Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a rare, progressive, neurodegenerative disease presenting with early onset dementia, epilepsy, myoclonic seizures, and varied psychomotor deficits. With autosomal dominant inheritance, a point mutation in the SERPINI1 gene on chromosome 3 results in aberrant neuroserpin production. Neuroserpins are a family of serine protease inhibitors expressed by neurons throughout the CNS. Neuroserpins contribute to axonogenesis, synaptogenesis, synaptic plasticity, and control of emotional behavior.

We present the case of 20-year-old female with FENIB who presented with myoclonic status epilepticus and discuss how pathophysiology should guide management choices in patients with FENIB.

Patient presents with a history of FEN1B epilepsy, seizures, learning delays, and suspected dementia. Patient’s chief complaint of sustained right-sided tremors after experiencing seizure-like activity. Patient has been having monthly seizures, but usually returns to her baseline after a few hours. The seizure started out like her normal seizures with diffuse myoclonic jerking but continued to have sustained myoclonic jerking and/or tremors of mostly the right upper extremity. Furthermore, her seizure medication was recently modified with the addition of ethosuximide 250 mg BID. Upon admission, the patient was continued on Levetiracetam 2000 mg in the morning and 1500 mg at bedtime. Patient was also started on Lorazepam 1 mg TID to decrease her sustained myoclonic jerks and tremors. A deeper dive into the patients’ medical history reveals that she has SERPINI1 gene mutation and thus suffers from familial encephalopathy with neuroserpin inclusion bodies which unfortunately is a progressively neurodegenerative disease. Patients’ symptoms did appear to respond well to the scheduled Lorazepam and continued anti-epileptic medications. Ultimately, the patient went home with hospice due to her poor overall prognosis from her disease and difficulty with controlling her symptoms.

Patient was discharged with ethosuximide, levetiracetam, cenobamate, and lorazepam. As the disease progresses multiple antiepileptics are often needed and targeting multiple receptors throughout the seizure propagation pathway may best counteract the uninhibited NMDA receptor propagation. There is currently no cure for FENIB. However, continued research proving the relationship between neuroserpins, tPA, and seizure activity provides the opportunity for research into novel, life-prolonging treatments.

References and Resources

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2. Drislane, F.W. (2022). Convulsive status epilepticus in adults: Management. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. http://www.uptodate.com.
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