Typical trigeminal neuralgia associated with brainstem white matter lesions on MRI in patients without criteria of multiple sclerosis.

INTRODUCTION

Although compression of the trigeminal nerve by a vascular loop is thought to be the most common cause of trigeminal neuralgia (TN), other aetiologies, such as multiple sclerosis or brainstem infarction may be associated with this disorder. MRI may detect lesions different from vascular loop compression of the trigeminal nerve that may be related to TN.

PATIENTS AND

METHODS

The pre-operative MRIs of 68 patients without the diagnosis of multiple sclerosis who were operated for typical TN between 1998 and 2003 were retrospectively reviewed Four of these showed hyperintense lesions in the pons on T2 MRI sequences. No patient had prior surgery. These four patients underwent different operations for the control of pain but in two of them only ablative procedures were effective

DISCUSSION: Although it is uncertain whether the occurrence of TN in our patients may be attributed to the brainstem abnormalities seen on MRI, the presence of these lesions appears to be the most convincing explanation for the occurrence of pain. We believe that, in the presence of such imaging changes, a destructive procedure should be regarded as the elective surgical treatment in patients presenting with typical TN with or without apparent vascular loop compression of the trigeminal root.