Cerebellar lesions

Causes of Cerebellar Lesions: Cerebellar lesions arise from diverse etiologies including vascular insults (ischaemic or haemorrhagic stroke), autoimmune conditions, infections, neoplasms, traumatic injuries, and neurodegenerative diseases. In particular, autoimmune encephalitis mediated by anti-mGluR1 antibodies prominently causes subacute cerebellar ataxia, representing an immune-mediated cerebellar dysfunction Ban et al. 2026 Ban et al. 2026. Vascular causes, such as brainstem haemorrhages involving cerebellar pathways, may cause Holmes tremor characterized by combined rest, postural, and intention tremors due to disruption of cerebellar and associated motor circuits Lodhia et al. 2026 Lodhia et al. 2026. Other causes include paraneoplastic syndromes, metabolic disorders, and genetic ataxias Ban et al. 2026.

Clinical Features of Cerebellar Lesions: The hallmark clinical presentation is cerebellar ataxia, often manifesting as gait instability, incoordination, dysmetria, intention tremor, dysarthria, and nystagmus Ban et al. 2026 Ban et al. 2026. In anti-mGluR1 encephalitis, patients typically develop acute to subacute cerebellar ataxia with truncal imbalance, limb ataxia, and dysarthria, sometimes accompanied by neuropsychiatric symptoms such as cognitive and behavioral changes, especially in encephalitic variants Ban et al. 2026. Holmes tremor secondary to cerebellar or brainstem lesions presents as a low-frequency (<5 Hz), high-amplitude tremor combining resting, postural, and intention components, predominantly affecting proximal upper limbs and often delayed weeks to months after the insult Lodhia et al. 2026 Lodhia et al. 2026. Additional signs may include dysphagia, oculomotor impairment, and sensory changes depending on lesion location Ban et al. 2026. On neuroimaging, cerebellar lesions may show signal abnormalities or progressive atrophy, with hypertrophic olivary degeneration noted in some brainstem-associated tremor cases Ban et al. 2026 Ban et al. 2026 Lodhia et al. 2026.

Management Options for Cerebellar Lesions: Treatment strategies vary according to etiology. In autoimmune cerebellar syndromes such as anti-mGluR1 encephalitis, immunotherapy is the mainstay, beginning with first-line agents including high-dose corticosteroids, intravenous immunoglobulin (IVIG), and plasma exchange, with escalation to second-line immunosuppressants like rituximab or cyclophosphamide and maintenance immunosuppression as needed Ban et al. 2026 Ban et al. 2026. Early recognition and timely immunotherapy improve outcomes but residual deficits are common, underlining the need for sustained treatment and rehabilitation Ban et al. 2026.

For vascular or structural causes leading to tremor syndromes such as Holmes tremor, pharmacological management is challenging and often yields partial responses. Levetiracetam, an anticonvulsant modulating synaptic activity, may provide partial symptomatic improvement aiding rehabilitation Lodhia et al. 2026 Lodhia et al. 2026. Dopaminergic agents can be helpful for select symptoms, though responses are variable. When medical therapy fails, surgical interventions including deep brain stimulation (DBS) targeting the globus pallidus internus (GPi), ventrointermediate nucleus (VIM) of the thalamus, or subthalamic nucleus (STN) may be considered to reduce tremor severity and improve functional status Lodhia et al. 2026 Lodhia et al. 2026. Non-invasive lesioning techniques such as MRI-guided focused ultrasound (MRgFUS) are also emerging options for tremor control in cerebellar circuitry involvement.

Rehabilitation including multidisciplinary neurorehabilitation remains a cornerstone for all cerebellar lesions, aiming to maximize function despite residual ataxia or tremor Ban et al. 2026. Supportive measures, symptomatic treatments for associated complications, and surveillance for underlying malignancies in paraneoplastic cases are integral to comprehensive care Ban et al. 2026 Ban et al. 2026.