Rigby, Michael J.

Cerebral amyloid angiopathy related inflammation (CAA-ri) is a rare neuroinflammatory condition that may present with a wide spectrum of clinical and radiographic findings. Classic imaging features include areas of asymmetric subcortical white matter hyperintensities due to vasogenic edema, together with the classic hemorrhagic lesions of cerebral amyloid angiopathy (CAA) including microhemorrhages, superficial siderosis, or convexity subarachnoid hemorrhage. We describe a case of CAA-ri appearing as fulminant leptomeningitis without other obvious radiographic features of CAA at presentation.

Abstract Background Immunohistochemically detected phosphorylated α‐synuclein (p‐α‐syn) in cutaneous nerves has been found in >95% of patients meeting consensus criteria for dementia with Lewy bodies (DLB); however, its performance in prodromal stages (mild cognitive impairment‐Lewy body [MCI‐LB]) and clinical practice is unknown. Objective We evaluated skin biopsy for p‐α‐syn in a convenience cohort of patients with suspected MCI‐LB or DLB in a tertiary care setting. Methods 53 patients underwent commercially available skin biopsy for skin nerve p‐α‐syn as part of a clinical evaluation for suspected MCI‐LB/DLB. Consensus MCI‐LB/DLB criteria blinded to skin biopsy result were applied through retrospective chart review; those not definitively meeting criteria were considered questionable synucleinopathy (QS). Results Median age at skin biopsy was 70 years (range, 43–87 years) with 81% men. 36 patients (68%) had positive skin biopsies. 32/43 (74%) patients meeting clinical consensus criteria for DLB/MCI‐LB had a positive skin biopsy, with higher frequency in MCI‐LB (87%) compared with DLB (60%). 4/10 (40%) QS had positive biopsies. One patient with a positive skin biopsy had no evidence of central nervous system (CNS) α‐syn on autopsy. Conclusions Positive skin biopsy for p‐α‐syn occurs across the spectrum of cognitive presentations of Lewy body disease including prodromal DLB, albeit at a lower frequency in this retrospective review of atypical cases compared with typical clinical presentations. A positive skin biopsy may not reflect CNS synucleinopathy as the etiology for a patient's symptoms in some cases. Longitudinal studies of skin biopsies for p‐α‐syn in suspected MCI‐LB/DLB with autopsy confirmation are needed. © 2025 International Parkinson and Movement Disorder Society.

Dermatoneuro syndrome (DNS) is a rare diagnosis of exclusion characterised by fever, altered mental status and seizures in patients with scleromyxoedema. We present a complex case of a patient presenting with a fever, coma, seizures, rigidity and deep T2 fluid-attenuated inversion recovery hyperintensities in the context of both scleromyxoedema and influenza A with extensive, negative infectious workup. This case highlights the shared clinical features of DNS and influenza-associated encephalopathy, the latter being the eventual diagnosis for our patient. We review the DNS literature focusing on presentation, adequacy of investigation, treatment and prognosis. Finally, we provide an initial workup for patients with suspected DNS, including nasopharyngeal influenza PCR.