Acute Reversible Hemi-Parkinsonism for a Diabetic Uremic Patient: Findings from MRI, MRS, FDG-PET, Tc-TRODAT-1 SPECT, and TMS studies

Received 1/11/2007; revised 1/23/2007; accepted 1/24/2007. For correspondence or reprints contact: Shih-Jung Cheng, M.D., Department of Neurology, Mackay Memorial Hospital, 92 Section 2, Chun-San North Road, Taipei 104, Taiwan. Tel: (886)2-25433535 ext. 2316, E-mail: [email protected] Background: There exists growing medical awareness regarding the syndrome bilateral basal ganglia lesions for patients suffering from diabetes mellitus and uremia. Neuroimaging findings for such patients have been described previously for several different imaging modalities, including magnetic resonance (MR) imaging, MR spectroscopy, positron emission tomography (PET), and perfusion single photon emission computed tomography (SPECT). Herein, we have attempted to correlate the clinical features of hemi-parkinsonism by conducting two additional investigating modalities, TcTRODAT-1 SPECT and transcranial magnetic stimulation (TMS) studies. Case report: A 62-year-old diabetic uremic male patient presented with acute right hemi-parkinsonism, dysarthria and dysphagia. Head MR imaging revealed focal enhancement within the left lenticular nuclei. MR spectroscopy displayed findings such as a symmetrical N-acetyl aspartate (NAA) reduction and a bilateral inverted lactate peak within the lenticular nuclei. PET also disclosed a bilateral low uptake of FDG within the lenticular nuclei, although this effect was more pronounced on the left side. Tc-TRODAT-1 SPECT demonstrated a low uptake of dopamine transporter in the left putamen. TMS study revealed a shorter cortical silent period (CSP) for right abductor digiti minimi (ADM) muscles. Conclusion: Bilateral basal ganglia lesions may occur in an asymmetrical manner. Consequently, hemi-parkinsonism is one of the clinical manifestations. These new findings of asymmetrical low uptake upon a dopamine transporter scan and a reduced cortical silent period for the affected side could be correlated with hemi-parkinsonism. Thus, Tc-TRODAT-1 SPECT and TMS-CSP modalities are able to serve as clinical correlates.