The Evaluation of Neurotoxicity after Intrathecal Restorative Fluid Injection in the Rat

OBJECTIVE: To assess neurotoxicity of intrathecal restorative fluid leakage in the course of the intradiscal restorative fluid injection. METHOD: Twenty male Sprague-Dawley rats, body weight range of 300~350 gm, were divided randomly into four groups. Control group, group A (mixed solution of glucosamine hydrochloride 5%, chondroitin sulfate 5%, and bupivacaine hydrochloride 2%), group B (glucosamine hydrochloride 8%, chondroitin sulfate 2%, and bupivacaine hydrochloride 2%) and group C (glucosamine hydrochloride 16%, chondroitin sulfate 2%, and bupivacaine hydrochloride 2%). The behavioral test for cold allodynia (tail flick test) was conducted 1 day prior to the injection and 7 days postoperatively. Histopathologic evaluation was performed using light microscopy by a neuropathologist. The severity of nerve and cord injury were graded according to injury scoring system. RESULTS: Each group showed no significant difference in sensory function test using tail flick test before and after intrathecal restorative fluid injection. Cold allodynia was not showed statistically significant difference among the group. Histological examination showed statistically significant difference between control group and group B, group C, and between group A and group B, C in both cord and root. CONCLUSION: Intrathecal injection of restorative fluid shows neurotoxic changes in roots and spinal cord in histopathologic studies. Although same ingredients of restorative solution, the different concentration of the ingredients revealed different neurotoxicity.

Recurrent Episodic Vertigo Controlled by Phenytoin Sodium

BACKGROUND:Many patients with symptom of recurrent episodic vertigo can neither be diagnosed nor treated. The purpose of this study is to review clinical features of a group of patients with recurrent episodic vertigo that is not defined to specific diagnosis of vertigo and to test the effectiveness of phenytoin sodium in the patients. METHOD & MATERIAL:11 of 32 patients with recurrent vertigo not defined to specific diagnostic category of vertigo who visited dizziness center of a tertiary care university hospital from November 1995 to April 2004 were studied. The patient's charts were reviewed retrospectively. A thorough otolaryngologic and neurotologic evaluation was performed in every case to determine the specific cause of dizziness. Vestibular function test, hearing test, magnetic resonance imaging of brain, electroencephalogram, and 24 hour Holter EKG monitoring were performed in all cases. Consultations to psychiatrist and neurologist were obtained. All patients were treated with phenytoin sodium. RESULT:The results of the vestibular function test, audiogram, MRI of brain, electroencephalogram, 24-hr holter monitoring were normal. Any definitive diagnosis could not be reached to this group. Vertigo was controlled by phenytoin sodium in all 11 cases. CONCLUSION:We report a group of patients with recurrent episodic vertigo that is not defined to any specific diagnosis of vertigo. The vertigo symptom was controlled successfully by phenytoin sodium. This patients were diagnosed as benign episodic vertigo as a separate disease entity.

Ultrasonographic Findings of Median Nerve Change according to the Wrist Position

OBJECTIVE: To assess the changes of ultrasonographic findings of median nerve according to wrist position change in normal and carpal tunnel syndrome hands. METHOD: We studied 31 carpal tunnel syndrome and 34 normal hands that were diagnosed by nerve conduction study and evaluated crossectional area, flattening ratio and distance to ulnar artery with diagnostic ultrasound. The parameters were tested according to the change of wrist position with neutral, extension and flexion in normal control and carpal tunnel syndrome. RESULTS: Crossectional area of carpal tunnel syndrome was larger than that of control. Flattening ratio of carpal tunnel syndrome was larger than that of control at extended position. Flattening ratio was greater in neutral and extended position than flexed position in carpal tunnel syndrome. Distance to ulnar artery were greater in flexed position than other positions in carpal tunnel syndrome. Frequency of least flattening ratio at flexion position in carpal tunnel syndrome was 64.52% and frequency of longest distance to ulnar artery at flexion position was 58.05%. CONCLUSION: Ultrasonography of median nerve showed no consistent findings according to change of wrist position between control and patients. Ultrasonographic diagnosis of carpal tunnel syndrome need further study for anatomical variations.

The Prognosis of Preganglionic Brachial Plexus Injuries by Electrodiagnosis

OBJECTIVE: To document the neurological recovery of the preganglionic lesion of brachial plexus, both clinically and electrodiagnostically. METHOD: Sixteen male and three female patients were evaluated. Ages of the patients ranged from 1 to 45 years with the mean age of 25.2+/-14.3 years. We studied retrospectively the improvements of 43 injured nerves and its innervated muscles of 19 patients retrospectively according to the complete or incomplete nature of the injuries by the electromyographic findings. We compred the results of initial and final examinations by the electromyographic and clinical findings including a muscle strength test. RESULTS: In the complete injuries, 84.0% of the cases showed a minimal or no improvement in muscle strength whereas in the incomplete injuries, 88.2% of the cases showed a greater than moderate improvement in muscle strength. The cases in which no compound muscle action potential could be evoked on the initial study, showed the improvements of greater than 3/5 muscle strength only in 20.0%. However 71.5% of cases with the initial amplitude between 0.1 & 0.5 mV and 100.0% of cases with the initial amplitude greater than 0.5 mV showed the muscle strength greater than 3/5. CONCLUSION: The prognosis for the neurological recovery was significantly poor in the complete preganglionic lesions of brachial plexus injuries but in the incomplete lesions, the prognosis was extremely good. It would be crucial for the initial CMAP being greater than 0.5 mV to expect the recovery of muscle strength to the functional level. Rehabilitative or operative management should be instituted based on the electrodiagnostic findings.