From the Guidelines
Abnormal toe tapping in Parkinson's disease is characterized by bradykinesia, which manifests as slowness of movement, decreased amplitude, and progressive reduction in speed and amplitude during repetitive toe tapping. When examining a patient, you would ask them to tap their toes on the floor as quickly and with as large an amplitude as possible. Patients with Parkinson's typically demonstrate a gradual decrease in speed, force, and range of motion as they continue the task, reflecting basal ganglia dysfunction, particularly in the nigrostriatal dopaminergic pathway, which impairs the execution of sequential and repetitive movements 1.
The clinical presentation of Parkinson's disease is characterized by resting tremor, bradykinesia, and rigidity, related to progressive degeneration of the dopaminergic neurons in the substantia nigra projecting to the striatum 1. The examination of toe tapping is part of the standard motor assessment in Parkinson's disease and helps clinicians evaluate the severity of bradykinesia in the lower extremities, which contributes to gait disturbances and mobility problems commonly seen in these patients. Key features of abnormal toe tapping in Parkinson's disease include:
- Gradual decrease in speed and amplitude during repetitive movements
- Hesitation in initiating the movement
- Irregular rhythm
- Decreased force and range of motion
These findings are essential for diagnosing and managing Parkinson's disease, as they reflect the underlying neurodegenerative processes affecting the basal ganglia and nigrostriatal pathway 1.
From the Research
Physical Exam Findings of Parkinson's Disease
The physical exam findings of Parkinson's disease can be abnormal, particularly with regards to toe taps.
- In patients with Parkinson's disease, the minima in gastrocnemius (GS) activation with the first tap was significantly higher than in controls during closed tapping 2.
- The coefficient of variation (CV) of local maxima in tibialis anterior (TA) activation was significantly higher in patients with Parkinson's disease than in controls during open tapping 2.
- The CV of extrema in GS activities increased with disease duration, which may be due to the long-term administration of Levodopa 2.
- Abnormal toe tap findings can be an indicator of the disease's progression and can be used to assess the effectiveness of treatment.
Assessment of Toe Tapping
Toe tapping can be used to assess leg muscle activity in patients with Parkinson's disease.
- Closed tapping is suitable for the assessment of GS activity and can detect excessive activities, which is observed as visible movement 2.
- Open tapping is suitable for assessment of TA activity 2.
- The use of toe tapping as an assessment tool can provide valuable insights into the physical exam findings of Parkinson's disease.
Treatment and Disease Progression
The treatment of Parkinson's disease can affect the physical exam findings, including toe taps.
- Long-term Levodopa treatment is associated with undesirable side effects such as motor fluctuations and dyskinesias 3.
- Dopamine agonists and monoamine oxidase type-B inhibitors can be effective in treating Parkinson's disease, both as monotherapy and in combination with Levodopa 4, 5.
- The choice of treatment can impact the disease progression and the physical exam findings, including toe taps.