Single-photon emission computed tomography 123I-ioflupane imaging in CSF1R mutation carriers.

Area of Science:

• Neuroscience
• Genetics
• Radiology

Background:

• CSF1R-related disorder (CSF1R-RD) is a rare autosomal dominant microgliopathy causing leukoencephalopathy.
• Extrapyramidal symptoms are common in CSF1R-RD, but the dopaminergic system's integrity is unclear.

Purpose of the Study:

• To investigate dopamine transporter availability using SPECT 123I-ioflupane in CSF1R mutation patients.
• To differentiate the pathophysiology of parkinsonism in CSF1R-RD.

Main Methods:

• Retrospective review of 112 electronic medical charts.
• SPECT 123I-ioflupane imaging in four patients with CSF1R variants.
• Assessment of clinical data, MRI, and genetic pathogenicity.

Main Results:

• Three of four patients with parkinsonian symptoms had normal SPECT 123I-ioflupane results.
• The patient with abnormal SPECT imaging had a pathogenic CSF1R variant and classic Parkinson disease phenotype.
• Symptoms included tremor, rigidity, and bradykinesia.

Conclusions:

• Parkinsonism in CSF1R-RD can present with normal SPECT 123I-ioflupane.
• Motor deficits likely result from white matter degradation and disrupted connectivity.
• This contrasts with primary nigrostriatal loss seen in typical Parkinson disease.