Trigeminal neuralgia secondary to Epidermoid Cyst: A Review of 21 Cases during the North American Skull Base Surgery Anual Meeting held as Virtual Meeting Neurologia Segura Medical Center www.neurologiasegura.net

1. Trigeminal Neuralgia Secondary to Epidermoid
Cyst: A Review of 21 Cases.
Segura Lozano MA, MD, PhD; Maldonado-Olvera AN, NP; Oseguera-Zavala SB, MD;
Carranza-Rentería O, MD; Segura-Zenón AF, MD; Campero A, MD, PhD; Munguía-Rodríguez
AG, PhD.

2. We have no actual or potential conflict of interest in relation to this presentation.

3. Introduction
Epidermoid cysts are slow-growing brain tumors with
embryonic origin manifested in advanced life, being the
CPA its most frequent location.
It represents approximately 1% of intracranial tumors.
Present in 1.5% of patients debuting with trigeminal
neuralgia.
The study of choice is MRI.

4. Objective
To present a case series of patients operated to remove the epidermoid cyst located in
the anterolateral cisterns of the brainstem and to describe our operative technique.

5. Patients and methods
From January 2011 to November 2020, 1,996 patients were clinical and imaging
diagnosed with trigeminal neuralgia. We included 19 patients with diagnosis of
trigeminal neuralgia secondary to epidermoid cyst and operated by the author in
that period. Follow-up was registered at 6, 12 months and annually.

6. Surgical technique
1.-Positioning
2.-Skin incision of 3cm in
retromastoid region
3.-Dissection until reaching the
surface of the skull
4.- Dissection of the muscular
aponeurotic plane.
5.-Subasterional craniectomy.
6.-Durotomy

7. Surgical technique
7.-Depletion of the posterior fossa
and cerebellum.
8.-Tumor resection
9.-Treatment in the implant area.
10.-Duroplasty.

8. Results
Case Surgery date Gender Age Nationality
Anesthetic
time (min)
Surgery
time (min)
Stay time
(days)
Follow-up
time (months)
Years of pain Affected side
1 2011-01-02 M 38 Mexico
2 2011-01-13 F 25 US
3 2011-03-01 F 45 Mexico
4 2013-01-09 M 35 Mexico
5 2014-01-01 M 50 Bolivia - - - 66 5 R
6 2014-04-30 F 70 Mexico - - - 63 2 L
7 2014-07-22 F 37 Mexico - - - 60 1 R
8 2015-09-08 F 32 Mexico 231 210 2 46 2 L
9 2015-12-03 M 23 Mexico 239 219 3 44 1 L
10 2016-04-16 F 26 Mexico - - - 39 8 R
11 2016-05-06 M 50 US - - - 37 3 L
12 2017-02-03 F 50 Mexico 138 99 2 29 10 R
13 2017-07-24 M 47 Portugal 201 154 2 24 2 R
14 2017-11-14 M 72 Peru 264 217 2 20 1 L
15 2018-01-05 F 25 Mexico 207 165 2 18 2 L
16 2018-03-28 F 34 Mexico 215 177 2 15 1 R
17 2018-06-08 M 82 Mexico 210 133 4 14 10 R
18 2018-06-26 M 21 Bolivia 332 320 4 12 4 R
19 2018-12-17 M 48 Mexico - - - 7 1 L
20 2019-03-04 F 42 Mexico 197 170 3 16 10 R
21 2019-05-20 F 27 Mexico 181 170 2 14 1 R
22 2019-06-04 F 26 Mexico 170 151 2 13 3 R
23 2019-07-31 F 39 Mexico 223 180 2 12 1 R
24 2020-08-03 F 69 Mexico 209 162 3 3 7 L
25 2020-10-06 F 56 Mexico 267 237 2 1 10 R
26 2020-11-12 M 33 Mexico 238 199 3 0 3 R
F= 15
Average: 42
Mexico:20 Average:
220
Average:
185
Average:
2.5
Average:
25
Average:
4
R = 14
M=11 Foreign: 6 L = 8
Results
Operated in another
institution with
residual tumor
Non-operated with
pharmacologically
controlled pain
Operated in our clinic

9. Results
Maneuver during the clinical examination 48
hours after her minimally invasive surgery.
Preoperative MRI Postoperative MRI.

10. Conclusion
As one of the largest series of epidermoid cyst of cerebellopontine angle published
in Latin America and with the excellent long-term clinical results obtained, we
propose this microsurgical approach as the best treatment.
Due to the rarity of the entity, we recommend that the neurosurgeon interested in
treating the subject should be trained in laboratories with a cadaver, software for 3D
virtual surgery and under the mentorship of an expert neurosurgeon to resolve the
contingencies of the learning curve.