Imaging of Cranial Neuralgias

Cranial neuralgia (CN) can cause significant debilitating pain within a nerve dermatome. Accurate diagnosis requires detailed clinical history and examination, understanding of pathophysiology and appropriate neuroimaging to develop an optimal treatment plan. The objective of this article is to review and discuss some of the more common CNs including trigeminal neuralgia and its associated painful neuropathies, occipital neuralgia, and less common glossopharyngeal neuralgia (GPN). The neuroanatomy, pathophysiology, diagnostic imaging, and treatment of each of these pathologies are reviewed with emphasis on the role of CT and MR imaging findings in guiding diagnosis. Although CT is often used to initially identify an underlying cause such as neoplasm, infection, or vascular malformation, MRI is optimal. Clinical history and examination findings along with MRI constructive interference steady state/fast imaging employing steady-state acquisition sequences and MRA of the brain can be used to distinguish between primary and secondary cranial neuropathies and to discern the best treatment option. Pharmacologic and noninvasive therapy is the first-line of treatment of these cranial and cervical neuralgias. If symptoms persist, stereotactic radiosurgery is an option for some patients, although microvascular decompression surgery is the most curative option for both trigeminal and GPN. Refractory occipital neuralgia can be treated with a nerve block, an ablative procedure such as neurectomy or ganglionectomy, or more recently occipital nerve stimulation.