Case Presentation: A 51-year-old female with a history of lumbar stenosis (status post-transforaminal epidural steroid injection), hypertension, and migraines presented with altered mental status and severe acute headache. The day before, she experienced unusual lower back pain and, after consuming shrimp scampi, developed abdominal pain, nausea, flaccidity in her upper extremities, dysarthria, and a severe headache. She denied vomiting or recent illness.In the emergency department, her vitals were: temperature 38.7°C, heart rate 117 bpm, blood pressure 100/60 mmHg, respiratory rate 18, and oxygen saturation 96%. Lab results showed potassium 3.4 mmol/L, creatinine 1.7 mg/dL, glucose 128 mg/dL, platelets 121 × 10^9/L, lactate 2.3 mmol/L, and procalcitonin 23 ng/mL. Imaging, including a CTA of the head and neck, and non-contrast CT, were unremarkable. A neurological exam revealed mild right-sided weakness and confusion. Differential diagnoses included stroke, meningoencephalitis, and CNS infections. She was empirically treated with ceftriaxone, ampicillin, acyclovir, dexamethasone, and IV fluids.The recent shellfish consumption and acute neurological symptoms led to a diagnosis of paralytic shellfish poisoning (PSP). Cerebrospinal fluid (CSF) analysis showed elevated glucose but normal protein levels and negative Gram stain. Blood cultures revealed Klebsiella pneumoniae. After antimicrobial sensitivities resulted, her treatment was de-escalated to oral cefuroxime 500 mg twice daily for 10 days. The patient’s symptoms improved by day one, and she was discharged and fully recovered on day four.
Discussion: Paralytic shellfish poisoning (PSP) is caused by saxitoxins, which block sodium channels, leading to muscle weakness, paralysis, and altered mental status. Initial gastrointestinal symptoms, such as nausea and abdominal pain, typically precede neurological manifestations. Severe cases may lead to respiratory paralysis and death if not recognized early. The clinical presentation can mimic stroke or CNS infections, complicating the diagnosis. A history of shellfish consumption and the rapid onset of symptoms are critical diagnostic clues, as assays for saxitoxins are not commonly available.This patient’s fever and elevated inflammatory markers were atypical for PSP. The Klebsiella bacteremia was likely secondary to gastrointestinal translocation due to diarrhea. Her clinical history and rapid neurological decline prompted the diagnosis of PSP. Treatment is primarily supportive, focusing on airway management and symptomatic relief. Early recognition and timely intervention led to a full recovery without complications in this case.
Conclusions: Paralytic shellfish poisoning, although rare, should be considered in patients presenting with acute neurological symptoms and a history of shellfish consumption. Early diagnosis is essential for successful management, with supportive care being the cornerstone of treatment. This case highlights the importance of considering PSP in the differential diagnosis of neurological emergencies when accompanied by relevant dietary history.