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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemifacial spasm is defined as unilateral, involuntary, irregular clonic or tonic movement of muscles innervated by the seventh cranial nerve. Most frequently attributed to vascular loop compression at the root exit zone of the facial nerve, there are many other etiologies of unilateral facial movements that must be considered in the differential diagnosis of hemifacial spasm. The primary purpose of this review is to draw attention to the marked heterogeneity of unilateral facial spasms and to focus on clinical characteristics of mimickers of hemifacial spasm and on atypical presentations of nonvascular cases. In addition to a comprehensive review of the literature on hemifacial spasm, medical records and videos of consecutive patients referred to the Movement Disorders Clinic at Baylor College of Medicine for hemifacial spasm between 2000 and 2010 were reviewed, and videos of illustrative cases were edited. Among 215 patients referred for evaluation of hemifacial spasm, 133 (62%) were classified as primary or idiopathic hemifacial spasm (presumably caused by vascular compression of the ipsilateral facial nerve), and 4 (2%) had hereditary hemifacial spasm. Secondary causes were found in 40 patients (19%) and included Bell's palsy (n=23, 11%), facial nerve injury (n=13, 6%), demyelination (n=2), and brain vascular insults (n=2). There were an additional 38 patients (18%) with hemifacial spasm mimickers classified as psychogenic, tics, dystonia, myoclonus, and hemimasticatory spasm. We concluded that although most cases of hemifacial spasm are idiopathic and probably caused by vascular compression of the facial nerve, other etiologies should be considered in the differential diagnosis, particularly if there are atypical features.
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PMID:The many faces of hemifacial spasm: differential diagnosis of unilateral facial spasms. 2249 36

The intimate anatomical relationship of the facial nerve to the parotid parenchyma has a significant influence on the presenting signs and symptoms, diagnosis and treatment of parotid neoplasms. However, to our knowledge, hyperactivity of this nerve, presenting as facial spasm, has never been described as the presenting sign or symptom of a parotid malignancy. We report a case of carcinoma arising in a recurrent pleomorphic adenoma of the left parotid gland (i.e., carcinoma ex pleomorphic adenoma) that presented with hemifacial spasms. We outline the differential diagnosis of hemifacial spasm as well as a proposed pathophysiology. Facial paralysis, lymph node enlargement, skin involvement, and pain have all been associated with parotid malignancies. To date the development of facial spasm has not been reported with parotid malignancies. The most common etiologies for hemifacial spasm are vascular compression of the ipsilateral facial nerve at the cerebellopontine angle (termed primary or idiopathic) (62%), hereditary (2%), secondary to Bell's palsy or facial nerve injury (17%), and hemifacial spasm mimickers (psychogenic, tics, dystonia, myoclonus, myokymia, myorthythmia, and hemimasticatory spasm) (17%). Hemifacial spasm has not been reported in association with a malignant parotid tumor but must be considered in the differential diagnosis of this presenting symptom.
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PMID:Intermittent facial spasms as the presenting sign of a recurrent pleomorphic adenoma. 2824 88