Here are the last 3 of the 7 research posters on clinical features of PSP from the Movement Disorder Society’s August 2023 meeting in Copenhagen. My editorial comments in italics.

Narcolepsy type 1, supranuclear vertical gaze palsy, and agrypnia excitata in a patient with anti-Ma associated encephalitis.

C. Espinoza-Vinces, A. Horrillo, R. Villino, A. Solis, P. Domínguez, J. Arbizu, MR. Luquin, E. Urrestarazu, I. Avilés-Olmos (Pamplona, Spain)

Ma is a normal protein located in the parts of the brain serving vertical gaze, sleep, memory, personality, and motor control.  The immune system can make antibodies against Ma, usually in the process of fighting off a cancer that contains that protein or sometimes for no apparent reason.  The result is usually one of severe cognitive/behavioral changes or cerebellar ataxia but can occasionally mimic PSP.  This poster is such a case report in of a 53-year-old man with a 3-year diagnosis of narcolepsy who then rapidly developed features of PSP.  His spinal fluid and MRI were diagnostic of encephalitis.  The authors caution physicians that in patients with apparent PSP presenting with important sleep problems, to consider anti-Ma encephalitis.  That condition may respond to steroids or to removal of an underlying tumor. 

Anti-Ma encephalitis is one of the 52 disorders listed in the guide to the differential diagnosis of PSP that a working group of CurePSP Centers of Care is about to submit for publication.  Neurologists have long known it as a potential but rare cause of cerebellar ataxia but should also consider it in someone with apparent PSP that develops rapidly or at a relatively early age.

Atypical progression of motor symptoms in facio-scapulo-humeral dystrophy: clinical worsening or overlap?

D. Calisi, M. de Rosa, M. Russo, A. Thomas, M. Onofrj, S. Sensi (Chieti, Italy)

Facio-scapulo-humeral dystrophy, unlike most other kinds of muscular dystrophy, can start at any age and allow many decades of survival.  This case report describes a man in his 60s with FSHD since childhood confirmed on muscle biopsy and genetic testing.  The typical weakness in his face, neck, shoulders and upper arms progressed very slowly until he started to show slowness, vertical gaze palsy, falls, freezing and dysphagia.  His symptoms were attributed to the FSHD until imaging proved consistent with PSP.  The authors’ caution physicians that the diagnosis of PSP can be missed for years when it develops in the context of an unrelated, progressive motor disorder.

While the previous poster, on anti-Ma encephalitis mimicking PSP, is an example of a false positive, this one is a false negative.  These are excellent teaching cases for neurology residents.  I always taught my students and residents to consider concomitant neurological diagnoses and diagnostic mimics at each follow-up visit with a patient with a chronic disease, no matter how routine the visit was expected to be.

Prognostic impact of frontal-lobe clinical bedside signs in progressive supranuclear palsy

Ruiz Barrio, A. Horta Barba, S. Martinez Horta, J. Kulisevsky, J. Pagonabarraga (Barcelona, Spain)

These researchers tabulated frontal lobe signs in 61 people with PSP and compared those results with overall disability in the form of PSP Rating Scale total score.  (Problems with the frontal lobe explain the common PSP symptoms of loss of inhibition, repetition of words or movement, grasping, and many others.)  They found that grasping, orobuccal apraxia (inability to coordinate movements of the muscles around the mouth), and anosognosia (loss of awareness of illness) each correlated with PSPRS score independent of other neurological or demographic features.  In a sub-analysis of 51 patients evaluated during the first 4.3 years of the disease, groping was found to be an independent risk factor for shorter eventual survival.

Such observations can be highly variable across studies, but if confirmed, data like this could allow more rational analysis of neuroprotection drug trial outcomes and could also assist in patient and family counseling.

Next post on MDS conference posters:  Two science-nerdy ones on what’s working wrong in the brain in PSP.