This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
A 60-year old female presented with decreased movements for the last 2 years with rigidity and veical large square wave jerks. The most likely diagnosis is: 
Select and explain. 
A. Parkinson's disease, B. Lewy body dementia, C. Multisystem atroph, D. Progressive supranuclear palsy
D: Progressive supranuclear palsy
Answer: D: Progressive supranuclear palsy 
Explanation: Ans. d. Progressive supranuclear palsy The most likely diagnosis in a 60-year old female presenting with decreased movements for the last 2 years with rigidity and veical large square wave jerks is progressive supranuclear palsy. "Progressive supranuclear palsy should be considered whenever a middle aged or elderly person person presents with history of repeated falls and has an extrapyramidal syndrome accompanied by nuchal dystonia and paralysis of voluntary down gaze." Parkinson's disease A degenerative disorder caused by degeneration of substantia nigra (pars compacta), and idiopathic in etiology. Clinical feature: Tremors, rigidity and bradykinesia. Lewy body dementia Progressive cognitive decline and dementia are essential for diagnosis Other features: fluctuating cognition, recurrent well formed detailed visual hallucinations, spontaneous features of Parkinsonism Multisystem atrophy Characterized by: Autonomic failure involving urinary incontinence or an ohostatic decrease of blood pressure within 3 min of standing by at least 3o mm Hg systolic or 15 mm Hg diastolic, Poorly levodopa responsive parkinsonism Cerebellar syndrome (gait ataxia with cerebellar dysahria, limb ataxia or cerebellar oculomotor dysfunction) Progressive supranuclear palsy Marked impairment of voluntary downward gaze and horizontal gaze.Q Extended rather than flexed dystonic posturingQ Absence of tremorQ Poor response to antiparkinsonian medicationQ Supranuclear Gaze Palsy (Steel-Richardson syndrome) A degenerative disorder where in there occurs loss of neurons in midbrain, pons, basal ganglion and cerebellum "Progressive supranuclear palsy should be considered whenever a middle aged or elderly person person presents with history of repeated falls and has an extrapyramidal syndrome accompanied by nuchal dystonia and paralysis of voluntary down gaze Factors which distinguish this from Parkinson's Marked impairment of voluntary downward gaze and horizontal gaze.Q Extended rather than flexed dystonic posturingQ Absence of tremorQ Poor response to antiparkinsonian medicationQ