Atypical parkinsonisms or Parkinson Plus are degenerative diseases that show some motor symptoms similar to those found in Parkinson’s disease but, unlike Parkinson’s disease, show a poor or bad response to pharmacological treatments. In addition, this type of parkinsonisms usually add a series of symptoms or clinical course different from what we see in Parkinson’s disease.
In atypical parkinsonisms, there is an accumulation in the brain of a type of proteins that end up damaging the cellular function, thus giving rise to the symptoms. The proteins that are related to these diseases are the so-called Tau protein and alpha-synuclein, therefore, atypical Parkinsonisms are called “taupathies” or “alpha-synucleinopathies” depending on the proteins involved.
Compared to Parkinson’s disease, atypical parkinsonisms show a more rapid progression pattern, even though the age of onset may be similar to that of Parkinson’s disease.
They are minority diseases, generally poorly understood and often associated with misdiagnosis in the early stages. Some of the most common confusions are the misdiagnosis of:
- Parkinson’s disease
- Alzheimer’s disease
- Frontotemporal dementia
From the neuropsychological point of view, atypical parkinsonisms may show certain characteristic symptoms that help to elucidate the diagnosis. In any case, cognitive disorders, memory problems and behavioral changes are a characteristic symptom of atypical parkinsonisms.
What is progressive supranuclear palsy (PSP)?
PSP is the most common atypical parkinsonism. It has a prevalence of 6 cases per 100,000 inhabitants, although only 1 or 2 cases are correctly diagnosed. The average age of onset of symptoms is around 60 years of age, following a progressive course associated with a severe loss of independence after 3 years of evolution.
Some of the characteristic signs of PSP include supranuclear gaze palsy or difficulty in directing the gaze in the vertical plane, slowing of eye movements and postural and gait instability with multiple falls. Generally, patients also present with slowness of movement and symmetrical rigidity in both extremities. In some cases, abnormal neck postures, word articulation difficulties and swallowing problems appear. In all cases the response to pharmacological treatments used to treat Parkinson’s disease is poor or limited.
At the cognitive and behavioral level, patients usually show an early decline of higher mental functions, associating loss of motivation, difficulties in abstract reasoning and performance of stereotyped movements and behaviors.
There are different forms of presentation of PSP, the most common being the form known as Richardson’s syndrome.
What is corticobasal degeneration (CBD)?
CBD is a slowly progressive, adult-onset neurodegenerative process that typically presents with asymmetrical parkinsonism and cognitive dysfunction. The disease usually appears between the ages of 50 and 70 years, with a median survival time of 3 to 12 years. From the diagnostic point of view, CBD is complex, as there is usually a significant overlap with other pathologies such as PSP, Alzheimer’s disease or frontotemporal dementia.
Unlike other atypical parkinsonisms, one of the characteristic features of CBD is the markedly asymmetric presentation of the associated motor symptoms. These include upper limb rigidity, slowness of movement, postural instability, abnormal gait, tremor and abnormal postures that usually affect one part of the body more markedly than another.
From a cognitive point of view, CBD shares symptoms with Alzheimer’s disease, PSP and frontotemporal dementia. The progression of cognitive impairment to dementia follows a relatively rapid course in coexistence with mood and motivation disorders. A symptom that some patients with CBD present and that has sometimes been considered characteristic of this disease is the so-called “phantom limb syndrome” or having the sensation that a hand or arm has a life of its own and acts on its own.
As in PSP, there is no single form of BDD, with behavioral disturbances, dementia or language impairment being the central feature.
What is dementia with Lewy body disease (DLB)?
DLB is one of the most common forms of neurodegenerative dementia. After Alzheimer’s disease and vascular dementia, it is the third most common cause of dementia, affecting up to 1% of the population over 70 years of age.
From the point of view of the symptoms that guide the diagnosis of MCI, parkinsonism and cognitive disorders stand out as the central symptom. Fluctuations in alertness and cognitive status are characteristic of MCI, with the patient having “good or very good” moments and “bad or very bad” moments throughout the day. Impaired memory and reasoning is usually present from the early stages of the disease at the time of diagnosis. One of the most characteristic symptoms of this form of dementia is the recurrent presentation of complex visual hallucinations.
In some cases, where the diagnosis has been missed, some patients are treated with antipsychotic drugs to treat the visual hallucinations, which in the end produces a dramatic worsening of the patient’s condition, with poor response to neuroleptics being a characteristic sign of this disease.
What is multiple system atrophy (MSA)?
MSA is a progressive neurodegenerative disease characterized by a combination of symptoms affecting both the autonomic nervous system and movement. As in other atypical parkinsonisms, in MSA we observe decreased movement production, slowness, tremor and limb rigidity together with clumsy gait, tendency to fall and speech difficulties. Unlike other parkinsonisms, in MSA there are clear symptoms of autonomic nervous system involvement such as fainting or dizziness due to pressure changes and problems in sphincter control.
Clinically, MSA can present in the parkinsonian form (MSA-P) or in the cerebellar form (MSA-C). MSA-P has many symptoms analogous to Parkinson’s disease, but with the addition of the autonomic nervous system disturbances already described. In AMS-C the central symptoms are related to swallowing difficulties, tremulous voice and slurred speech together with balance and gait coordination problems or ataxia.
In some cases AMS is associated with other symptoms such as muscle twitching, Pisa syndrome or abnormal tilting of the body to one side, disproportionate or inappropriate laughing and crying responses, gasping or sighing and abnormal neck postures.
What treatments are available for atypical parkinsonisms?
The treatment of atypical parkinsonisms focuses on minimizing the impact of the set of symptoms that the patient experiences. As with other neurodegenerative diseases, there are currently no curative treatments available to stop or cure these diseases. In spite of this, there are several active clinical trials, through which the possible efficacy of certain drugs potentially modifying the course of these diseases is being tested.
So far, however, treatments are symptomatic and are aimed at improving gait and posture problems, speech and swallowing difficulties, behavioral disorders or dysautonomia symptoms.
Taking into account the complex constellation of symptoms associated with atypical parkinsonisms, we cannot say that there is a single treatment for these diseases but rather a set of therapeutic approaches. These range from the use of certain drugs, to physiotherapy, speech therapy, cognitive stimulation, psychotherapy and nursing resources.