123I-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, 123I-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 123I-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.

I123-FP-CIT single-photon emission tomography in patients with long-standing mixed tremor.

BACKGROUND AND PURPOSE: Essential tremor is an abnormal movement characterized by postural and/or kinetic tremor. In some essential tremor patients, rest tremor (RT) is observed but it is not clear if this RT is a feature of essential tremor or a symptom of Parkinson's disease (PD). I123-FP-CIT single-photon emission tomography is used to distinguish essential tremor and PD. OBJECTIVES: To analyse I123-FP-CIT single-photon emission tomography in a larger series of patients with mixed tremor (i.e. action tremor associated with RT) without PD criteria. METHODS: We studied 33 consecutives patients (18 men and 15 women) with mixed tremor, clinically and by neuroimaging in all cases. RESULTS: I123-FP-CIT single-photon emission tomography was abnormal in 25 of our patients (75.7%) with mixed tremor, and we noted a reduced uptake mostly in the putamen. In our patients with abnormal imaging, RT was unilateral in 52%. In 15 of these 25 patients, putaminal reduced uptake was bilateral and symmetrical. In the other 10 patients, putaminal reduced uptake was asymmetrical or unilateral. In these 10 cases, six had a unilateral RT corresponding to (crossed) predominant reduced uptake in three cases. In our patients with normal imaging, RT was unilateral in 87.5%. CONCLUSIONS: This study shows that mixed tremor is a heterogeneous entity. The majority of patients with mixed tremor showed nigrostriatal dysfunction on I123-FP-CIT single-photon emission tomography, suggesting that mixed tremor may be a parkinsonian syndrome rather than a clinical variant of essential tremor.