ABSTRACT
Asterixis is a involuntary movement with spontaneous interruptions and intermittent muscle tone. It occurs during posture maintenance. It is usually bilateral and, in this case, is observed in metabolic encephalopathy. Unilateral asterixis is more uncommon. We report 12 cases which occurred in patients with focal brain lesions. In all cases asterixis involved the upper limb and the lower limb in only 2 cases. Asterixis was transient, discrete and always associated with other neurological signs. The causal lesions (7 infracts, 2 haematomas, 2 abscesses, 1 meningioma) were unique in 7 cases and multiple in 5. Asterixis was always contralateral to the unilateral lesions. Lesions mainly involved the thalamus (7 cases) and other structures (lenticular nucleus, frontal lobe, internal capsule, precentral regions and cerebellum). The frequency of thalamic involvement suggested dysfunction of the thalamo-cortical loop.
Subject(s)
Brain Diseases/complications , Movement Disorders/etiology , Aged , Brain Abscess/complications , Brain Abscess/diagnosis , Brain Diseases/diagnosis , Cerebral Hemorrhage/complications , Cerebral Hemorrhage/diagnosis , Cerebral Infarction/complications , Cerebral Infarction/diagnosis , Electromyography , Female , Hematoma/complications , Hematoma/diagnosis , Humans , Magnetic Resonance Imaging , Male , Meningeal Neoplasms/complications , Meningeal Neoplasms/diagnosis , Meningioma/complications , Meningioma/diagnosis , Middle Aged , Tomography, X-Ray ComputedABSTRACT
The suprascapular nerve passes through the spinoglenoid notch with a risk of entrapment. This results in distal nerve lesion characterized by isolated paralysis of the infraspinatus muscle and, most often, by shoulder pain. We report 7 clinical and electromyographical cases of pure infraspinatus muscle paralysis. The value of the electrodiagnosis, which demonstrated prolonged suprascapular distal nerve latencies (over 5 milliseconds) in the infraspinatus muscle affected while latencies were normal in the supraspinatus muscle, is emphasized. Mechanical factors were associated with paralysis in 5 cases. Compressive synovial cysts were found in 2 patients operated upon. Surgical enlargement of the spinoglenoid notch regularly and rapidly relieves pain and sometimes helps in recovery of the infraspinatus muscle.