Levodopa-responsive Holmes' Tremor Caused by a Single Inflammatory Demyelinating Lesion.

Area of Science:

• Neurology
• Neuroimaging
• Movement Disorders

Background:

• Holmes tremor involves rest, postural, and kinetic tremor, often linked to cerebello-thalamo-cortical and nigrostriatal pathway disruption.
• Current medical treatments for Holmes tremor are frequently unsatisfactory.

Purpose of the Study:

• To investigate a case of Holmes tremor with a transient midbrain abnormality on MRI.
• To explore the relationship between persistent tremor and resolved imaging findings.
• To assess the utility of dopamine transporter imaging in predicting treatment response.

Main Methods:

• A 16-year-old female patient with Holmes tremor underwent magnetic resonance imaging (MRI) and dopamine transporter single-photon emission computed tomography (DaT-SPECT) using 123I-ioflupane.
• DaT-SPECT assessed dopamine transporter binding in the striatum.
• Treatment response to levodopa was evaluated.

Main Results:

• MRI revealed a transient midbrain abnormality.
• DaT-SPECT showed significantly reduced dopamine transporter binding in the right striatum.
• Levodopa administration resulted in a dramatic improvement of the tremor.

Conclusions:

• This case, the second reported, involves a transient midbrain MRI abnormality affecting nigrostriatal pathways.
• Morphologic imaging may not always detect functional deficits, underscoring the value of functional imaging.
• DaT imaging can predict levodopa responsiveness in Holmes tremor.