Gut-microbiome-brain axis: the crosstalk between the vagus nerve, alpha-synuclein and the brain in Parkinson's disease.

This critical review of the literature shows that there is a close link between the microbiome, the gut, and the brain in Parkinson's disease. The vagus nerve, the main component of the parasympathetic nervous system, is involved in the regulation of immune response, digestion, heart rate, and control of mood. It can detect microbiota metabolites through its afferents, transferring this gut information to the central nervous system. Preclinical and clinical studies have shown the important role played by the gut microbiome and gut-related factors in disease development and progression, as well as treatment responses. These findings suggest that the gut microbiome may be a valuable target for new therapeutic strategies for Parkinson's disease. More studies are needed to better understand the underlying biology and how this axis can be modulated for the patient's benefit.

Reversible cerebral vasoconstriction syndrome associated with probable drug poisoning.

Reversible cerebral vasoconstriction syndrome (RCVS) is a clinical condition characterized by arterial involvement of the intracranial vessels, manifesting with vasospasm. The most common clinical manifestation related to the syndrome is the thunderclap headache, which consists of a severe headache that reaches the peak of pain within minutes. The imaging study assumes a leading role in the complementary investigation. Laboratory tests and cerebrospinal fluid analysis are often nonspecific and without significant diagnostic importance. Non-contrast studies of the brain parenchyma reveal variable results that can often be normal. Angiographic findings, which initially may not reveal any changes, allow the visualization of diffuse narrowing of the vessels, with the posterior cerebral circulation being preferentially affected. The present study reports the case of a 19-year-old woman with no relevant medical history, except that she was a regular user of marijuana and a drug based on chloroform and ether. The patient showed clinical and imaging signs compatible with RCVS, and the narcotics used by her were considered precipitating factors.

Impact of dysexecutive syndrome in quality of life in Alzheimer disease: What we know now and where we are headed.

Alzheimer's disease (AD) is a common form of dementia that leads to multiple repercussions in the patient's life. This condition's clinical characteristics include loss of memory, temporal and spatial disorientation, language or executive dysfunction, and subsequent decline of social function. Dysexecutive syndrome (DS), the second most frequent neuropsychological dysfunction in AD, affects multiple brain areas and causes cognitive, behavioral, and emotional difficulties. We aimed to analyze the association between DS and AD and elucidate possible lack of evidence that may urge further research on this theme. Especially when dealing with such a disabling disease, where new findings can directly imply a better prognosis.

Cerebral cryptococcoma successfully treated by isavuconazole in an immunocompetent patient: A case report.

Cryptococcosis has been recognized as an increasing cause of severe systemic mycosis in immunocompetent patients in the last few years. Cerebral cryptococcomas are a more uncommon manifestation of cryptococcal meningitis, which are not usually included in the differential of brain masses. We report a case of a young, immunocompetent woman that rapidly developed severe neurological deficits. She was ultimately diagnosed with cerebral cryptococcoma caused by both Cryptococcus neoformans and Cryptococcus gattii, and was treated with amphotericin B and isavuconazole. After several complications during hospitalization, including hydrocephalus and cerebellitis, she was discharged home on isavuconazole. On follow-up, she only complained of anosmia. We review the clinical and radiological findings of similar cases. It is the first time that this form of cryptococcal meningitis is favorably treated with isavuconazole and is caused by 2 species of Cryptococcus. We emphasize that cerebral cryptococcomas should be suspected in immunocompetent patients that present with brain masses.

Role of enteric glia and microbiota-gut-brain axis in parkinson disease pathogenesis.

The microbiota-gut-brain axis or simple gut-brain axis (GBA) is a complex and interactive bidirectional communication network linking the gut to the brain. Alterations in the composition of the gut microbiome have been linked to GBA dysfunction, central nervous system (CNS) inflammation, and dopaminergic degeneration, as those occurring in Parkinson's disease (PD). Besides inflammation, the activation of brain microglia is known to play a central role in the damage of dopaminergic neurons. Inflammation is attributed to the toxic effect of aggregated α-synuclein, in the brain of PD patients. It has been suggested that the α-synuclein misfolding might begin in the gut and spread "prion-like", via the vagus nerve into the lower brainstem and ultimately to the midbrain, known as the Braak hypothesis. In this review, we discuss how the microbiota-gut-brain axis and environmental influences interact with the immune system to promote a pro-inflammatory state that is involved in the initiation and progression of misfolded α-synuclein proteins and the beginning of the early non-motor symptoms of PD. Furthermore, we describe a speculative bidirectional model that explains how the enteric glia is involved in the initiation and spreading of inflammation, epithelial barrier disruption, and α-synuclein misfolding, finally reaching the central nervous system and contributing to neuroinflammatory processes involved with the initial non-motor symptoms of PD.

Tumefactive demyelination after covid-19 successfully treated with betainterferon 1A.

The Marburg variant of MS is a rare variant that leads to a severe clinical course, with a high rate of mortality or severe residual deficits and unclear pathophysiology. A 20-year-old female patient, presented at the hospital emergency with left inferior limb paresis and visual blurring. The neurologic exam showed complete and proportionate left hemiparesis with pyramidal signs and clonus, loss of proprioception and vibration in lower limbs, tactile, and painful hypoesthesia on the left side. This report describes a rare case of Marburg variant associated with COVID-19 infection.

Ocular contrapulsion followed by ipsipulsion in Wallenberg syndrome: The first case report in literature.

Wallenberg syndrome is also called lateral medullary syndrome, a neurological disorder resulting from occlusion of the vertebral artery or the posterior inferior cerebellar artery. The clinical presentations are associated with a variety of indications, including vestibulocerebellar symptoms, autonomic dysfunction and ipsilateral cerebellar signs. The ipsipulsion, an abnormality of the ocular movement associated with the Wallenberg syndrome, is more specific to the lateral medullary syndrome and is characterized by a tonic deviation of the eyes in the direction of the damaged side, more prominently when the visual fixation is interrupted. A 51-year-old male patient presented with a sudden permanent rotatory dizziness, unsteady gait, numbness in the left hemibody, left palate paresis, incoordination on left side and horizontal jerk nystagmus with left fast fase. Magnetic resonance imaging showed infarction in the left medulla and cerebellar. The ocular exam revealed saccadic lateropulsion ipsilateral to lesion. In the neurologic evaluation of the patient with Wallenberg syndrome, numerous abnormalities manifestations are present, such as vestibulo-ocular reflex deficiency, saccadic abnormalities, low pursuance movements and gaze fixation, and eye alignment dysfunction. This semiologic feature had not been described in literature until now. We hypothesize that an initial vasogenic edema extending to the left medial medulla following the acute stroke could explain the early presentation with saccadic counterpulsion. After one week and regression of the edema, the finding of lateropulsion has alternated to the classic ipsipulsion related to Wallenberg syndrome. The following case report depicts a rare case of Wallenberg syndrome associated with alterations of the ocular motricity.