Tremor

INDEX

Anatomical sites important in the generation of tremor1

From: Puschmann A, Wszolek ZK. Diagnosis and treatment of common forms of tremor. Semin Neurol. 2011;31(1):65-77.

 

Two sets of neuronal networks are of particular importance (see Figure above):

  1. One is the corticostriatal projection, and the ensuing thalamocortical loop which connects motor cortex and basal ganglia; the nature of this loop being the integration of different muscle groups for motor programs.
  2. Secondly, there is a circuit which involves the red nucleus, inferior olivary nucleus (ION), and the dentate nucleus, forming the Guillain-Mollaret triangle. This circuit’s main physiologic task is to fine-tune voluntary precision movements. Among its components, probably the ION plays the most important role in the genesis of tremor. The neurons of the ION receive their input from the red nucleus, and project as climbing fibres to Purkinje cells in the cerebellar cortex. The individual ION neurons are connected by gap junctions and therefore act as a synchronized neuronal ensemble. Normally, the ION neurons exhibit regular oscillatory depolarizations mediated by calcium-channels. These oscillations serve an important physiologic purpose as pacemakers in the timely processing and temporal coordination of the cerebellar modulation of precision movements as well as in cerebellar motor learning. Synchronized oscillations of ION neurons are likely to be involved in the genesis of tremor.

References

  1. Puschmann A, Wszolek ZK. Diagnosis and treatment of common forms of tremor. Semin Neurol. 2011;31(1):65-77. doi:10.1055/s-0031-1271312