Parkinson’s Disease and ICD-10-CM

highlighting the importance of correct medical coding for parkinson’s disease in a book

The prevalence of Parkinson’s Disease or PD, which is a progressive brain disorder, continues to be significant in the adult population. Although the signs and symptoms of PD can vary across patients, there are several that are common to recognize, such as tremors or shaking of the hand or head. The clinical signs and symptoms gradually increase over time, along with a variety of other manifestations. These manifestations can also enhance over time requiring ongoing medical attention. Clinical documentation is always important for each medical encounter, especially to capture the associated manifestations of PD, as those help to tell the full and true patient story. ICD-10-CM coding should always follow the Official Guidelines for Coding and Reporting to ensure accuracy and compliance.

Dr. James Parkinson was the first person to systematically describe six individuals with symptoms of the disease “shaking palsy” (in 1817) that bears his name. (Birthdate: April 11th, now International Parkinson’s Awareness Day). Thus, April is the national Parkinson’s Disease (PD) awareness month.

Parkinson’s disease is a brain disorder that causes a gradual loss of muscle control. The symptoms of Parkinson’s tend to be mild at first and can sometimes be overlooked. Distinctive signs of the disease include tremors, stiffness, slowed body movements, and poor balance.

While Parkinson’s can be a very frightening diagnosis, life expectancy is about the same as for people without the disease in most cases. For some people, symptoms like lack of coordination evolve slowly over 20 years. Early treatment can provide years that are virtually symptom-free. About 5% to 10% of cases occur before age 50. Two advocates for research developed Parkinson’s early: boxer Muhammad Ali at age 42 and actor Michael J. Fox at age 30. The average age however that people get Parkinson’s is 62, and as a whole those individuals over 60 have only a 2% to 4% chance of getting the disease. Having a family member with PD slightly increases one’s risk. There is recent evidence that this disease does effect men and women a little differently. The risk of developing PD is twice as high in men than women, but women experience a more rapid disease progression and a lower survival rate.

With PD, patients can experience related dementia. According to the National Institute of Health, dementia is defined as the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities to such an extent that it interferes with a person’s daily life and activities.

Other associated PD manifestations can include:

  • Gait disturbance
  • Swallowing difficulties
  • Constipation
  • Hallucinations
  • Sleep disturbances

Medication and treatment for PD might include the following:

  • Levodopa
  • Carbidopa
  • Safinamide (Xadago) – an add-on medicine
  • Dopamine agonists (delay movement symptoms of Parkinson’s): Apokyn, Mirapex, Parlodel, the skin patch Neupro, and Requip
  • Apokyn, an injectable
  • Surgical: Deep Brain Stimulation

As we know healthcare costs continue to rise and Parkinson direct and indirect costs, including treatment, social security payments and lost income from inability to work, is estimated to be nearly $25 billion per year in the United States alone. The Parkinson’s Association reports that medication costs for an individual person with PD average $2,500 a year, and therapeutic surgery can cost up to $100,000 dollars per patient.

Truly understanding the epidemiology of a disease, its manifestations, its stages, and treatment are important when reviewing the medical record for ICD-10-CM coding. The medical coding professional will need to interpret provider documentation and then understand and apply the coding guidelines as these are critical for proper code assignment and sequencing. Of note, is that the Official Guidelines for Coding and Reporting are part of HIPAA law and therefore MUST be followed.

One ICD-10-CM guideline that can impact the coding of PD related manifestations is #13 Etiology/manifestation convention (“code first”, “use additional code” and “in diseases classified elsewhere” notes). Part of this guideline states the following (read over the full content):

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first, if applicable, followed by the manifestation. Wherever such a combination exists, there is a “use additional code” note at the etiology code, and a “code first” note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

An example of the etiology/manifestation convention is dementia with Parkinson’s disease. In the Alphabetic Index, code G20 is listed first, followed by code F02.80 or F02.81- in brackets. Code G20 represents the underlying etiology, Parkinson’s disease, and must be sequenced first, whereas codes F02.80 and F02.81- represent the manifestation of dementia in diseases classified elsewhere, with or without behavioral disturbance.

“Code first” and “Use additional code” notes are also used as sequencing rules in the classification for certain codes that are not part of an etiology/ manifestation combination.

ICD-10-CM Chapter 6: Diseases of the Nervous System (G00-G99), is where in the tabular the Parkinson’s Disease code G20 is located.

Clinical documentation should reflect when “Dementia” is associated with Parkinson’s Disease. In addition, documentation should include when there is “behavioral disturbance” associated with PD or if “Paralysis agitans” is present. Coding professionals should identify if a drug or external agent(s) induced a “Secondary Parkinsonism”. A best practice is to have a query form for Parkinson’s Disease and to confirm and/or clarify associated manifestations.

Remember that in the hospital inpatient setting for “Additional or Secondary diagnosis” it is any condition that is documented by the physician (provider) and one of the following (only one) criteria below needs to be met to report the additional/secondary diagnosis:

Clinically evaluated, or

Diagnostically tested, or

Therapeutically treated, or

Causes an increased Length of Stay (LOS) or

Nursing care and/or monitoring

With Parkinson’s patients you may see “Repeated Falls” documented or “Risk of Falling”, so these would be coded in addition. Notice the R29.6 code for “Repeated Falls” versus the “History of Falling” code Z91.81. There is some other important guidance in AHA Coding Clinic 2016, page 6 that should be reviewed carefully.

Here is a patient example that you may encounter which indicates several PD related manifestations:

An 82-year-old male has known Parkinson’s disease for 12 years now with hand tremors. He has Parkinson’s constipation (treated with stool softener and diet) and gait disturbance which results in him being unsteady. Currently he is using a Parkinson’s walker to ambulate as he has fallen a few times over the past 2 years and is at risk for falling. His mental status indicates PD related dementia with his family handling his finances currently.

Upon further evaluation and assessment, it was noticed that the patient also had some speech and swallowing difficulties due to PD, thus a Speech evaluation was ordered, and the patient was advised to cut his food into small pieces before eating. He may need to move to more fluid diet in the future.

Impression: Parkinson’s stage 3, unsteady gait, Parkinson’s constipation, dementia related to Parkinson’s, dysphagia due to progressing PD, and risk of falling.

For ICD-10-CM coding of “Systemic Diseases”, such as, diabetes mellitus, hypertension, and Parkinson’s disease) these are always coded, even in the absence of documented active intervention since these types of conditions meet one or more of the elements of the definition given above, see that (AHA Coding Clinic, Second Quarter, 1990, page 14 for full details.

As you can tell from the above information PD is a significant clinical condition that can have many manifestations for which the ICD-10-CM coding is important to capture accurately and fully. Ongoing medical research needs the clinical data, so improved treatments can be developed and ultimately a cure can be found.

References: WebMD;;   National Institute of Health; ICD-10-CM Official Guidelines for Coding and Reporting;;; Silvia Cerri et al, Parkinson’s Disease in Women and Men: What’s the Difference?, Journal of Parkinson’s Disease (2019). DOI: 10.3233/JPD-191683

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