title: Isolated bilateral trochlear nerve palsy as the first clinical sign of a metastatic [correction of metastasic] bronchial carcinoma.
abstract: OBJECTIVE
  To report a case with isolated, nontraumatic bilateral fourth nerve palsy as the first clinical sign of a metastatic lung carcinoma.
  
  
  METHODS
  Case report. A 56-year-old man presented with isolated, nontraumatic bilateral fourth nerve palsy. Magnetic resonance imaging (MRI) of the brain and orbits and, subsequently, chest x-ray and a computer tomographic (CT)-scan of the thorax, the abdomen, and the pelvis were performed.
  
  
  RESULTS
  Magnetic resonance imaging confirmed the presence of a midline brain stem lesion in the region of decussation of the trochlear nerves. Computed tomographic scan of the chest revealed that the lesion was caused by a metastatic lung carcinoma.
  
  
  CONCLUSIONS
  The findings of isolated bilateral fourth nerve palsy in the absence of trauma should alert the clinician to the possibility of a posterior fossa lesion in the region of the trochlear nerves. Besides urgent scanning of the dorsal midbrain, investigations should be directed to search for the primary tumor.
authors.affiliation: Department of Ophthalmology, Luton and Dunstable Hospital NHS Trust, Luton LU4 0DZ, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Mielke
authors.forename: M S
authors.initials: MS
authors.lastname: Alexander
authors.forename: N
authors.initials: N
authors.lastname: Anand
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary; D002283:Carcinoma, Bronchogenic / Q000175:diagnosis* / Q000556:secondary; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014321:Trochlear Nerve / Q000473:pathology*; D020432:Trochlear Nerve Diseases / Q000175:diagnosis* / Q000209:etiology