A rare case of systemic mastocytosis (SM) manifesting as generalized seizures was recently published in Neurology.
SM manifestations are varied and can affect multiple organ systems. Neurological complications such as headaches, fatigue, vertigo and depression-like symptoms are relatively common, mostly due to histamineHistamine A chemical released by mast cells when they are activated. Histamine causes many of the allergy-type symptoms in mastocytosis, including flushing, itching and hives. release and mast cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. infiltration in the central nervous system (CNS).
Read more about SM signs and symptoms
However, seizures and alterations in consciousness are very rare. The case report’s authors said that to their knowledge, there had only been one recorded case report prior to the present one.
“The potential development of seizures and other neurological symptoms in systemic mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults. is theorized to be related to the release of vasoactive substances, including histamine, and to mast cell infiltration within the meninges,” the authors wrote.
The case involved a 77-year-old man with a known diagnosis of diabetes mellitus (DM), who presented to the neurology clinic due to recurrent episodes of loss of consciousness. The episodes began the year prior to his consultation, and occurred approximately three times per year. At the time, he was being treated with a JAK inhibitor to manage gastrointestinal symptoms that had been present since his diagnosis.
Brain wave analysis via electroencephalogram (EEG) revealed bitemporal slowing and left temporal sharp waves. This indicated slowed brain activity in both temporal lobes, along with abnormal electrical spikes on the left side — findings commonly associated with epilepsy.
Additionally, magnetic resonance imaging (MRI) of the brain revealed generalized atrophy and periventricular white matter hyperintensities. The brain atrophy suggested shrinkage of brain tissue, while the hyperintensities were indicative of small vessel disease in the brain.
Based on these results, the patient was started on levetiracetam (an anti-seizure medication). However, he experienced his first generalized seizure a few years later and was subsequently switched to brivaracetam. The patient has remained seizure-free since 2023.
“Our case highlights the importance of considering seizures in the differential diagnosis of paroxysmal spells in patients with systemic mastocytosis,” the authors wrote.
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