This Article Abstract Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Woolfall, P Articles by Coulthard, A Search for Related Content PubMed PubMed Citation Articles by Woolfall, P Articles by Coulthard, A

Trigeminal nerve: anatomy and pathology

Department of Radiology, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-Upon-Tyne NE1 4LP, UK

View larger version (63K): [in a new window]   Figure 1. 3D-FISP image reconstructed in the sagittal oblique plane (TR/TE 30/7; flip angle 20°). The normal root entry zone (REZ) and the cisternal course of the right trigeminal nerve are demonstrated (asterix). Flow within blood vessels is shown as very high signal intensity using the 3D-FISP sequence. A small cisternal vessel lying inferior to the REZ (arrow) is well clear of the nerve and is of no pathological significance (compare with Figures 8–10).

View larger version (73K): [in a new window]   Figure 2. (a) T2 weighted axial plane FSE image from a 43-year-old woman presenting with sudden onset of facial numbness and hemianaesthesia. There is diffuse signal hyperintensity within the right side of the pons. (b) T1 weighted sagittal image acquired 8 months later shows a mature pontine infarct (arrow).

View larger version (76K): [in a new window]   Figure 3. (a) Coronal plane STIR image through the brain stem of a 41-year-old woman with multiple sclerosis, presenting with a short history of altered facial sensation. There is a high signal intensity plaque of demyelination within the right brachium pontis (arrow). (b) Axial plane T2 weighted FSE image at the level of the centrum semiovale. Typical ovoid lesions of primary demyelination in the periventricular and subcortical white matter.

View larger version (74K): [in a new window]   Figure 4. (a) Axial T2 weighted FSE image at mid pontine level from a 29-year-old patient with Type I neurofibromatosis and recent onset of facial pain. There is an ill defined mass within the pons on the right (arrow). (b) An image from a FLAIR sequence acquired in the coronal plane confirms the diffuse mass. The diagnosis was pontine glioma. Such tumours tend to run a relatively benign course in patients with neurofibromatosis.

View larger version (73K): [in a new window]   Figure 5. Cavernous haemangioma of the midbrain in a 29-year-old woman presenting with vague facial sensory disturbance and ataxia. (a) Axial plane T2 weighted FSE image and (b) coronal plane FLAIR image. Both sequences show the typical MRI appearances of a cavernous haemangioma: central high signal intensity (methaemaglobin) surrounded by a rim ofvery low signal intensity (haemosiderin deposition).

View larger version (93K): [in a new window]   Figure 6. Viral rhombencephalitis in a 20-year-old woman who presented with headache, vertigo and photophobia and went on to develop left-sided paraesthesia and left facial weakness. (a,b) Axial plane T1 weighted SE images after iv gadolinium-DTPA. There is marked enhancement of the left trigeminal nerve (a) and nucleus (b). (c) Repeat examination after 4 months. Axial plane T1 weighted SE image after iv gadolinium-DTPA. The trigeminal nerve and nucleus now appear normal. Herpes simplex virus is the commonest cause of viral rhomboencephalitis, although often (as in this case) no specific pathogen can be isolated.

View larger version (124K): [in a new window]   Figure 7. Syringobulbia and syringomyelia in a 20-year-old man presenting with horizontal diplopia and left facial sensory loss. Sagittal T2 weighted FSE image showing a large syrinx extending cranially through the foramen magnum to involve the brain stem. The foramen magnum is stenosed. Parasagittal sections showed a Chiari I malformation.

View larger version (84K): [in a new window]   Figure 8. Neurovascular compression of the trigeminal nerve in a 63-year-old woman with severe right trigeminal neuralgia. 3D-FISP sequence reconstructed in the coronal plane. There is a small high signal intensity vessel in close contact with the right trigeminal nerve (small arrow). On the left side there is a vessel lateral to but not in contact with the trigeminal nerve (arrowhead).

View larger version (112K): [in a new window]   Figure 9. Neurovascular compression and trigeminal neuralgia in a different patient. (a) 3D-FISP sequence reconstructed in the sagittal oblique plane to show the right trigeminal nerve. There are two vessels in contact with the upper and lower aspects of the nerve (arrows). (b) An axial reconstruction may occasionally be helpful. One of the vessels shown in (a) is in contact with the lateral surface of the right trigeminal nerve (arrow). The other vessel seen in (a) lies posterolateral to the arrowed vessel on this section.

View larger version (60K): [in a new window]   Figure 10. Neurovascular contact with the trigeminal nerve in an asymptomatic 31-year-old male subject. Sagittal oblique reconstruction from a 3D-FISP study shows a vessel crossing the left trigeminal nerve at the root entry zone (arrow). Vascular compression is the cause of trigeminal neuralgia in many patients with symptoms unresponsive to medical treatment, but it is important to remember that small vessels may also be found in the vicinity of the trigeminal nerve in up to 27% of normal subjects [8].

View larger version (144K): [in a new window]   Figure 11. Dolichoectasia of the vertebral or basilar arteries may result in vascular compression of the trigeminal nerve. (a) Coronal plane STIR image at the level of the pons. The ectatic basilar artery is seen as a flow void (long arrow) displacing the left trigeminal nerve superiorly and laterally (short arrow). (b) Parasagittal reconstruction of a 3D-FISP sequence in the plane of the left trigeminal nerve. The ectatic vessel is shown as a high signal intensity structure (long arrow) impinging on the trigeminal nerve (arrowhead).

View larger version (140K): [in a new window]   Figure 12. Perineural metastasis from a malignant melanoma in a 77-year-old woman. Axial T1 weighted SE image after iv gadolinium-DTPA. There is an enhancing metastatic deposit spreading along the right trigeminal nerve and invading the pons. The right orbital apex is also involved.

View larger version (143K): [in a new window]   Figure 13. Cerebellopontine angle meningioma in a 64-year-old man with trigeminal neuralgia. Axial T1 weighted SE image after iv gadolinium-DTPA. There is a mass within the left cerebellopontine angle, which enhances strongly.

View larger version (145K): [in a new window]   Figure 14. Arachnoid cyst in the cerebellopontine angle in a 28-year-old woman with trigeminal neuralgia. Axial T2 weighted FSE image showing a well defined lesion of similar signal intensity to CSF within the left cerebellopontine angle.

View larger version (117K): [in a new window]   Figure 15. Epidermoid cyst in the left cerebellopontine angle, CSF signal intensity. (a) Axial plane T1 weighted SE section at the level of upper medulla. Apparent widening of the cistern on the left side (arrow). (b) Coronal plane T1 weighted SE image. Apparent asymmetry of the cisterns is due to the presence of an epidermoid cyst. The left trigeminal nerve is displaced superiorly (arrow).

View larger version (142K): [in a new window]   Figure 16. Neuroma of the trigeminal ganglion in a 31-year-old woman. Axial T1 weighted SE image after iv gadolinium-DTPA. There is an enhancing mass within Meckel's cave on the right (arrow). The patient presented with altered sensation in the distribution of the right trigeminal nerve.

View larger version (106K): [in a new window]   Figure 17. Transient enhancing lesion in Meckel's cave. The 29-year-old female patient presented with left facial pain and numbness. (a) Coronal plane T1 weighted SE image after iv gadolinium-DTPA. An enhancing mass in Meckel's cave on the left (arrow). Initial diagnosis was trigeminal neuroma. (b) Repeat examination 14 months after (a). Complete resolution of the enhancing mass lesion corresponding with disappearance of the patient's symptoms. In retrospect, the mass was presumably inflammatory in aetiology.

View larger version (120K): [in a new window]   Figure 18. Internal carotid artery aneurysm arising within the cavernous sinus. (a) Coronal plane T1 weighted image at the level of the cavernous sinus in a patient presenting with symptoms including left V1 and V2 distribution sensory disturbance. The cavernous aneurysm is arrowed. (b) Maximal intensity projection reconstruction of a time-of-flight MR angiography sequence confirming the left cavernous carotid aneurysm (arrow).