Seizures and muscle wasting were treated as psychiatric. Acute intermittent porphyria was missed.

An unexplained decline

A 28-year-old man began suffering from intermittent abdominal pain that occurred two to three times a week. The episodes lasted several hours and had no obvious triggers. One month after the pain began, he noticed a growing weakness in his muscles, finding it increasingly difficult to lift his arms. Over the course of six months, his weight dropped from 80 kg to 65 kg because the pain made it difficult to eat.

The emergence of encephalopathy

The domestic physical crisis escalated into a neurological one. Fifteen days before he was admitted to the hospital, the man began experiencing episodes of unconsciousness and limb twitching. He was suffering from seizures alongside his daily abdominal pain. When he was examined, he was found to be emaciated, with visible muscle atrophy in his shoulders and upper arms. His blood pressure was high at 178/94 mmHg.

An out-of-hospital cranial MRI showed abnormal signals in the back of his brain and cerebellum. He was diagnosed with epilepsy and started on sodium valproate to control the seizures. However, sodium valproate is a known exacerbant for certain metabolic conditions, and its use may have worsened his state.

Hidden in the light

While the patient was hospitalized, the clinical team reconsidered the combination of persistent abdominal pain, seizures, and muscle weakness. They collected a sample of his urine and exposed it to sunlight. Under the light, the accumulated porphyrin precursors underwent photooxidation, and the urine turned a distinct wine color. This simple observation pointed toward porphyria.

The actual diagnosis

A qualitative test for porphobilinogen (PBG) in his urine came back positive. Genetic testing confirmed a heterozygous c.445C > T mutation in the HMBS gene. This mutation causes a functional defect in the enzyme hydroxymethylbilane synthase, leading to Acute Intermittent Porphyria (AIP). Further, his brain imaging and clinical state were identified as Posterior Reversible Encephalopathy Syndrome (PRES), a rare complication triggered by the metabolic crisis.

Recovery and resolution

Treatment focused on stopping the metabolic attack. Doctors immediately discontinued the sodium valproate and replaced it with levetiracetam. He was given intravenous hemin for seven days to reduce the accumulation of toxic precursors and placed on a high-carbohydrate diet.

The turnaround was significant. By his one-month follow-up, he had gained 5 kg and his seizures and abdominal pain had vanished. Within two months, his weight reached 75 kg, his muscle strength returned to normal, and he was able to return to his daily life and work.