Jerks of the latissimus dorsi muscle and intercostal neuralgia after posterolateral thoracotomy

Introduction

Post-thoracotomy pain syndrome (PTPS) is a common complication related to intercostal nerve injury. During this type of surgery, although less frequently, thoracodorsal and long thoracic nerves can also be injured, and jerks of peripheral origins may appear. We report a case with intercostal neuralgia and latissimus dorsi muscle jerks after posterolateral thoracotomy.

Case report

A 55-year-old woman with Ehlers-Danlos Syndrome presented with a typical picture of PTPS along the right T5 dermatome following posterolateral thoracotomy at the level of the fifth intercostal space. Approximately six months after the surgery she developed frequent jerk-like involuntary movements of the right latissimus dorsi muscle. Neuropathic pain along the T5 dermatome was partially relieved with thoracic epidural block. No special attention was paid to the jerks until three years later. A neurophysiological study demonstrated a peripheral origin of these movements and the patient was then treated with periodic injections of botulinum toxin. In response, involuntary movements of the latissimus dorsi muscle disappeared.

Significance

To our knowledge, this is the first case with PTPS and post-thoracotomy latissimus dorsi muscle jerks in a patient with Ehlers-Danlos Syndrome. A correct diagnosis together with identification of iatrogenic neuropathic disorders allow the delivery of targeted treatments. In such cases clinical neurophysiology helps to determine a correct diagnosis.

Connectivity measures suggest a sub-cortical generator of myoclonus in Angelman syndrome

OBJECTIVE

The clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients.

METHODS

We performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC).

RESULTS

Twenty-four patients (aged 3-35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group.

CONCLUSIONS

These neurophysiological findings suggest a subcortical generator of myoclonus in AS.

SIGNIFICANCE

Myoclonus in AS has not a cortical origin as previously hypothesised.