title: Clinical features and diagnosis of the MM2 cortical subtype of sporadic Creutzfeldt-Jakob disease.
abstract: OBJECTIVE
  To describe clinical features and diagnostic tests of the MM2 cortical subtype in sporadic Creutzfeldt-Jakob disease.
  
  
  METHODS
  Clinical symptoms, magnetic resonance imaging studies, electroencephalograms, and cerebrospinal fluid markers were studied in 12 patients with genetically and neuropathologically verified sporadic Creutzfeldt-Jakob disease. Histological findings were semiquantitatively evaluated.
  
  
  RESULTS
  Compared with classical sporadic Creutzfeldt-Jakob disease, the disease duration was prolonged (median, 14 months). All patients had dementia and early and prominent neuropsychological signs such as spatial disorientation, aphasia, or apraxia. Alzheimer disease was the most frequent initial diagnosis (33%). Increased S100B protein in the cerebrospinal fluid was found in 100%; the 14-3-3 protein test was positive in 91%. Electroencephalograms revealed periodic sharp wave complexes in 42%. T2-weighted magnetic resonance imaging showed basal ganglia hyperintensities in only 1 patient, and cortical hyperintensities were not necessarily present. Severe cortical damage was the most prominent histological feature.
  
  
  CONCLUSIONS
  The S100B (100%) and 14-3-3 (91%) protein investigations were the most sensitive diagnostic tests. Prolonged disease duration, dementia as the only typical Creutzfeldt-Jakob disease symptom for a longer time, and low sensitivity of magnetic resonance imaging studies and electroencephalograms make the diagnosis in the MM2 cortical subtype difficult. Therefore, detailed clinical investigation is especially important in this sporadic Creutzfeldt-Jakob disease subtype. We suggest that rapidly progressive dementia with early and prominent neuropsychological deficits in older patients should lead to suspicion of the MM2 cortical subtype even if other neurological deficits are absent. At least some cases of MM2 cortical sporadic Creutzfeldt-Jakob disease may be misdiagnosed as rapidly progressive Alzheimer disease.
authors.affiliation: Department of Neurology, Georg-August University, Göttingen, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Krasnianski
authors.forename: Bettina
authors.initials: B
authors.lastname: Meissner
authors.forename: Walter
authors.initials: W
authors.lastname: Schulz-Schaeffer
authors.forename: Kai
authors.initials: K
authors.lastname: Kallenberg
authors.forename: Mario
authors.initials: M
authors.lastname: Bartl
authors.forename: Uta
authors.initials: U
authors.lastname: Heinemann
authors.forename: Daniela
authors.initials: D
authors.lastname: Varges
authors.forename: Hans A
authors.initials: HA
authors.lastname: Kretzschmar
authors.forename: Inga
authors.initials: I
authors.lastname: Zerr
mesh_terms: D048948:14-3-3 Proteins / Q000134:cerebrospinal fluid; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D003072:Cognition Disorders / Q000503:physiopathology; D007562:Creutzfeldt-Jakob Syndrome / Q000134:cerebrospinal fluid / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000134:cerebrospinal fluid; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000134:cerebrospinal fluid
chemical_list: D048948:14-3-3 Proteins; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human