Abdominal Tremor in Parkinson's disease
Authors: Nobuyuki Tanaka MD, Toshihiro Hayashi MD, PhD, Shoji Tsuji MD, PhD and Atsushi Iwata MD, PhD
Article first published online: 24 FEB 2015 | DOI: 10.1002/mdc3.12119
A 66-year-old male visited our clinic with a 1-year history of walking difficulty and stomach shaking while lying down. Examination revealed very mild right-arm akinesia, bilateral leg rest tremor, and tremor in his abdominal muscles (see Video; Fig. 1A,B). Abnormal 123I-ioflupane single-photon emission CT (SPECT; Fig. 1C) and 123I-metaiodobenzylguanidine scintigraphy (heart-to-mediastinum ratio: 1.89) supported the diagnosis of Parkinson's disease (PD). Pramipexole was prescribed up to 3 mg/day, and his symptoms, including abdominal tremor, improved. Abdominal tremor is a rare symptom in PD. In addition, this might indicate that the presence of striatum somatotopy found in macaque monkeys are also present in humans.
Figure 1. (A) Surface electromyography recording at a supine position revealed 5 to 6 Hz rest tremor activities in the right rectus abdominis. (B) Upon forced calculation, the tremor worsened and spread to lower-extremity adductor muscles, which is a typical feature of parkinsonian tremor. (C)123I-ioflupane SPECT study of the patient.