Preceding Head Trauma in Four Cases of Sporadic Cerebral Amyloid Angiopathy - Case Report Series

Recurrent Intracerebral Haematomas Due to Amyloid Angyopathy after Lyodura Transplantation in Childhood

The number of published cases of presumed iatrogenic cerebral amyloid angiopathy (iCAA) due to the transmission of amyloid β during neurosurgery is slowly rising. One of the potential ways of transmission is through a cadaveric dura mater graft (LYODURA) exposure during neurosurgery. This is a case of a 46-year-old female patient with no chronic conditions who presented with recurrent intracerebral haemorrhages (ICHs) without underlying vessel pathology. Four decades prior, the patient had a neurosurgical procedure with documented LYODURA transplantation. Brain biopsy confirmed CAA. This is a rare case of histologically proven iCAA after a documented LYODURA transplantation in childhood. Our case and already published iCAA cases emphasize the need for considering neurosurgery procedure history as important data in patients who present with ICH possibly related to CAA.

Iatrogenic cerebral amyloid angiopathy: A multinational case series and individual patient data analysis of the literature

BACKGROUND

The transmission of amyloid β (Aβ) in humans leading to iatrogenic cerebral amyloid angiopathy (iCAA) is a novel concept with analogies to prion diseases. However, the number of published cases is low, and larger international studies are missing.

AIMS

We aimed to build a large multinational collaboration on iCAA to better understand the clinical spectrum of affected patients.

METHODS

We collected clinical data on patients with iCAA from Austria, Croatia, Italy, Slovenia, and Spain. Patients were included if they met the proposed Queen Square diagnostic criteria (QSC) for iCAA. In addition, we pooled data on disease onset, latency, and cerebrospinal fluid (CSF) biomarkers from previously published iCAA cases based on a systematic literature review.

RESULTS

Twenty-seven patients (22% women) were included in this study. Of these, 19 (70%) met the criteria for probable and 8 (30%) for possible iCAA. Prior neurosurgical procedures were performed in all patients (93% brain surgery, 7% spinal surgery) at median age of 8 (interquartile range (IQR) = 4-18, range = 0-26 years) years. The median symptom latency was 39 years (IQR = 34-41, range = 28-49). The median age at symptom onset was 49 years (IQR = 43-55, range = 32-70). Twenty-one patients (78%) presented with intracranial hemorrhage and 3 (11%) with seizures.

CONCLUSIONS

Our large international case series of patients with iCAA confirms a wide age boundary for the diagnosis of iCAA. Dissemination of awareness of this rare condition will help to identify more affected patients.

Case report of iatrogenic cerebral amyloid angiopathy after exposure to Lyodura: an Australian perspective

Background

Recently proposed diagnostic criteria for iatrogenic cerebral amyloid angiopathy (iCAA) have sparked increased recognition of cases across the globe. Whilst these patients tend to have a tumultuous course, much like sporadic CAA, there is a high degree of variability. What is unique in this case is the breadth of clinicoradiological data available, including handwritten surgical notes from 1985. In retrospect, early imaging changes of what would ultimately lead to profound morbidity, were apparent 30 years after inoculation with cadaveric dural tissue.

Aim

In this case study we examine the clinicoradiological features of a case of probable iCAA and draw awareness to the presence of this disease in Australia.

Methods

This case was admitted under the care of the author at the Royal Brisbane and Women's Hospital (RBWH). Clinical details and data were gathered during the patient's care and consent for publication provided by the enduring power of attorney.

Results

This 56-year-old female presented in 2018 with left hemiparesis, neglect, and dysarthria secondary to a large right frontal lobe intracerebral hemorrhage (ICH) without an underlying macrovascular cause. MRI brain demonstrated diffuse superficial siderosis assumed related to previous surgical interventions during the mid-1980s for a Chiari malformation and cervical syrinx. There was evidence of extensive white matter disease, discordant with her lack of cerebrovascular disease risk factors. Brain biopsy confirmed CAA. Archived surgical notes confirmed exposure to Lyodura in 1985 and 1986. Two decades of MRI data were available for review and illustrate the evolution of CAA, from normal post-operative findings to marked and unrecognized abnormalities 4 years prior to her first ICH.

Discussion

This is the first Australian case of probable iatrogenic CAA (iCAA) to have such extensive documentation of clinicoradiological evolution. It demonstrates the aggressive course iCAA can take and provides insights into early disease manifestations, relevant to the more common sporadic cases. A brief review of the history of commercial cadaveric tissue use in Australia highlights enormous changes in medical practice over the last 50 years. Awareness within Australia should be raised for this clinical phenomenon, and cases collated to contribute to the growing international pool of evidence.

Iatrogenic Cerebral Amyloid Angiopathy Post Neurosurgery: Frequency, Clinical Profile, Radiological Features, and Outcome

BACKGROUND

Prion-like transmission of amyloid-ß through cadaveric dura, decades after neurosurgical procedures, has been hypothesized as an iatrogenic cause of cerebral amyloid angiopathy (CAA). We investigated new and previously described patients to assess the clinical profile, radiological features, and outcome of this presumed iatrogenic CAA-subtype (iCAA).

METHODS

Patients were collected from our prospective lobar hemorrhage and CAA database (n=251) with patients presenting to our hospital between 2008 and 2022. In addition, we identified patients with iCAA from 2 other Dutch CAA-expertise hospitals and performed a systematic literature-search for previously described patients. We classified patients according to the previously proposed diagnostic criteria for iCAA, assessed clinical and radiological disease features, and calculated intracerebral hemorrhage (ICH)-recurrence rates. We evaluated the spatial colocalization of cadaveric dura placement and CAA-associated magnetic resonance imaging markers.

RESULTS

We included 49 patients (74% men, mean age 43 years [range, 27-84]); 15 from our database (6% [95% CI, 3%-10%]; 45% of patients <55 years), 3 from the 2 other CAA-expertise hospitals, and 31 from the literature. We classified 43% (n=21; 1 newly identified patient) as probable and 57% (n=28) as possible iCAA. Patients presented with lobar ICH (57%), transient focal neurological episodes (12%), or seizures (8%). ICH-recurrence rate in the new patients (16/100 person-years [95% CI, 7-32], median follow-up 18 months) was lower than in the previously described patients (77/100 person-years [95% CI, 59-99], median follow-up 18 months). One patient had a 10 year interlude without ICH-recurrence. We identified no clear spatial relationship between dura placement and CAA-associated magnetic resonance imaging markers. During follow-up (median, 18 months), 20% of the patients developed transient focal neurological episodes and 20% cognitively declined.

CONCLUSIONS

iCAA seems common in patients presenting with nonhereditary CAA under the age of 55. Clinical and radiological features are comparable with sCAA. After diagnosis, multiple ICH-recurrences but also long symptom-free intervals can occur. Harmonized registries are necessary to identify and understand this potentially underrecognized CAA-subtype.

Iatrogenic cerebral amyloid angiopathy: an emerging clinical phenomenon

In the last 6 years, following the first pathological description of presumed amyloid-beta (Aβ) transmission in humans (in 2015) and subsequent experimental confirmation (in 2018), clinical cases of iatrogenic cerebral amyloid angiopathy (CAA)-attributed to the transmission of Aβ seeds-have been increasingly recognised and reported. This newly described form of CAA is associated with early disease onset (typically in the third to fifth decade), and often presents with intracerebral haemorrhage, but also seizures and cognitive impairment. Although assumed to be rare, it is important that clinicians remain vigilant for potential cases, particularly as the optimal management, prognosis, true incidence and public health implications remain unknown. This review summarises our current understanding of the clinical spectrum of iatrogenic CAA and provides a diagnostic framework for clinicians. We provide clinical details for three patients with pathological evidence of iatrogenic CAA and present a summary of the published cases to date (n=20), identified following a systematic review. Our aims are: (1) To describe the clinical features of iatrogenic CAA, highlighting important similarities and differences between iatrogenic and sporadic CAA; and (2) To discuss potential approaches for investigation and diagnosis, including suggested diagnostic criteria for iatrogenic CAA.