National Board of Chiropractic Examiners (NBCE) Practice Test

Rigidity during passive joint movement is most characteristic of which type of lesion?

1. Basal ganglia

2. Cerebellar

3. Spinal cord

4. Cortical

The correct answer is: Basal ganglia

Rigidity during passive joint movement is primarily associated with basal ganglia lesions. This phenomenon is a characteristic feature of parkinsonism, where there is an increase in muscle tone that is not dependent on the speed of movement, leading to a consistent resistance throughout the passive range of motion. In conditions like Parkinson's disease, this rigidity results from an imbalance of neurotransmitters in the basal ganglia, particularly involving dopaminergic pathways, which affects motor control. In contrast, cerebellar lesions typically lead to issues such as ataxia and intention tremors, which do not present with rigidity but rather an unsteady gait and coordination problems during voluntary movements. Spinal cord lesions might result in spasticity or weakness but do not present with the same type of rigidity associated with basal ganglia dysfunction. Cortical lesions can lead to weakness or changes in consciousness and may affect voluntary movement but also differ from the rigidity seen in basal ganglia conditions. Understanding these distinctions is crucial for recognizing the underlying pathophysiology of various neurological conditions and how they manifest in physical examination findings.