Cerebellar mutism after posterior fossa tumor resection in children: a multicenter international retrospective study to determine possible modifiable factors.

PURPOSE: A preliminary survey of pediatric neurosurgeons working at different centers around the world suggested differences in clinical practice resulting in variation in the risk of pediatric cerebellar mutism (CM) and cerebellar mutism syndrome (CMS) after posterior fossa (PF) tumor resection. The purposes of this study were (1) to determine the incidence and severity of CM and CMS after midline PF tumor resection in children treated at these centers and (2) to identify potentially modifiable factors related to surgical management (rather than tumor biology) that correlate with the incidence of CM/CMS. METHODS: Attending pediatric neurosurgeons at British Columbia's Children's Hospital (BCCH) and neurosurgeons who completed a pediatric neurosurgery fellowship at BCCH were invited to provide data from the center where they currently practiced. Children aged from birth to less than 18 years who underwent initial midline PF tumor resection within a contemporary, center-selected 2-year period were included. Data was obtained by retrospective chart and imaging review. Modifiable surgical factors that were assessed included pre-resection surgical hydrocephalus treatment, surgical positioning, ultrasonic aspirator use, intraoperative external ventricular drain (EVD) use, surgical access route to the tumor, and extent of resection. CM was defined as decreased or absent speech output postoperatively and CMS as CM plus new or worsened irritability. RESULTS: There were 263 patients from 11 centers in 6 countries (Canada, Germany, the Netherlands, India, Indonesia, and the USA). Median age at surgery was 6 years (range < 1 to 17 years). The overall incidence of postoperative CM was 23.5% (range 14.7-47.6% for centers with data on ≥ 20 patients). The overall incidence of CMS was 6.5% (range 0-10.3% for centers contributing data on ≥ 20 patients). A multivariate logistic regression on the full data set showed no significant association between pre-resection surgical hydrocephalus treatment, prone position, ultrasonic aspirator use, EVD use, telovelar approach, complete or near total resection, or treating center and either postoperative CM or CMS. CONCLUSIONS: While there was variation in surgical management of midline PF tumors among centers participating in this study, the factors in management that were examined did not predict postoperative CM or CMS.

Charles Bonnet Syndrome With Superimposed Delirium.

Charles Bonnet Syndrome (CBS) is diagnosed when a patient who is psychiatrically intact experiences visual hallucinations in the setting of significant visual acuity or field loss. The exact pathophysiology of the CBS hallucinations remains largely unknown. The main theories include the deafferentation theory and perceptual release theory. There are suspected neurotransmitters involved, including acetylcholine and dopamine. There is no defined treatment protocol with medication for CBS, but various psychotropic medications have been used with varying degrees of remission of symptoms. This case report describes a 64-year-old male with Charles Bonnet Syndrome in the setting of superimposed delirium. We note the different medications that were trialed to reduce his CBS symptoms and decrease episodes of behavioral disturbances. Clinical features of this rare syndrome with superimposed delirium are summarized in hopes of providing directions for management and future study.

A Case Report of Nephrotic Syndrome While Undergoing Quinine Therapy.

We summarize the case of an 81-year-old Caucasian female who presented to her family physician with signs and symptoms of nephrotic syndrome following a brief exposure to quinine. Prior to that visit, she was clinically well with no chronic medical ailments and met with her family physician for annual physical assessments. She had taken 11 tablets of quinine for nocturnal leg cramps over the course of 28 days before starting to notice mild peripheral edema, which subsequently progressed, leading to a family physician review. Her initial serum albumin level was 12 g/L, and a 24-hour urine protein output was quantified at 8.14 g/day; she was diagnosed as having nephrotic syndrome. A kidney biopsy confirmed the diagnosis of minimal change disease (MCD). Quinine therapy was stopped, and she was initiated on a tapering regime of prednisone with concurrent cyclosporine therapy. Within a fortnight of starting therapy, she went into remission and her immunosuppressive medications were rapidly tapered and discontinued. This paper reports an association between the use of quinine and subsequent MCD. This case report proposes that the use of quinine has an association with, and may be causal for, the development of minimal change disease. As this is yet an unreported adverse effect, this paper seeks to increase the knowledge of the varied and numerous effects of quinine.

Cyclooxygenase-2 inhibitor-induced acute interstitial nephritis.

A 64-year-old female patient presented to the emergency department with a 3-week history of persistent nausea and vomiting. Her serum creatine prior to admission was 118 µmol/L and on presentation was elevated to 420 µmol/L. On clinical history, she indicated that 3 weeks prior, she had been initiated on a cyclooygenase-2 (COX-2) inhibitor, celecoxib, for her osteoarthritis of her knees. Renal biopsy confirmed the diagnosis of acute interstitial nephritis (AIN). Celecoxib was discontinued and the patient's renal function improved to a discharge creatine of 205-220 µmol/L. Nine months later, her creatine had decreased to 195 µmol/L and she was initiated on tapering doses of prednisone therapy for 4 months, after which time her creatine had improved further to 143 µmol/L. She was later transitioned to mycophenolatemofetil for 9 months and her creatine improved to 110 µmol/L. This report provides further evidence that COX-2 inhibitors are associated with AIN.