Spinal myoclonus in the periscapular muscles after mastectomy assessed by FDG-PET.

We describe a 64-year-old woman who developed spinal myoclonus around the left scapula after long thoracic nerve injury by mastectomy. Involuntary muscle twitching was semi-rhythmic, and ultrasonography identified contraction of the serratus anterior, teres major, and rhomboid muscles. FDG-PET imaging revealed markedly increased glucose uptake only in the serratus anterior. Lidocaine injection into this muscle resulted in complete cessation of the involuntary movement, and then she was successfully treated with botulinum toxin type A. These findings raise the possibility that the myoclonus was primarily caused by ectopic firing of the injured long thoracic nerve, then spreading to adjacent muscles possibly via a central mechanism mediated by group Ia afferents. The new imaging tools, such as FDG-PET and ultrasonography, were useful to determine the therapeutic target muscle.

Sudomotor, skin vasomotor, and cardiovascular reflexes in 3 clinical forms of Lewy body disease.

OBJECTIVE: To elucidate the differences among dementia with Lewy bodies (DLB), Parkinson disease with dementia (PDD), and Parkinson disease without dementia (PD), with respect to the involvement of the autonomic nervous system, we clinically investigated the cutaneous and cardiovascular autonomic functions in patients with Lewy body disease. METHODS: We studied 36 patients with Lewy body disorders, including 12 patients with DLB (age, 75.4 +/- 5.9 years), 12 patients with PDD (71.0 +/- 6.8 years), and 12 patients with PD (70.9 +/- 4.2 years), and 12 healthy control subjects (69.9 +/- 5.3 years). Sympathetic sweat response (SSwR) and skin vasomotor reflex (SkVR) on the palm were recorded to estimate the cutaneous sympathetic function, and the head-up tilt test was performed and coefficient of variation of R-R intervals (CV(R-R)) was studied to estimate the cardiovascular function. RESULTS: The patients with DLB, patients with PDD, and patients with PD showed severely reduced SSwR amplitudes, significantly lower than that in the controls. The mean SkVR amplitudes in the patients with DLB and patients with PDD were significantly lower than that in the controls, but not in the patients with PD. The mean decreases in the systolic blood pressure during the head-up tilt test in the patients with DLB and patients with PDD were less than that in the controls. The mean CV(R-R) value was significantly lower in the patients with DLB. CONCLUSION: Sudomotor function on the palm may be severely affected in Lewy body disorders, while skin vasomotor function and the cardiovascular system may be more severely affected in dementia with Lewy bodies and Parkinson disease with dementia than in Parkinson disease.