Neurovascular compression syndrome (NVCS) arises from direct contact between blood vessels and cranial nerves, leading to direct compression or pulsatile effects caused by arterial pulsation. The primary conditions associated with neurovascular compression syndrome include trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia.
Trigeminal Neuralgia
Primary trigeminal neuralgia (TN) is one of the most common types of neuropathic pain. Neurological examination may reveal mild sensory loss, and it is more prevalent among the elderly. Clinically, it is characterized by brief, recurrent episodes of shock-like severe pain localized to one branch or multiple branches of the trigeminal nerve on one side. More than half of patients exhibit a fixed trigger area, also referred to as a "trigger point." Pain is typically unilateral and often remains confined to a specific branch, with the second and third branches being most commonly involved.
In the early stages, pain can often be well-controlled with carbamazepine. However, as the disease progresses, tolerance to the medication may develop, leading to decreased effectiveness, necessitating surgical intervention.
Hemifacial Spasm
Hemifacial spasm (HFS) involves intermittent, painless, involuntary spasmodic muscle contractions limited to the unilateral facial nerve distribution. These spasms typically affect the upper or lower face and may be accompanied by excessive tearing. It is more common in middle-aged and older adults, with women being slightly more frequently affected than men. However, there is a trend toward earlier onset in younger individuals. Neurological examination in most cases does not reveal any significant positive signs. The condition progresses slowly and rarely resolves spontaneously.
The most common offending blood vessel is the anterior inferior cerebellar artery (AICA), but other potential vessels include the posterior inferior cerebellar artery (PICA), superior cerebellar artery (SCA), tortuous vertebral artery, cochlear artery, or an elongated and dilated basilar artery. Posterior fossa MRI allows the exclusion of tumors or arteriovenous malformations.
Pharmacological treatment includes carbamazepine, oxcarbazepine, and botulinum toxin injections. These options are most suitable for patients in the early stages of the disease, those unable to tolerate surgical intervention, those who refuse surgery, or those with persistent symptoms after surgery requiring adjunctive management.
Glossopharyngeal Neuralgia
Glossopharyngeal neuralgia causes excruciating, tearing pain in the distribution of the glossopharyngeal and vagus nerves. The pain most commonly involves the pharynx and the base of the tongue, radiating to the ear and posterior jaw or, occasionally, to the neck. It may also be accompanied by excessive salivation and coughing. The condition is more common in men and typically begins after the age of 40.
Pharmacological treatment includes the use of oral carbamazepine and phenytoin. Over months or years, medications may gradually lose efficacy, requiring surgical treatment.
Surgical Treatment
Surgical options primarily consist of microvascular decompression (MVD) and nerve destruction procedures.
Microvascular decompression offers significant results, with 80–90% of patients with trigeminal neuralgia experiencing pain relief or satisfactory control post-surgery. For hemifacial spasm, the surgical success rate can reach as high as 92%.
Nerve destruction procedures include percutaneous radiofrequency thermocoagulation and balloon compression of the trigeminal ganglion. These methods are appropriate for elderly or frail patients who cannot tolerate microvascular decompression.