I-FP-CIT SPECT imaging in blepharospasm.

INTRODUCTION

Blepharospasm is a focal dystonia characterized by involuntary cocontraction of the eyelid protractors, causing spasmodic closure of the eyelids. Apraxia of eyelid opening is caused by an inability to initiate lid opening without paralytic abnormality. Some studies suggest that patients with either pure blepharospasm or blepharospasm associated with apraxia of eyelid opening are more prone to developing Parkinson's disease.

METHODS

In our study, I-FP-CIT (DAT) SPECT was performed in 24 patients with either pure blepharospasm or blepharospasm associated with apraxia of eyelid opening and no signs of parkinsonism to identify dopaminergic dysfunction.

RESULTS

DAT-SPECT was abnormal in 11 (46%) cases (five patients with isolated blepharospasm and six patients with blepharospasm associated with apraxia of eyelid opening) whose mean disease duration was 11 years.

CONCLUSION

Our study revealed presynaptic dopaminergic dysfunction, as determined by I-FP-CIT or DAT-SPECT, in nearly half of our blepharospasm patients (with or without apraxia of eyelid opening). Thus, the presence of blepharospasm might be an early sign of a parkinsonian syndrome.