such severity that it prevents continuous tracing, at the investigator's discretion.
• Cognitive or affective pathology that limits the ability to collaborate with the study procedures.
• Participation in another clinical study involving an intervention, procedure, or visit frequency that is incompatible with the present study.
• Participants diagnosed with any of the following conditions:

Alcoholism of sufficient intensity to influence handwriting or cause neuropathy, at the investigator's discretion. Peripheral neuropathy of any cause. Dystonias. Previous stroke.

The participants will be contacted based on the patient registry with follow-up in the neurology clinic of the study center.

IPD (without personal identification data) could be shared by requirement from other researchers after the end of the study, and only for research purposes and previous approval of promotor center of the study (CSAPG). Anyway, Spanish and European Union legal policy about data protection will strictly be followed (IPD will not be transferred outside European Union).

After publication of main results of the study.

IPD will be shared only for scientific research purposes and following the Spanish and European Union normative law about data protection. The requirements will be directed to the IP of the study. The IP will evaluate the request to verify and evaluate the data that is requested and the purposes for which it is requested. Next, the IP will transfer the request to the promotor center the study for the final decision.