04134 An unusual case of variegate porphyria with nerve enlargement, conduction block and idiopathic intracranial hypertension
Year: 2024
Type: conference-paper
Study design: Case Report
Abstract: Background Acute porphyrias are associated with chronic symptoms which are frequently reported but still poorly investigated. We report a patient with variegate porphyria with unusual findings during follow up.Case Report Female patient with previous history of acute attack (abdominal pain, urinary retention and tetraplegia) at age 27. She was evaluated at age 42 and as sequelae she had mild distal weakness and neuropathic pain in both hands and feet. She was diagnosed after genetic panel showed a pathogenic variant on PPOX - c.503G>A. Electrodiagnostic studies (EDX) were performed and revealed reduced compound motor action potential (CMAP) amplitudes in nerves of the lower limbs and both median nerves. Also, conduction block in both median nerves suggested acquired demyelinating neuropathy. Late responses showed absence of F waves and H reflexes in the tibial nerves. Sensory studies were normal. Neuromuscular ultrasound showed enlarged cross-sectional area in both median nerves in the forearm, consistent with neural thickening outside typical compression site. Six months later, she presented with psychosis and reported migrainous headache. Brain MRI suggested idiopathic brain hypertension. Lumbar puncture demonstrated increased opening pressure of 32 cmH2O. A new attack was discarded with biochemical exams.Discussion Acute porphyric neuropathy is described as an axonal predominantly motor neuropathy. Secondary demyelinating findings have been described. A primary demyelinating neuropathy and partial conduction block, as seen in our case, have been reported in the acute phase and related to more severe acute attacks. A chronic distal axonal sensory-motor polyneuropathy can persist. Specific ultrasonography features of porphyric neuropathy have not been reported. This unpredicted finding can be a source of misleading diagnosis as inflammatory neuropathy. Finally, intracranial hypertension is not usually seen and further studies are needed to establish a relationship.Abstract 04134 Figure 1
Institution: Universidade de São Paulo
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
OpenAlex ID: W4402696281