Small Fiber Neuropathy After SARS-CoV-2 Infection and Vaccination: A Case-Based Comparison.

COVID-19-associated neuropathies, whether post-infection or post-vaccination, have not been fully described. A variety of theories exist to explain these phenomena, many of them centering on immune dysregulation. We aim to contribute to the discussion on the similarities and differences behind the two conditions and to bolster the call for further research to be done in this area. We will discuss two different case presentations, one patient experiencing a post-COVID-19 infection neuropathy and the other experiencing a post-COVID-19 vaccination neuropathy.

Artery of Percheron Strokes: Three Cases in Three Months.

The artery of Percheron (AOP) is a rare variant of thalamic vasculature and is a single dominant thalamoperforating artery supplying bilateral paramedian thalamic territories. Occlusion of the AOP results in a characteristic pattern of bilateral paramedian thalamic infarcts and is estimated to represent between 0.1%-0.3% of all ischemic strokes and 4% to 35% of all thalamic strokes. Four distinct ischemic patterns of AOP infarcts have been identified: bilateral paramedian thalamic region with midbrain (43%), bilateral paramedian thalamic without midbrain (38%), bilateral paramedian thalamic with anterior thalamus and midbrain involvement (14%), and bilateral paramedian thalamic with anterior thalamus without midbrain involvement (5%). Despite our knowledge of the characteristic radiologic features of an AOP stroke, the true incidence of AOP strokes is challenging to estimate due to non-specific clinical symptoms and subtle findings on computed tomography (CT) and/or magnetic resonance imaging (MRI). Here, we present a case series of three patients seen within a 3-month span at one community hospital seen by one single neurologist with confirmed AOP stroke by radiologic imaging. The frequency of these cases suggests that the incidence of AOP infarctions may be higher than previously estimated and instead are underreported due to broad differential on clinical and imaging presentation.

Post-infectious focal encephalitis due to COVID-19.

INTRODUCTION: Several publications described neurological manifestations caused by SARS-CoV-2. Immune-mediated neurological damages caused by COVID-19 are increasingly recognized. CASE REPORT: A young male presented in March 2020 with a new-onset seizure. Later, he started to experience a severe headache. During the second admission in May, the MRI of the brain showed left frontal lesion. Nasal PCR for SARS-CoV-2 was negative, but the serology was positive, raising the suspicion of immune-mediated encephalitis. Elevated cerebrospinal fluid immunoglobulin G with two oligoclonal bands were also seen. The patient received IV immunoglobulin and showed improvement in headache. Follow-up MRIs of the brain revealed complete resolution of the lesion. DISCUSSION: Neurological complications from COVID-19 have been increasingly recognized. The proposed pathophysiology is either direct damage of neurological tissues, or indirectly through immune-mediated mechanisms. The timeline of the patient's presentation with seizure, as well as the lesion on the brain MRI with complete resolution after the IV immunoglobulin, strongly suggest that the patient had immune-mediated encephalitis after exposure to SARS-CoV-2. CONCLUSIONS: Several cases of encephalitis caused by SARS-CoV-2 have been reported. Immune-mediated encephalitis as probable pathophysiology is described here.

Acquired Spinal Arteriovenous Fistula Presenting as Brown-Séquard Syndrome and Endovascular Treatment Outcome.

BACKGROUND: Brown-Séquard syndrome is typically caused by penetrating trauma to the cervical spinal cord; however, other compressive and vascular occlusive etiologies have been previously described. It is extremely uncommon to have a delayed presentation as an extramedullary compressive lesion from the venous varix of an acquired spinal arteriovenous fistula. CASE DESCRIPTION: We present a case of a patient in the fifth decade of life, with a remote history of gunshot wound to the left thorax with progressive left-sided weakness and contralateral pain and temperature sensory loss secondary to cord compression from an acquired spinal arteriovenous fistula. CONCLUSIONS: Subsequent treatment occurred with coil embolization with good outcome.

Histopathological evidence that hippocampal atrophy following status epilepticus is a result of neuronal necrosis.

Medial temporal lobe epilepsy is commonly associated with hippocampal atrophy on MRI and hippocampal sclerosis on histopathological examination of surgically-resected specimens. Likewise, it is well-established that prolonged seizures and status epilepticus can lead to hippocampal edema as noted on MRI. In this paper, the authors present an unusual patient with prolonged refractory status epilepticus, due to limbic encephalitis associated with anti-GAD antibody, who underwent palliative epilepsy surgery. Bilateral hippocampal edema was noted on preoperative MRI. Histologic evaluation confirmed presence of acute necrosis and neuronal loss in the left hippocampal formation. Follow-up MRI several months after surgery demonstrated severe atrophy of the contralateral right hippocampus. This is the first clear histopathological evidence that hippocampal atrophy following status epilepticus is the result of acute neuronal necrosis and cell loss.

Peduncular hallucinosis: unusual complication of cardiac catheterization.

Peduncular hallucinosis (PH) is a rare form of visual hallucination characterized by vivid, nonstereotypical visual images of people, animals, and plants of brief duration that are nonthreatening to the patient. The clinical syndrome of PH consists of formed visual hallucinations, localizing signs of the offending lesion, and sleep disturbances. In the absence of localizing focal neurologic deficits, it is easily confused with a delirium or psychosis. It is seen with lesions involving the upper brainstem and diencephalon. The authors report a case of PH due to ischemic infarction of the midbrain after cardiac catheterization. Although PH has been reported after vertebral angiography, it has never been reported as a complication of cardiac catheterization.