General description

Porphyrias are congenital metabolic disorders caused by abnormalities in one of the eight enzymes involved in heme synthesis, leading to nine different types, with varying modes of inheritance depending on the specific enzyme affected. These disorders affect pigment metabolism and disrupt the synthesis of heme, which is found in hemoglobin, myoglobin, catalase, peroxidase, and cytochromes.

Porphyrias are classified into acute and cutaneous forms. Acute porphyrias present primarily with neurovisceral symptoms, such as abdominal pain, vomiting, constipation, muscle weakness, altered consciousness, behavioral changes, limb pain, and sensory neuropathy, without hematological symptoms. In contrast, cutaneous porphyrias are more often associated with hematological symptoms and rarely show neurovisceral manifestations.

Radiographic features

MRI shows bilaterally symmetrical cortical to subcortical hyperintensity resembling Posterior reversible encephalopathy syndrome (PRES), with high signal observed in the frontal, parietal, and occipital lobes on T2WI and FLAIR.