Neuropathological findings in possible normal pressure hydrocephalus: A post-mortem study of 29 cases with lifelines

Authors

  • Joni J. Hänninen The Department of Pathology, Kuopio University Hospital and the Institute of Clinical Medicine – Pathology, University of Eastern Finland, Kuopio, Finland; The Department of Neurosurgery, Kuopio University Hospital and the Institute of Clinical Medicine – Neurosurgery, University of Eastern Finland, Kuopio, Finland
  • Madoka Nakajima The Department of Neurosurgery, Juntendo University Faculty of Medicine, Tokyo, Japan
  • Aleksi Vanninen The Department of Pathology, Kuopio University Hospital and the Institute of Clinical Medicine – Pathology, University of Eastern Finland, Kuopio, Finland; The Department of Neurosurgery, Kuopio University Hospital and the Institute of Clinical Medicine – Neurosurgery, University of Eastern Finland, Kuopio, Finland
  • Santtu Hytönen The National Institute for Health and Welfare, Forensic Medicine, Kuopio, Finland
  • Jaana Rummukainen The Department of Pathology, Kuopio University Hospital, Kuopio, Finland
  • Anne Maria Koivisto The Department of Neurology, Kuopio University Hospital and the Institute of Clinical Medicine – Neurology, University of Eastern Finland, Kuopio, Finland; The Department of Neurosciences, Medical Faculty, University of Helsinki, Helsinki, Finland; The Department of Geriatrics/Rehabilitation and Internal Medicine, Helsinki University Hospital, Helsinki, Finland
  • Juha E. Jääskeläinen The Department of Neurosurgery, Kuopio University Hospital and the Institute of Clinical Medicine – Neurosurgery, University of Eastern Finland, Kuopio, Finland
  • Hilkka Soininen The Department of Neurology, Kuopio University Hospital, Kuopio, Finland
  • Anna Sutela The Department of Radiology, Kuopio University Hospital and the Institute of Clinical Medicine – Radiology, University of Eastern Finland, Kuopio, Finland
  • Ritva Vanninen The Department of Radiology, Kuopio University Hospital and the Institute of Clinical Medicine – Radiology, University of Eastern Finland, Kuopio, Finland
  • Mikko Hiltunen The Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
  • Ville Leinonen The Department of Neurosurgery, Kuopio University Hospital and the Institute of Clinical Medicine – Neurosurgery, University of Eastern Finland, Kuopio, Finland
  • Tuomas Rauramaa The Department of Pathology, Kuopio University Hospital and the Institute of Clinical Medicine – Pathology, University of Eastern Finland, Kuopio, Finland

DOI:

https://doi.org/10.17879/freeneuropathology-2022-3331

Keywords:

Hydrocephalus, Normal pressure hydrocephalus, Post-mortem, Neuropathology, Neurodegeneration

Abstract

Aims: There are very few detailed post-mortem studies on idiopathic normal-pressure hydrocephalus (iNPH) and there is a lack of proper neuropathological criteria for iNPH. This study aims to update the knowledge on the neuropathology of iNPH and to develop the neuropathological diagnostic criteria of iNPH.
Methods: We evaluated the clinical lifelines and post-mortem findings of 29 patients with possible NPH. Pre-mortem cortical brain biopsies were taken from all patients during an intracranial pressure measurement or a cerebrospinal fluid (CSF) shunt surgery.
Results: The mean age at the time of the biopsy was 70±8 SD years and 74±7 SD years at the time of death. At the time of death, 11/29 patients (38%) displayed normal cognition or mild cognitive impairment (MCI), 9/29 (31%) moderate dementia and 9/29 (31%) severe dementia. Two of the demented patients had only scarce neuropathological findings indicating a probable hydrocephalic origin for the dementia. Amyloid-β (Aβ) and hyperphosphorylated τ (HPτ) in the biopsies predicted the neurodegenerative diseases so that there were 4 Aβ positive/low Alzheimer’s disease neuropathological change (ADNC) cases, 4 Aβ positive/intermediate ADNC cases, 1 Aβ positive case with both low ADNC and progressive supranuclear palsy (PSP), 1 HPτ/PSP and primary age-related tauopathy (PART) case, 1 Aβ/HPτ and low ADNC/synucleinopathy case and 1 case with Aβ/HPτ and high ADNC. The most common cause of death was due to cardiovascular diseases (10/29, 34%), followed by cerebrovascular diseases or subdural hematoma (SDH) (8/29, 28%). Three patients died of a postoperative intracerebral hematoma (ICH). Vascular lesions were common (19/29, 65%).
Conclusions: We update the suggested neuropathological diagnostic criteria of iNPH, which emphasize the rigorous exclusion of all other known possible neuropathological causes of dementia. Despite the first 2 probable cases reported here, the issue of “hydrocephalic dementia” as an independent entity still requires further confirmation. Extensive sampling (with fresh frozen tissue including meninges) with age-matched neurologically healthy controls is highly encouraged.

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Published

2022-01-26

How to Cite

Hänninen, J. J., Nakajima, M., Vanninen, A., Hytönen, S., Rummukainen, J., Koivisto, A. M., Jääskeläinen, J. E., Soininen, H., Sutela, A., Vanninen, R., Hiltunen, M., Leinonen, V., & Rauramaa, T. (2022). Neuropathological findings in possible normal pressure hydrocephalus: A post-mortem study of 29 cases with lifelines. Free Neuropathology, 3, 2. https://doi.org/10.17879/freeneuropathology-2022-3331

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Original Papers