title: Assessment of electromyograghic findings in peroneus tertius, tibialis posterior and dorsal interoseous pedis muscles in patients with axonal polyneuropathy.
abstract: BACKGROUND
  Axonal polyneuropathy (APN) is a common kind of neurologic disorders, which is normally diagnosed by electrodiagnostic methods. Different muscles were studied to find a muscle, which can be considered as a reliable site for early diagnosis of mild APN; this muscle should be easily activated by patient, has the highest sensitivity to EMG changes of APN, and has the lowest rate of false positive results in normal subjects.
  
  
  METHODS
  Based on the inclusion and exclusion criteria, 32 patients were recruited, and all of them underwent needle EMG of 3 different muscles including Peroneus tertius (PT), tibialis posterior (TP), and dorsal interoseous pedis (DIP). EMG Findings of different muscles [Motor Unite Action Potential (MUAP) duration, MUAP amplitude, polyphasic MUAP, fibrillation potential (FP), and the ability of subjects to contract special muscle] were recorded and compared.
  
  
  RESULTS
  Mean of MUAP amplitude was significantly different between all 3 muscles (P-values < 0.001). PT showed a significantly higher frequency of polyphasic MUAP than others (P-value: 0.001). The frequency of FP was significantly lower in TP than PT and DIP (P-values: 0.03 and 0.001, respectively). DIP showed significantly shorter MUAP duration than PT and TP (P-values 0.002 and 0.003, respectively). All cases were able to activate TP and PT voluntarily though only 20 patients could activate DIP (P-value < 0.0001).
  
  
  CONCLUSIONS
  The higher frequency of polyphasic MUAP, the higher frequency of FP, and finally, the ability of all patients in activation of PT voluntarily, all support the usefulness of PT for EMG studies in APN patients.
authors: Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: Majid
authors: M
authors: Ghasemi
authors: Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: Zahra
authors: Z
authors: Rajaei
authors: Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: Fariborz
authors: F
authors: Khorvash
authors: Medical University of AJA, Tehran, Iran.
authors: Bahador
authors: B
authors: Asadi
authors: Department of Neurosurgery, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: Majid
authors: M
authors: Rezvani
keywords: Axonal polyneuropathy; dorsal interoseous pedis; electromyographic; peroneus tertius; tibialis posterior