PROGRESSIVE SUPRANUCLEAR PALSY (PSP): AN ATYPICAL CASE

Abstract

Progressive Supranuclear Palsy (PSP), also known as Steele-Richardson-Olszewski syndrome, is recognized as one of the most common extrapyramidal neurodegenerative disorders, following in prevalence after Parkinson's disease. This condition typically manifests in individuals over the age of 40, with the highest frequency occurring between 60 to 65 years (M, 2018).
We are going to present a case of a 63-year-old female patient with difficulties with walking difficulties and sudden falls. According to her medical history, the issues began three years earlier. She also mentioned incidents of dropping objects she held and suffering a multiple falls especially when rising from a chair, causing her to fall backward. Her (initial) neurological examination revealed impairment of the upward gaze. No bulbar symptoms. Mild dysarthria. Bilateral dysdiadochokinesis. Brisk tendon reflexes. Bilateral positive Babinski sign. Impaired tandem walk, it was notable that she was walking with extended legs on a wide basis. Reduction of the synkinetic movements of the arms. Retrocolis was seen due to neck dystonia.
Her MRI showed atrophy of the mesencephalon- “the hummingbird sign”. Diagnostic scales were used to distinguish the diagnosis according to the clinical phenotype, the interpretation of the score was in favor of PSP.
She was started on Levodopa/Carbidopa, later COMT inhibitor was added but no therapeutic response was seen. On later follow ups she presented with gradual worsening of her cognitive and motor symptoms. Soon she developed orthostatic hypotension. She ended up in a wheelchair 2,5 years after her diagnosis and treatment, or roughly 5,5 years after the initial symptoms.
Synucleinopathies and taupathies are characterized by distinct patterns of regional atrophy in the brain, leading to differences in the involvement of specific brain nuclei and resulting in variations in the affected neurotransmitter systems. In synucleinopathies (Peng C, 2018 Jan;) (Uemura N, 2020 Oct;), the primary focus of neurodegeneration is typically observed in the substantia nigra, brainstem, and limbic system, whereas tau-related neurodegeneration is predominantly localized within the frontal lobe structures and their connections to the basal ganglia. Midbrain atrophy is a well-established feature of Progressive Supranuclear Palsy (PSP). The distinct brainstem shape observed in MRI images of PSP patients, characterized by a reduced midbrain/pons ratio, has been coined as the "hummingbird sign" (Tsuboi Y, 2003) (Paviour DC, 2005). In contrast, when examining patients with MSA using conventional 1.5 T MRI, abnormalities may include atrophy in the lower brainstem, middle cerebellar peduncles (MCPs), cerebellum, and pons putaminal rim sign" (Thi Thuong Doan MD, 2023) (Alster P, 2022 Feb) (T., 2020 Apr;).
In the field of atypical parkinsonism, it becomes evident that there are considerable overlaps in symptom presentations, making the diagnosis of a patient particularly challenging (Jecmenica-Lukic M, 2014 Aug;). This challenge is compounded by the fact that a definitive diagnosis typically relies on histological evidence, such as the presence of Lewy bodies in neurons for Parkinson's Disease (PD), glyal cytoplasmic inclusions of alpha-synuclein in astrocytes for Multiple System Atrophy (MSA) (Gregor K Wenning, 2004), or the existence of tau-positive astrocytes in the mesencephalon and brain cortex (PSP). Therefore, careful observation and the chronological tracking of symptoms, along with the patient's response or lack to response to dopaminergic therapy, become crucial factors in the diagnostic process.