ABSTRACT
Hemifacial spasm is a rare condition of intermittent, painless, involuntary, spasmodic contractions of muscles innervated by the facial nerve on one side of the face only. As other movement disorders, it is responsible for neurological disability with potentially severe social and aesthetic impact on patients’ daily quality of life. Hemifacial spasm was categorized by Janetta (1) among hyperactive cranial nerve dysfunction syndromes caused by vascular compression at the root exit or entry zone of the cranial nerve with trigeminal and glossopharyngeal neuralgia. This benign condition was first described more than a century ago by Schultze (2) in 1875 who described a typical case of left hemifacial spasm without other cranial nerve symptoms or signs in a patient who died from a tuberculous pneumonia. Autopsy revealed a compression of the seventh cranial nerve by a small aneurysm of the left vertebral artery. Gowers (3) also described in 1884 a case of hemifacial spasm due to mechanical pressure on the facial nerve by a vertebral artery aneurysm. At that time, the cause of hemifacial spasm was presumed to be idiopathic
in most cases or, rarely, to be secondary to gross organic lesions, such as cerebellopontine angle (CPA), neurinomas, cholesteatomas, or meningiomas. At the beginning of the 20th century, Cushing (4) was the first to suggest that palsies of the cranial nerves could be caused by vascular compression. At the same time, many neurosurgeons were working on trigeminal neuralgia, and Dandy in 1929 (5) observed that in trigeminal neuralgia, the fifth nerve was compressed and distorted by a vascular arterial contact of the superior cerebellar artery with the dorsal root of the nerve.
