Objective To report a case of a patient infected with severe acute respiratory syndrome coronavirus 2 (SARS–CoV-2) who acutely developed a hypokinetic-rigid syndrome. Methods Patient data were obtained from medical records from the Hospital Universitario 12 de Octubre in Madrid, Spain. [¹²³I]-ioflupane dopamine transporter (DaT) SPECT images were acquired 4 hours after a single dose of 185 MBq of ¹²³I-FP-CIT. Quantitative analysis was performed with DaTQUANT software providing the specific binding ratio and z score values of the striatum. Results We report a previously healthy 58-year-old man who developed hyposmia, generalized myoclonus, fluctuating and transient changes in level of consciousness, opsoclonus, and an asymmetric hypokinetic-rigid syndrome with ocular abnormalities after a severe SARS–CoV-2 infection. DaT-SPECT confirmed a bilateral decrease in presynaptic dopamine uptake asymmetrically involving both putamina. Significant improvement in the parkinsonian symptoms was observed without any specific treatment. Conclusion This case study provides clinical and functional neuroimaging evidence to support that SARS–CoV-2 can gain access to the CNS, affecting midbrain structures and leading to neurologic signs and symptoms.

Background and Objectives Information about humoral and cellular responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and antibody persistence in convalescent (COVID-19) patients with multiple sclerosis (PwMS) is scarce. The objectives of this study were to investigate factors influencing humoral and cellular responses to SARS-CoV-2 and its persistence in convalescent COVID-19 PwMS. Methods This is a retrospective study of confirmed COVID-19 convalescent PwMS identified between February 2020 and May 2021 by SARS-CoV-2 antibody testing. We examined relationships between demographics, MS characteristics, disease-modifying therapy (DMT), and humoral (immunoglobulin G against spike and nucleocapsid proteins) and cellular (interferon-gamma [IFN-γ]) responses to SARS-CoV-2. Results A total of 121 (83.45%) of 145 PwMS were seropositive, and 25/42 (59.5%) presented a cellular response up to 13.1 months after COVID-19. Anti–CD20-treated patients had lower antibody titers than those under other DMTs (p < 0.001), but severe COVID-19 and a longer time from last infusion increased the likelihood of producing a humoral response. IFN-γ levels did not differ among DMT. Five of 7 (71.4%) anti-–CD20-treated seronegative patients had a cellular response. The humoral response persisted for more than 6 months in 41/56(81.13%) PwMS. In multivariate analysis, seropositivity decreased due to anti-CD20 therapy (OR 0.08 [95% CI 0.01–0.55]) and increased in males (OR 3.59 [1.02–12.68]), whereas the cellular response decreased in those with progressive disease (OR 0.04 [0.001–0.88]). No factors were associated with antibody persistence. Discussion Humoral and cellular responses to SARS-CoV-2 are present in COVID-19 convalescent PwMS up to 13.10 months after COVID-19. The humoral response decreases under anti-CD20 treatment, although the cellular response can be detected in anti–CD20-treated patients, even in the absence of antibodies.

The cavernous sinus is a structure in the base of the skull that houses several nerve and vascular structures. Its compromise leads to cavernous sinus syndrome, which is a combination of oculomotor disorders and others affecting the first two trigeminal branches, often accompanied by pain or proptosis. Infiltration due to Burkitt's lymphoma is a rare cause of this syndrome. A 43-year-old male, carrier of human immunodeficiency virus, with good control of the disease, who developed a clinical picture consisting of progressive painful ophthalmoplegia in the presence of a laterocervical adenopathy. Complementary tests allowed a diagnosis of Burkitt's lymphoma with extranodal extension to the cavernous sinus. A review of the cases published in Medline was also carried out: a total of 15 cases were detected and their epidemiological characteristics, form of presentation, extracranial involvement at the time of diagnosis and clinical progression were described. Burkitt's lymphoma is a high-grade lymphoproliferative syndrome. Its form associated with immunodeficiency is an important cause of morbidity and mortality in this subgroup of patients. In the cases analysed in the literature, the age of presentation varied and the form of onset was a progressive painful ophthalmoplegia or numb chin syndrome. Exclusive involvement of the cavernous sinus was infrequent, but in that case it entailed a poor prognosis. It is important to rule out a primary extracranial origin and not to confuse it with an idiopathic Tolosa-Hunt syndrome that would delay the beginning of antitumour treatment.

Background: Toxic oil syndrome (TOS) was a major food-borne epidemic that occurred in Spain in May 1981, caused by the ingestion of rapeseed oil adulterated with aniline. While the somatic sequelae of TOS have been well documented, its long-term cognitive consequences remain poorly understood more than four decades after exposure. Methods: In this case-control study, 50 individuals with clinically confirmed TOS were compared to 50 healthy controls matched for age, sex, and education. All participants completed a comprehensive neuropsychological assessment, along with questionnaires evaluating fatigue, anxiety, depression, and health-related quality of life. Multivariate regression models were adjusted for demographic and vascular risk factors, as well as for mood symptoms, fatigue, and use of central nervous system-acting medications. Structural equation modeling was used to explore the potential mediating effects of affective and fatigue symptoms on cognitive performance. Results: TOS survivors showed significantly poorer performance than controls in attention, executive function, processing speed, and global cognition after adjusting for demographic and vascular risk factors. However, these differences were no longer statistically significant after additional adjustment for fatigue, depression, anxiety, and central nervous system-acting medications. Structural equation modeling analyses revealed that affective symptoms—particularly fatigue—substantially mediated the relationship between TOS and cognitive performance. Conclusions: The cognitive profile observed mirrors that of disorders characterized by subcortical dysfunction and impaired neural connectivity, such as multiple sclerosis and vascular cognitive impairment. Although early postmortem studies in TOS did not demonstrate overt white matter lesions, our findings raise the possibility of long-lasting alterations involving both white and gray matter networks. These results emphasize the need to consider mood and fatigue symptoms when evaluating cognition in TOS survivors and point to the potential for widespread, enduring neurobiological effects stemming from the original toxic exposure.

Toxic oil syndrome (TOS) is a multisystemic disease that emerged in Spain in 1981 due to the ingestion of aniline-adulterated rapeseed oil fraudulently sold as olive oil. Although neurological sequelae, including cognitive deficits, have been documented in long-term survivors, it remains unclear whether TOS leads to chronic or progressive neurodegeneration. In this case-control study, we measured blood concentrations of neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and phosphorylated tau 217 (pTau217) in 50 individuals with clinically confirmed TOS and 50 matched healthy controls. Biomarkers were quantified using ultrasensitive immunoassay platforms (Quanterix SIMOA SR-X and Fujirebio Lumipulse G600II). Group differences were evaluated using non-parametric tests, and multiple linear regression was applied to assess associations between biomarkers and clinical variables. While NfL levels were slightly higher in TOS patients (p = 0.025), no significant group differences were observed for pTau217 or GFAP. Age was a consistent predictor of biomarker levels, particularly for GFAP and pTau217, and female sex was independently associated with higher GFAP concentrations. Lower educational attainment was linked to increased NfL levels. Clinical status (TOS vs. control) did not significantly predict biomarker concentrations in any model. These findings suggest no evidence of overt or ongoing neurodegeneration in long-term TOS survivors as detected by current blood biomarkers. However, the possibility of subtle, compartmentalized, or slowly evolving neurotoxic processes cannot be excluded. Future longitudinal studies incorporating serial biomarker assessments, advanced neuroimaging, and oxidative stress markers are warranted to clarify the long-term neurological consequences of TOS and to detect subclinical trajectories of delayed neurotoxicity in this population.