The Case of a 37-Year-Old Woman Presenting With Subacute Weakness and Paresthesias.

Acute intermittent porphyria (AIP) is a rare metabolic disorder that may present with subacute neuropathy and systemic symptoms, often leading to diagnostic delay. We report a 37-year-old woman with eight weeks of progressive bilateral upper extremity weakness and paresthesias, followed by lower extremity involvement and falls, in the setting of chronic abdominal pain, presyncope, weight loss, and neuropsychiatric symptoms. Examination revealed profound proximal arm weakness, sensory deficits, bulbar involvement, and autonomic features. MRI of the brain and spine and cerebrospinal fluid analysis were normal. Electrodiagnostic studies demonstrated a severe diffuse motor neurogenic process. Markedly elevated urinary porphobilinogen and aminolevulinic acid levels confirmed the diagnosis of acute intermittent porphyric neuropathy, supported by identification of a variant of uncertain significance in the HMBS gene. This case underscores the importance of considering AIP in patients with subacute motor-predominant neuropathy accompanied by abdominal pain and autonomic dysfunction, as early diagnosis enables timely treatment and improved outcomes.