title: Cranial base manifestations of neurosarcoidosis: a review of 305 patients.
abstract: OBJECTIVE
  Neurosarcoidosis is a rare granulomatous disease that can result in cranial neuropathy, chronic meningitis, and intracranial granuloma formation. Meningeal involvement may cause focal nodular enhancement that can simulate common cranial base tumors. The objective of the current study is to further define the clinical features of neurosarcoidosis in a large cohort of patients, focusing on characteristics relevant to the skull base surgeon.
  
  
  METHODS
  Retrospective series.
  
  
  METHODS
  Two tertiary academic referral centers.
  
  
  METHODS
  Consecutive patients diagnosed with neurosarcoidosis.
  
  
  METHODS
  Review of clinical presentation, physical examination, radiologic findings, biopsy results, and laboratory testing.
  
  
  METHODS
  Prevalence and distribution of cranial neuropathy, radiologic features of meningeal enhancement, and patterns of simulated tumors.
  
  
  RESULTS
  A total of 305 patients met study criteria. The mean age at diagnosis was 47 years and 53% were female. The optic nerve was the most commonly involved cranial nerve, followed by the trigeminal and the facial nerve. Meningeal enhancement was present in 67% of cases with 17% demonstrating focal or multicentric nodular enhancement simulating tumor. The most common locations of inflammatory tumor development included the cavernous sinus, petrous temporal bone, and sphenoid wing; six patients had bilateral internal auditory canal lesions, several mimicking neurofibromatosis type II.
  
  
  CONCLUSIONS
  Establishing the diagnosis of neurosarcoidosis remains challenging. Meningeal involvement and cranial neuropathy often mimic other more common conditions. Careful review of patient history and clinical imaging can reveal important clues toward the diagnosis of neurosarcoidosis. The clinician must maintain a high index of suspicion in patients with atypical presentation to avoid misdiagnosis and facilitate early medical treatment.
authors.affiliation: *Departments of Otolaryngology-Head and Neck Surgery, †Neurologic Surgery, ‡Radiology, and §Neurology, Mayo Clinic School of Medicine, Rochester, MN, U.S.A.; and ∥Departments of Otolaryngology-Head and Neck Surgery, ¶Neurology, Vanderbilt University Medical Center, Nashville, TN, U.S.A.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Carlson
authors.forename: James R
authors.initials: JR
authors.lastname: White
authors.forename: Mana
authors.initials: M
authors.lastname: Espahbodi
authors.forename: David S
authors.initials: DS
authors.lastname: Haynes
authors.forename: Colin L W
authors.initials: CL
authors.lastname: Driscoll
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Aksamit
authors.forename: Siddharama
authors.initials: S
authors.lastname: Pawate
authors.forename: John I
authors.initials: JI
authors.lastname: Lane
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
mesh_terms: D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D002493:Central Nervous System Diseases / Q000150:complications* / Q000473:pathology*; D003389:Cranial Nerve Diseases / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012507:Sarcoidosis / Q000150:complications* / Q000473:pathology*; D019291:Skull Base / Q000473:pathology*