Observations of Thoracic Neuromuscular Oscillation Subsequent to Thoracic Pathology

In this paper we propose that a tremor occurring over a thoracic myotomal region as representative of a motor manifestation of thoracic radicular injury. We term this process thoracic neuromuscular oscillation. It is characterized by synchronous firing of the unilateral oblique muscles at one or more adjacent thoracic myotomal distributions at a frequency of 8 to 10 Hz. Six cases of observed regular continuous abdominal wall muscular tremor occurring after traumatic thoracic spine pathology are presented. These cases were drawn retrospectively from patient files obtained over 20 years. We refer to this tremor, measured to be 8–10 Hz, as thoracic neuromuscular oscillation. The neuromuscular oscillation was influenced by mechanical forces, specifically spine loading in either a bending or compressive mode. In some cases, cervical position modulated the tremor. Other examples of thoracic spine pathology that occurred comorbid to thoracic neuromuscular oscillation are noted.