A 29 year old woman was hospitalized on 03/2018 due to severe abdominal pain lasting 30 days, evolving with systemic arterial hypertension, right lower limb paraesthesia, paraparesis, psychomotor agitation, visual hallucinations and dysautonomia. Neuroleptics and antidepressants were initially prescribed and she developed dysarthria, dysphagia, drug hepatitis and tetraparesis. Cerebrospinal fluid was normal, brain magnetic resonance imaging (MRI) showed non-enhancing T2 and FLAIR hyperintense lesions disposed in occipital cortices and in the posterior and anterior horn of the right lateral ventricle. MRI angiography was normal. The patient was admitted in our service on 05/2018 with an ataxic gait, hypotonia in the upper limbs, proximal tetraparesis and anterior thigh hypoesthesia for all sensory modalities. The hypothesis of acute intermittent porphyria (AIP) and reversible posterior encephalopathy syndrome (PRES) was made. Urine exposed to sunlight became reddish and electroneuromyography showed motor polyneuropathy of axonal and proximal predominance. Urinary porphobilinogen and delta-aminolevulinic acid (> 12 mg / g) were positive. Genetic test identified HMBS gene with pathogenic variant in intron 5  (c.266+1G>A). There was history of aunt deceased by porphyria. She was treated with hypercaloric diet and physical therapy with complete improvement of symptoms.

AIP is a rare, autosomal dominant genetic disease that results from a disturbance in the heme biosynthesis pathway due to reduced levels of the porphobilinogen deaminase enzyme. PRES is a clinico-radiological syndrome characterized by headache, seizures, visual disturbances, mental confusion, and bilateral white and / or gray matter lesions. Seizures are present in 95% of patients with PAI and associated PRES and such association is more frequent in females (92%). Although peripheral neuropathy is considered the most common neurological manifestation of AIP, rarely, other neurological manifestations - e.g. PRESS - may occur. The association between PRES and AIP is an unusual phenomenon and needs further studies to understand its pathophysiology.