Completion Corpus Callosotomy with Stereotactic Radiosurgery for Drug-Resistant, Intractable Epilepsy.

BACKGROUND: Stereotactic radiosurgery (SRS) offers a noninvasive technique for division of the corpus callosum, which can confer improved seizure control to patients suffering from frequent atonic seizures due to rapid interhemispheric generalization. This noninvasive approach is well-suited for use in a palliative intervention for improved seizure control in this patient population. To our knowledge, this is the first report of radiosurgical completion corpus callosotomy in an adult in the United States. CASE DESCRIPTION: A 20-year-old ambidextrous nonverbal man with a history of refractory generalized epilepsy status post open anterior corpus callosotomy at age 10 years, Lennox-Gastaut syndrome, and autism presented after 2 years of incremental, progressive deterioration in seizure control and behavior including 1 year. The family decided to pursue SRS corpus callosotomy. Under general anesthesia, a volume of interest encompassing a full midsagittal plane of the corpus callosum was defined to deliver 60 Gy to the 50% isodose line fully encompassing the target. Gamma Knife was used with 2 isocenters at 90° and 1 at 110° and isodose lines of 60, 20, and 12 Gy. Treatment was carried out without difficulty or complications while the patient remained under close monitoring. The patient was discharged the next day with a 2-week taper of dexamethasone. CONCLUSIONS: Eight months postradiosurgical corpus callosotomy, the patient is free of atonic seizures and is ambulatory. In carefully selected cases and with protective radiosurgical planning, SRS for completion corpus callosotomy represents an effective option for refractory seizure control.

Effect of a Novel, Orally Active Matrix Metalloproteinase-2 and -9 Inhibitor in Spinal and Trigeminal Rat Models of Neuropathic Pain.

AIMS: To study the effects of a novel matrix metalloproteinase-2 (MMP-2) and MMP-9 inhibitor, AQU-118, on mechanical allodynia in the spinal nerve ligation (SNL) model of neuropathic pain and the chronic constriction injury of the infraorbital nerve (CCI-IoN) model of neuropathic orofacial pain. METHODS: Five groups of SNL rats were given daily oral doses of AQU-118 (5, 10, 20 mg/kg), gabapentin (100 mg/kg), or vehicle (0.5% methylcellulose) and then paw withdrawal threshold was measured with von Frey filaments (VF). Three groups of CCI-IoN rats were given daily oral doses of either AQU-118 (40 mg/kg), gabapentin (100 mg/kg), or vehicle (0.5% methylcellulose) and then mechanical allodynia was measured with facial VF and non-reflex-based orofacial stimulation test (OFST) assay. Naïve rats were also tested for the effect of AQU-118 (40 mg/kg) on basal sensitivity to mechanical stimulation/locomotive activity. RESULTS: Mechanical allodynia in SNL rats was attenuated by gabapentin (100 mg/kg) and AQU-118 (in a dose-dependent manner). Mechanical allodynia in CCI-IoN rats was also attenuated (in an equipotent manner) by both AQU-118 (40 mg/ kg) and gabapentin (100 mg/kg) as measured by both facial VF and OFST assay. Upon cessation of either AQU-118 or gabapentin, VF-related responses in both models and OFST assay times reverted to levels observed in vehicle-treated rats. No statistically significant change was observed in locomotive activity/paw withdrawal threshold by AQU-118 (40 mg/kg) in naïve rats. CONCLUSION: The results demonstrated that oral AQU-118 attenuates mechanical allodynia in both neuropathic pain models and with efficacies that mirror gabapentin at the 40 mg/kg dose used in the CCI-IoN model but without effect on basal sensitivity to mechanical stimulation/locomotive activity. These findings support a possible role for MMP-2/-9 in the etiology of neuropathic pain and also suggest that inhibition strategies represent a viable treatment option.

Heatstroke.

Heatstroke is a syndrome consisting of life-threatening central nervous system and multiple organ dysfunction from complications of hyperthermia. Additionally, there is an associated complex immunological and inflammatory component to the illness that resembles sepsis. Core body temperature exceeds 40 degrees C with associated mental status changes such as delirium and coma. Generalized tonic/clonic seizures can occur. A variable degree of organ involvement is present that contributes to the severity of the medical picture. Heatstroke can be viewed as a tropical neurological disorder especially for unacclimated travelers going to warm climates. Heatstroke can be categorized into two types depending on the cause. Classic heatstroke is nonexertional, environmentally related and exertional heatstroke occurs in the setting of strenuous exercise. Heatstroke is actually the most severe of a continuum of heat-related illnesses that carries a high incidence of mortality. Treatment is directed at rapidly reducing core body temperature and the management of life-threatening systemic complications.

fMRI in patients implanted with a vagal nerve stimulator.

OBJECTIVE: To demonstrate the feasibility and safety of using functional magnetic resonance imaging (fMRI) to determine the blood oxygen level dependent changes (BOLD) in patients undergoing vagal nerve stimulation (VNS) for the treatment of epilepsy. METHODS: Four patients with an implanted vagus nerve stimulator had fMRI images acquired during several cycles of intermittent VNS. Blood oxygen level dependent changes were detected. These regions were then superimposed upon the patients' structural MR images. RESULTS: Patients undergoing VNS tolerated fMRI without difficulty. No complications with the implanted stimulators were encountered. Areas of activation were noted in several cortical regions, including frontal, temporal, parietal, and occipital cortices. CONCLUSION: Our study in four patients shows fMRI can be performed safely in patients with an implanted vagal nerve stimulator. The successful use of fMRI during VNS offers potential advantages over PET imaging by allowing rapid image acquisition and the ability to repeatedly study patients over time. Our preliminary results differ from previous PET or SPECT studies in failing to detect changes in subcortical areas. This finding could be due to the smaller n in this study compared with the other studies.

Intractable epilepsy with ring chromosome 20 syndrome treated with vagal nerve stimulation: case report and review of the literature.

We report a case of a 6-year old girl with ring chromosome 20 syndrome whose medically intractable seizures were successfully treated with vagal nerve stimulation therapy. Medically intractable seizures are an expected part of this rare syndrome, and the dramatic improvement in seizure control with vagal nerve stimulation is emphasized. Earlier use of vagal nerve stimulation in similar cases should be considered.