gms | German Medical Science

Introduction: Only 0.8% of TN are associated with tumors causing alteration in sensitivity, and derived pain is frequently atypical and constant, there are approximately 100 case reports of CPA lipomas comprising 0.14% of all CPA tumors and just 0.05% of the operated ones, most intracranial lipomas are supratentorial (81%), 82% are midline, 47% close to the corpus callosum and only 12% in the CPA. This lessions are rare and to attempt surgical excision is associated with significant morbidity, these are frequently in close relation with cranial vessels and cranial nerves(CN), with adipocytes separating or infiltrating nerve fibers. This intimate relationship makes difficult the resection without incurring lesions, or CN deficits associated with significant morbidity in operated patients. Anglelipomas surgery has poor results with studies showing improvement without causing additional neurological deficit only in 18 to 19% of patients and presenting with new deficit in up to 68% to 72% of surgical patients.

Clinical Case: We present a case of refractory trigeminal neuralgia of one year of progression, caused by left lipoma of the cerebellopontine angle. A 28-year-old male who is a High performance athlete (footballer) presented with severe left-sided trigeminal neuralgia, specifically in V1, daily presentation and rated for VAS in 7, without hypoacusis, facial asymmetry or sensory symptoms nor affection of any other cranial nerve.

Imaging and Treatment: The MRI shows a lesion of 14x16mm at the left trigeminal exit, hyperintense in T1, hypointense in T2, without contrast enhancing and fat suppression in FLAIR sequence, without restriction to diffusion, fulfilling the classic features by MRI of the intracranial pontocerebellar angle lipomas (APC). Initially received pharmacological treatment with Oxcarbazepine without good tolerance and persistent pain the first six weeks of treatment. Was used Amitriptyline and gabapentin at different doses and combinations, presenting side effects that generate interference with his soccer training and his normal activity, reporting mild daytime sedation, dizziness, difficulty concentrating, so he decides to stop medication voluntarily at the 3rd month of treatment. Peripheral radiofrequency was performed in supratrochlear and supraorbital without satisfactory response. Balloon compression was proposed but the patient was not confident to undergo interventionism despite our clear explanation about the low invasiveness and low morbidity of this procedure. The patient wanted something less invasive and a safer option, with fewer days of laboral inhability considering his profession. The literature available of treatment for trigeminal neuralgias secondary to benign tumors was reviewed, emphasizing viability of radiosurgery in this cases, finding no reports of radiosurgery, specifically in lipomas of the APC. The group agreed and justified to offer radiosurgery from the beginning, regarding some studies that report better results with radiosurgery in patients who have not been treated with surgery or interventional procedures, and extrapolating results of studies in patients with meningiomas and schwannomas with persistent neuralgia, where after treating the lession, the pain continues and was decided to manage the symptom as classical neuralgia irradiating the cisternal portion of the nerve. After one month of treatment with cyberknife the pain has completely disappeared. The results will be presented with follow-up at one year of radiosurgery.

Radiosurgery with cyberknife singlefraction, 60 gy at 80% isodose. Maximum dose 75gy.

Figure 1 [Fig. 1], Figure 2 [Fig. 2]