Postcraniotomy Temporalis Muscle Atrophy: A Clinical, Magnetic Resonance Imaging Volumetry and Electromyographic Investigation

Aims: To evaluate both cosmetic and functional effects of temporalis muscle atrophy, by means of clinical examination, magnetic resonance imaging (MRI), and electromyographic (EMG) activity in patients who underwent craniotomy in order to treat refractory mesial temporal lobe epilepsy (MTLE). Methods: A total of 18 controls and 18 patients who underwent surgery for MTLE were investigated. The temporalis muscle volume of the patients was assessed by a 3D reconstruction. The image analysis software (ITK-SNAP) was used for the 3D reconstruction. In addition, the amplitude of the EMG signal during a maximum voluntary clench was recorded from both temporalis muscles by surface electrodes. The presence of temporomandibular disorder (TMD) signs was assessed by clinical examination that was performed only after surgery. Data were analyzed statistically by means of the Mann-Whitney U test, paired t-test, Pearson χ2 and linear regression. Results: The volume of the temporalis muscle of the operated side was significantly reduced (P = .004). The EMG results confirmed the presence of muscle atrophy, the amplitude of the EMG signal being significantly decreased on the operated side (P < .05). Also the patients’ maximum mouth opening after surgery was signifi-cantly reduced compared to that of the controls (P < .0001). Patients presented facial asymmetry, signs of TMD (pain, disc displacement, and joint sounds), and masticatory abnormalities. Conclusion: These preliminary results showed that, despite the good control of seizures, some patients may experience cosmetic and functional abnormalities of temporalis muscle secondary to atrophy and fibrosis.

craniotomy;electromyography;epilepsy surgery;magnetic resonance imaging;temporal muscle atrophy;volumetry

1. Wiebe S, Blume WT, Girvin JP, Eliasziw M. A randomized, controlled trial of surgery for temporallobe epilepsy. N Engl J Med 2001;345:311–318.

2. Yasuda CL, Tedeschi H, Oliveira EL, et al. Comparison of short-term outcome between surgical and clinical treatment in temporal lobe epilepsy: A prospective study. Seizure 2006;15:35 –40.

3. Arruda F, Cendes F, Andermann F, et al. Mesial atrophy and outcome after amygdalohippocampectomy or temporal lobe removal. Ann Neurol 1996;40:446–450.

4. Yasargil MG, Reichman MV, Kubik S. Preservation of the frontotemporal branch of the facial nerve using the inter-fascial temporalis flap for pterional craniotomy. Technical article. J Neurosurg 1987;67:463–466.

5. Seoane E, Tedeschi H, de Oliveira E, Wen HT, Rhoton AL Jr. The pretemporal transcavernous approach to the inter-peduncular and prepontine cisterns: Microsurgical anatomy and technique application. Neurosurgery 2000;46: 891–898.

6. de Oliveira E, Tedeschi H, Siqueira MG, Peace DA. The pretemporal approach to the interpeduncular and petroclival regions. Acta Neurochir (Wien) 1995;136:204–211.

7. Coscarella E, Vishteh AG, Spetzler RF, Seoane E, Zabramski JM. Subfascial and submuscular methods of temporal mus-cle dissection and their relationship to the frontal branch of the facial nerve. Technical note. J Neurosurg 2000;92: 877–880.

8. Oikawa S, Mizuno M, Muraoka S, Kobayashi S. Retrograde dissection of the temporalis muscle preventing muscle atrophy for pterional craniotomy. Technical note. J Neuro-surg 1996;84:297–299.

9. Kawaguchi M, Sakamoto T, Furuya H, Ohnishi H, Karasawa J. Pseudoankylosis of the mandible after supratentorial craniotomy. Anesth Analg 1996;83:731–734.

10. Kawaguchi M, Sakamoto T, Ohnishi H, Karasawa J, Furuya H. Do recently developed techniques for skull base surgery increase the risk of difficult airway management? Assessment of pseudoankylosis of the mandible following surgical manipulation of the temporalis muscle. J Neurosurg Anesthesiol 1995;7:183–186.

11. Coonan TJ, Hope CE, Howes WJ, Holness RO, MacInnis EL. Ankylosis of the temporomandibular joint after temporal craniotomy: A cause of difficult intubation. Can Anaesth Soc J 1985;32:158–160.

12. Badie B. Cosmetic reconstruction of temporal defect following pterional [corrected] craniotomy. Surg Neurol 1996;45:383–384.

13. de Andrade Junior FC, de Andrade FC, de Araujo Filho CM, Carcagnolo FJ. Dysfunction of the temporalis muscle after pterional craniotomy for intracranial aneurysms. Compara-tive, prospective and randomized study of one flap versus two flaps dieresis. Arq Neuropsiquiatr 1998;56:200–205.

14. Dworkin SF, LeResche L. Research diagnostic criteria for temporomandibular disorders: Review, criteria, examination and specifications, critique. J Craniomandib Disord 1992;6:301–355.

15. Yasargil MG, Wieser HG, Valavanis A, von AK, Roth P. Sur-gery and results of selective amygdala-hippocampectomy in one hundred patients with nonlesional limbic epilepsy. Neurosurg Clin N Am 1993;4:243–261.

16. Engel J Jr, Van Ness PC, Rasmussen TB, Ojemann LM. Outcome with respect to epileptic seizures. In: Engel J Jr (ed). Surgical Treatment of the Epilepsies, ed 2. New York: Ra-ven, 1993:609–621.

17. Yushkevich PA, Piven J, Hazlett HC, et al. Userguided 3D active contour segmentation of anatomical structures: Sig-nificantly improved efficiency and reliability. Neuroimage 2006;31:1116–1128.

18. Geers C, Nyssen-Behets C, Cosnard G, Lengele B. The deep belly of the temporalis muscle: An anatomical, histological and MRI study. Surg Radiol Anat 2005;27:184–191.

19. Suvinen TI, Kemppainen P. Review of clinical EMG studies related to muscle and occlusal factors in healthy and TMD subjects. J Oral Rehabil 2007;34:631–644.

20. De Felicio CM, Sidequersky FV, Tartaglia GM, Sforza C. Electromyographic standardized indices in healthy Brazilian young adults and data reproducibility. J Oral Rehabil 2009;36:577–583.

21. Ikebe K, Hazeyama T, Iwase K, et al. Association of symptomless TMJ sounds with occlusal force and masticatory performance in older adults. J Oral Rehabil 2008;35: 317–323.

22. Engel J Jr. Update on surgical treatment of the epilepsies. Summary of the second international Palm Desert confer-ence on the surgical treatment of the epilepsies (1992). Neu-rology 1993;43:1612–1617.

23. Spetzler RF, Lee KS. Reconstruction of the temporalis muscle for the pterional craniotomy. Technical note. J Neurosurg 1990;73:636–637.

24. Matsumoto K, Akagi K, Abekura M, Ohkawa M, Tasaki O, Tomishima T. Cosmetic and functional reconstruction achieved using a split myofascial bone flap for pterional craniotomy. Technical note. J Neurosurg 2001;94:667–670.

25. Meldolesi GN, Di GG, Quarato PP, et al. Changes in depression, anxiety, anger, and personality after resective surgery for drug-resistant temporal lobe epilepsy: A 2-year follow-up study. Epilepsy Res 2007;77:22–30.

26. Miyazawa T. Less invasive reconstruction of the temporalis muscle for pterional craniotomy: Modified procedures. Surg Neurol 1998;50:347–351.

27. Porter MJ, Brookes GB. False ankylosis of the temporomandibular joint after otologic and neurotologic surgery. Am J Otol 1991;12:139–141.

28. Gonzalez-Martinez JA, Srikijvilaikul T, Nair D, Bingaman WE. Long-term seizure outcome in reoperation after failure of epilepsy surgery. Neurosurgery 2007;60:873–880.

29. Salanova V, Markand O, Worth R. Temporal lobe epilepsy: Analysis of failures and the role of reoperation. Acta Neurol Scand 2005;111:126–133.

30. Gaudy JF, Zouaoui A, Bravetti P, Charrier JL, Laison F. Functional anatomy of the human temporal muscle. Surg Radiol Anat 2001;23:389–398.

31. Bowles AP Jr. Reconstruction of the temporalis muscle for pterional and cranioorbital craniotomies. Surg Neurol 1999;52:524–529.

32. Webster K, Dover MS, Bentley RP. Anchoring the detached temporalis muscle in craniofacial surgery. J Craniomaxil-lofac Surg 1999;27:211–213.