Biomedical subjects

William S Anderson

Publications and source records attributed to William S Anderson.

4 recordsLinked to original sources

PubMed2006

Case of microarteriovenous malformation-induced trigeminal neuralgia treated with radiosurgery.

Radiosurgery to the right fifth cranial nerve was performed with the Gamma Knife on a 39- year-old patient who presented with classic symptoms of trigeminal neuralgia (TN), but was found on imaging studies to harbour a small intrinsic vascular malformation within the nerve. Based on size and drainage, the arteriovenous malformation (AVM) was Spetzler-Martin Grade III and no previous history of bleeding was reported. The patient had failed a trial of carbamazepine, and no surgical procedures had been performed. A decrease in symptoms was reported by the 6-month follow-up. A review of the literature on microAVM-induced TN is provided as well as a discussion of management.

Adult↗

PubMed2006

Surgery insight: Deep brain stimulation for movement disorders.

Over the past two decades, deep brain stimulation (DBS) has supplanted lesioning techniques for the treatment of movement disorders, and has been shown to be safe and efficacious. The primary therapeutic indications for DBS are essential tremor, dystonia and Parkinson's disease. In the case of Parkinson's disease, DBS is effective for treating the primary symptoms--tremor, bradykinesia and rigidity--as well as the motor complications of drug treatment. Progress has been made in understanding the effects of stimulation at the neuronal level, and this knowledge should eventually improve the effectiveness of this therapy. Preliminary studies also indicate that DBS might be used to treat Tourette's syndrome, obsessive-compulsive disorder, depression and epilepsy. As we will discuss in this review, the success of DBS depends on an appropriate rationale for the procedure, and on collaborations between neurologists and neurosurgeons in defining outcomes.

Deep Brain Stimulation↗

PubMed2005

The application of surgical cordectomy in the management of an intramedullary-extramedullary atypical meningioma: case report and literature review.

BACKGROUND: The English literature describes only four cases of intraspinal tumors requiring surgical intervention in the form of cordectomy; none of these cases was for meningiomas. Intraspinal meningiomas, typically extramedullary-intradural, require treatment in the form of resection with dural margin excision. The presentation of an intramedullary atypical World Health Organization grade II meningioma is rare. The authors report a case of a transformed intramedullary-extramedullary atypical meningioma treated with cordectomy. METHODS: The patient was a 65-year-old woman who presented with a recurrent thoracic meningioma status post three attempted resections, radiation therapy, and a trial of hydroxyurea chemotherapy. The patient presented paraplegic with reports of burning paresthesias bilaterally in her upper extremities 12 months after her third resection attempt. RESULTS: Magnetic resonance imaging on this current presentation revealed a heterogeneously enhancing hypointense mass extending from T2 to T6. Extension of abnormal T2 signal within the cord superiorly to C7 was noted with a 1-cm enhancing extra-axial lesion at T10 and an extradural mass posteriorly T12 also noted. The patient underwent a T2-T7 laminectomy with a T2-T8 cordectomy. Two months postoperatively, the patient was doing well with no further deterioration in neurologic function. CONCLUSIONS: This case highlights the viability of surgical cordectomy in the treatment of varying intramedullary processes under appropriate indications.

Aged↗

PubMed2002

Naloxone increases pain induced by topical capsaicin in healthy human volunteers.

Opioid receptors occur in locations of strategic importance within the central nervous system for modulation of pain. Is pain reduced by ongoing inhibition mediated by activation of these receptors? Experiments to date in which the opioid-receptor antagonist, naloxone, is administered during a painful event have yielded unclear results. Topically applied capsaicin can be used to induce tonic pain of moderate to severe intensity without tissue injury and is an ideal stimulus for studying acute pain modulation. We therefore conducted a placebo-controlled double-blind crossover study to investigate the effects of naloxone on capsaicin-induced pain (five men, four women, aged 29 +/- 5 years). Capsaicin (10%) was applied topically and subjects rated pain every 2 min. The subjects were told that any drug given to them could increase, decrease, or not change their pain sensation. Pain plateaued after 20 min. At 26 min subjects received either naloxone or placebo in double-blind fashion. At 56 min subjects received the alternative (placebo or naloxone). In a second session the order of presentation was reversed. The naloxone induced a significant increase in pain compared both to baseline (P < 0.01) and placebo (P < 0.01). The peak effect, reached at 12-20 min after naloxone delivery, was 59% greater than placebo. This experiment suggests that acute pain is actively suppressed by endogenous opioid-receptor activation.

Administration, Topical↗