✓Choroid plexus cysts are common and typically asymptomatic abnormal folds of the epithelial lining of the choroid plexus. Rarely, these cysts may gradually enlarge and cause outflow obstruction of cerebrospinal fluid. The authors present a case of a large choroid plexus cyst causing acute hydrocephalus in a previously healthy 2-year-old boy. The patient presented with markedly declining mental status, vomiting, and bradycardia over the course of several hours. Computed tomography scans demonstrated enlarged lateral and third ventricles with sulcal effacement, but no obvious mass lesions or hemorrhage. There was no antecedent illness or trauma. A right frontal external ventricular drain was placed in the patient, resulting in decompression of only the right lateral ventricle. Magnetic resonance (MR) imaging demonstrated a lobulated cyst arising from the choroid plexus of the left lateral ventricle and herniating through the foramen of Monro into the third ventricle, occluding both the foramen of Monro and the cerebral aqueduct. The patient underwent an endoscopic fenestration of the cyst, and histological results confirmed that it was a choroid plexus cyst. Postoperative MR imaging showed a marked reduction in the cyst size. The cyst was no longer in the third ventricle, the foramen of Monro and the aqueduct were patent, and the ventricles were decompressed. The patient was discharged home with no deficits. To the authors' knowledge, there are no previous reports of a choroid plexus cyst causing acute hydrocephalus due to herniation into the third ventricle. This case is illustrative because it describes this entity for the first time, and more importantly highlights the need to obtain a diagnosis when a patient presents with acute hydrocephalus without a clear cause.
Brian V. Nahed, Aneela Darbar, Robert Doiron, Ali Saad, Caroline D. Robson and Edward R. Smith
Aneela Darbar, Richard T. Stevens, Adnan H. Siddiqui, James S. McCasland and Charles J. Hodge
The brain shows remarkable capacity for plasticity in response to injury. To maximize the benefits of current neurological treatment and to minimize the impact of injury, the authors examined the ability of commonly administered drugs, dextroamphetamine (D-amphetamine) and phenytoin, to positively or negatively affect the functional recovery of the cerebral cortex following excitotoxic injury.
Previous work from the same laboratory has demonstrated reorganization of whisker functional responses (WFRs) in the rat barrel cortex after excitotoxic lesions were created with kainic acid (KA). In the present study, WFRs were mapped using intrinsic optical signal imaging before and 9 days after creation of the KA lesions. During the post-lesion survival period, animals were either treated with intraperitoneal D-amphetamine, phenytoin, or saline or received no treatment. Following the survival period, WFRs were again measured and compared with prelesion data.
The findings suggest that KA lesions cause increases in WFR areas when compared with controls. Treatment with D-amphetamine further increased the WFR area (p < 0.05) while phenytoin-treated rats showed decreases in WFR areas. There was also a statistically significant difference (p < 0.05) between the D-amphetamine and phenytoin groups.
These results show that 2 commonly used drugs, D-amphetamine and phenytoin, have opposite effects in the functional recovery/plasticity of injured cerebral cortex. The authors' findings emphasize the complex nature of the cortical response to injury and have implications for understanding the biology of the effects of different medications on eventual functional brain recovery.
Stefania Morbidini-Gaffney, Chung-Taik Chung, Tracy Erin Alpert, Nancy Newman, Seung Shin Hahn, Hemangini Shah, Lisa Mitchell, Daniel Bassano, Aneela Darbar, Saeed Ahmed Bajwa and Charles Hodge
The purpose of this study was to assess the efficacy of Gamma Knife surgery (GKS) in treating patients with trigeminal neuralgia (TN). Preliminary results of this study were previously reported. The updated results are reported in this paper.
Ninety seven patients with TN refractory to medical or surgical management underwent GKS between September 1998 and October 2005. Fifteen patients had multiple sclerosis (MS). The radiation dose was escalated from 70 to 99 Gy. The Barrow Neurological Institute Pain Scale (BNIPS) was used to assess pain before and after GKS.
Eighty-four patients were available for evaluation with a mean follow up of 8.9 months. The overall response and complete response rates were 70.2% and 36.9%, respectively. At 12 months, there was a greater improvement in BNIPS scores for patients who were treated with two isocenters compared with those treated with a single isocenter. The mean percentage of pain decrease was 56.26% compared with 11.53% (p < 0.001). Patients treated with two isocenters rather than one and patients receiving greater than 85 Gy compared with lower doses had a longer duration of response. Only nine patients (11%) had mild numbness attributable to the GKS. Five of the nine patients experienced complete resolution of facial numbness on follow up. Patients with MS have a shorter duration of response compared with those without MS (p = 0.35).
These updated results show that GKS continues to be an effective therapy for TN. It appears there is an enhanced response with doses 85 Gy or more and with two isocenters without increased complications.