While you may have never heard of the term “paralysis agitans,” chances are that you already know the disease. Paralysis agitans, which literally means “shaking palsy,” is another term for Parkinson’s disease.
When the disease was first discovered by Dr. James Parkinson in 1817, he described the condition as “the shaking palsy,” due to the presenting symptoms.
In the United States, about 50,000 to 60,000 people are diagnosed with this condition each year, according to the National Parkinson Foundation. Paralysis agitans is a movement disorder, which results from the dying of neurons in the substantia nigra, an area of the brain, that produce the neurotransmitter dopamine.
Without these neurons, the brain does not have the same supply of dopamine, which sends signals between the substantia nigra and another area of the brain, called the corpus striatum, to make smooth movements. As a result, patients have difficulty moving.
Paralysis agitans has four main motor symptoms: postural instability, bradykinesia, rigidity and tremors.
With postural instability, the patient has impaired balance, which affects walking. Complications of paralysis agitans include falls.
Bradykinesia is a slowness of movement. The patient can have difficulty either starting or continuing a movement.
The rigidity, or stiffness, can occur in the patient’s limbs and trunk.
The tremors of paralysis agitans can occur when the patient’s arm or leg is at rest, or when she is holding that limb out. They go away when the patient moves.
MedlinePlus noted that over time, a patient with paralysis agitans can also have the tremors in her feet, head, tongue or lips.
The progression of symptoms in paralysis agitans can take 20 or more years, though the National Institute of Neurological Disorders and Stroke noted that the disease may progress faster in certain patients. Using the Hoehn and Yahr scale, the progression of paralysis agitans can be broken up into five stages.
In the first stage, the patient has symptoms on only one side of her body.