Diagnosis and treatment of corticobasal degeneration.

OPINION STATEMENT: Corticobasal degeneration is a pathologic entity. Presenting clinical phenotypes include corticobasal syndrome (CBS), frontal behavioral spatial syndrome, aphasia, progressive supranuclear palsy-like syndrome (PSPS), and a predominantly cognitive phenotype often mistaken for Alzheimer's disease (AD). Treatment of CBD is symptomatic, particularly given recently negative neuroprotective studies. Given the relentless progression in CBD, all interested patients should be offered the opportunity to enroll in clinical neuroprotective trials as they arise. For symptomatic therapy, treatment options are necessarily based on evidence from other disorders given the lack of studies in CBD. In patients with CBS and PSPS, parkinsonism is treated with levodopa/carbidopa. This generally has modest and transient benefits at best and often results in no improvement. Botulinum toxin injections are the treatment of choice for limb dystonia. Clonazepam and levetiracetam are commonly used for myoclonus. Physical therapy is an important part of motor treatment, particularly for fall prevention strategies and assist device assessment. Whether medications such as cholinesterase inhibitors or memantine have any role in CBD is unclear given the various responses described in related phenotypes and diseases. Treating the behavioral symptoms associated with CBD is critical in an attempt to treat symptoms for which we have good pharmacologic interventions and to hopefully improve quality of life. General supportive care is important, including assessing for sores related to dystonia or immobility, monitoring dysphagia, and identifying needs for support services. Finally, as with other relentlessly progressive neurodegenerative diseases, it is critical to provide family and caregiver support and to assess for when palliative care services will serve the patient best.