Oculomotor, Vestibular, and Reaction Time Effects of Sports-Related Concussion: Video-Oculography in Assessing Sports-Related Concussion.

OBJECTIVE: The purpose of the study was to test the ability of oculomotor, vestibular, and reaction time (OVRT) metrics to serve as a concussion assessment or diagnostic tool for general clinical use. SETTING AND PARTICIPANTS: Patients with concussion were high school-aged athletes clinically diagnosed in a hospital setting with a sports-related concussion (n = 50). Control subjects were previously recruited male and female high school student athletes from 3 local high schools (n = 170). DESIGN: Video-oculography was used to acquire eye movement metrics during OVRT tasks, combined with other measures. Measures were compared between groups, and a subset was incorporated into linear regression models that could serve as indicators of concussion. MEASURES: The OVRT test battery included multiple metrics of saccades, smooth pursuit tracking, nystagmoid movements, vestibular function, and reaction time latencies. RESULTS: Some OVRT metrics were significantly different between groups. Linear regression models distinguished control subjects from concussion subjects with high accuracy. Metrics included changes in smooth pursuit tracking, increased reaction time and reduced saccade velocity in a complex motor task, and decreased optokinetic nystagmus (OKN) gain. In addition, optokinetic gain was reduced and more variable in subjects assessed 22 or more days after injury. CONCLUSION: These results indicate that OVRT tests can be used as a reliable adjunctive tool in the assessment of concussion and that OKN results appear to be associated with a prolonged expression of concussion symptoms.

Ketamine use in the treatment of refractory status epilepticus.

Refractory status epilepticus (RSE) occurs when status epilepticus (SE) fails to respond to appropriate therapy with typical antiepileptic drugs (AEDs). Animal studies have shown ketamine to be a highly efficacious agent in this setting, but very few case reports describe use of ketamine in human SE or RSE. We report a retrospective review of 11 patients who were treated for RSE with ketamine infusion in addition to other standard AEDs over a nine-year period. Data collection included age, gender, history of epilepsy, etiology of RSE, daily dose of ketamine, co-therapeutic agents, duration of seizures, treatment response, and disposition. RSE was successfully terminated in all 11 patients treated with ketamine. Dosing ranged from 0.45 mg/kg/h to 2.1 mg/kg/h based upon the preference of the treating clinician and response to therapy, with maximal daily doses ranging from 1392 mg to 4200 mg. Ketamine was the last AED used prior to resolution of RSE in 7/11 (64%) cases. In the remaining four cases, one other AED was added after ketamine infusion had begun. Time from ketamine initiation to seizure cessation ranged from 4 to 28 days (mean=9.8, SD=8.9). In 7/11 patients, RSE was resolved within one week of starting therapy. Administration of ketamine was uniformly associated with improvement in hemodynamic stability. Six of the seven patients (85%) who required vasopressors during early treatment for RSE were able to be weaned from vasopressors during ketamine infusion. No acute adverse effects were noted. These findings suggest that ketamine may be a safe and efficacious adjunctive agent in the treatment of RSE.

The efficacy of topiramate in adult refractory status epilepticus: experience of a tertiary care center.

Refractory status epilepticus (RSE) occurs in patients with SE when they fail to respond to traditional medical therapy. Because there are very few case reports of topiramate (TPM) treatment of RSE in adult patients, we examined our experience with TPM with regard to its safety and efficacy in seizure termination in RSE in an adult patient population. We report a retrospective review of 35 adult patients with RSE who were treated with TPM in addition to other antiepileptic drugs (AEDs) between 2003 and 2010. After failure of initial treatments of benzodiazepines and weight-based intravenous loading doses of standard AEDs, TPM tablets were crushed and administered via nasogastric tube. Data were collected on age, gender, history of epilepsy, etiology of RSE, daily dose of TPM, co-therapeutic agents, treatment response, and disposition. Following initiation of TPM use and discontinuation of continuous intravenous anesthetics with no additional AEDs administered, cumulative cessation of RSE in patients was 4/35 (11%) at one day, 10/35 (29%) at two days, and 14/35 (40%) at three days. However, when including all patients and comparing the two patient groups in which RSE was or was not terminated within three days of initiating TPM as the last or not last AED given, there was no significant difference. Time to TPM response was not associated with the type of seizures, etiology of SE, or whether there was a history of epilepsy. There were no documented side effects or complications of therapy with TPM. This study provides support for the use of TPM as an adjunctive agent in the treatment of RSE.