Abstract 16- 1315-1330
Category: Clinical

At the end of the session,
participants will be able to:

  1. To acquire knowledge of pathology findings of 8 NSUC cases
  2. To develop an understanding of the meaning of these pathology findings
  3. To learn that developing a new disease model is not an instinctive process

COI Disclosure:

Federal government-CJD Surveillance System Paid for medical advice to CJD surveillance, (no patient contact or treatment)


Gerard Jansen is a neuropathologist at EORLA, serving the Ottawa Hospital, where he practices general adult neuropathology. He also has been involved with clinical surveillance of Creutzfeldt-Jakob disease for 30 1/2 years, and has been the national responsible neuropathologist for this type of surveillance for a total of 26 years (11 years for the Netherlands and Belgium and 15 years for Canada). During that time he has seen all types of prion diseases passing by, with the exception of Kuru, but also many look-alike neurological diseases. Gerard holds an MD from Utrecht University (the Netherlands), received his neuropathology training at the Utrecht Medical Centre many eons ago, and works and lives in Canada since 2002.


Gerard H. Jansen1, Sidney E. Croul2, Angela K. Miller3, Alexander S. Easton2, John M. J. Woulfe1

  1. Department of Pathology and laboratory medicine, University of Ottawa, Ottawa
  2. Department of Pathology, QEII Health Science Centre, Halifax
  3. Department of Pathology, Health Sciences Centre, Winnipeg (previously Department of Pathology, Moncton Hospital, Moncton)

Target Audience:
Pathologists, Residents

Medical Expert (the integrating role), Leader, Professional, Health Advocate

Neuropathology of eight cases of the New Brunswick cluster of Neurological Syndrome of Unknown Cause (NSUC).


On March 17, 2021 a press conference aired featuring a Moncton neurologist and New Brunswick’s Chief Medical Health Officer, regarding a cluster of patients in New Brunswick, who had symptoms reminiscent of CJD, and were claimed to have a novel neurological syndrome. The onset of disease was between 2015 and 2021. All patients in that cluster had at that time been reported by one neurologist, although subsequently a few incidental cases were reported by other neurologists. The size of this cluster has been reported as around 50 cases. Further news publications have suggested that an environmental factor is the causative factor for this cluster.

This news has significantly disturbed the medical community. Since 2019 eight patients have died that belonged to this cluster. We report their neuropathological findings and hope this will bring some clarity.

There was one case of metastatic carcinoma, one case of FTLD-TDP43, one case of neocortical Lewy body pathology, one case of neocortical Lewy body pathology and AD, 2 cases of AD with vascular pathology, one case of mainly vascular pathology, and one case without significant pathology (consistent with patient’s previous history). In these 8 patients no evidence for a prion disease was found, nor novel pathology. We suggest that these 8 patients represent a group of misclassified clinical diagnoses.

Since June 3, 2021 the Oversight Committee was established in New Brunswick reviewing the clinical and epidemiological data of the patients in this cluster. We hope that our findings are useful to them.