Spinal coning after lumbar puncture in a patient with undiagnosed giant cervical neurofibroma

Lumbar puncture in the presence of an intracranial tumor with raised intracranial pressure is known to have catastrophic consequences due to herniation of intracranial contents through the tentorial hiatus or foramen magnum. There are relatively few case reports about the same sequence of events when lumbar puncture is performed below the level of a complete spinal block. The mechanism of such deterioration is also subject to conjecture as the spinal cord (unlike the uncus or cerebellar tonsils) is tethered by the dentate ligament and roots on either side, and is hence less mobile. We present one such case of spinal coning and review the available literature.