Neuropathological findings from an autopsied case showing posterior reversible encephalopathy syndrome-like neuroradiological findings associated with premedication including tacrolimus for autologous peripheral blood stem cell transplantation

A broad spectrum of posterior reversible encephalopathy syndrome - a case series with clinical and paraclinical characterisation, and histopathological findings

Background

Posterior reversible encephalopathy syndrome (PRES) is clinical-neuroradiologically defined and potentially reversible, so there are limited data about histopathological findings. We aimed to describe the clinical and paraclinical features of patients with PRES with regard to its reversibility.

Methods

This retrospective case series encompasses 15 PRES cases out of 1300 evaluated patients from a single German center between January 1, 2010, and June 15, 2020. PRES was established according to the diagnostic criteria as proposed by the Berlin PRES Study 2012. One of the cases studied was subject to brain autopsy.

Results

From the 15 patients studied (median age 53 years, range 17–73; 11 female), 67 % presented with epileptic seizures, 40 % suffered from encephalopathy with reduced consciousness and 53 % developed delirium, while 47 % had headache and visual disturbances. Subcortical brain MRI abnormalities related to PRES were observed in all patients. One patient developed spinal ischemia and another Guillain-Barré syndrome in addition to PRES. Hypertensive blood pressure was the main underlying/trigger condition in all patients. Clinical symptoms and MRI changes were not reversible in 42 %, even progressive in 3 out of these 5 patients. Median time from symptom onset to diagnosis in these non-reversible cases was 7 days (range 0–13), while the median delay in diagnosis in the reversible group was 1 day (range 0–3). Cerebellar/brain stem involvement and status epilepticus were more frequently in patients with non-reversible disease course. Mortality due to PRES occurred in 13 % of these patients. Neuropathological examination of the brain of a 57-year-old female patient revealed major leukencephalopathic changes, fibrinoid necrosis of endothelial cells and fresh petechial hemorrhages in accordance with PRES.

Conclusions

Our case series demonstrates that PRES was not reversible in 42 % of the studied patients. Delay in diagnosis seems to contribute to limited reversibility and poor outcome.

The phenomenon of clasmatodendrosis

Clasmatodendrosis derives from the Greek for fragment (klasma), tree (dendron), and condition (- osis). Cajal first used the term in 1913: he observed disintegration of the distal cell processes of astrocytes, along with a fragmentation or beading of proximal processes closer to the astrocyte cell body. In contemporary clinical and experimental reports, clasmatodendrosis has been observed in models of cerebral ischemia and seizures (including status epilepticus), in elderly brains, in white matter disease, in hippocampal models and cell cultures associated with amyloid plaques, in head trauma, toxic exposures, demyelinating diseases, encephalitides and infection-associated encephalopathies, and in the treatment of cancer using immune effector cells. We examine evidence to support a claim that clasmatodendrotic astrocyte cell processes overtly bead (truncate) as a morphological sign of ongoing damage premortem. In grey and white matter and often in relationship to vascular lumina, beading becomes apparent with immunohistochemical staining of glial fibrillary acidic protein when specimens are examined at reasonably high magnification, but demonstration of distal astrocytic loss of processes may require additional marker study and imaging. Proposed mechanisms for clasmatodendrotic change have examined hypoxic-ischemic, osmotic-demyelinating, and autophagic models. In these models as well as in neuropathological reports, parenchymal swelling, vessel-wall leakage, or disturbed clearance of toxins can occur in association with clasmatodendrosis. Clasmatodendrotic features may serve as a marker for gliovascular dysregulation either acutely or chronically. We review correlative evidence for blood-brain barrier (BBB) dysfunction associated with astrocytic structural change, with attention to interactions between endothelial cells, pericytes, and astrocytic endfeet.

Posterior reversible encephalopathy syndrome associated with focal segmental glomerulosclerosis in a child

Posterior reversible encephalopathy syndrome (PRES) is a rare neurological entity, typically manifested by reversible oedema in the parieto-occipital lobes. It is usually associated with primary hypertension, autoimmune diseases and immunosuppressants. Renal disease is an uncommon cause of PRES. We report a case of an 11-year-old boy with STimulator of INterferon Genes-associated vasculopathy with onset in infancy complicated by focal segmental glomerulosclerosis leading to hypertension and PRES. The patient presented with headache, acute bilateral visual loss and hypertension. Brain MRI showed atypical features revealed by parieto-occipital haemorrhage. The child improved few days after antihypertensive therapy. Follow-up MRI showed complete resolution of haemorrhage. It is important to keep high index of suspicion for the uncommon association of PRES with underlying kidney disease with or without immunosuppressive agents. This combination is the first to our knowledge to be described in paediatric population. Atypical MRI features such as haemorrhage should be kept in mind. Symptoms are reversible within days to weeks with early diagnosis and treatment.

PRES: Review of Histological Features

Posterior reversible encephalopathy syndrome was described in 1996 as a clinical-neuroimaging entity characterized by parieto-occipital watershed-region edema without overt infarction. It has been linked to hypertension, eclampsia, immunosuppressive therapies, infections, and autoimmune disorders. The condition usually has an acute onset, presents with seizures, and ameliorates within days. There have been few neuropathological studies, but in some cases, tissue damage may be more permanent.