Progress in Movement Disorders

The field of movement disorders, much like its moniker and the rest of neurology, is exciting and dynamic. Advances continue in symptomatic therapies as we move ever closer toward the goal of disease-modifying therapies (DMTs). Movement disorders also epitomize the basic tenets of neurology, relying on comprehensive history and a thorough neurologic exam to determine movement phenomenology and accurate diagnosis. Most movement disorders have a broad differential and therefore, can be initially intimidating; however, a systemic approach can assist us in patient encounters. In this issue, we are pleased to offer a comprehensive review of movement disorders, from diagnosis to symptomatic treatment, updates on clinical trials, and a glimpse into the future of the field.

Certainly not all gait disorders are due to cerebellar ataxias, and as any neurologist can tell by the low incidence of cerebellar ataxias in referrals labeled “ataxia,” these disorders are clearly challenging to understand. Because of overlapping clinical phenotypes and diverse causes and costs of a comprehensive genetic panel, adult-onset cerebellar ataxias pose a unique diagnostic challenge. Tiered testing is an extremely useful diagnostic framework, and in Adult-Onset Cerebellar Ataxias, Dr. Pravin Khemani provides just that, eloquently walking us through the diagnostic process for cerebellar ataxias.

Phenotypic overlap among Atypical Parkinsonian Syndromes can also make diagnosis challenging. Drs. Steven Frucht and Steve C. Han provide important clinical clues for narrowing your differential when encountering these conditions. In a clear and concise manner, they detail red flags in clinical history and key findings of the neurologic exam and ancillary testing for each of the major atypical parkinsonian syndromes.

Levodopa was identified as an effective symptomatic therapy for Parkinson disease (PD) over 50 years ago and remains the gold standard for treating PD. But in the intervening years since the discovery of levodopa, numerous other medications to optimize dopaminergic activity in the brain have enhanced quality of life for people with PD. Although the search continues for DMTs for PD, Drs. Bhavana Patel and Irene Malaty provide a comprehensive review of newly available symptomatic treatments over the last 5 years in Parkinson Disease Treatment Advances. These include both novel agents and new formulations of existing compounds and represent the ‘state of the science’ for PD treatments.

Tic disorders are the most common movement disorder in children and may also be encountered in adults. In a unique hybrid Case Challenge format, Tic Disorder in an Adult, Dr. Danielle Larson briefly discusses diagnosis and treatment of tic disorder in adults, including information on both nonpharmacologic and pharmacologic treatments that can improve tic frequency and severity in adults.

Despite the flurry of clinical trial activity for Huntington disease (HD) over the last 5 years, no DMT has yet broken through to the level of approval by the Food and Drug Administration. However, the science is truly cutting edge, leveraging knowledge of human genetics to explore methodologies such as antisense oligonucleotides, gene therapy, and splicing modifiers. Dr. Tiago Mestre provides an up-to-the minute summary of these clinical trials in Emerging Therapies to Slow the Progression of Huntington Disease.

Although we have made significant strides in our understanding of and ability to treat various movement disorders, there is still much work to be done. We hope you find these articles to be as informative, inspiring, and enjoyable as we did.