William L. Harrah, DO
Resident
University of Kansas Medical Center PM&R Program
Overland Park, Kansas, United States
Samantha Roque, n/a
Medical Student
Kansas City University
Kansas City, Missouri, United States
Namrata Raut, MD
Faculty Physician
University of Kansas Medical Center
Kansas City, Kansas, United States
HMGCR antibody-positive immune-mediated statin induced necrotizing myopathy.
Case Description:
50-year-old male with hyperlipidemia presented with dysphagia and proximal weakness in extremities. Work-up revealed positive anti-HMGCR, elevated creatine-kinase and liver enzymes. Biopsy confirmed necrotizing myopathy. He was initiated on corticosteroids, IVIG, and methotrexate, statin was discontinued. Rheumatology noted that extent of recovery would be unclear until 12 months post-treatment. At admission to rehabilitation patient was dependent assist x 2 and had impaired bowel/bladder control in addition to weakness and dysphagia. Urinary incontinence was managed with timed voids. Fecal incontinence and constipation were managed by titrating bowel regimen and timed toileting. Functional gains with therapies varied, though showed overall improvement. He achieved independence with ultralight manual wheelchair mobility, minimal assist with slideboard transfers, improved upper-body dressing, urinal use, self-feeding and grooming. He continued to require heavy assistance for shower/toilet transfers, tube feeds and bowel management, and donning/doffing footwear, but was able to direct care at discharge to a facility.
Discussions:
Statin-induced HMGCR antibody-positive immune-mediated necrotizing myopathy (IMNM) is uncommon among patients taking statins, occurring in about 2 to 3 cases per 100,000. While this case shares similar features in proximal weakness, and dysphagia, our patient additionally presented with bowel and bladder incontinence. Furthermore, this case highlights the unpredictable nature of functional recovery with IMNM despite stopping statin.
Conclusions:
The prognosis of HMGCR antibody-positive IMNM can be variable, with functional outcomes often remaining uncertain until after one year of treatment. This case stresses the important role of personalized plan of care in acute inpatient rehabilitation. Acute inpatient rehabilitation was crucial to facilitate ongoing autoimmune treatment and monitoring, supportive care for bowel, bladder, and dysphagia, as well as early/aggressive physical, occupational, and speech therapy. This allowed for improved functionality and patient education to best set up the patient for his long-term recovery.
