Acute intermittent porphyria presenting with seizures and posterior reversible encephalopathy syndrome: Two case reports and a literature review

Abstract

Introduction: Acute intermittent porphyria (AIP) is a rare and challenging hereditary neurovisceral disease with no specific symptoms. Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome with bilateral reversible posterior gyriform lesions that can be associated with many different conditions, including AIP. Usually, peripheral neuropathy is considered the most common neurological manifestation of AIP. However, AIP should also be considered when seizures and PRES are associated with unexplained abdominal pain.

Case presentation: Both the patients were presented with seizures and PRES on brain magnetic resonance imaging (MRI). Unexplained abdominal pain occurred before the onset of seizures. The AIP diagnosis was made after repeated Watson-Schwartz tests. Hematin was not available for these 2 patients. However, supportive treatment including adequate nutrition and fluid therapy as well as specific antiepileptic drugs aided the patient's recovery and no acute attacks had occurred by the 3-year follow-up.

Conclusion: In contrast to other causes of PRES patients, seizure is the most common symptom in AIP patients with PRES. This is a strong diagnostic clue for AIP when ambiguous abdominal pain patients presented with seizures and PRES on brain MRI. A positive prognosis can be achieved with the combination of early recognition, supportive and intravenous hematin therapy, and withdrawal of precipitating factors, including some antiepileptic drugs.

Figure 1

Magnetic resonance imaging of case 1 shows hyperintense gyriform lesions on T2-weighted (A, E) and fluid-attenuated inversion recovery images (B, F) of bilateral occipitoparietal and frontal lobes. Hypointense and patchy hyperintense lesions were found on diffusion-weighted images (C, G), apparent diffusion coefficient maps (D, H) showed hyperintensity of these lesions.

Figure 2

Urine samples of normal control (A) and case 1 after exposure to sunlight for a short (B) and long (C) time.

Figure 3

Gyriform lesions on both the cortical and subcortical bilateral occipitoparietal and frontal lobes in case 2. These lesions were hyperintense on T2-weighted (A, E) and T2-fluid-attenuated inversion recovery (B, F) images. They were hypointense on diffusion-weighted images (C, G) images and were hyperintense on apparent diffusion coefficient maps (D, H).

Figure 4

Six days later, gyriform lesions of case 2 resolve incompletely on T2 (A, E), T2-fluid-attenuated inversion recovery images (B, F), diffusion-weighted images (C, G), and apparent diffusion coefficient maps (D, H).

Figure 5

Follow-up brain magnetic resonance images of case 2 show complete resolution on T2 (A, E), T2-fluid-attenuated inversion recovery images (B, F), diffusion-weighted images (C, G), and apparent diffusion coefficient maps (D, H).