Cerebellar Dysfunction in Multiple Sclerosis: Considerations for Research and Rehabilitation Therapy

Introduction. Cerebellar pathology is common among persons with multiple sclerosis (PwMS). The cerebellum is well recognized for its role in motor control and motor learning and cerebellar pathology in multiple sclerosis is associated with enhanced motor impairment and disability progression. The Problem. To mitigate motor disability progression, PwMS are commonly prescribed exercise and task-specific rehabilitation training. Yet, whether cerebellar dysfunction differentially affects rehabilitation outcomes in this population remains unknown. Furthermore, we lack rehabilitation interventions targeting cerebellar dysfunction. The Solution. Here, we summarize the current understanding of the impact of cerebellar dysfunction on motor control, motor training, and rehabilitation in persons with multiple sclerosis. Recommendations. Additionally, we highlight critical knowledge gaps and propose that these guide future research studying cerebellar dysfunction in persons with multiple sclerosis.

P.162 Effects of Systemic Corticosteroid Treatment on Pseudotumoral Hemicerebellitis

Background: Pseudotumoral hemicerebellitis is an acute, unilateral inflammation of the cerebellum that typically affects the pediatric population. The etiology remains to be elucidated, however frequently is attributed to post-infectious inflammation. Though it tends to be self-resolving, treatment may reduce the time to symptomatic recovery. Systemic corticosteroid therapy has been proposed as a mechanism for improving outcomes and time to symptomatic recovery. Methods: We present a case report of a 12-year-old male with pseudotumoral hemicerebellitis and unilateral cerebellar dysfunction. Additionally, we briefly review the additional 35 reported cases of pseudotumoural hemicerebellitis with respect to length of time to symptomatic recovery with or without systemic corticosteroid treatment. Results: 30 cases reported length of time to symptomatic recovery. Including our case, the mean time to recovery for those treated with systemic corticosteroids (n=20) was 48.05 days(SE=16.3). The mean time to recovery for those treated without (n=10) was 86.7 days(SE=29.3). Conclusions: Treatment with systemic corticosteroids was associated with a faster time to symptomatic recovery compared to without. Regardless of etiology, reducing inflammation and mass effect involved in pseudotumoral hemicerebellitis may be integral to a more rapid return to neurological baseline.

Course of papilloedema following surgical decompression in CHIARI I malformation with raised intracranial pressure

Arnold-Chiari malformations (ACM) is a rare congenital hindbrain maldevelopment, leading to downward herniation of the cerebellar tonsils. Clinical features relates to cerebrospinal fluid disturbances, manifesting as symptoms of headaches, pseudotumour-like episodes, cranial nerve palsies and cerebellar dysfunction. Ocular manifestations includes varying ophthalmoloplegia and accommodation abnormalities. Papilloedema has been rarely implicated and remains an uncommon feature of ACM. We report a case of ACM who developed papilloedema and visual disturbance, that was successfully treated with suboccipital decompression. The presentation of patients with ACM-I and papilloedema unaccompanied by localising signs may resemble that of IIH. Neuroimaging with special attention to the craniocervical junction in saggital and transverse planes is crucial. Surgical decompression of the posterior fossa seems to improve headache symptoms and clinical signs of papilloedema.

A Case Report of Perceptual Disturbances with Incidental Calcifications in the Cerebellum

Background. The cerebellum has extensive connections with motor and nonmotor areas of the nervous system. These nonmotor areas include the cognitive, affective, and perceptual areas of the central nervous system. Extensive literature has emerged cognitive documents and mood disorders in patients with cerebellar dysfunction. Perceptual disturbances consistent with cerebellar connections with perceptual areas have not been as widely documented. Case Presentation. We present the case of a 58-year-old female presenting with new onset isolated auditory hallucinations and incidental findings of cerebellar calcifications. Conclusion. In light of this case, we discuss an expanding body of evidence that suggests the likely role of the cerebellum in perceptual functioning.

A Purkinje cell to parabrachial nucleus pathway enables broad cerebellar influence over the forebrain and emotional valence

In addition to its well-known contributions to motor control and motor learning, the cerebellum is involved in language, emotional regulation, anxiety, and affect1-4. We found that suppressing the firing of cerebellar Purkinje cells (PCs) rapidly excites forebrain areas that could contribute to such functions, including the amygdala, basal forebrain, and septum, but that the classic cerebellar outputs, the deep cerebellar nuclei (DCN), do not project to these regions. Here we show that parabrachial nuclei (PBN) neurons that receive direct PC input, project to and influence all of these forebrain regions and many others. Furthermore, the function of this pathway is distinct from the canonical pathway: suppressing PC to PBN activity is aversive, whereas suppressing the PC to DCN pathway is rewarding. Therefore, the PBN pathway allows the cerebellum to influence the entire spectrum of valence, modulate the activity of forebrain regions known to regulate diverse nonmotor behaviors, and may be the substrate for many nonmotor disorders related to cerebellar dysfunction.

Surgical Management of Jugular Foramen Schwannomas

Background: Resection of jugular foramen schwannomas (JFSs) with minimal cranial nerve (CN) injury remains difficult. Reoperations in this vital region are associated with severe CN deficits. Methods: We performed a retrospective analysis at a tertiary neurosurgical center of patients who underwent surgery for JFSs between June 2007 and May 2020. We included nine patients (median age 60 years, 77.8% female, 22.2% male). Preoperative symptoms included hearing loss (66.6%), headache (44.4%), hoarseness (33.3%), dysphagia (44.4%), hypoglossal nerve palsy (22.2%), facial nerve palsy (33.3%), extinguished gag reflex (22.2%), and cerebellar dysfunction (44.4%). We observed Type A, B, C, and D tumors in 3, 1, 1, and 4 patients, respectively. A total of 77.8% (7/9) underwent a retrosigmoid approach, and 33.3% (3/9) underwent an extreme lateral infrajugular transcondylar (ELITE) approach. Gross total resection (GTR) was achieved in all cases. The rate of shunt-dependent hydrocephalus was 22.2% (2/9). No further complications requiring surgical intervention occurred during follow-up. The median follow-up time was 16.5 months (range 3–84 months). Conclusions: Considering the satisfying outcome, the GTR of JFSs is feasible in performing well-known skull base approaches. Additional invasive and complicated approaches were not needed. Radiosurgery may be an effective alternative for selected patients.