Symptomatic Characteristics of Parkinson's Disease Induced by Neuroleptic Drugs, Based on a Functional Neuroimaging Diagnosis

Abstract

Objective When patients take neuroleptics, the distinction between Parkinson's disease (PD) and druginduced parkinsonism (DIP) based solely on clinical features can become difficult. At present, 123 I-FP-CIT SPECT (DAT-SPECT) and 123 I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy are widely used to supplement the differential diagnosis of parkinsonism. This study assessed the clinical symptoms and neurological findings in the patients suspected of having DIP based on DAT-SPECT findings. Methods Twenty-three patients (11 men, 12 women, age: 52-81 years old) presenting with DIP were recruited. All patients underwent neurological examinations, including brain magnetic resonance imaging and DAT-SPECT. Patients who showed abnormal DAT-SPECT results underwent MIBG myocardial scintigraphy. Results Eleven patients showed a reduction in the ligand uptake on DAT-SPECT (DAT-positive group), and nine of these patients showed a low delayed heart-to-mediastinum (H/M) ratio on MIBG myocardial scintigraphy. The remaining 12 patients showed normal results on DAT-SPECT (DAT-negative group). All patients in the DAT-positive group had asymmetric motor symptoms, whereas only 4 in the DAT-negative group exhibited this clinical feature (p=0.001). A detailed medical history showed that 7 of the 11 patients in the DAT-positive group had prodromal symptoms for PD. However, only 1 patient in the DAT-negative group exhibited these symptoms (p= 0.009). Although two patients in the DAT-negative group showed poor improvement, they showed a normal H/M ratio on MIBG and no response to levodopa. Conclusion The patients in the DAT-positive group might have prodromal symptoms that were worsened by neuroleptic drugs. The results of detailed history-taking and neurological findings seem to indicate cases of compromised dopaminergic transmission before the administration of neuroleptic drugs.

The potential role of the cardiac MIBG scan in differentiating the drug-induced Parkinsonism from Parkinson’s disease

“…To the best of our knowledge, merely one recent work has applied the MIBG scan to identify the DIP from the PD, in which the MIBG scan was preceded by the 123 I-FP-CIT SPECT (DAT-SPECT) [18] . In our work, however, all participants underwent the MIBG scan, and the results were compared between the two groups.…”

Drug-induced parkinsonism

“…В небольшом исследовании [66] поглощение 123 I-МИБГ было значительно снижено при БП и оставалось нормальным у пациентов с ЛИП. Другое исследование [67] с использованием DaTscan и сцинтиграфии с 123 I-МИБГ продемонстрировало потенциальную возможность этих методов, при использовании их в комбинации, диагностировать наиболее раннюю стадию БП, симптомы которой могут усиливаться при приеме антипсихотиков.…”

Respecting the Patient’s Choice: A Case of Possible Drug-Induced Parkinsonism

“…DIP symptoms can be misdiagnosed as idiopathic Parkinson’s disease as well as other drug-induced movement disorders such as extrapyramidal symptoms, tardive dyskinesia, and tremors [ 5 ]. Although PD and DIP may be clinically indistinguishable, differentiation may be possible by reviewing the patient’s medication history for any potential causative drugs correlating to the timeline of the onset of symptoms [ 6 ]. Onset of the symptoms typically occurs within a few weeks to months after initiation of the causative agent.…”

“…Onset of the symptoms typically occurs within a few weeks to months after initiation of the causative agent. In cases of DIP, if the causative agent is discontinued, the parkinsonism should resolve within six months [ 6 ].…”