September 7, 2025
Neurostorming (Paroxysmal Sympathetic Hyperactivity): Documentation and Coding Guidance
What Does “Neurostorming” Mean in Clinical Documentation?
- “Neuro storm” and other similar terms such as autonomic storms, hypothalamic dysregulation syndrome and sympathetic storms all equate to the condition paroxysmal sympathetic hyperactivity (PSH).
- This syndrome was formally named in 2014 by an international panel looking at preferred nomenclature, definition and diagnostic criteria.
- PSH is defined as a disorder in the regulation of autonomic function most observed in patients with acute brain injury, most notably severe traumatic brain injury.
Risk Factors Associated With Paroxysmal Sympathetic Hyperactivity
- Traumatic brain injury (TBI)
- Hypoxic ischemic injury
Clinical Indicators of Paroxysmal Sympathetic Hyperactivity
- Sinus tachycardia
- Elevated systolic blood pressure
- Tachypnea associated with respiratory alkalosis
- Diaphoresis that can progress to dehydration
- Hyperthermia in some cases
- Severe cases may have dystonic posturing
Treatment Approaches Documented for PSH
- Reducing stimulation
- Managing hyperthermia and hyperventilation
- Medications
- IV Morphine
- Gabapentin
- Beta blockers
- Baclofen
- Precedex infusion
- Dantrolene
Coding and CDI Considerations for Neurostorming Documentation
The ICD-10-CM condition code most appropriate for reporting of PSH is G90.89, Other disorders of autonomic nervous system. There is no specific code to identify neurostorm or PSH. There are also no instructional notes for the code G90.89.
Per the ICD10-CM Official Coding Guidelines, “ If a main term cannot be located, consider a synonym, an eponym, or another alternative term. Once the main term is located, search for subterms, notes, or cross-references. Subterms provide many types of more specific information and must be checked carefully, following all the rules of alphabetization. The main term code entry should not be assigned until all subterm possibilities have been exhausted. During this process, it may be necessary to refer again to the medical record to determine whether any additional information is available to permit assignment of a more specific code. If a subterm cannot be located, the nonessential modifiers following the main term should be reviewed to see whether the subterm may be included there. If not, alternative terms should be considered”
Current coding advice notes that when the index is confusing, leading to an inappropriate code, further research is needed when the title of the code suggested by the index clearly does not identify the condition correctly.
Regarding the CDI professional, it is allowable to report code G90.89, Other disorders of autonomic nervous system in the instance where “neurostorm” is documented by the provider. A query would not be needed for clarification.
Alyce Reavis, RN, MSN, CCDS, CCS
Senior CDI Educator, Consulting Services at UASI
Drawing on clinical experience in adult, pediatric, and neonatal acute care, Alyce brings valuable insight to CDI education and documentation improvement. She holds an MSN in Leadership/Education along with CCDS, CCS, and AHIMA’s outpatient CDI micro credential, supporting health systems in strengthening documentation accuracy, quality reporting, and reimbursement integrity. Passionate about truthful, clinically aligned health records, she helps organizations ensure documentation reflects true patient acuity. She is a past presenter for the ACDIS National Convention, Local chapter meetings, and the ACDIS Virtual Best Practices conference.
Works Cited
American Hospital Association. (2025). Paroxysmal sympathetic hyperactivity (neurostorming). Coding Clinic for ICD-10-CM/PCS, Second Quarter, 4.
Centers for Medicare & Medicaid Services. (2025). ICD-10-CM Official Guidelines for Coding and Reporting.
Available at
https://www.cms.gov/medicare/coding/icd10
Rabinstein, A. (2024). Paroxysmal sympathetic hyperactivity. UpToDate.
Available at
https://www.uptodate.com/contents/paroxysmal-sympathetic-hyperactivity
