By James S. Kennedy, MD, CCS
The CDC reports that stroke is the third leading cause of death in the United States. Since the integrity of ICD-9-CM and ICD-10-CM databases monitoring cerebral ischemia and its devastating consequences is essential, physicians will need to documentg cerebrovascular diseases in ICD-9-CM and ICD-10-CM language to facilitate accurate reporting.
Definitions are key
To accomplish this goal, critical definitions must be addressed. These include the following:
- Transient ischemic attack (TIA). Most physicians I interview define TIA as sudden focal ischemic neurologic or retinal symptoms resolving within 24 hours. That’s so 1990s. In 2002, the TIA Working Group redefined TIA as “a brief episode of neurologic dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction.” A 2009 American Heart Association (AHA) and American Stroke Association (ASA) Consensus Statement eliminated the time requirement, noting that diffusion-weighted imaging (DWI) is at least 33% positive when ischemic symptoms lasted less than one hour and up to 50% for those lasting 12-24 hours.
- Stroke. Even though the 2009 AHA/ASA Consensus Statement emphasizes a tissue-based definition of stroke, DWI may be negative in the setting of stroke, especially in the brain stem. Consequently, an AHA/ASA consensus document published in May 2013 emphasizes that in addition to abnormal imaging, brain ischemic symptoms lasting more than 24 hours qualify as a stroke if other etiologies are excluded. This article is required reading for all physicians who care for patients with acute cerebral ischemia.
Therefore, when differentiating TIA from stroke, use the 24-hour rule to define stroke, not TIA. If imaging is positive for stroke even though symptoms resolve within 24 hours, document a stroke, not a TIA. Likewise, if stroke symptoms last more than 24 hours and the DWI is negative, the patient still had a stroke.
tPA use presents challenges
The ECASS-3 study supports the use of tissue plasminogen activator (tPA) for ischemic stroke if given with 4.5 hours of symptom onset.
The associated MS-DRG allows additional reimbursement for onsite tPA administration only when stroke, not TIA, is the principal diagnosis. Thus, if stroke symptoms last less than 24 hours and the DWI is negative after tPA administration, and if the term “TIA” is documented as the final diagnosis, hospitals would lose any additional MS-DRG reimbursement and expected length of stay afforded for onsite tPA administration with stroke. Fortunately, ICD-9-CM and ICD-10-CM allow the term aborted stroke to be coded as stroke. Therefore, if “aborted stroke” is documented as the final diagnosis when tPA is administered for stroke symptoms, facilities are allotted this additional reimbursement when administering this expensive but helpful intervention.
Note underlying causes of stroke or TIA
Strokes may be ischemic or hemorrhagic, whereas TIAs are always ischemic. Ischemic strokes and TIAs are classified in ICD-10-CM according to the involved vessel, such as the carotid, vertebral, basilar, or specified (anterior, middle, or posterior) cerebral arteries and whether they are due to embolism or thrombosis. Many physicians do not document these parts of the anatomy and underlying causes, such as in the setting of atrial fibrillation, or the presence of a prosthetic valve with inadequate anticoagulation, where cerebral embolism is often the culprit.
Don’t forget that berry aneurysms often cause subarachnoid hemorrhages, or that accelerated hypertension or cerebral arteriovenous malformations can lead to cerebral hemorrhage.
While ICD-10-CM includes codes for cerebral hemorrhage locations (e.g., cerebellar, intraventricular, deep cortical), these locations must be explicitly documented in provider assessments because coders may not capture these from inpatient radiology reports.
Capture stroke consequences, even if transient
I can assure you from personal family experience that strokes are devastating. However, unless their consequences are documented by providers and coded, ICD-9-CM and ICD-10-CM databases cannot reflect these tragedies.
Underdocumented conditions include the following:
- Monoparesis or hemiparesis. Many physicians only document “weakness,” which does not influence severity or risk adjustment. Note whether it impacts the dominant or nondominant side; ICD-10-CM will presume the right side to be dominant unless stated otherwise.
- Apraxia, dysphagia, facial weakness, and ataxias as stroke sequelae. These symptoms must be explicitly documented, even if they are transient.
- Speech and language. Note any aphasias, dyphasias, fluency disorders (e.g., stuttering), or dysarthrias, specifying if they are due to the stroke.
- Cognitive disorders. For some strange reason, the term multi-infarct dementia is not coded as a stroke consequence unless explicitly documented as “dementia as a sequela of (multiple) stroke(s).”
- Seizures. While acute stroke does not often cause seizures, new onset seizures later in life are not due to old strokes unless diagnosed and documented as such.
- Cerebral edema or herniation. These conditions are usually due to large mass effects often seen in anterior circulation strokes or cerebral hemorrhages. Even in the setting of “mid-line shifts” on CT or MRI scans or progressive neurological decline, coders may not code any underlying cerebral edema or subfalcine (or other) herniations unless explicitly diagnosed and documented.
- Terminal events of stroke. Many physicians attribute stroke as a cause of death, but do not describe its terminal events such as Cheyne-Stokes respirations, coma, or acute respiratory failure requiring ventilator treatment, that are “mechanisms of death.” Unless documented in the discharge summary, coded databases cannot differentiate the risk of mortality of inpatients who survived or died in the setting of stroke.
The ICD-10-CM Table of Diseases organizes cerebrovascular disease codes as follows:
· I60-I62: Non-traumatic intracranial hemorrhage (i.e., spontaneous subarachnoid, intracerebral, or subdural hemorrhages)
- I63: Cerebral infarctions (i.e., due to a vessel thrombosis or embolus)
- I65-I66: Occlusion and stenosis of cerebral or precerebral vessels without infarction
- I67-I68: Other cerebrovascular diseases
- I69: Sequelae of cerebrovascular disease (late effect)
Codes I60-I62 specify the location or source of a hemorrhage as well as its laterality. For example, ICD-10-CM code I60.11 denotes nontraumatic subarachnoid hemorrhage from right middle cerebral artery.
ICD-10-CM code category I63 specifies the following:
- Cause of the ischemic stroke (e.g., thrombosis, ¬embolus, or unspecified)
- Specific location and laterality of the occlusion (i.e., specific artery)
To report sequela of a stroke, coders will use category I69- (sequelae of cerebrovascular disease). The sequela include conditions specified as such or as residuals which may occur at any time after the onset of the causal condition. These codes are divided into the following main subcategories:
- I69.1-, sequelae of nontraumatic intracerebral hemorrhage
- I69.2-, sequelae of other nontraumatic intracranial hemorrhage
- I69.3, sequelae of cerebral infarction
- I69.8-, sequelae of other cerebrovascular diseases
- 69.9-, sequelae of unspecified cerebrovascular diseases
The code categories are further divided to show the specific sequela, such as apraxia following cerebral infarction (I69.390) and ataxia following nontraumatic intracerebral hemorrhage (I69.193).
Category I69- specifically excludes the following:
- Personal history of cerebral infarction without residual deficit (Z86.73)
- Personal history of prolonged reversible ischemic neurologic deficit (PRIND) (Z86.73)
- Personal history of reversible ischemic neurologcial deficit (RIND) (Z86.73)
- Sequela of traumatic intracranial injury (S06.-)
- TIA (G45.9)
Editor’s note: Dr. Kennedy is a general internist and certified coder, specializing in clinical effectiveness, medical informatics, and clinical documentation and coding improvement strategies. Contact him at 615-479-7021 or at jkennedy@cdimd.com. Advice given is general. Readers should consult professional counsel for specific legal, ethical, clinical, or coding questions.