You've been diagnosed with Functional Neurological Disorder. The seizures come without warning, your leg drags when you walk, or your hand won't grip a pen. Speech slows to a crawl some days. A Massachusetts disability attorney recognizes that FND creates real disability even when brain scans otherwise look normal.
Social Security Disability Insurance (SSDI) benefits exist to help people whose conditions prevent sustained work. FND can qualify when properly documented, but these cases require careful medical evidence.
What Is Functional Neurological Disorder?
Functional Neurological Disorder (FND) affects how the nervous system sends and receives signals. The hardware looks fine on scans, but the software isn't running correctly. People with FND experience genuine neurological symptoms without the structural brain lesions that typically cause those problems.
Common symptoms include:
- Paralysis
- Seizures
- Tremors
- Gait problems
- Speech difficulties
Current research suggests that FND involves disrupted connectivity in brain networks that control movement, sensation, and attention. The symptoms are real manifestations of a nervous system processing information incorrectly. MRIs come back normal because the problem isn't visible tissue damage but functional disruption in how brain regions communicate.
Does FND Have Its Own Blue Book Listing?
The Social Security Blue Book doesn't include a listing specifically titled "Functional Neurological Disorder." However, claimants may still meet or equal Listing 12.07 for Somatic Symptom and Related Disorders, which describes symptoms such as pseudoseizures and pseudoneurological symptoms. It specifically lists conversion disorder as an example of a covered disorder.
FND claims may be evaluated under Section 11.00 (Neurological Disorders) when the focus is on disorganized motor function, speech, or other neurological findings. Alternatively, they may be evaluated under Listing 12.07 when the diagnosis is framed as conversion disorder or somatic symptom disorder, especially for psychogenic nonepileptic seizures.
Meeting Mental Health Listing 12.07
To meet Listing 12.07 with Functional Neurological Disorder, you must show:
- Symptoms of altered voluntary motor or sensory function, or one or more distressing somatic symptoms, or preoccupation with having a serious illness
- Extreme limitation of one, or marked limitation of two, of the four areas of mental functioning in paragraph B (understanding and remembering information, interacting with others, concentrating and persisting at tasks, or adapting and managing yourself)
Social Security's Disability Standard
To qualify for disability benefits, your FND must prevent you from working at substantial gainful activity (SGA) levels for at least 12 months, not just during short flares. Social Security only finds someone disabled if they're unable to engage in SGA because of a medically determinable impairment, and it must last (or be expected to last) at least 12 months or result in death.
How Can RFC Assessment Determine Disability for FND?
Many FND cases are decided through Residual Functional Capacity (RFC) assessments. RFC measures what you can still do despite your limitations. Social Security then determines whether any jobs exist matching your remaining capabilities.
RFC assessment considers both physical limitations and non-physical impacts.
Physical Limitations
When your legs give out unpredictably, you cannot maintain jobs requiring prolonged standing. If FND affects your hands, you're excluded from jobs requiring fine manipulation. Unpredictable seizures eliminate jobs near heights, moving machinery, or involving driving.
Non-Physical Limitations
Speech impairment eliminates customer-facing positions and telephone work. Cognitive symptoms like brain fog and memory problems limit your ability to maintain attention or complete tasks within standard timeframes. Frequent unscheduled breaks make sustained work impossible.
What Medical Evidence Strengthens an FND Claim?
Strong medical evidence makes the difference between approval and denial.
Diagnosis With Positive Clinical Signs
Your FND diagnosis must come from a neurologist or physician qualified to diagnose neurological conditions. Rather than just ruling out other diseases, modern FND practice emphasizes positive clinical signs, including Hoover's sign, tremor entrainment, and inconsistency that normalizes with distraction. These positive findings are what show Social Security that your condition is "medically determinable" even when imaging is normal.
Treatment Records Showing Persistence
Social Security needs to see that symptoms persist despite appropriate treatment, like physical therapy, occupational therapy, cognitive behavioral therapy, and medications. Your treatment records should document your participation in recommended treatment and the response over time, demonstrating that the condition's duration meets the 12-month requirement.
Documentation of Comorbid Conditions
FND commonly exists alongside anxiety, depression, trauma-related disorders, and other psychiatric conditions. Social Security considers the combined impact of all medically determinable impairments. The cumulative effect of multiple conditions often proves disabling even when no single condition alone meets a listing.
Functional Assessments From Treating Physicians
A Medical Source Statement from your treating neurologist should specify limitations in terms Social Security uses. You need specifics: "Patient experiences speech disruption lasting two to three hours approximately three times weekly. Patient's concentration deficits would prevent sustained focus on work tasks for the full workday."
How to Address Symptom Variability
Functional Neurological Disorder symptoms fluctuate. You might walk normally one day and use a wheelchair the next. This variability is a core feature of FND, and it creates documentation challenges.
Your medical records need to capture symptom patterns over time. Keep your own symptom diary, noting when symptoms occur, how long they last, and what activities they prevent. Share this information with your doctors so they can incorporate it into their clinical notes. When symptoms are absent during appointments, tell your doctor anyway. That information needs to be in your records to paint an accurate picture of how the condition affects you day to day.
