Nerve Damage During Spinal Taps

Nerves Damaged Spinal Tap Nerves Damaged During Spinal Tap: Can a spinal tap cause a person pain, numbness and weakness in the right lower leg for life? The complications resulting from lumbar puncture (spinal tap) have been well documented in the neurosurgical literature. These complications include mild backache, persistent headache, meningitis, and herniated disc, as well as inoculation of epidermal tissue, and the associated growth of epidermoid tumors (Siddiqi and Buchheit, 1982). There have also been documented cases of nerve root injury associated with spinal tap.

Siddiqi and Buchheit have reported a case of an impacted or herniated nerve root associated with lumbar puncture. The patient presented with pain in the lower left leg into the ankle. Their finding of an impacted herniated nerve root, presumably causing postmyelogram sciatica and worsening of the preexisting low-back pain, appears unique. The mechanism of such an injury is thought to be herniation of the nerve root into the spinal needle while the contrast medium or cerebrospinal fluid is being withdrawn after the spinal tap.

This suggests that the stylet should be placed before the needle is withdrawn. This phenomenon occurs as the etiology of sciatica and persistent headaches following myelography. In addition to the nerve root strangulation, this event may prevent the normal closure of the arachnoid and dura at the puncture site and facilitate the prolongation of postspinal tap headaches. Hasegawa and Yamamoto (1999) present a case of herniated nerve root associated with lumbar puncture. A 66-year-old woman experienced progressive right-sided sciatic pain on gait without any causative episode.

She had not had low back pain before this episode. She had hypertension and asymptomatic multiple cerebral infarction, which had been treated by hypotensor and anticoagulant. On initial examination, she could not walk more than 100 m because of her right sciatic pain, which improved at rest. She showed no limitation on bilateral straight leg raising test. Neither sensory nor motor deficit of her lower extremities was apparent. Vesicorectal functions and reflexes were normal. Plain lumbosacral radiography showed mild lumbar spondylosis.

Magnetic resonance imaging (MRI) of the lumbar region disclosed compression of the thecal sac at L4 -- L5 caused by a narrowed spinal canal. Lumbar puncture for myelography was performed without confirmation of the spinal level by an image intensifier. It was difficult to insert a needle (Termo spinal needle, 0.8 mm in diameter and 70 mm in length) into the intrathecal space at the lower lumbar level. Although the puncture was repeated three times in two levels, the procedure was unsuccessful and abandoned because of remarkable bleeding from the needle hole.

Right-sided sciatic pain was significantly increased thereafter. A straight leg raising test showed limitation of the right lower extremity to 60°. During surgery, the herniated nerve root was placed back into the intrathecal space, and the dura mater was repaired. Although the patient improved steadily after surgery, low back pain and bilateral numbness of the lower extremities developed 9 days after surgery after readministration of an anticoagulant (Hasegawa and Yamamoto 1999). Abducens nerve palsy is also a complication of lumbar puncture.

Anwar et al.,(2007) present a case of a 40-year-old man with headache who had a lumbar puncture. Four days later, he developed signs of a left abducens palsy which resolved over four weeks. Computerised tomography and magnetic resonance imaging of his head were normal. Leakage of cerebrospinal fluid (CSF) through the dural puncture site exceeding the rate of production results in intracranial hypotension and shifting of the brain with traction on the cranial nerves.

Paralysis of cranial nerves, except the first and tenth, has been reported but the sixth is most common because of its long intracranial course. Signs are rare before the fourth day and the mean presentation time is 10 days. 67% of patients show complete resolution within 1 week after diagnosis, 25% may remain symptomatic.