title: Sporadic lower motor neuron disease with a snake eyes appearance on the cervical anterior horns by MRI.
abstract: OBJECTIVE
  Lower motor neuron disease (LMND) is the term generally used to describe diseases in which only lower motor neuron signs are detected. A snake eyes appearance on magnetic resonance imaging (MRI) is associated with a wide spectrum of neurological conditions including LMND. The author reports on three unique LMND patients with upper limb muscle weakness and atrophy who show a snake eyes appearance by MRI.
  
  
  METHODS
  The patients were aged 18, 40 and 52 years, respectively, at the onset of the disease and had a longstanding clinical course (more than 10 years for two patients and 8 years for one patient). They were followed up for more than 6 years.
  
  
  RESULTS
  Clinical manifestations were characterized by (1) longstanding slow progression or delayed spontaneous arrest of asymmetric lower motor neuron signs localized exclusively in the upper extremities with unilateral predominance and distal or proximal preponderance; (2) the absence of upper motor neuron signs, bulbar signs, sensory disturbances and respiratory involvement; (3) a snake eyes appearance on the anterior horns of the cervical cord over more than 3 vertebrae by axial T2-weighted MRI and a longitudinal linear-shaped T2-signal hyperintensity by sagittal MRI; (4) neurogenic change with fasciculation and denervation potentials (fibrillation and a positive sharp wave) confined to the affected muscles by needle electromyogram; and (5) normal cerebrospinal fluid and a normal creatine kinase level. These cases did not fall into any existing category of LMND, such as progressive muscular atrophy, flail arm syndrome or Hirayama disease.
  
  
  CONCLUSIONS
  These patients should be classified as sporadic LMND with snake eyes on MRI with a relatively benign prognosis.
authors.affiliation: Department of Neurology, Tokyo Women's Medical University, Tokyo, Japan. Electronic address: sasaki.shoichi@twmu.ac.jp.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Sasaki
mesh_terms: D000328:Adult; D066193:Cervical Cord / Q000473:pathology; D002574:Cervical Vertebrae / Q000473:pathology*; D018450:Disease Progression; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000175:diagnosis / Q000473:pathology*; D018908:Muscle Weakness / Q000175:diagnosis / Q000473:pathology*; D009134:Muscular Atrophy, Spinal / Q000175:diagnosis / Q000473:pathology*; D013116:Spinal Cord / Q000473:pathology*
keywords: Amyotrophic lateral sclerosis; Lower motor neuron disease; MRI; Motor neuron disease; Snake eyes appearance