Idiopathic spinal cord herniation at the cervicothoracic junction level presenting with unilateral sensory symptoms

Idiopathic spinal cord herniation (ISCH) most commonly occurs through a ventral dural defect at the midthoracic levels with a predilection to affect middle-aged females. It can have various presentations, the most common of which are Brown-Séquard syndrome and spastic paraparesis. Due to its rarity in clinical practice, the diagnosis of ISCH can be challenging to physicians unfamiliar with this entity. We report an exceedingly rare case of ISCH at the C7-T1 intervertebral disc level in a 44-year-old male presenting with eight months of isolated unilateral sensory symptoms. The diagnosis was made based on the findings on the patient's magnetic resonance imaging of the spinal cord, including the presence of an extradural cerebrospinal fluid collection. Surgical reduction of the herniated segment and patching of the dural defect resulted in a remarkable clinical improvement beginning in the immediate postoperative period. Follow-up MRIs showed no sign of reherniation, and the patient remained asymptomatic after one year of follow-up. Early diagnosis and surgical intervention led to an excellent early outcome in this case. However, long-term follow-up is necessary to monitor for reherniation and relapse of the symptoms in ISCH patients.