Authors: Yannis Hadjiyannis, MD; Kenichi Tamama, MD, PhD
Clinical History
A male patient - with a past medical history of attention-deficient hyperactive disorder, pica, and autism spectrum disorder (ASD) - presented for evaluation of chronic abdominal pain, vague seizure-like activity, and recent aggressive behavior. Physical examination was limited due to patient aggression and intolerance to physical touch. However, he was alert and oriented and without evident visual abnormalities. The patient has a remote history of two previous seizures several years ago in adolescence with associated postictal aggressive behavior. At the time, no evident provocation, such as illness or recent head trauma, was observed and several years passed between episodes without establishing an underlying etiology. Previous electroencephalogram and magnetic resonance imaging were unrevealing.
At present, laboratory evaluation was largely unremarkable: Organic acid urine profile and amino acid plasma profile were within expected limits. Ammonia was 34 µmol/L [reference range (RR): 11-35 µmol/L]. A comprehensive metabolic panel, complete blood count (CBC), and iron studies were within normal limits (Table 1). Free thyroxine was 1.17ng/dL [RR: 0.93 - 1.70 ng/dL], thyroid stimulating was 2.090 [RR: 0.700-5.700 ulU/mL], and phosphorus was 5.3 mg/dL [RR: 4.0-5.7 mg/dL]. Liver transaminases were unremarkable (Table 1). Total creatine phosphokinase was slightly elevated at 171 IU/L [RR: 30-150 IU/L].
Notably, zinc protoporphyrin testing was elevated at 102 mcg/dL [RR, industrial exposure: < 100 mcg/dL]. Venous heavy metal testing with inductively coupled plasma/mass spectrometry (ICP/MS) was pending. A foreign body X-ray demonstrated nonspecific intraluminal punctate radiopacities throughout the intestines.