title: Cervical spine disease may result in a negative lumbar spinal drainage trial in normal pressure hydrocephalus: case report.
abstract: OBJECTIVE
  In this case report, we present a patient with normal pressure hydrocephalus in whom a lumbar drainage trial yielded a false-negative result secondary to cervical spondylosis.
  
  
  METHODS
  An 80-year-old woman presented with classic symptoms of normal pressure hydrocephalus as well as evidence of cervical myelopathy. Magnetic resonance imaging of the brain and spine showed enlarged ventricles and single-level cervical canal narrowing.
  
  
  METHODS
  An initial lumbar drainage trial was performed, which revealed negative results. The patient then underwent cervical decompression and fusion. Despite this procedure, the patient's symptoms continued to worsen. A repeat lumbar drainage trial was performed with positive results. Subsequently, a ventriculoperitoneal shunt was placed, resulting in significant improvement of her symptoms.
  
  
  CONCLUSIONS
  This case report illustrates how altered cerebrospinal fluid flow dynamics may impact the accuracy of the lumbar spinal drainage trial in patients with normal pressure hydrocephalus.
authors.affiliation: Department of Neurosurgery, Columbia University, New York, New York 10032, USA.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Komotar
authors.forename: Brad E
authors.initials: BE
authors.lastname: Zacharia
authors.forename: J
authors.initials: J
authors.lastname: Mocco
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kaiser
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Frucht
authors.forename: Guy M
authors.initials: GM
authors.lastname: McKhann
mesh_terms: D000369:Aged, 80 and over; D015170:Cerebrospinal Fluid Pressure; D002574:Cervical Vertebrae / Q000473:pathology / Q000503:physiopathology*; D019299:Decompression, Surgical; D003943:Diagnostic Techniques, Neurological; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D011237:Predictive Value of Tests; D013123:Spinal Fusion; D055009:Spondylosis / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt