Neurological presentations of COVID-19: Findings from the Spanish Society of Neurology neuroCOVID-19 registry.

OBJECTIVE: We report the findings from the Spanish Society of Neurology's NeuroCOVID-19 Registry. METHODS: We performed a multicentre study of patients with neurological manifestations of COVID-19. Participating physicians reported demographic, clinical, and paraclinical data and judged the involvement of COVID-19 in causing neurological symptoms. RESULTS: A total of 233 cases were submitted, including 74 different combinations of manifestations. The most frequently reported were stroke (27%), neuromuscular symptoms (23.6%), altered mental status (23.6%), anosmia (17.6%), headache (12.9%), and seizures (11.6%). The mean age of patients was 61.1 years, with 42.1% being women; a higher proportion of women was recorded among patients with altered mental status, anosmia, and headache. The onset of symptoms differed within categories. Onset of anosmia occurred a mean (standard deviation) of 2.9 (2.5) days after the first general symptom, whereas neuromuscular symptoms appeared after 13.9 (10.1) days. Neurological symptoms were persistent in 33% of patients. General symptoms were present in 97.7% of patients, and results from general laboratory studies were abnormal in 99.4% of patients. Cerebrospinal fluid analysis findings were abnormal in 62.7% of the cases in which this test was performed (n = 51), but positive results for SARS-CoV-2 were only found in one case. CONCLUSIONS: The neurological manifestations of COVID-19 are diverse. Anosmia, myalgia, and headache occur earlier in the course of the disease. Altered mental status, neuromuscular symptoms, and stroke are associated with greater severity. COVID-19 must be incorporated into most clinical and radiological differential diagnoses. COVID-19 may cause persistent and disabling neurological symptoms.

Familial globular glial tauopathy linked to MAPT mutations: molecular neuropathology and seeding capacity of a prototypical mixed neuronal and glial tauopathy.

Globular glial tauopathy (GGT) is a progressive neurodegenerative disease involving the grey matter and white matter (WM) and characterized by neuronal deposition of hyper-phosphorylated, abnormally conformed, truncated, oligomeric 4Rtau in neurons and in glial cells forming typical globular astrocyte and oligodendrocyte inclusions (GAIs and GOIs, respectively) and coiled bodies. Present studies centre on four genetic GGT cases from two unrelated families bearing the P301T mutation in MAPT and one case of sporadic GGT (sGGT) and one case of GGT linked to MAPT K317M mutation, for comparative purposes. Clinical and neuropathological manifestations and biochemical profiles of phospho-tau are subjected to individual variations in patients carrying the same mutation, even in carriers of the same family, independently of the age of onset, gender, and duration of the disease. Immunohistochemistry, western blotting, transcriptomic, proteomics and phosphoproteomics, and intra-cerebral inoculation of brain homogenates to wild-type (WT) mice were the methods employed. In GGT cases linked to MAPT P301T mutation, astrocyte markers GFAP, ALDH1L1, YKL40 mRNA and protein, GJA1 mRNA, and AQ4 protein are significantly increased; glutamate transporter GLT1 (EAAT2) and glucose transporter (SLC2A1) decreased; mitochondrial pyruvate carrier 1 (MPC1) increased, and mitochondrial uncoupling protein 5 (UCP5) almost absent in GAIs in frontal cortex (FC). Expression of oligodendrocyte markers OLIG1 and OLIG2mRNA, and myelin-related genes MBP, PLP1, CNP, MAG, MAL, MOG, and MOBP are significantly decreased in WM; CNPase, PLP1, and MBP antibodies reveal reduction and disruption of myelinated fibres; and SMI31 antibodies mark axonal damage in the WM. Altered expression of AQ4, GLUC-t, and GLT-1 is also observed in sGGT and in GGT linked to MAPT K317M mutation. These alterations point to primary astrogliopathy and oligodendrogliopathy in GGT. In addition, GGT linked to MAPT P301T mutation proteotypes unveil a proteostatic imbalance due to widespread (phospho)proteomic dearrangement in the FC and WM, triggering a disruption of neuron projection morphogenesis and synaptic transmission. Identification of hyper-phosphorylation of variegated proteins calls into question the concept of phospho-tau-only alteration in the pathogenesis of GGT. Finally, unilateral inoculation of sarkosyl-insoluble fractions of GGT homogenates from GGT linked to MAPT P301T, sGGT, and GGT linked to MAPT K317M mutation in the hippocampus, corpus callosum, or caudate/putamen in wild-type mice produces seeding, and time- and region-dependent spreading of phosphorylated, non-oligomeric, and non-truncated 4Rtau and 3Rtau, without GAIs and GOIs but only of coiled bodies. These experiments prove that host tau strains are important in the modulation of cellular vulnerability and phenotypes of phospho-tau aggregates.