Fluoroscopic-Guided Paramedian Approach for Lumbar Catheter Placement in Cerebrospinal Fluid Shunting: Assessment of Safety and Accuracy

BACKGROUND Spinal catheter insertion in lumboperitoneal (LP) shunt surgery for idiopathic normal pressure hydrocephalus (iNPH) is frequently associated with technical difficulties especially in patients with obesity and elderly patients with vertebral deformities. OBJECTIVE To elucidate the accuracy and safety of image-guided spinal catheter placement using a paramedian approach (PMA). METHODS We retrospectively analyzed 39 consecutive iNPH patients treated by LP shunting with spinal catheter insertion via the PMA. The success rate of catheter placement and the number of changes in puncture location were evaluated. Accuracy of catheter insertion was assessed by measuring both vertical and horizontal deviations in the point of catheter dural penetration from the center of the interlaminar space. RESULTS The success rate of catheter placement was 100% (39/39). The difficulty rate for catheter insertion, measured by the number of changes in puncture location, was 2.6% (1/39). No bloody punctures or surgical infections were observed. Accuracy of catheter insertion, measured as the degree of deviation, was 0.5 ± 1.9 mm horizontally and 0.0 ± 2.4 mm vertically. The rates of minor complications, including caudal catheter insertion, transient low-pressure headache, and root pain, were 5.1% (2/39), 10.4% (4/39), and 0% (0/43), respectively. Subdural hematoma requiring surgical intervention occurred in 1 case (2.6%). During the mean follow-up period of 36 mo, spinal catheter rupture at the level of the spinous processes was not observed. CONCLUSION Fluoroscopic-guided spinal catheter placement via the PMA was safe, accurate, and reliable, even for use in geriatric and obese patients.

Epidural Blood Patch

Post-dural-puncture headache (PDPH) is a consequence of neuraxial anesthesia, diagnostic lumbar puncture, intrathecal drug delivery systems, or any other technique involving dural trespass. The spinal headache results from a dural puncture that leads to cerebrospinal fluid (CSF) leakage from the subarachnoid space to the epidural space, culminating in intracranial hypotension and development of a low-pressure headache. A key element of PDPH is an increase in pain severity upon a change in position from supine to upright, which corresponds to a gravity-induced influence on CSF pressure dynamics. Age, sex, and design of the needle used correlate with the risk of headache. Sometimes, the headache resolves spontaneously. At other times, conservative treatment or aggressive measures are required to terminate the pain. An autologous epidural blood patch is an established way preventing or treating PDPH. A careful history must be obtained to identify other causes of headache before the blood patch is attempted.

Ringing in the Ears and Pain in the Head

The case illustrates the classic clinical features of a low-pressure headache. The pathophysiology results from the loss of cerebrospinal fluid (CSF). This causes sagging of the brain, stretching of the bridging veins, and venodilatation. The clinical history is of a headache that is worse in the upright position and remits when the patient is supine. Due to the connection of the perilymphatic fluid and CSF, postural tinnitus is a frequent symptom. Risk factors for low-pressure headache include those that are patient-specific: female sex, low body mass index, prior history of a low-pressure headache, and an underlying headache disorder. Operator-specific factors that decrease the risk of a postdural puncture headache (PDPH) include greater operator experience and the use of a smaller-gauge, non-cutting lumbar puncture needle. The best treatment for low-pressure headache is a blood patch with resolution in over 90% of low-pressure headaches.

Peripartum Isolated Cortical Vein Thrombosis in a Mother with Postdural Puncture Headache Treated with an Epidural Blood Patch

A 32-year-old woman presented with low pressure headache 3 days after delivery of her baby. An assessment of postdural puncture headache was made. This was initially treated with analgesia, caffeine, and fluids for the presumed cerebrospinal fluid (CSF) leak. The woman was readmitted two days after her hospital discharge with generalised seizures. A brain scan showed features of intracranial hypotension, and she was treated for CSF leak using an epidural blood patch. Her symptoms worsened and three days later, she developed a left homonymous quadrantanopia. An MRI scan confirmed a right parietal haematoma with evidence of isolated cortical vein thrombosis (ICVT).

Assessment of a Quick Reference Table Algorithm for Determining Initial Postoperative Pressure Settings of Programmable Pressure Valves in Patients With Idiopathic Normal Pressure Hydrocephalus

BACKGROUND: Management of overdrainage complications in shunted patients with idiopathic normal pressure hydrocephalus (INPH) remains a difficult task despite the use of programmable pressure valves. OBJECTIVE: To assess the usefulness of a quick reference table (QRT) algorithm for achieving a suitable initial programmable pressure valve setting in INPH patients who participated in the Study for INPH on Neurological Improvement (SINPHONI). METHODS: One hundred registered patients diagnosed with probable INPH were treated with ventriculoperitoneal shunts using Codman-Hakim programmable valves (CHPVs). In this series, the initial CHPV setting was decided prospectively according to the QRT algorithm. Shunt effectiveness, complications, and the number of CHPV readjustments during follow-up periods were investigated. RESULTS: Eighty patients were considered better than shunt responders (more than 1 point improvement in modified Rankin Scale at any follow-up period). Readjustments of CHPVs within 3 months after treatment with ventriculoperitoneal shunt were performed 56 times in 44 cases (44%, 0.56 times/patient). Low-pressure headache occurred in 9 patients, all of whom improved by readjustment alone. Nontraumatic subdural fluid collections and chronic subdural hematomas occurred in 15 cases (15%); however, most of the cases were subclinical and improved after CHPV readjustments alone. Burr hole irrigation was necessary in only 1 case. CONCLUSION: Use of the QRT algorithm was associated with a decrease in postoperative CHPV readjustments and serious overdrainage complications during the follow-up period. The QRT algorithm is an easy, safe, and effective method for determining the initial CHPV pressure setting in INPH patients.