Individuals with X-linked Adrenoleukodystrophy (X-ALD) may manifest symptoms of their disease following head trauma or neurologic infection. We report a case of adult-onset cerebral ALD in a 21-year-old man, who also had a remote history of head trauma and recent history of neurosyphilis. He presented with a generalized tonic-clonic seizure and left-sided weakness, along with recent weight loss, headaches, and low-grade fevers. Initial workup revealed a positive cerebrospinal fluid VDRL, and no evidence of peripheral neuropathy or endocrinopathy. Frontal lobe biopsies revealed loss of myelin staining by Luxol fast blue and white matter macrophages and T lymphocytes, consistent with a demyelinating or dysmyelinating disease. The diagnosis of X-ALD was made through detection of elevated very long-chain fatty acids. This patient’s presentation is highly unusual for someone with X-ALD. The majority of patients present either in childhood with an often-lethal inflammatory cerebral dysmyelinating phenotype, or in adulthood with a non-inflammatory distal axonopathy. Most patients who are asymptomatic during childhood do not go on to develop cerebral ALD in adulthood, especially not without first presenting with peripheral neuropathy or adrenal dysfunction. This patient’s head trauma and/or neurosyphilis may have provided the inflammatory trigger for the manifestation of the inflammatory cerebral demyelinating phenotype of X-ALD in adulthood.