Lipomatosis of the Trigeminal Nerve Causing Trigeminal Neuralgia: Case Report and Literature Review

Abstract

Cerebellopontine angle lipomas are rare and attempts at surgical excision are associated with significant morbidity. Lipomatosis of nerve, the fatty infiltration of nerves, is a distinct entity. We present a case of intractible trigeminal neuralgia caused by lipomatosis of the trigeminal nerve. Clinical case: A 25-year-old male presented with severe right-sided trigeminal neuralgia. Imaging showed a lesion involving the trigeminal nerve with signal characteristics of fat. At surgery the lesion was found to be a fatty infiltration of the nerve itself. Surgery was therefore limited to arachnoid adhesiolysis. The patient remains symptom-free and neurologically intact to date. Correctly identifying these lesions as lipomatosis of nerve rather than lipoma of the cerebellopontine angle make it clear that even partial surgical excision will inevitably result in neurological deficit and should not be attempted. However, in the case of intractable trigeminal neuralgia we demonstrate that surgery can still play a role.

Trigeminal Neuralgia Associated with Cerebellopontine Angle Lipoma in Childhood

“…Supratentorial intracranial lipomas are associated with other congenital malformations (55%) such as agenesis or dysgenesis of the corpus callosum, absence of the septum pellucidum, cranium bifidum, spina bifida, encephalocele, myelomeningocele, vermian hypoplasia and cortical malformations [4,6]. Conversely CPA lipomas, first described by Kolb in 1859, usually are isolated lesions [4,11]. …”

“…Intracranial lipomas are very rare lesions with a prevalence ranging from 0.08 to 5% [3,4]. They are rare congenital abnormalities, which are not true neoplasms.…”

“…They are rare congenital abnormalities, which are not true neoplasms. They originate from the primitive meninx and contain adipose tissue [3,4,5,6]. Intracranial lipomas affect more frequently females than males (2:1) [3].…”

“…Intracranial lipomas affect more frequently females than males (2:1) [3]. Most lipomas occur at or near the midline, and only 9-12% are found in the CPA [4,6,7]. In symptomatic cases lipomas of the CPA can cause vertigo, dizziness, tinnitus, and loss of hearing [3,4,8].…”

“…Most lipomas occur at or near the midline, and only 9-12% are found in the CPA [4,6,7]. In symptomatic cases lipomas of the CPA can cause vertigo, dizziness, tinnitus, and loss of hearing [3,4,8]. To our knowledge, 3 cases of TGN associated with CPA lipoma in childhood have been reported (table 1) [1,9,10].…”