PSP presents gradually and is insidious. The age of presentation is usually between 55-70 years. Typical symptoms may include the following key features

• The early symptoms of PSP may be dysphagia and dysarthria.
• Progressive difficulty with walking (gait) and balance resulting in frequent falls. Postural instability is a key feature of the disorder. Patients often have slow unsteady gait. The bradykinesia is usually symmetrical and the rigidity is axial. Both these symptoms fail to respond to levodopa. Motor exam will reveal difficulty that often involves the axial rather than limb muscles. In the axial musculature, the neck muscles are more affected than trunk muscles. Motor symptoms are slow and upper body appears stiff and rigid. Rigidity with abnormal posturing of the neck (retrocollis).
• Visual symptoms are obvious and characteristic for PSP. There is progressive loss of voluntary control of eye movements. Earlier findings are slowing of vertical saccades, blepharospasm, vertical gaze palsy, difficulty with eye-opening and closing, reduced blinking, constantly raised eyebrows facial expression and a fixed stare. The gaze abnormalities can make it difficult to have eye contact and scan or read a page. Other ocular symptoms that also tend to occur in the early phase include blurred vision, diplopia, light sensitivity and burning eyes.
• Difficulty eating because of inability to look down at food.
• Conversations are impossible because of delay in responses and pronunciations.
• Eventually patients are unable to swallow and even eating, motions become uncoordinated.
• Aspiration pneumonia is common due to difficulty swallowing, coughing and drooling.
• Cognitive and behaviour problems due to frontal lobe involvement. There is progressive decline in concentration, concrete thinking, difficulty planning, impaired reasoning and shifting to another task.
• Behaviours changes include lack of motivation, apathy, withdrawal, perseveration and impulsivity. Depression is common.
• Unlike Parkinson disease, patients with PSP can experience falls early in disease. This is due to stiff upper body posture and tendency to fall backwards.
• Dysarthria (slow or slurred speech) is an early feature and may be mixed with a combination of hypokinetic, spastic and ataxic features. Pyramidal signs occur in about 30% of patients
• Because of the development of frontal lobe dysfunction, the occasional individual with PSP may suddenly jump on his or her feet from a sitting position without thinking only to fall backwards because of postural instability. This is known as the “rocket sign”.[8]

Differential diagnosis of PSP:

• Alzheimer's disease
• Corticobasal degeneration
• Multiple system atrophy
• Parkinson's disease
• Pick's disease
• Postencephalitic parkinsonism

Differentiating PSP from Parkinson disease

• Sometimes it can be very difficult to differentiate PSP from Parkinson disease during the early stages of the disease. Some PSP patients may not develop postural instability and ophthalmoplegia early in the course of the disease.
• In general, features of PD are asymmetric whereas this is not so with PSP. In addition, treatment with L-dopa will only have a limited response in patients with PSP.
• Dysphagia occurs much early in PSP whereas in PD it is usually seen in advanced cases and is delayed.
• The progression of PSP is much faster clinically
• PD patients generally do not have dementia, which is a common feature of PSP

If PSP is suspected the following investigations are necessary:

• Electro oculographic recordings may be useful in differentiating PSP from other related disorders. Individuals with PSP have horizontal hypometric voluntary saccades while individuals with corticobasal degeneration have the opposite findings. Parkinsonian patients tend to have saccades of normal amplitude and latency.
• MRI will show thinning of the quadrigeminal plate and atrophy of the midbrain and area around the 3rd ventricle, supporting a diagnosis of PSP.
• MRI can also help exclude other disorders such as hydrocephalus, multi infarct dementia, and tumors.
• Other research tools used to support early diagnosis of PSP include polysommnography, evoked potentials and PET scan.

Diagnostic criteria
Criteria have been established to help improve diagnostic accuracy of PSP and include the following [9]:

• Age onset at age 40 or later
• Gradual progression
• Vertical supranuclear palsy and slowing of vertical saccades
• Prominent postural instability with falls in the first year

Supportive features to help diagnosis include:

• Symmetric akinesia or rigidity
• Proximal muscle involvement more than distal
• Retrocollis
• Poor or absent response to levodopa therapy
• Early dysarthria or dysphagia
• Early cognitive impairment including at least 2 of the following features: impaired abstract thought, apathy, decreased verbal fluency, frontal release signs and imitation behaviour.

A Neurologist consultation is vital when evaluating a patient with PSP. The disorder is not easy to diagnose and can often be mistaken for Parkinson disease. The history should be obtained from the family or primary caregiver as it may reveal changes in behavior, daily functional activity and mobility.
So far there is no effective treatment of PSP [10].  All treatments are supportive. Even though dopaminergic agents have been tried, they only work in mild cases and the symptom relief is short-lived. Only a few patients see benefit from these agents. Even though there is significant loss of cholinergic neurons in the brain of PSP patients, administration of cholinergic agents like physostigmine has not been helpful.
Other anecdotal reports indicate slight improvement after treatment with methysergide, trazodone, amitriptyline and idazoxan. However, the benefits are often short-lived and inconsistent.
Botulinum toxin has been used to treat levator inhibition and blepharospasm but the success rates are low. To prevent exposure keratopathy, artificial tears are recommended. In patients who have depression, have emotional apathy or pseudo bulbar crying episodes, antidepressants may help.
Supportive therapies include use of ambulatory devices like a wheelchair, communication aids and walker. Refer to occupation and physical therapies to help with posture and daily living activities. Speech therapist may help some patients with difficulty in swallowing.

PSP is progressive disorder without a cure. Eventually all patients become wheelchair bound and many require a feeding tube. The median survival time from symptom onset is about 5 years. Individuals who fall during the first year, have early dysphagia and incontinence with negative prognostic signs. In most cases aspiration pneumonia leads to death. The quality of life is very poor and the disorder can create stress in the family or caregiver.

The cause of PSP is not known and it is thought to be a sporadic disorder. Very few familial cases have been reported but the mode of inheritance is not well understood. It is believed that the disorder has an autosomal dominant inheritance with reduced penetrance [5].
The role of viruses and toxins as a cause is pure speculative since there is no study that has even shown such a link. Currently there are studies indicating that perhaps genes leading to formation of neurofibrillary tangles may play an important role [6][7].

PSP tends to occur after the 5th decade of life. Based on small series, the annual incidence of PSP is about 2- 5.3 new cases per 100,000 people every year. It is believed that these numbers are underestimated because many healthcare workers either have not heard about the disorder or fail to make the diagnosis. It is more likely that most of the patients are not diagnosed from the disorder and probably die from an unrelated disorder that is present at the same time. Review of the UK Parkinson Disease Society Brain Bank revealed that nearly 6% of patients diagnosed with Parkinson disease were found to have PSP at autopsy. The incidence of PSP is known to increase with age and overall the disorder affects more males than females.

Unlike Alzheimer dementia, PSP is not associated with amyloid plaques in the brain but is associated with abnormal accumulation of tau protein. Some experts have classified PSP as a Pick complex disorder. The major neurotransmitter subsystems involved in PSP are the GABAergic, dopaminergic nigrostriatal pathway, and cholinoceptive striatal neurons including the cholinergic brainstem and basal forebrain nuclei.

At autopsy the chief macroscopic abnormality seen in the brain is the significant loss of pigment in the substantia nigra and locus coerulus which are often shrunken and discolored. There is also significant degeneration of cholinergic nucleic and loss of choline acetyltransferase activity in many parts of the brain.

Degeneration may be seen in the subthalamus, substantia nigra and pallidum. There is also widespread distribution of neurofibrillary tangles in the hippocampus, subthalamus, putamen caudate, frontal cortex, red nucleus, dentate and inferior olive regions. The National Institute of Neurological Disorders and Stroke (NINDS) criteria for PSP requires high density of neurofibrillary tangles and neuropil threads in at least three of the following anatomical sites: subthalamic nuclei, pallidum, pons or substantia nigra or pons, mild to moderate density in at least three of the following sites: medulla, striatum, dentate nucleus and oculomotor complex.

Because the cause of PSP is not known prevention is not possible. However, it is important that healthcare providers understand the clinical presentation of PSP so that an early diagnosis can be made. The  disorder is very disabling and of enormous stress to the caregiver, so an early diagnosis can mean prompt referral to physical, as well as speech and occupational therapy [11].

Progressive supranuclear palsy (PSP) also known as the Steel Richardson Olzewski syndrome is a neurodegenerative disorder very similar to Parkinson disease. The disorder occurs after the 5th decade of life and is progressive. Since the description of the disorder nearly 50 years ago, many small series have reported on the disorder. It is under-diagnosed not only by general physicians but also by neurologists. The cause of PSP is not known. Exposure to toxins and viruses has been proposed in the etiology of PSP without any concrete evidence. The features of PSP resemble those of Parkinson's disease and the two diseases are often confused. Despite certain common features with Parkinson's disease, PSP is a much aggressive disorder with many neuropsychiatric and motor abnormalities that it often leads to rapid decline and eventually to death.[1][2][3][4]

Progressive supranuclear palsy (PSP), also known as Steele Richardson Olzewski syndrome, is a degenerative motor disorder very similar to Parkinson disease.
Initially most patients have difficulty with visual difficulties, walking and balance but as the disorder advances, cognitive and behaviour changes may also develop. Late in the course of PSP, walking and eye movements become very difficult . The cognitive impairment progresses to full blown dementia
Use of ambulatory aids may help during the early phase of the disease but the risk of fall is always present. Because of difficulty with chewing and swallowing, most patients can only take in liquid or pureed foods. Physical and occupational therapy may help with mobility in the early stages. When swallowing difficulty is severe, patients should have a feeding tube placed in the stomach. The risk of aspiration is always present.
As family members and caregivers of patients with PSP may develop feelings of anger, frustration and guilt, it is important for them to seek support for these difficulties.

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