[Tremor: update and controversy].
BACKGROUND
Tremor is the most common movement disorder. The differential diagnosis on its origin is sometimes difficult and the number of conditions that include this symptom as part of their clinical spectrum continues to increase.


OBJECTIVE
To provide an update on aspects that may help in the process of diagnosis, to review the main lines of therapy and to reflect on tremor within the context of Parkinson's disease.


METHODS
Complementary techniques in the study of Parkinson's disease, such as DaT-SCAN or the study of the cardiac sympathetic pathway by means of cardiac scintigraphy with meta-iodobenzylguanidine (MIBG), have helped in the aetiological diagnosis of this symptom; nevertheless, the patient's clinical history continues to be the main source of information for an accurate diagnosis. Pharmacologically, the therapeutic approach has varied very little and the outcomes of surgical procedures are still described as an alternative in medication-resistant cases. In Parkinson's disease, tremor at rest is a characteristic clinical sign that comprises a series of peculiarities, and the interrelation between essential tremor and this disease is always a controversial issue. The appearance of cases that have been diagnosed as Parkinson's disease, but in which the nigrostriatal pathway remains intact, opens up the spectrum even wider.


CONCLUSIONS
In this paper we review the data available today that help in the differential diagnosis of tremor; the particularities concerning Parkinson's disease from the diagnostic, therapeutic and genotypic point of view are also discussed.
Ruiz-Martínez
J
J
Servicio de Neurología, Hospital Donostia, P. Doctor Beguiristain, s/n. E-20014 San Sebastián, Guipúzcoa, España. javier.ruizmartinez@osakidetza.net
Arratibel-Echarren
I
I
Gorostidi-Pagola
A
A
Bergareche
A
A
Martí-Massó
J F
JF
D003937:Diagnosis, Differential; D006801:Humans; D010300:Parkinson Disease / Q000150:complications; D014202:Tremor / Q000145:classification / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology*