ED Coding and Reimbursement Alert

ICD-10 Coding:

Use These Tips to Get Top Neurology Diagnoses Out of Your Head

Do you know how to code headache syndromes?

In an ED, there are going to be a number of different diagnoses for which patients will seek treatment. When a patient reports with a common neurological disorder, it’s up to the coder to accurately assign ICD-10 codes to paint a picture of the patient’s condition.

Some diagnoses are rare and exotic; others are kind of routine, if you know what to look for.

We’ve compiled a list of some of the most common diagnoses in neurology, and the basics of how to assign ICD-10 codes for each condition.

Headache Type Vital to Correct Code

Everyone knows what a headache is, but the type of headache is key for ICD-10 coding. If it’s a standard, run of the mill headache, you’ll choose from the following diagnosis codes:

  • R51.0 (Headache with orthostatic component, not elsewhere classified)
  • R51.9 (Headache, unspecified)

If, however, the headache is more specific, then so is the diagnosis coding. ‘

Migraine: For migraine patients, you’ll look to the G43.- (Migraine) code set. The set includes diagnoses for a multitude of migraines, including:

  • G43.0- (Migraine without aura)
  • G43.1- (Migraine with aura)
  • G43.4- (Hemiplegic migraine)
  • G43.5- (Persistent migraine aura without cerebral infarction)
  • G43.6- (Persistent migraine aura with cerebral infarction)
  • G43.7- (Chronic migraine without aura)
  • G43.B- (Ophthalmoplegic migraine)
  • G43.D- (Abdominal migraine)

You’ll need to go to the 6th character for most migraine diagnoses, as the 5th and 6th characters add detail to the diagnosis. These details include:

  • Intractable/not intractable
  • With/without aura
  • With/without status migrainosus

Other headache syndromes: Though they might be migraine-adjacent, headache syndromes other than migraine have their own ICD-10 code set, G44.- (Other headache syndromes). Housed within this coding family are diagnoses for different headache syndrome afflictions, such as:

  • G44.0- (Cluster headaches and other trigeminal autonomic cephalgias (TAC))
  • G44.1- (Vascular headache, not elsewhere classified)
  • G44.2- (Tension-type headache)
  • G44.3- (Post-traumatic headache)
  • G44.4- (Drug-induced headache, not elsewhere classified)
  • G44.5- (Complicated headache syndromes)

When a patient is suffering from a headache syndrome, coding is often as specific as for migraines. Some of these codes go only to the 5th character, but there are some that will require you to assign a 6-character ICD-10 code.

Laterality a Concern on Stroke Dx

When a patient presents with a stroke — or cerebral infarction (CI) — you’ll head to the I63.- (Cerebral infarction) code set.

The CI set contains diagnosis codes for several stroke types, including:

  • I63.0- (Cerebral infarction due to thrombosis of precerebral arteries)
  • I63.1- (Cerebral infarction due to embolism of precerebral arteries)
  • I63.2- (Cerebral infarction due to unspecified occlusion or stenosis of precerebral arteries)
  • I63.3- (Cerebral infarction due to thrombosis of cerebral arteries)
  • I63.4- (Cerebral infarction due to embolism of cerebral arteries)
  • I63.5- (Cerebral infarction due to unspecified occlusion or stenosis of cerebral arteries)
  • I63.6- (Cerebral infarction due to cerebral venous thrombosis, nonpyogenic)

You’ll use the 5th character of your stroke diagnosis to represent specifics such as stenosis or embolism. Stroke diagnoses nearly always go to the 6th character, which identifies laterality: right (1); left (2); bilateral (3); or unspecified (9).

Check Out These New Parkinson’s Codes

Prior to 2024, there was only a single code to represent Parkinson’s disease: G20 (Parkinson’s disease). ICD-10 2024 added a 4th character to G20, making it a parent code and spawning these diagnosis offspring:

  • G20.A (Parkinson’s disease without dyskinesia)
  • G20.A1 (Parkinson’s disease without dyskinesia, without mention of fluctuations)
  • G20.A2 (Parkinson’s disease without dyskinesia, with fluctuations)
  • G20.B (Parkinson’s disease with dyskinesia)
  • G20.B1 (Parkinson’s disease with dyskinesia, without mention of fluctuations)
  • G20.B2 (Parkinson’s disease with dyskinesia, with fluctuations)
  • G20.C (Parkinsonism, unspecified)

There are also separate codes for secondary Parkinsonism in the G21.- (Secondary parkinsonism) code set. With a couple of exceptions, these codes go to the 4th character for complete diagnosis coding. Find the secondary Parkinsonism ICD-10 codes in the G21.- set.

Disturbance Type Marks Dementia Dx

There are three distinct sets of dementia diagnoses: F01.- (Vascular dementia), F02.- (Dementia in other diseases classified elsewhere), and F03.- (Unspecified dementia). Each of these diagnoses contains a 4th character explaining the severity of the condition: mild, moderate, or severe.

From there, the dementia codes will extend out to the 5th or 6th character. The 5th or 6th character options will provide more specific details about the patient’s dementia, including with/without:

  • Behavioral disturbance
  • Psychotic disturbance
  • Mood disturbance
  • Anxiety
  • Agitation.