By Heba Bensaad
Progressive supranuclear palsy (PSA) is an uncommon neurological disorder that is often characterized by gaze dysfunction and decreased cognition. It often develops after the 6th- 7th decade of life and progresses to death within 10 years from the diagnosis. Multiple system atrophy (MSA) is another neurological disorder characterized by heart, movement, and bladder problems such as Transient Ischaemic Attack and partial or complete paralysis. Early and accurate diagnoses of PSP and MSA are of great importance as they can create a considerable difference in the diseases’ progression.
Imaging in these cases is often performed to eliminate other entities in a differential diagnosis such as Corticobasal degeneration. Increasingly advanced imaging techniques are now becoming widely available, with magnetic resonance imaging (MRI) and computerized tomography (CT) being the most significant. In this article, we will shed light on the significance of MRI in diagnosing patients with progressive supranuclear palsy and multiple system atrophy cases.
Progressive supranuclear palsy (PSA) is usually caused by a gradual deterioration of brain cells, mainly in the brain stem. The indicator of this disease is the accumulation of deposits of the protein tau in the nerve cells of the brain, leading to the death of the cell. When the patient undergoes an MRI, a “penguin looking sign” is often found - a major indicator of the disease.
Regarding multiple system atrophy disorder, patients are usually found to have had previous diseases, the most common being ataxia, which is caused by damage to the cerebellum (the part of the brain that is responsible for coordinating voluntary movement) and can also be caused by damage in the spine. Spasticity is another condition that patients could have previously had, which causes hyperactive reflexes.
The first case belongs to a 61 year old patient:
Complaints: Difficulty in walking and slow, slurred speech
The patient suffered from “alien hand syndrome” in which he was unable to control his hand.
First approach: The usage of MRI.
Results indicated a midbrain atrophy, which is a major indicator of progressive supranuclear palsy disorder. Peripheral cerebrospinal fluid (CSF) spaces were enlarged due to atrophy.
Atrophy was also present in the brainstem, but results showed that the atrophy in the mesencephalon (also known as midbrain) was more prominent. The appearance of the brainstem due to atrophy was termed as “penguin sign”. Finally, bilateral cerebellar hemispheres results showed a slight atrophy.
Another test was carried out to further prove the diagnosis of progressive supranuclear palsy; the patient was asked to draw a cube and a clock. Results showed that the patient was unable to draw in the correct sequence, indicating a problem in the executive functions of the patient. It was observed that there was a significant problem in his cognitive processes related to orientation.
Case 2:
This case is very similar to the previous one; the patient is a 75 year old male with a history of gait instability with parkinsonian features (defining features of progressive supranuclear palsy and are the most severe out of all the other symptoms that a patient could possibly encounter). An MRI was carried out and the following results were shown:
The “penguin sign” and a significant atrophy of the mesencephalon were observed, leading to the diagnosis of the patient with progressive supranuclear palsy.
Case 3 belongs to a 70 year old female patient:
Complaint: Spasticity
Spasticity is a condition in which muscles stiffen, causing prevention of normal fluid movement.
Results: MRI results demonstrate a prominent “hot cross bun” sign, which is a clear indication of multiple system atrophy disorder.
In conclusion, it can be challenging for radiologists to differentiate PSP and MSA from other degenerative neurological disorders, mostly because Parkinson’s disease, MSA and PSP, are characterized by similar features. As a result, many of the same dysfunctions occur in those conditions which results in a difficulty of establishing them with certainty. However, with modern technology’s rapid development, it is likely that these imaging techniques will improve vastly in the next few years, giving out more precise results and, therefore, identifying patients with accurate diagnoses.
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