An Epidurogram is an Alternative Diagnostic Tool for Discovering the Site of CSF Leakage in Spontaneous Intracranial Hypotension / 대한마취과학회지

Spontaneous intracranial hypotension (SIH) is a rare disease with a symptom of a postural headache, which is aggravated by the erect position and relieved by the supine position. This persistent headache is dramatically improved with an epidural blood patch. C6-7 is the most common site of leakage of cerebrospinal fluid (CSF) from the subarachnoid space in SIH. The diagnosis of SIH is based on a typical history. It is supported by low CSF pressure in a lumbar puncture and diffuse dural enhancement on a brain MRI, and confirmed by a CSF leakage site on a radioisotope cisternography or on a myelography. However, we had two patients of SIH whose CSF leakage site was not found on cisternography. We tried an epidurogram just before an injection of autologous blood for an epidural blood patch, and found specific finding on the epidurogam suggesting the CSF leakage site, such as a filling defect on C6-7 during dye injection, and delayed washout of dye around the filling defect on the epidurogram performed at C7-T1/C6-7. Therefore, we suggest that an epidurogram is occasionally a useful diagnostic tool when looking for the site of CSF leakage in SIH.

Minimal Concentration of Lidocaine for a Diagnostic Stellate Ganglion Block / 대한마취과학회지

BACKGROUND: The aim of this study was to determine an adequate minimal concentration of lidocaine in a stellate ganglion block for decreasing a false positive response to a diagnostic sympathetic blockade determining whether the patient's pain is SMP or SIP. METHODS: This crossover study was performed in twenty patients with sudden sensory neural hearing loss. All patients received three times SGB using three different concentrations (1%, 0.5% and 0.25%) of 8 ml lidocaine at the sixth cervical vertebral level via an anterior paratracheal approach. The blocks were separately done at one week intervals in random order. The occurrence, onset time and action duration of Horner's syndrome were observed after each SGB. RESULTS: Positive cranial sympathetic blockade (Horner' syndrome) was present in all patients using 1% and 0.5% lidocaine. It was present in 60% of the patients using 0.25% lidocaine. Onset time was not significantly different among the three groups. Action duration of 1% and 0.5% lidocaine groups was significantly longer than the 0.25% lidocaine group. There was no critical side effects, and temporary foreign body sensation was the most common side effect. CONCLUSIONS: The results of this study suggest that 0.5% lidocaine is an adequate minimal concentration for diagnostic SGB. Therefore, we recommend that 0.5% lidocaine instead 1% should be used in diagnostic SGB to decrease a false positive response to a sympathetic blockade.