What’s new in March for Neurology features: Cognitive Disorders Other Than Alzheimer Disease, Tics.
Cognitive and Behavioral Neurology
SETH A. GALE, MD
Associate Neurologist, Division of Cognitive and Behavioral Neurology, Brigham and Women’s Hospital, and Instructor of Neurology, Harvard Medical School, Boston, MA
KIRK R. DAFFNER, MD, FAAN
Chief, Division of Cognitive and Behavioral Neurology, Brigham and Women’s Hospital, J. David and Virginia Wimberly Professor of Neurology, Harvard Medical School, Boston, MA
The pathogenesis of frontotemporal lobar degeneration (FTLD) is complicated, and continued research is needed to fully explain the physiology. Interestingly, some evidence has suggested that developmental, language-based learning disabilities are also associated with patterns of handedness and hemispheric language dominance and may increase the risk of later-life primary progressive aphasia (PPA), which is a clinical syndrome characterized by initial and prominent language-based cognitive deficits. This raises the notion that in some cases, PPA or FTLD may arise as a delayed manifestation of long-standing vulnerability in a specific brain region, which then becomes a natural starting point for a degenerative process.
JUSTYNA R. SARNA, MD, PHD
Clinical Assistant Professor, Division of Neurology, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB
TAMARA PRINGSHEIM, MD, MSC
Assistant Professor, Division of Neurology, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB
Epidemiologic studies have emphasized the limitations of accurately studying the prevalence of tic disorders. Epidemiologic reports of the prevalence of obsessive-compulsive disorder (OCD) in Tourette syndrome (TS) vary greatly based on the definitions used and range from 10 to 35% to approximately 40%. Some studies have cited higher levels of comorbidity when including obsessive-compulsive symptoms without fulfilling disorder criteria. Interestingly, patients with comorbid OCD have a higher likelihood of complex tics at the initial presentation, which can further blur the distinction between tics versus compulsions in this cohort. Obsessive-compulsive symptoms may occur later compared with tic onset, and psychoeducation should emphasize this possibility. However, OCD associated with TS has earlier onset compared with OCD alone.
As seen in Scientific AmericanTM Neurology.