Is there a time window for MRI in Wernicke encephalopathy - a decade of experience from a tertiary hospital.

OBJECTIVE: Wernicke encephalopathy (WE) is a neuropsychiatric syndrome caused by thiamine deficiency. Despite its low sensitivity, brain magnetic resonance imaging (MRI) is the most useful diagnostic technique. Our aim was to investigate whether the timing of the imaging study, and thiamine replacement can influence brain MRI findings in these patients. METHODS: Retrospective observational study of hospitalized patients between January/2008 and December/2020 with a clinical diagnosis of WE. Data from clinical presentation, diagnostic features, therapeutic approach, and outcomes were collected. RESULTS: We identified 41 patients (55 ± 13.3 years) with WE. Brain MRI was performed in 36 patients, and one third had T2/FLAIR hyperintensities suggestive of WE. We found an association between a history of poor diet and periventricular hyperintensities (p = 0.023), especially on the ventral surface of the thalamus and the periaqueductal region. It was found that the odds of having a typical imaging of WE decreased by 5.3% for each additional unit (100 mg) of thiamine administered (p = 0.046) (95% CI [0.89, 0.99]). On the other hand, the number of days from clinical presentation was not found to be a viable predictor (p = 0.254) (95% CI [0.88, 1.03]) Recovery was positively correlated with the total dose of thiamine received until discharge (p = 0.020). CONCLUSIONS: MRI hyperintensities seem to be dependent on the timing of thiamine correction and, particularly, on the thiamine dosage prescribed at admission. Nevertheless, thiamine replacement should not be delayed, as its timely prescription is associated with a better prognosis at discharge.

Optimized T1- and T2-weighted volumetric brain imaging as a diagnostic tool in very preterm neonates.

BACKGROUND: T1- and T2-W MR sequences used for obtaining diagnostic information and morphometric measurements in the neonatal brain are frequently acquired using different imaging protocols. Optimizing one protocol for obtaining both kinds of information is valuable. OBJECTIVE: To determine whether high-resolution T1- and T2-W volumetric sequences optimized for preterm brain imaging could provide both diagnostic and morphometric value. MATERIALS AND METHODS: Thirty preterm neonates born between 24 and 32 weeks' gestational age were scanned during the first 2 weeks after birth. T1- and T2-W high-resolution sequences were optimized in terms of signal-to-noise ratio, contrast-to-noise ratio and scan time and compared to conventional spin-echo-based sequences. RESULTS: No differences were found between conventional and high-resolution T1-W sequences for diagnostic confidence, image quality and motion artifacts. A preference for conventional over high-resolution T2-W sequences for image quality was observed. High-resolution T1 images provided better delineation of thalamic myelination and the superior temporal sulcus. No differences were found for detection of myelination and sulcation using conventional and high-resolution T2-W images. CONCLUSION: High-resolution T1- and T2-W volumetric sequences can be used in clinical MRI in the very preterm brain to provide both diagnostic and morphometric information.

MR imaging for diagnostic evaluation of encephalopathy in the newborn.

Magnetic resonance (MR) imaging is used with increasing frequency to evaluate the neonatal brain because it can provide important diagnostic and prognostic information that is needed for optimal treatment and appropriate counseling. Special care must be taken in preparing encephalopathic neonates for an MR study, transporting them from the intensive care unit, monitoring their vital signs, and optimizing MR sequences and protocols. Moreover, to accurately interpret the findings, specific knowledge is needed about the normal MR imaging appearances of the physiologic processes of myelination, cell migration, and sulcation, as well as patterns of injury, in the neonatal brain at various stages of gestational development. Hypoxic-ischemic injury, the most common cause of neonatal encephalopathy, has characteristic appearances that depend on the severity and duration of the insult as well as the stage of brain development. Diffusion-weighted MR imaging and MR spectroscopy depict abnormalities earlier than do conventional MR imaging sequences. However, diffusion-weighted imaging, if performed in the first 24 hours after the insult, might lead to underestimation of the extent of injury. When the MR findings are atypical, the differential diagnosis of neonatal encephalopathy also should include congenital and metabolic disorders and infectious diseases. Despite recent advances in the MR imaging-based characterization of these conditions, the clinical history must be borne in mind to achieve an accurate diagnosis.

Isolated velopalatine paralysis associated with parvovirus B19 infection.

A case of isolated velopalatine paralysis in an 8-year-old boy is presented. The symptoms were sudden-onset of nasal speech, regurgitation of liquids into the nose and dysphagia. Brain MRI and cerebrospinal fluid examination were normal. Infectious serologies disclosed an antibody arrangement towards parvovirus B19 that was typical of recent infection. In the absence of other positive data, the possibility of a correlation between the tenth nerve palsy and parvovirus infection is discussed.

Neonatal pyruvate dehydrogenase deficiency due to a R302H mutation in the PDHA1 gene: MRI findings.

Pyruvate dehydrogenase (PDH) deficiency is one of the most common causes of congenital lactic acidosis. Correlations between the genetic defect and neuroimaging findings are lacking. We present conventional and diffusion-weighted MRI findings in a 7-day-old male neonate with PDH deficiency due to a mosaicism for the R302H mutation in the PDHA1 gene. Corpus callosum dysgenesis, widespread increased diffusion in the white matter, and bilateral subependymal cysts were the main features. Although confirmation of PDH deficiency depends on specialized biochemical analyses, neonatal MRI plays a role in evaluating the pattern and extent of brain damage, and potentially in early diagnosis and clinical decision making.

Diffusion-weighted magnetic resonance imaging findings in a patient with cerebral syphilitic gumma.

Cerebral syphilitic gummas are rare entities, consisting of masses of granulation tissue that result from an exacerbated cell-mediated inflammatory response to Treponema pallidum, usually arising from the meninges of the convexity. Conventional magnetic resonance imaging and computed tomography findings of cerebral gummas have been reported, but diffusion-weighted imaging findings have not been previously described. In our patient, magnetic resonance imaging revealed a juxtacortical lesion with nodular enhancement, moderately restricted diffusion, a dural tail, and surrounding vasogenic edema. The role of diffusion-weighted imaging findings in the diagnosis of this condition is underscored.

Isolated velopalatine paralysis associated with parvovirus B19 infection / Paralisia velopalatina isolada associada a infecção por parvovírus B 19

A case of isolated velopalatine paralysis in an 8-year-old boy is presented. The symptoms were sudden-onset of nasal speech, regurgitation of liquids into the nose and dysphagia. Brain MRI and cerebrospinal fluid examination were normal. Infectious serologies disclosed an antibody arrangement towards parvovirus B19 that was typical of recent infection. In the absence of other positive data, the possibility of a correlation between the tenth nerve palsy and parvovirus infection is discussed.

Apresentamos um caso de paralisia velopalatina isolada, num menino de 8 anos, que se manifestou por voz nasalada, regurgitação de líquidos pelo nariz e disfagia, de início súbito. A ressonância magnética encefálica e o estudo do líquido cefalo-raquidiano foram normais. O perfil serológico dos anticorpos anti-parvovírus B19 era típico de infecção recente. Na ausência de outros dados positivos, discute-se a possibilidade de uma correlação entre a parésia do X nervo e a infecção por parvovírus.