Coding corner: proper documentation of hemiparesis and weakness

Coding hemiparesis can be a challenge when the documentation surrounding the diagnosis is too vague. For example, documentation may only note weakness, which doesn’t map to hemiparesis in ICD-9-CM coding terms. The documentation should be descriptive to indicate left-sided or right-sided weakness.

Symptom versus condition
Generalized weakness is a symptom that maps to the ICD-9 CM code 780.79. Hemiparesis is a condition that maps to ICD-9 CM code 342.9X. A physician’s documentation to describe the patient’s diagnoses may not link with the language in the ICD-9 CM alpha and tabular index. If applicable, the documentation should link weakness with hemiparesis; otherwise, the description may only map to a generalized weakness ICD-9-CM code. Hemiparesis is a chronic condition, according to the Centers for Medicare & Medicaid Services, whereas generalized weakness is not.

Types of weakness
It’s important to document the specific type of weakness, which may be all over the body or only in one area. Here are the codes for weakness:

• Generalized weakness: 780.79
• Muscle weakness (generalized): 728.87
• Weakness due to cerebrovascular hemiparesis. Two codes needed: 438.89 (other late effects of a cerebral vascular accident) and: 728.87 (muscle weakness)

Hemiparesis and hemiplegia
Both hemiplegia and hemiparesis (code 342.XX) refer to paralysis of one side of the body. The fourth-digit subcategory conveys the type of hemiplegia. The fifth-digit subclassification conveys whether the side affected is dominant, non-dominant or unspecified. Here are the codes for hemiparesis:

• Hemiparesis, affecting unspecified side: 342.90
• Hemiparesis, affecting dominant side: 342.91
• Hemiparesis, affecting nondominant: side 342.92

Late effects of cerebrovascular hemiparesis
Late effects of cerebrovascular disease, hemiparesis and hemiplegia (code 438.2X) may occur at any time after the onset of the causal condition. The fifth-digit subclassification conveys whether the side affected is dominant, non-dominant or unspecified. Here are the codes for late effects of CVA-hemiparesis:

• Hemiparesis due to CVA-affecting unspecified side: 438.20
• Hemiparesis due to CVA-affecting dominant side: 438.21
• Hemiparesis due to CVA-affecting non-dominant side: 438.22

For example, a physician’s documentation may note “weakness due to CVA,” which maps to ICD-9-CM codes 438.89 (other late effects of cerebrovascular disease) and 728.87 (general muscle weakness), identifying the late effects of the CVA.

Physicians should be specific when documenting whether the patient’s weakness is current or related to conditions, such as a late effect of a previous stroke. Weakness is a vague term, while hemiparesis is specific to diminished function. A physician’s documentation determines the accuracy of the ICD-9-CM code selection for weakness versus hemparesis.

Additionally, specific documentation may result in better outcomes of care, as well as continuity of patient care between providers and the health care plan.

None of the information included in this article is intended to be legal advice and, as such, it remains the provider’s responsibility to ensure that all coding and documentation are done in accordance with applicable state and federal laws and regulations.