Acute hemorrhagic leukoencephalitis (AHLE), is a rare inflammatory demyelinating disorder, variant of acute disseminated encephalomyelitis. The diagnosis of AHLE remains challenging due to the rarity of the disease and the lack of a reliable biomarker. We report here a case of a 73-year-old male patient with a progressive, low-grade febrile confusional syndrome 20 days after receiving the first dose of BNT162b2 vaccine against SARS-CoV-2. Evidence indicative of the underlying condition by an extensive panel of imaging (brain magnetic resonance imaging, computed tomography and digital subtraction angiography), laboratory (complete blood count, biochemistry, coagulation, tests for autoimmune or infectious disorders, tumor markers, hormonal levels, cerebrospinal fluid analysis) and electrodiagnostic tests were scarce, and mainly non-specific. Sequential neuroimaging revealed the appearance of extensive T2 lesions (signs of gliosis) along with multiple hemorrhagic lesions at various cortical sites. The patient was treated with corticosteroids, discontinued due to severe adverse effects, and subsequently with sessions of plasmapheresis and monthly intravenous administration of cyclophosphamide. Considering the rapid aggravation of the patient's neurological status, the MRI findings of cortical lesions and the lack of response to any treatment, a biopsy of a frontal lobe lesion was conducted, confirming the presence of confluent, inflammatory-edematous lesions with scattered areas of necrosis and hemorrhage, and ultimately areas of demyelination, thus confirming the diagnosis of AHLE. After more than 5 months of hospitalization the patient was transferred in a primary care facility and remained in a permanent vegetative state until his death, more than 2 years later.

Cerebrotendinous xanthomatosis (CTX) is a rare inherited disorder of the alternative pathway of bile acid biosynthesis, due to mutation(s) of the gene CYP27A1, leading to sterol 27-hydroxylase deficiency. The latter results in a systematic deposition of cholestanol and cholesterol to the central nervous system and tendons, premature cataract, as well as the manifestation of systematic symptoms, such as chronic diarrhea, osteoporosis, and premature atherosclerosis. Due to its marked clinical heterogeneity, prompt diagnosis of this disorder is challenging. We present a case of a 38-year-old male with gait difficulty, a progressive deterioration in ambulation, several episodes of vertigo and episodic diarrhea. Clinical history revealed neonatal jaundice, juvenile bilateral cataracts, borderline intellectual capacity, hypothyroidism, testicular cancer. Magnetic resonance imaging demonstrated increased T2-weighted signal in internal capsules, midbrain, cerebellum, and spinal cord. Electrodiagnostic study showed mixed polyneuropathy. Genetic analysis revealed a novel, biallelic, most likely pathogenic mutation, in gene CYP2A1 (c.1410_1411del). Plasma sterol profiling confirmed the diagnosis of CTX. Our patient was treated with chenodeoxycholic acid and one year later, he shows a progressive improvement of gait, normalization of plasma sterol biochemistry and electrophysiological parameters. This case highlights the importance of maintaining a high index of suspicion as the key to an early diagnosis of CTX, taking into consideration its clinical variability and, if promptly identified, the good response to treatment.

Background and Clinical Significance: Carotid stump syndrome (CSS) is a rare and unexpected cause of recurrent ischemic ipsilateral events in the carotid vascular territory despite the demonstrated occlusion of the internal carotid artery (ICA). It is believed to be caused by microemboli due to turbulent blood flow in the patent stump of the occluded ICA that passes through anastomotic channels and retrograde flow into the middle cerebral artery circulation. Case Presentation: We describe the case of a 65-year-old male patient who suffered multiple concurrent transient ischemic attacks (TIAs) with a totally occluded ipsilateral ICA revealed by computed tomography angiography (CTA). He was diagnosed with CSS, which required the safest therapeutic approach. A further investigation with digital subtraction angiography (DSA) was performed, and a trickle of blood flow was observed in the reportedly occluded ICA. The diagnosis of a true ICA occlusion was withdrawn, and a diagnosis of pseudo-occlusion was established, affecting the final treatment strategy. Therefore, the patient underwent an ipsilateral carotid endarterectomy (CEA), and he has remained asymptomatic since then. Conclusions: The differentiation between a pseudo-occlusion and a true ICA occlusion is essential in promptly managing acute recurrent ipsilateral ischemic strokes in the carotid vascular territory. A further investigation with DSA in cases with a totally occluded ICA using CTA is essential for excluding pseudo-occlusions in ipsilaterally symptomatic patients.