G93.44
BillableAdult-onset leukodystrophy with axonal spheroids
HCC Category Mapping
V28HCC 200 — Cerebellar Ataxia and Other Degenerative Diseases of Nervous System
0.262What This Code Means
A rare adult-onset inherited brain disorder affecting white matter with characteristic spheroid structures in nerve fibers.
Coding Tips
- •This is a specific leukodystrophy with adult onset; document age of symptom onset
- •Pathological findings of axonal spheroids help confirm this diagnosis
Clinical Significance
Adult-onset leukodystrophy with axonal spheroids (ALSP, also known as hereditary diffuse leukoencephalopathy with spheroids) is a progressive neurodegenerative white matter disease caused by CSF1R gene mutations. It typically presents in the third to fifth decade with behavioral changes, cognitive decline, and motor dysfunction that may mimic frontotemporal dementia or multiple sclerosis. Accurate diagnosis is critical for genetic counseling and distinguishing from treatable conditions.
Documentation Requirements
- ✓Genetic testing confirming CSF1R gene mutation
- ✓MRI demonstrating progressive white matter changes with frontal predominance
- ✓Clinical documentation of adult onset with progressive cognitive, behavioral, or motor decline
- ✓Neuropathology findings if available (axonal spheroids on biopsy)
- ✓Family history assessment for autosomal dominant inheritance pattern
Commonly Confused Codes
G35 — Multiple sclerosis: relapsing-remitting course, different imaging pattern, no genetic basisG31.09 — Other frontotemporal dementia: may present similarly but lacks the white matter changes and genetic mutationG93.42 — Megalencephalic leukoencephalopathy with subcortical cysts: childhood onset, different genetic causeG90.B — LMNB1-related leukodystrophy: different gene (LMNB1 vs CSF1R), different clinical progression
Code Hierarchy
└G93Other disorders of brain└G93.4Other and unspecified encephalopathy└G93.44Adult-onset leukodystrophy with axonal spheroids
└G93.44Adult-onset leukodystrophy with axonal spheroids