Wallerian degeneration of the bilateral middle cerebellar peduncles secondary to pontine infarction

Infarct of the Middle Cerebellar Peduncle Mimicking Bell's Palsy: A Case Report

The anterior inferior cerebellar artery (AICA) supplies the middle cerebellar peduncle, lower pons, upper medulla, and anterior inferior cerebellum. Ischemia in the AICA can cause the lateral inferior pontine syndrome. AICA syndrome is characterized by facial sensory loss and weakness, Horner syndrome, prolonged vertigo, audio-vestibular loss, and cerebellar signs. Many studies on AICA territory infarcts have demonstrated the rarity of complete AICA syndrome. In all cases of AICA territory infarcts, involvement of the middle cerebellar peduncle was observed, with the seventh cranial nerve (facial nerve) being the most frequently involved cranial nerve, vertigo was the most common presenting symptom, and atherosclerosis was the most common etiology. This case report aims to investigate the occurrence of middle cerebellar peduncle infarcts that mimic Bell's palsy, highlighting the importance of accurate diagnosis and appropriate management in such cases. Recognizing the unique characteristics and clinical presentation of middle cerebellar peduncle (MCP) infarcts is essential for distinguishing them from more common conditions like Bell's palsy, thereby ensuring timely and effective treatment.

Neuroimaging and clinical features of bilateral Wallerian degeneration of middle cerebellar peduncles subsequent to pontine infarction

OBJECTIVE

Wallerian degeneration (WD) of the middle cerebellar peduncles (MCPs) following pontine infarction is a rare secondary degenerative neurological condition. Due to its infrequency, there is limited research on its characteristics.

METHODS

This study aims to present three cases of WD of MCPs following pontine infarction and to analyze the prognosis, clinical manifestations, and neuroimaging features by amalgamating our cases with previously reported ones.

RESULTS

The cohort consisted of 25 cases, comprising 18 men and 7 women aged 29 to 77 years (mean age: 66.2 years). The majority of patients (94%) exhibit risk factors for cerebrovascular disease, with hypertension being the primary risk factor. Magnetic resonance imaging (MRI) can detect WD of MCPs within a range of 21 days to 12 months following pontine infarction. This degeneration is characterized by bilateral symmetric hyperintensities on T2/FLAIR-weighted images (WI) lesions in the MCPs. Moreover, restricted diffusion, with hyperintensity on diffusion-weighted imaging (DWI) and low apparent diffusion coefficient (ADC) signal intensity may be observed as early as 21 days after the infarction. Upon detection of WD, it was observed that 20 patients (80%) remained asymptomatic during subsequent clinic visits, while four (16%) experienced a worsening of pre-existing symptoms.

CONCLUSIONS

These findings underscore the importance of neurologists enhancing their understanding of this condition by gaining fresh insights into the neuroimaging characteristics, clinical manifestations, and prognosis of individuals with WD of bilateral MCPs.

Modifications of polysaccharide-based biomaterials under structure-property relationship for biomedical applications

Polysaccharides are well accepted biomaterials that have attracted considerable attention. Compared with other materials under research, polysaccharides show unique advantages: they are available in nature and are normally easily acquired, those acquired from nature show favorable immunogenicity, and are biodegradable and bioavailable. The bioactivity and possible applications are based on their chemical structure; however, naturally acquired polysaccharides sometimes have unwanted flaws that limit further applications. For this reason, carefully summarizing the possible modifications of polysaccharides to improve them is crucial. Structural modifications can not only provide polysaccharides with additional functional groups but also change their physicochemical properties. This review based on the structure-property relation summarizes the common chemical modifications of polysaccharides, the related bioactivity changes, possible functionalization methods, and major possible biomedical applications based on modified polysaccharides.

Hypertrophic olivary degeneration concomitant with bilateral middle cerebellar peduncles Wallerian degeneration following unilateral pontine infarction

Background

Wallerian degeneration (WD) can occur in different projecting systems, such as corticospinal tract, dentate-rubro-olivary pathway, and corticopontocerebellar tract. However, the co-occurrence of hypertrophic olivary degeneration (HOD) and middle cerebellar peduncles (MCPs) degeneration secondary to unilateral pontine infarction in a single patient is extremely rare.

Case presentation

A 71-year-old man presented with acute onset of dizzness, slurred speech, and right-sided weakness. On the next day, his previous neurologic deficits deteriorated. Brain magnetic resonance imaging (MRI) revealed acute ischemic stroke of the left pons. After treatment with thrombolysis, antiplatelets, and rehabilitation training, his speaking and motor function improved moderately. At the 3-month follow-up, the MRI showed hyperintensity in the left medulla oblongata and bilateral MCPs on T2-weighted and FLAIR images, suggesting HOD as well as MCPs degeneration.

Conclusions

It is of great importance for us to know the anatomic knowledge of dentate-rubro-olivary and corticopontocerebellar pathways.