Muscle & nerve
-
Multicenter Study
Utility of trapezius EMG for diagnosis of amyotrophic lateral sclerosis.
Needle electromyography (EMG) of the tongue is traditionally used as a key to the diagnosis of amyotrophic lateral sclerosis (ALS), although relaxation of the tongue is often difficult to achieve. Recently, frequent abnormalities in the EMGs of the sternocleidomastoid (SCM) and upper trapezius muscles in ALS have been reported. To elucidate the diagnostic utility of these muscles we performed a multicenter prospective study to examine EMGs of the tongue (genioglossus), SCM, and trapezius in 104 ALS or suspected ALS patients. ⋯ We did not observe Fib/PSWs or fasciculation potentials in any of our CS patients, thus these findings have excellent specificity. Tongue EMG added little utility over the clinical sign of tongue atrophy. Abnormal spontaneous activity in the trapezius would be more useful for the early diagnosis of ALS.
-
In 38 amyotrophic lateral sclerosis (ALS) patients and 28 controls, we performed motor unit potential (MUP) analysis in the C-6 and T-5 paraspinal and biceps muscles. In ALS cases, we found similar abnormalities in MUPs in paraspinal and limb muscles. Fasciculation potentials (FPs) were more frequent in biceps than in paraspinal muscles, but fibrillation potentials and positive sharp waves (fibs-sw) were equally frequent in all three muscles. These results confirm the value of paraspinal MUP analysis in the diagnosis of ALS.
-
In this study we sought to determine whether axonal damage in severe Guillain-Barré syndrome (GBS) was secondary to critical illness polyneuropathy (CIP) in the intensive care unit (ICU) by reviewing comorbidities in patients who had initial and follow-up electromyographic (EMG) studies. Patients were classified as demyelinating (EMG-D) or axonal (EMG-A) according to findings on the second EMG. A critical illness (CI) score, derived from components of the APACHE II score, assessed the severity of critical illness in the ICU. ⋯ Mean strength (0-100, Medical Research Council scale) and Hughes disability scores for the EMG-A group were significantly worse at admission, nadir, and discharge. EMG-A patients had significantly more days on the ventilator (25 vs. 11), in the ICU (26 vs. 15), and in the hospital (29 vs. 18). Sixty-eight percent of patients with GBS in the ICU developed axon loss, but this was not related to the usual precipitants of CIP.