title: Frontotemporal brain sagging syndrome: an SIH-like presentation mimicking FTD.
abstract: BACKGROUND
  Behavioral variant frontotemporal dementia (bvFTD) is a relatively well-defined clinical syndrome. It is associated with frontal and temporal lobe structural/metabolic changes and pathologic findings of a neurodegenerative disease. We have been evaluating patients with clinical and imaging features partially consistent with bvFTD but with evidence also suggestive of brain sagging, which we refer to as frontotemporal brain sagging syndrome (FBSS).
  
  
  METHODS
  Retrospective medical chart review to identify all patients seen at our institution between 1996 and 2010, who had a clinical diagnosis of FTD and imaging evidence of brain sag.
  
  
  RESULTS
  Eight patients, 7 male and 1 female, were diagnosed with FBSS. The median age at symptom onset was 53 years. All patients had insidious onset and slow progression of behavioral and cognitive dysfunction accompanied by daytime somnolence and headache. Of the 5 patients with functional imaging, all showed evidence of hypometabolism of the frontotemporal regions. On brain MRI, all patients had evidence of brain sagging with distortion of the brainstem; 3 patients had diffuse pachymeningeal enhancement. CSF opening pressure was varied and CSF protein was mildly elevated. A definite site of CSF leak was not identified by myelogram or cisternography, except in one patient with a site highly suggestive of leak who subsequently underwent surgery confirming a CSF leak. In 2 patients with a neuropathologic examination, there was no evidence of a neurodegenerative disease.
  
  
  CONCLUSIONS
  This case series demonstrates that FBSS may mimic typical bvFTD but should be recognized as an unusual presentation that is potentially treatable.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Wicklund
authors.forename: B
authors.initials: B
authors.lastname: Mokri
authors.forename: D A
authors.initials: DA
authors.lastname: Drubach
authors.forename: B F
authors.initials: BF
authors.lastname: Boeve
authors.forename: J E
authors.initials: JE
authors.lastname: Parisi
authors.forename: K A
authors.initials: KA
authors.lastname: Josephs
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology*; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D057180:Frontotemporal Dementia / Q000134:cerebrospinal fluid / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D019585:Intracranial Hypotension / Q000150:complications*; D008279:Magnetic Resonance Imaging; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000008:administration & dosage; D009483:Neuropsychological Tests; D011859:Radiography; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D018696:Neuroprotective Agents; D008775:Methylprednisolone