Unexplained neurological symptoms may be indicative of hemophagocytic lymphohistiocytosis, even in the absence of typical HLH symptoms such as fever, a new case report highlights.
The report, “Neurological symptoms of familial hemophagocytic lymphohistiocytosis type 2,” was published in the Journal of Integrative Neuroscience.
HLH is a condition caused by abnormal activity of the body’s immune system. The symptoms typical of HLH include fever, enlarged spleen and liver (hepatosplenomegaly), and low blood cell counts, called cytopenia.
More rarely, HLH causes neurological symptoms, but these are often unspecific, such as dizziness, blurry vision, and mood disorders.
The new report details the case of a 14-year-old male. Five years earlier, a few months before the patient turned nine years old, he experienced dizziness and blurred vision, accompanied by irritable mood and worse performance in school. There was no clear cause for these symptoms, which resolved without treatment.
However, at age 10, the boy experienced weakness in the lower limbs, which gradually got worse. That led to difficulty walking, then to an inability to go up stairs or to stand from a squatting position.
Imaging of the brain with an MRI, and analysis of the fluid that surrounds the brain (cerebrospinal fluid), were broadly suggestive of inflammation damaging the nervous system. Based on those findings, the clinicians began considering a possible diagnosis of a viral infection causing inflammation.
The child was then given anti-viral medications and corticosteroids to decrease inflammation. Following that treatment, the patient “recovered to an almost normal state,” the researchers wrote. However, once the corticosteroids were stopped, after about three weeks of treatment, the symptoms returned.
Additional testing for viral infections came back negative, leading the clinicians to propose a diagnosis of bacteria-driven inflammation instead. Specifically, they named tuberculous meningitis, in which tuberculosis bacteria attack the membrane around the brain.
The patient was given anti-tuberculosis treatment, but his condition continued to decline. He was unable to walk and had progressing muscle twisting in the upper limbs, called dyskinesia. Other symptoms included blurry vision, nausea, vomiting, dizziness, and trouble speaking. Later on, the boy started experiencing seizures.
Further diagnostic tests continued to point to an inflammation-mediated disease. As such, the child was treated with corticosteroids and other anti-inflammation medications, which led to improvements in his symptoms. However, those symptoms got worse again after the treatment was stopped.
Ultimately, genetic testing revealed that the patient had mutations in both copies — one from each biological parent — of the gene PRF1. Mutations in this gene are the cause of familial HLH type 2. With that, the boy was diagnosed with HLH.
The child was started on a weekly course of anti-inflammatory medications, specifically methotrexate in addition to the corticosteroid dexamethasone. The team has plans to perform a hematopoietic stem cell transplant, which is a bone marrow transplant that replaces the stem cells that produce blood cells.
The researchers say this case report illustrates that HLH can present itself with neurological symptoms in the absence of typical symptoms of the immune system disease.
“The possibility of HLH needs to be considered in patients with unexplained central nervous system symptoms, even if the patient does not have typical HLH symptoms, such as fever, cytopenia, or hepatosplenomegaly,” the researchers wrote. “Early diagnosis and treatment are important to prevent irreversible [nervous system] injury and improve prognosis.”
We are sorry that this post was not useful for you!
Let us improve this post!
Tell us how we can improve this post?