Combined use of DAT-SPECT and cardiac MIBG scintigraphy in mixed tremors.
The cooccurrence of rest and postural tremor (mixed tremor) as the predominant clinical manifestation in patients who do not fulfill diagnostic established criteria for essential tremor (ET) or Parkinson's disease (PD) poses a clinical diagnostic challenge. Twenty-two patients with mixed tremor and additional mild extrapyramidal features, such as bradykinesia and rigidity, 20 patients with probable PD, 10 patients with probable ET, and 18 controls were investigated through the combined use of dopamine transporter (123)I-FP-CIT-single-photon emission tomography (DAT-SPECT) and cardiac (123)metaiodobenzylguanidine (MIGB) scintigraphy. Six of the 22 mixed-tremor patients had normal DAT-SPECT, a condition usually found in patients with ET, whereas 16 patients showed damage to the nigrostriatal system. Cardiac MIBG allowed further differentiation between these 16 patients because eight of them had decreased tracer uptakes (heart/mediastinum [H/M] ratio in delayed image, H/M ratio delayed: 1.16 +/- 0.11, P < 0.001 vs controls), indicating a PD, whereas the remaining eight had normal cardiac tracer uptakes, a finding suggestive of a parkinsonian syndrome (H/M ratio delayed: 1.90 +/- 0.13). Both DAT-SPECT and cardiac MIBG scintigraphies were abnormal in the 20 patients with probable PD, whereas these were normal in both the patients with probable ET as well as in the controls. Our study suggests that the combined use of both DAT-SPECT and MIBG scintigraphy in mixed tremors with additional extrapyramidal features can help distinguish patients with ET from those with PD and parkinsonism.
Department of Medical Sciences, Institute of Neurology, University Magna Graecia, Catanzaro, Italy.
Fabiana
F
Novellino
Gennarina
G
Arabia
Antonio
A
Bagnato
Giuseppe Lucio
GL
Cascini
Maria
M
Salsone
Giuseppe
G
Nicoletti
Demetrio
D
Messina
Maurizio
M
Morelli
Sandra
S
Paglionico
Laura
L
Giofrè
Antonino
A
Restuccia
Giusi
G
Torchia
Francesca
F
Condino
Aldo
A
Quattrone
D019797:3-Iodobenzylguanidine; D000368:Aged; D000704:Analysis of Variance; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014202:Tremor / Q000000981:diagnostic imaging*; D014326:Tropanes
D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D019797:3-Iodobenzylguanidine