(See also Overview of Movement and Cerebellar Disorders.)
The cause of progressive supranuclear palsy is unknown.
Neurons in the basal ganglia and brain stem degenerate; neurofibrillary tangles containing an abnormally phosphorylated tau protein are also present.
Symptoms and Signs of PSP
Symptoms of progressive supranuclear palsy usually begin in late middle age.
The first symptom may be
Voluntary eye movements, particularly vertical, are difficult, but reflexive eye movements are unaffected.
Movements are slowed, muscles become rigid, and axial dystonia develops. Patients tend to fall backward.
Dysphagia, dysarthria with emotional lability (pseudobulbar palsy), depression, and disordered sleep are common. Resting tremor may develop.
Dementia eventually occurs. Many patients become incapacitated within about 5 years and die within about 10 years.
Progressive supranuclear palsy (PSP) has several different clinical types based on the predominant symptoms or signs (1):
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Richardson syndrome: Classic progressive supranuclear palsy with progressive supranuclear ophthalmoplegia and severe balance problems (the most common form, in ≥ 70% of cases)
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PSP-P: Parkinsonian type of progressive supranuclear palsy, which responds to levodopa, resulting in transient, slight improvement
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PSP-PAFG: Characterized by pure akinesia with freezing of gait
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PSP-PGF: Characterized by progressive gait freezing
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PSP-PNFA (PSP-SL): Characterized by progressive nonfluent aphasia or speech or language disorders
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PSP-AOS: Characterized by apraxia of speech
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PSP-FTLD (PSP-F): Characterized by frontotemporal degeneration
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PSP-CBS: Characterized by corticobasal syndrome, causing profound asymmetric symptoms
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PSP-MN (PSP-PLS): Characterized by motoneuron symptoms related to primary lateral sclerosis
Other possible forms include
In forms other than Richardson syndrome (nonclassical forms [called atypical parkinsonism]), ophthalmoplegia may be delayed by years.
Diagnosis of PSP
Diagnosis of progressive supranuclear palsy is clinical.
MRI is usually done to exclude other disorders. In advanced cases, MRI shows a characteristic decrease in midbrain size that is best seen on midsagittal views and that causes the midbrain to be shaped like a hummingbird or emperor penguin. On axial views, the midbrain may resemble a morning glory (2).
Diagnosis references
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1.Höglinger GU, Respondek G, Stamelou M, et al: Clinical diagnosis of progressive supranuclear palsy: The Movement Disorder Society criteria. Mov Disord (32) 6,:853–864, 2017. doi: 10.1002/mds.26987. Epub 2017 May 3.
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2. Adachi M, Kawanami T, Ohshima H, et al: Morning glory sign: a particular MR finding in progressive supranuclear palsy. Magn Reson Med Sci 3 (3):125–132, 2004.
Treatment of PSP
Treatment of progressive supranuclear palsy focuses on relieving symptoms but is unsatisfactory. Occasionally, levodopa and/or amantadine partially relieve rigidity. Physical and occupational therapy may help improve mobility and function and reduce the risk of falls.
Because progressive supranuclear palsy is fatal, patients should be encouraged to prepare advance directives soon after the disorder is diagnosed. These directives should indicate what kind of medical care people want at the end of life.
Key Points about PSP
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The first symptom of classic progressive supranuclear palsy may be difficulty looking up or down without moving the neck or difficulty climbing up and down stairs.
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Diagnose based on symptoms, but do MRI to exclude other disorders.
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Focus on relieving symptoms; consider levodopa and/or amantadine to relieve rigidity, and prescribe physical and occupational therapy.
