Progressive supranuclear palsy (PSP) is a late-onset neurodegenerative disease involving the gradual deterioration and death of specific volumes of the brain.

[1][2] The condition leads to symptoms including loss of balance, slowing of movement, difficulty moving the eyes, and cognitive impairment.

[1] The initial symptoms in two-thirds of cases are loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, and falls.

The most common behavioural symptoms in patients with PSP include apathy, a lack of inhibition, anxiety, and a profound state of unease or dissatisfaction.

This vertical gaze paresis will correct when the examiner passively rolls the patient's head up and down as part of a test for the oculocephalic reflex.

[citation needed] On close inspection, eye movements called "square-wave jerks" may be visible when the patient fixes gaze at distance.

Because the eyes have trouble coming together to focus at short distances, the patient may complain of diplopia (double vision) when reading.

A variant in the gene for tau protein called the H1 haplotype, located on chromosome 17 (rs1800547), has been linked to PSP.

[8] Nearly all people with PSP received a copy of that variant from each parent, but this is true of about two-thirds of the general population.

Especially, mitochondrial complex I inhibitors (such as acetogenins and quinolines contained in Annonaceae plants, as well as rotenoids) are implicated in PSP-like brain injuries.

The neurons display neurofibrillary tangles (NFTs), which are clumps of tau protein, a normal part of a brain cell's internal structural skeleton.

[15][16][17][18][19] The principal areas of the brain affected are the:[citation needed] Some consider PSP, corticobasal degeneration, and frontotemporal dementia (especially FTDP-17) to be variations of the same disease.

Both Parkinson's and PSP have an onset in late middle age and involve slowing and rigidity of movement.

PSP cases are often split into two subgroups, PSP-Richardson (the classic type) and PSP-Parkinsonism, where a short-term response to levodopa can be obtained.

[51] Evidence-based approaches to rehabilitation in PSP are lacking and, currently the majority of research on the subject consists of case reports involving only a small number of patients.

[50] The observations made from these case studies can be useful however, in helping to guide future research concerning the effectiveness of balance and gait training programs in the management of PSP.

[53] The use of an appropriate mobility aid helps to decrease the individual's risk of falls and makes them safer to ambulate independently in the community.

[54] Due to their balance problems and irregular movements, individuals need to spend time learning how to safely transfer in their homes and in the community.

In 1951, Chavany and others reported the clinical and pathologic features of a 50-year-old man with a rigid and akinetic form of parkinsonism with postural instability, neck dystonia, dysarthria, and staring gaze.

In the 2020 American musical comedy-drama television series, Zoey's Extraordinary Playlist, the title character's father (Mitch Clarke, played by Peter Gallagher) has PSP.