title: Postcraniotomy temporalis muscle atrophy: a clinical, magnetic resonance imaging volumetry and electromyographic investigation.
abstract: OBJECTIVE
  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 significantly 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurology/Neurosurgery, UNICAMP (University of Campinas), Campinas, SP/Brazil.
authors.forename: Clarissa Lin
authors.initials: CL
authors.lastname: Yasuda
authors.forename: Andre Luiz Ferreira
authors.initials: AL
authors.lastname: Costa
authors.forename: Marcondes
authors.initials: M
authors.lastname: Franca
authors.forename: Fabricio Ramos Silvestre
authors.initials: FR
authors.lastname: Pereira
authors.forename: Helder
authors.initials: H
authors.lastname: Tedeschi
authors.forename: Evandro
authors.initials: E
authors.lastname: de Oliveira
authors.forename: Fernando
authors.initials: F
authors.lastname: Cendes
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003399:Craniotomy / Q000009:adverse effects*; D004566:Electrodes; D004576:Electromyography; D004833:Epilepsy, Temporal Lobe / Q000601:surgery; D005146:Facial Asymmetry / Q000209:etiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D009133:Muscular Atrophy / Q000175:diagnosis* / Q000209:etiology*; D018709:Statistics, Nonparametric; D013703:Temporal Muscle / Q000473:pathology* / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis / Q000209:etiology*