Brain Blood Flow Changes May Be Complication of LOPD
Case report links stroke-like symptoms to man's late-onset Pompe disease
A report describes the unusual case of a man with late-onset Pompe disease (LOPD) that manifested with abnormalities in blood flow in the brain causing stroke-like symptoms.
Abnormalities affecting blood vessels in the brain may be an under-recognized complication of LOPD, the researchers said.
The study, “Late-onset Pompe disease with a novel mutation and a rare phenotype: A case report,” was published in the journal CNS Neuroscience & Therapeutics.
A team of scientists in China described the case of a 39-year-old man who went to the hospital with complaints of dizziness and double vision that had lasted several days. The man had a history of high blood pressure and gout, and six years prior he had undergone treatment for kidney stones. He also remembered being easily fatigued as he was growing up.
Physical examination revealed several eye-related abnormalities, including nystagmus (rapid, uncontrolled eye movements) and limited abduction of both eyes (difficulty rotating the eyes outward).
He also had decreased strength in the muscles that are used to keep the head lifted, and laboratory evaluations revealed increased levels of muscle damage markers, including creatine kinase. Other assessments of muscle strength were mostly within normal ranges, but his ankle reflexes — tested by holding the relaxed foot with one hand and tapping the Achilles tendon with a reflex hammer — were absent.
Imaging of the man’s brain revealed evidence of an infarction, which is a failure of blood supply in the brain, specifically affecting the lowermost part of the brain called the brainstem.
Enzyme tests showed reduced activity of the GAA enzyme, whose deficit causes Pompe disease. Genetic testing revealed mutations in both copies of the GAA gene that provides instructions for making this enzyme.
Specifically, one copy of the GAA gene, inherited from his biological father, contained a mutation dubbed c.2238G>C, which is one of the most common Pompe-causing mutations in China. The other copy, inherited from the man’s mother, contained a mutation called c.2296T>C. This mutation has never been reported, but analyses suggested that it probably would have a detrimental effect on the GAA enzyme and be linked with a genetic risk of ischemic stroke (when a vessel supplying blood to the brain is obstructed).
Based on all of these findings the man was diagnosed with LOPD and brainstem infarction. He was started on a modified diet and given treatment with Lumizyme (alglucosidase alfa), as well as blood-thinning and fat-lowering medications.
“After 6 months of follow-up, he was free of visual double vision with normal eye movement in all directions,” the researchers reported.
The team noted that, although abnormalities in brain blood flow are not considered a typical symptom of LOPD, prior reports also have documented similar complications in patients, suggesting that changes in brain blood flow “may be an underrecognized complication” of LOPD.