Misoprostol for Spinal Stenosis
Misoprostol for Spinal Stenosis
This single-group cross-sectional cohort study will enroll approximately 25 patients at the
 North Texas VA Health Care System (VANTHCS) who have previously received off-label
 prescriptions of misoprostol for lumbar spinal stenosis for any duration and who are willing
 to provide verbal and informed consent. Patients will answer a questionnaire regarding pain
 and functional improvement especially in reference to misoprostol treatment. Patients will
 also be selected to have their walking tolerance (claudication distance) measured in an
 outpatient clinic setting to determine the severity of their lumbar spinal stenosis symptoms
 after having received misoprostol.
Lumbar spinal stenosis (LSS) is clinically described as a neurogenic claudication that is
 associated with increased mechanical compression on the spinal nerve roots as well as
 potential compromise of the vascular supply of the spinal nerve roots. This compression
 typically leads to symptoms of lumbar pseudoclaudication, which include pain, paresthesias,
 and discomfort in the lower extremities, commonly exacerbated by walking. Broadly speaking,
 this compression can be the result of a degenerative narrowing of the spinal or nerve root
 canals. While spinal stenosis is typically considered idiopathic, causes can also include
 malignancy, injury, and chronic inflammation. It is often debilitating to patients and can
 lead to a wide variety of negative health outcomes (pre-operative lower levels of function,
 psychological distress, high self-reported disability scores and operative risks of surgical
 correction) related to attempted surgical correction of lumbar spinal stenosis. Spinal
 stenosis continues to be a leading indication for spine surgery in adults older than 65 years
 old. Furthermore, estimated total Medicare costs for surgeries treating lumbar spinal
 stenosis amounted to over $1.65 billion for 37,598 individual operations.

 Physiologically, the venous blood flow in the lumbar spinal region is disproportionately
 affected by pressure gradients generated secondary to normal movement and pathologic
 constriction. Studies have found that patients diagnosed with lumbar spinal stenosis with
 intermittent claudication, while walking on a treadmill, experienced larger amounts of
 vascular congestion which resolved with sitting. This was measured with a myeloscope in the
 intrathecal space.

 The current vascular pathologic mechanism of the symptomatic effects of lumbar spinal
 stenosis is thought to be a consequence of constriction leading to increasing vascular
 congestion and inflammation. Authors first described the effect of constriction on vascular
 flow through a post mortem study of a patient with chronic lumbar spinal stenosis at L4-L5.
 Most significantly, they found that venous supply proximal to constriction in fact showed
 reduced and collapsed veins with gross congestion proximal to the lesion. Further
 investigation found that venous congestion led to increased inflammatory markers in nerves
 with atrophy, Wallerian degeneration, and perineural fibrosis in more severe patients. Most
 importantly, these pathologic changes were associated with vascular changes in the absence of
 direct nerve root compression at these sites. This venous congestion is a potential target
 for therapy.

 There has been previous work done with medications that are PGE1 analogs such as limaprost
 and lipo-PGE1. PGE1 analogs hypothetically treat the above lumbar spinal stenosis pathology
 by improving blood flow to nerve roots through vasodilatory and antiplatelet aggregation
 effects. However, misoprostol (PGE1 analog) has not been thoroughly evaluated as a possible
 treatment for symptoms of lumbar spinal stenosis.
Inclusion Criteria:

 -  Adults aged 18 years or older.

 -  Previous diagnosis of lumbar spinal stenosis, mild-severe lumbar central canal
 stenosis identified by MRI or CT scan.

 -  Symptoms:

 -  Lower extremity symptoms consistent with neurogenic claudication.

 -  Pain, weakness &/or numbness triggered by standing or walking, and relieved by
 sitting.

 -  Must be able to read English and complete questionnaire.

 -  Was prescribed Misoprostol specifically for lumbar spinal stenosis.

 Exclusion Criteria:

 -  Cognitive impairment that renders the patient unable to give informed consent or
 provide accurate data

 -  Clinical co-morbidities that could interfere with the collection of data concerning
 pain and function

 -  Severe vascular, pulmonary, or coronary artery disease that limits ambulation
 including recent myocardial infarction (within 6 months)

 -  Spinal instability requiring surgical fusion

 -  Severe osteoporosis as defined by multiple compression fractures or a fracture at the
 same level as the stenosis

 -  Metastatic cancer

 -  Excessive alcohol consumption or evidence of non-prescribed or illegal drug use

 -  Pregnancy

 -  Concordant pain with internal rotation of the hip (or known hip joint pathology)

 -  Active local or systemic infection

 -  Previous lumbar spine surgery

 -  Prisoners

 -  Use of misoprostol for any other indication then lumbar spinal stenosis

 -  Rheumatological disorders such as rheumatoid arthritis, psoriatic arthritis, systemic
 lupus erythematosis.