Table 1 Structural imaging studies reporting on tremor and cerebellum in Parkinson’s disease.

Benninger et al.²⁰

Comparison of GMV in basal ganglia, thalamus, brainstem and cerebellum in PD patients with rest tremor vs. PD patients without rest tremor

Decreased GMV mainly in quadrangular lobe and declive was found in PD patients with rest tremor

Piccinin et al.²¹

Comparison of cerebellar GMV in HC vs. ARPD vs. TPD

(1) Changes in cerebellar GMV seems driven solely by TPD.

(2) Decreased GMV in the left cerebellar lobule VIIIa was found in TPD when compared with ARPD.

(3) Decreased GMV in multiple cerebellar lobules was found in TPD patients when compared with HC.

Lopez et al.²²

(1) Comparison of cerebellar lobule volumes in PD patients vs essential tremor patients

(2) Correlation of severity of symptoms and lobule volume in PD patients and ET separately.

In PD patients, lobule volume of cerebellar lobule IV was positively correlated with resting tremor and total tremor severity.

Choi et al.²³

Comparison of volumes of different brain structures in PD patients with tremor vs. ET vs. healthy controls.

No significant difference in GMV and white matter volume existed between PD patients with tremor and HC.

Luo et al.²⁴

Comparison of white matter integrity in TPD^a vs. NTPD vs. HC by tract-based spatial statistics.

White matter integrity differences in the white matter tract, including middle cerebellar peduncle and superior cerebellar peduncle, existed when compared TPD with HC or NTPD.