neurovascular compression syndromes are due to compression of a cranial nerve. compression of the trigeminal neural can cause trigeminal neuralgia and microvascular decompression (mvd) of the nerve can cure that condition . trigeminal neuralgia is far more common than helps and its painful sensory symptoms are often well controlled with anti-epileptic medications. compression of the facial nerve can cause hemifacial spasm and mvd of the nerve can cure that condition. in hemifacial spasm, the motor symptoms (episodic contractions of the facial muscles) typically do not respond to anti-epileptic medications but can be symptomatically controlled with botox injections in the affected muscles. compression of the glossopharyngeal nerve can cause glossopharyngeal neuralgia and mvd of the nerve can cure that condition. this is a rare condition and is very similar to trigeminal neuralgia except the pain is in the distribution of the glossopharyngeal nerve. hemi-laryngopharyngeal spasm is due to unilateral compression of the vagus nerve and can be cured with mvd of the nerve. every reported case of helps has been due to compression of the vagus nerve by a loop of the posterior inferior cerebellar artery (pica). the compression can occur at the root entry zone of the nerve or in its cisternal portion. no nerve biopsies have been performed to investigate the pathology at the compression site but it is assumed to be similar to compressions previously reported of the trigeminal and facial nerves.