Intramedullary Sarcoidosis: MRI and PET Diagnosis
A 54-year-old male patient presented with three transient episodes of horizontal diplopia and gait disturbance. Neurological examination demonstrated a left sixth nerve palsy, brisk reflexes and upgoing plantars, with sustained ankle clonus bilaterally. CSF analysis revealed a glucose of 1.7 mmol/L and protein of 2.74 g/L, with mild lymphocytosis (count of 24). CSF cultures were negative. T1- and T2-weighted MR cervico-thoracic spine revealed cord expansion with edema at T1–T3 consistent with a transverse myelitis (Fig. A, B). Fluorodeoxyglucose (FDG) PET-CT showed avid bilateral hilar and mediastinal lymph nodes, and markedly increased uptake in the upper thoracic spinal cord at the affected area, highly suspicious for intramedullary neurosarcoidosis (Fig. C, D). A histopathology specimen from cervical mediastinoscopy demonstrated granulomatous inflammation. A diagnosis of sarcoidosis/neurosarcoidosis was made, and corticosteroid treatment was commenced, with symptom improvement in the subsequent weeks.