A 66-year-old previously well man presented with an 18-year history of upper thoracic spine pain. The pain was initially intermittent and mild, but in the 14 months prior to presentation, it had gradually increased in severity and persistence. The pain radiated to the left side of the neck, and when severe, spread around both sides of the chest. The patient reported two episodes of left arm weakness lasting a few hours with spontaneous resolution, but denied paresthesia, sensory loss, or sphincter disturbance. There was no history of spinal surgery, trauma, or spinal disorders. Clinical examination demonstrated an upper thoracic spine gentle kyphosis. There were no abnormal findings on neurological motor, sensory, and reflex examination. A suboptimal quality MRI of the thoracic spine performed at a different institution was interpreted as an intradural mid-thoracic lesion, with a described intradural extramedullary mass indenting the dorsal aspect of the spinal cord. These findings were initially thought to be a dorsal arachnoid cyst. Repeat MRI at our institution demonstrated findings consistent with the characteristic features of ISCH. T2-weighted images showed anterior kinking and mild flattening of the spinal cord at T5, with widening of the subarachnoid space posterior to the cord and pulsation artifact within the CSF space []. The patient was treated with conservative management, with clinical and radiological surveillance. The patient remained neurologically stable at 4 months after presentation.
This 58-year-old female complained about temperature changes and hyperpathy in her left leg for the past 12 months. On the right side, the sensibility was different but not normal. The strength in her left leg was diminished. These complaints ascended over time, initially starting at the foot and developing further to the groin at the time of presentation.\nNeurological examination revealed only a paretic quadriceps femoris muscle on the left side. Vital sensibility was disturbed on the left side below T10. The plantar reflexes on both sides were indifferent.\nAn MRI revealed a herniation of the SC at T8 (Figure ).\nDuring surgery, a laminectomy on T8 and T7 was performed. The dentate ligaments were transected. While gently mobilizing the SC from the left to the right, a large defect in the ventral dura was observed. The same maneuver at the right side revealed a fixed SC with the defect. After transection of some adhesions, a tumor-like extension of the SC was seen (Figure ) and was finally mobilized completely intradurally. To prevent re-herniation, an artificial graft was gently placed in front of the SC covering the defect and fixated laterally to the dural sleeve. Throughout the entire surgery, MEPs, SSEPs, and D-waves were monitored. Changes were not noticed. Post-operatively, the patient did not notice any new complaints.