Parkinson’s disease, atypical and secondary parkinsonism

Parkinson’s disease is a progressive condition of the nervous system that affects movement. Parkinson’s disease occurs when nerve cells in the brain responsible for producing the neurotransmitter dopamine die off. The cause for this is not known, but two factors that may play a role in developing the disease include genetic mutations and exposure to environmental triggers like toxins. At present, researchers are focused on determining the role Lewy bodies (clumps of substances within brain cells) play in the development of the condition.

The symptoms usually develop gradually and often start with a slight tremor in one hand; other early signs include not swinging one’s arms when walking and not showing facial expressions. Over time, the symptoms will increase:

• More severe tremors in both hands
• A slowing of movement (bradykinesia)
• Dragging the feet
• Taking shorter steps when walking
• Posture and balance problems
• Decreased ability to perform automatic movements like blinking
• Impaired speech
• Difficulty in writing
• Muscle stiffness or rigidity

Other symptoms a patient may encounter with Parkinson’s disease include thinking difficulties, emotional changes, depression, problems sleeping, difficulty swallowing, bladder and bowel control, sexual dysfunction and sudden drops in blood pressure (orthostatic hypotension). Some of these symptoms can be managed.

Parkinsonism (also referred to as atypical or secondary parkinsonism or Parkinson-plus syndromes) occurs when a condition appears that copies a combination of the movement abnormalities seen in Parkinson's disease. Several causes or triggers for parkinsonism exist:

• Medications can trigger the condition, including from amphetamines, calcium channel blockers and drugs used to treat nausea and major psychiatric disorders like psychosis
• Repeated head trauma
• Multiple small strokes
• Some neurodegenerative disorders such as multiple system atrophy and progressive supranuclear palsy 
• Exposure to toxins like carbon monoxide, cyanide and organic solvents
• Some brain lesions or tumors
• Metabolic disorders such as chronic liver failure and hypoparathyroidism
• Lewy body dementia (the second most common form of dementia)

Not everyone who experiences parkinsonism has Parkinson’s disease.

Houston Methodist offers a comprehensive approach to treating patients with Parkinson's disease and other parkinsonism disorders.

Diagnosing Parkinson’s Disease 
No test exists to diagnose Parkinson’s disease, so our neurology team will obtain a medical history, review of signs and symptoms and perform a neurological and physical examination. Tests may be used to eliminate the possibility of other conditions causing symptoms; these tests may confirm the existence of a parkinsonism disorder.

Treating Parkinson’s Disease 
No cure exists for Parkinson’s disease, but medications, surgery and lifestyle changes can help to manage the symptoms. A range of medications exist to help manage Parkinson’s symptoms.

• The combination of carbidopa and levodopa is used to introduce more dopamine to the brain.
• Dopamine agonists (such as pramipexole) mimic the effects of dopamine in the brain.
• MAO-B inhibitors prevent the breakdown of brain dopamine.
• Catechol O-methyltransferase inhibitors prolong the effect of levodopa therapy.

As a surgical option, our team at Houston Methodist may recommend deep brain stimulation (DBS), a procedure in which our surgeons implant electrodes into the brain; the electrodes are connected to a generator implanted in the patient’s chest that sends electrical pulses to the brain. DBS has proven to be effective in reducing or stopping involuntary movements, reducing tremor and rigidity and improving slowing of movement; DBS has even provided the added benefit of stabilizing patients’ responses to erratic fluctuations of levodopa medication.

Lifestyle changes we may suggest include getting more rest and participating in a program of regular aerobic exercise. Physical therapy may also be  an option.

Treatments for movement disorders and their complications range from medical to surgical:

• Oral medication, such as Botox®
• Deep brain stimulation (details follow)
• Intrathecal administration of baclofen

Deep Brain Stimulation (DBS) 
At Houston Methodist, our teams use advanced treatment options for movement disorders that include robotic therapy and deep brain stimulation. They collaborate worldwide to research and develop new technologies and treatments. 

DBS is proven to reduce the incidence of stiffness, tremors and dyskinesia (involuntary movement disorders) in patients with movement disorders, such as Parkinson’s disease and essential tremor. In the case of Parkinson’s disease, DBS enables many patients to respond longer to medication by up to a decade. 

Recent advancements in DBS implantation include surgery guided by MRI (magnetic resonance imaging), which enables patients to undergo the procedure under general anesthesia and permits the treatment team to make real-time adjustments. In addition, our physicians are studying to determine whether DBS can help stop the propensity of Parkinson’s patients of falling and injuring themselves.

Learn more about our Functional and Movement Disorder Surgical Program.