Endoscopic resection of hypothalamic hamartomas for refractory symptomatic epilepsy.

BACKGROUND: Hypothalamic hamartomas (HHs), rare developmental abnormalities of the inferior hypothalamus, often cause refractory, symptomatic, mixed epilepsy, including gelastic seizures. We present 37 patients with HH who underwent transcortical transventricular endoscopic resection. METHODS: Between October 2003 and April 2005, 42 consecutive patients with refractory epilepsy who underwent endoscopic resection of HH were studied prospectively. The endoscope was held by an articulated pneumatic arm and tracked with a frameless stereotactic neuronavigation system. Data collection and follow-up were performed by personal interview. Five patients were excluded. The remaining 37 patients (22 males, 15 females; median age 11.8 years; range 8 months to 55 years) had frequent and usually multiple types of seizures. RESULTS: Postoperative MRI confirmed 100% resection of the HH from the hypothalamus in 12 patients. At last follow-up (median 21 months; range 13-28 months), 18 (48.6%) patients were seizure free. Seizures were reduced more than 90% in 26 patients (70.3%) and by 50% to 90% in 8 patients (21.6%). Overall, the mean postoperative stay was shorter in the endoscopic patients compared with our previously reported patients who underwent transcallosal resection (mean 4.1 days vs 7.7 days, respectively; p = 0.0006). The main complications were permanent short-term memory loss in 3 patients and small thalamic infarcts in 11 patients (asymptomatic in 9). CONCLUSIONS: Endoscopic resection of hypothalamic hamartoma (HH) is a safe and effective treatment for seizures. Its efficacy seems to be comparable to that of transcallosal resection of HH, but postoperative recovery time is significantly shorter.

Surgical treatment of posttraumatic cystic and tethered spinal cords.

Posttraumatic syringomyelia as a cause of progressive neurologic deterioration has been well described. More recently, the noncystic posttraumatic tethered cord has been associated with identical progressive neurologic deterioration. A retrospective analysis of patients treated surgically with spinal cord untethering and/or cyst shunting to arrest a progressive myelopathy from a posttraumatic tethered and/or cystic cord was performed. Emphasis was on outcome using the American Spinal Injury Association (ASIA) sensory and motor scoring systems. During an 18-month period from May 1993 to December 1994, 70 patients with spinal cord injury were operated upon for tethered and/or cystic spinal cords because of a progressive myelopathy and deteriorating ASIA sensory/motor scores. Fifty-nine patients had follow-up data 1 year postoperatively. At the 1 year follow-up, there was small improvement in light touch sensory scores (0.67 points), pinprick scores (1.3 points), and motor scores (0.41 points) demonstrating that the progression of the myelopathic process was arrested. Thirty-four of these 59 patients had no previous surgery to their spinal cords. At 1 year follow-up, light touch scores improved on average 2.38 points, pinprick scores 3.88 points (p < 0.05), and motor scores 1.47 points, suggesting better outcome with first-time surgery. Of this latter group, 64.3% regained a lost function, 62.5% saw improvement in spasticity, 55.6% had substantial improvement in neurogenic pain, and 95.8% felt that surgery prevented further neurologic deterioration.

Ethanol endovascular management of brain arteriovenous malformations: initial results.

OBJECTIVE: The goal was to determine the safety and efficacy of absolute ethyl alcohol treatment in the management of intra-axial brain arteriovenous malformations (AVMs). METHODS: Seventeen patients (eight female and nine male patients; mean age, 41 yr) underwent ethanol endovascular therapy for treatment of their brain AVMs. Superselective amytal testing preceded all procedures. Neuroleptic intravenous anesthesia was used for 16 patients, and general anesthesia was used for 1 patient. Follow-up monitoring consisted of clinical evaluations, magnetic resonance imaging, and arteriography. RESULTS: In follow-up evaluations (mean follow-up period, 13 mo) after embolization of brain AVMs, neither vascular recanalization nor the neovascular recruitment phenomenon was observed in any patient. Progressive AVM thrombosis at arteriographic follow-up evaluation was a constant feature. Seven patients were cured of their AVMs with ethanol endovascular therapy alone. Three patients were cured of their lesions with ethanol embolization plus surgical resection. One patient was cured of his lesion with ethanol embolization and radiation therapy of the residual nidus. Three patients underwent only partial therapy, with significant improvement in symptoms. Three patients are currently undergoing ethanol endovascular therapy. Complications occurred with 8 of 17 patients, most of which were transient. Two patients died because of late subarachnoid hemorrhages, one patient 4 months and one patient 14 months after partial therapy. CONCLUSION: Progressive and permanent AVM occlusion is a common finding in arteriographic follow-up evaluations. In no patients did arterial recanalization or the neovascular recruitment phenomenon occur. Our initial results indicate that ethanol has a permanence that is seldom encountered with other embolic agents. With aggressive decadron therapy, the complications related to swelling in the brain are largely reversible.

Facial nerve stimulation after Nucleus 22-channel cochlear implantation.

OBJECTIVE: To review the clinical features, radiographic findings, and programming strategies used in our population of patients who developed facial nerve stimulation after cochlear implantation. STUDY DESIGN AND SETTING: Patients referred to our nonprofit, outpatient facility were studied prospectively. PATIENTS: The study consisted of 14 patients with facial nerve stimulation after placement of the Nucleus 22-channel cochlear implant. INTERVENTIONS: Records were reviewed retrospectively, and patients were studied with three-dimensional computed tomographic scanning techniques. Electrical testing was performed, and various cochlear implant programming strategies were evaluated. MAIN OUTCOME MEASURES: Important clinical features were reviewed. The radiographic and anatomical relationships of the facial nerve to the cochlea were evaluated, and the programming strategies used to effectively control facial nerve stimulation were reviewed. RESULTS: Prevalence of facial nerve stimulation in our population was 7%. The most common cause was otosclerosis. Anatomical data confirmed the close proximity of the basal turn of the cochlea and the labyrinthine segment of the facial nerve. There was a high correlation between the electrodes causing symptoms and those found radiographically to be closest to the labyrinthine segment of the facial nerve. We were able to control facial nerve stimulation in all patients through programming mode changes. CONCLUSIONS: Otosclerosis appears to be a risk factor for developing facial nerve stimulation after cochlear implantation, and the site of stimulation appears to be the labyrinthine segment of the facial nerve. Familiarity with more elaborate programming techniques is critical to managing patients with this complication.

Normal evoked otoacoustic emissions with a profound hearing loss due to a juvenile pilocytic astrocytoma.

An interesting case is reported of an 11-year-old girl who experienced a sudden, profound right-sided hearing loss at the age of 5 years after hearing a "pop" and the sound of rushing water in her right ear. At that time the patient was thought to have Mondini's deformity, and a perilymphatic fistula of the oval window in the right ear. Six years later she was diagnosed with a juvenile pilocytic astrocytoma of the pons with an exophytic component extending into the cerebellopontine angle. Of particular interest in this case is the presence of evoked otoacoustic emissions in the right ear with a profound neural hearing loss. The presence of transient evoked and distortion product otoacoustic emissions confirmed normal sensory outer hair cell function and an intact peripheral auditory system in a clinically deaf ear, thus indicating hearing loss due to a neural component instead of a sensory component, which was previously assumed.

Dermoids of the eustachian tube: CT and MR findings with histologic correlation.

Two patients with congenital dermoids of the eustachian tube presented with recurrent otitis media and chronic otorrhea resistant to antimicrobial therapy. CT demonstrated fat density, homogeneous lesions, filling and expanding the eustachian tube. On MR, signal from the lesions was consistent with fat, and the relationship with the internal carotid artery was better delineated than by CT. Microscopically, the masses consisted of a conglomeration of ectodermal and mesodermal elements.

Review of the embryologic development of the pituitary gland and report of a case of hypophyseal duplication detected by MRI.

We describe the clinical manifestations, associated abnormalities, MRI appearances and pathologic significance of a case of hypophyseal duplication. A 16-year-old girl presented with delayed sexual development and history of midline craniofacial anomalies. MRI revealed paired infundibula extending inferiorly to two small pituitary glands, a midline hypothalamic mass, and a midline cleft in the basisphenoid. Twelve cases of pituitary duplication have previously been described. The suggested pathogenesis is duplication of the prechordal plate and anterior end of the notochord during early embryologic development.

Meningioangiomatosis of the brain stem. Case report.

The case is reported of meningioangiomatosis of the brain stem in a 3 1/2-year-old girl who suffered from vomiting, left facial weakness, difficulty in swallowing, and ataxia. This is believed to be the first reported case of meningioangiomatosis in the brain stem. Computerized tomography showed an intensely enhancing hyperdense mass in the left restiform body. Magnetic resonance imaging revealed that the lesion was isointense to gray matter on the T1-weighted image and hypointense on the T2-weighted image, with a surrounding zone of high T2 signal and intense enhancement. Angiography was normal. Surgical exploration demonstrated an intramedullary firm mass that was partially resected. Histologically, the mass consisted of a low-grade lesion of meningeal origin with spindle cells in a whorling pattern that were occasionally focused around small vessels. On 2-year follow-up imaging, the lesion remains unchanged in size. Certain particularities of this lesion are discussed in the context of the literature.

Acquired Chiari malformations: incidence, diagnosis, and management.

The acquired descent of the cerebellar tonsils radiographically indistinguishable from Chiari I malformations has been previously reported. The relationship between lumbar shunting procedures for hydrocephalus and symptomatic Chiari malformations has been established. We report the cases of 10 children with lumboperitoneal shunts in whom previous radiographic studies had confirmed a normal hindbrain configuration. Seven of the 10 patients acquired tonsillar descent into the foramen magnum, detected by magnetic resonance imaging, whereas the others remained normal. Four of seven patients were symptomatic; two underwent the removal of the lumboperitoneal shunt and conversion to a ventriculoperitoneal shunt, and two underwent posterior fossa decompression. Further magnetic resonance imaging revealed that one of the two patients who underwent conversion shows ascent of the cerebellar tonsils. All four patients became asymptomatic less than 6 months after treatment. In this article, we discuss seven cases of acquired Chiari malformations and the complete reversal of an acquired Chiari malformation after surgical treatment, as documented by magnetic resonance imaging. Cases of asymptomatic acquired Chiari malformations are reported, including those resulting from shunting for intracranial hypertension without hydrocephalus. We conclude that a craniospinal pressure gradient creates a potential for cerebellar tonsil descent and recommend that ventriculoperitoneal shunting be performed in children with communicating hydrocephalus to avoid this potential complication. We also recommend annual surveillance of the cervicomedullary junction in children with lumboperitoneal shunting. Finally, if symptomatic tonsillar descent occurs from lumbar shunting, a trial conversion to ventriculoperitoneal shunting may eliminate the need for posterior fossa decompression.

Comparison of T2-weighted spin-echo and fast spin-echo techniques in the evaluation of myelination.

To evaluate T2-weighed fast spin-echo (FSE) and conventional spin-echo (CSE) magnetic resonance (MR) techniques in the assessment of brain myelination, 100 consecutive pediatric patients were imaged prospectively with both CSE and FSE sequences. All patients underwent a routine MR examination that included T2-weighted CSE imaging (imaging time, 10 minutes 21 seconds) and T2-weighted FSE imaging (imaging time, 2 minutes 5 seconds). The two techniques were compared for estimating the degree of myelination (using normal anatomic landmarks) by blind review. With T2-weighted CSE images as the "gold standard" for estimation of normal myelination, FSE images were evaluated to determine if they showed the degree of myelination similarly to CSE images. There was a strong correlation (P < .01) between CSE and FSE images in the estimation of myelination over a wide range of patient ages.

Cystic malformations of the posterior fossa: differential diagnosis clarified through embryologic analysis.

Cystic or cyst-like malformations of the posterior fossa represent a spectrum of disorders, including the Dandy-Walker malformation, vermian-cerebellar hypoplasia, mega cisterna magna, and arachnoid cyst. Differentiation of these lesions may be difficult with routine cross-sectional imaging; however, an accurate diagnosis is essential for proper treatment planning and genetic counseling. Dandy-Walker malformation is easily diagnosed on the basis of the classic triad: complete or partial agenesis of the vermis, cystic dilatation of the fourth ventricle, and enlarged posterior fossa. Vermian-cerebellar hypoplasia is a general classification that describes congenital malformations with a normal-sized posterior fossa, varying degrees of vermian and cerebellar hypoplasia, and a prominent retrocerebellar cerebrospinal fluid space that communicates freely with a normal or dilated fourth ventricle. Mega cisterna magna can be asymmetric and can manifest apparent mass effect, simulating the appearance of an arachnoid cyst; therefore, ventriculography or cisternography may be needed to demonstrate communication of the cystic mass with the subarachnoid space. A careful review of the embryologic development is essential in understanding these malformations and in making a more accurate radiologic diagnosis.

Stroke in children within a major metropolitan area: the surprising importance of intracerebral hemorrhage.

Our objective was to determine the incidence rate of stroke and stroke subtypes in children. We reviewed the medical records, autopsy records, and brain imaging studies of all children with a possible stroke within the Greater Cincinnati metropolitan area population of nearly 1.3 million during 1988 and 1989. Traumatic brain hemorrhages and germinal matrix hemorrhages were excluded. Of the 295,577 children in Greater Cincinnati, medical records of 178 children were screened. Sixteen cases (13 whites and three blacks) less than age 15 years fit strictly defined criteria for first-ever stroke. The incidence rate for cerebral infarction was 1.2 cases per 100,000 (95% confidence interval, 0.3 to 2.0). The combined incidence rate for intracerebral hemorrhage and subarachnoid hemorrhage was 1.5 cases per 100,000 children (95% confidence interval, 0.4 to 2.3). The incidence rate of all stroke in white children was 2.6 cases per 100,000 (95% confidence interval, 1.2 to 4.1), compared to 3.1 per 100,000 in black children (95% confidence interval, 0 to 6.6). The combined 30-day mortality for intracerebral hemorrhage and subarachnoid hemorrhage was 22% (two of nine) compared to 14% (one of seven) for cerebral infarction. We conclude that in contrast to the picture in adults, hemorrhagic stroke among infants and children is at least as common as ischemic infarction.

Sigmoid sinus thrombosis after closed head injury in children.

In the literature, clinical descriptions of sigmoid sinus thrombosis occurring after closed head injury in children are rare. One to 5 days after trauma to the back of the head, five children (aged 1 to 7 yr) presented with gait ataxia, vomiting, and headache. Trauma was mild in four children. Computed tomography of all the children, performed within 5 days after the injury, showed focal hyperdensity in the region of the left sigmoid sinus. Four children had extra-axial hyperdense collections along the left transverse sinus, and three had skull fractures adjacent to the left sigmoid sinus. Magnetic resonance imaging (MRI) of all the children, performed 2 to 6 days after injury, showed left sigmoid-sinus thrombosis and decreased flow or thrombosis within the lateral third of the left transverse sinus. All the children had MRI scans 4 to 6 weeks after their diagnosis and were followed up for 1 to 12 months. In four children whose symptoms subsided completely within 2 to 10 weeks, MRI showed recanalization of the sigmoid sinus within 4 to 6 weeks after injury. In one child whose symptoms resolved after 6 months, sigmoid-sinus thrombosis persisted with the formation of collateral flow. We conclude that traumatic sigmoid-sinus thrombosis should be suspected when a child has persistent or delayed gait ataxia and vomiting after injury to the back of the head. Computed tomography characteristically demonstrated focal hyperdensity within the sigmoid sinus that we term the dense sigmoid-sinus sign. Because the sinus recanalized and the symptoms subsided in most children within 6 weeks, we conclude that prophylactic medical or surgical intervention is not indicated.

Phase III multicenter clinical investigation to determine the safety and efficacy of gadoteridol in children suspected of having neurologic disease.

A phase III open-label clinical trial was conducted at 11 institutions to determine the safety and efficacy of gadoteridol in children suspected of having neurologic disease. One hundred three children were included in the safety analysis; 92 were evaluated for efficacy (76 intracranial and 16 spinal examinations). Three adverse events were reported in two children. All adverse events were considered minor and resolved spontaneously without treatment or sequelae. In a comparison of enhanced T1-weighted magnetic resonance images with unenhanced T1- and T2-weighted images, enhancement of disease was noted in 70% of the intracranial and 38% of the spinal examinations. Additional diagnostic information was reported in 82% of the postcontrast intracranial examinations and 62% of the spinal examinations. Use of this additional information contributed to a potential modification of patient diagnosis in 48% of intracranial and 20% of spinal cases with additional information. These results indicate excellent safety and efficacy for use of gadoteridol in children with suspected intracranial or spinal disease.

Evaluation of the craniocervical junction in Down syndrome: correlation of measurements obtained with radiography and MR imaging.

Measurement of the atlas-dens interval is the radiographic standard for identification of patients with Down syndrome at high risk for neurologic injury from spinal cord compression. In 17 pediatric patients with Down syndrome, measurements of the atlas-dens interval, distance between the clivus and posterior odontoid process, and width of the neural canal obtained with plain radiographs were compared to predict the width of the subarachnoid space on magnetic resonance (MR) images. In all patients, cervical radiography and craniocervical MR imaging were prospectively performed during lateral flexion and extension. The width of the subarachnoid space was measured with MR imaging. When the 95% confidence interval for correlation coefficients of regression was used, subarachnoid space width on MR images correlated with neural canal width on radiographs better than with either atlas-dens interval or clivus-posterior odontoid process distance (P = .05). Measurement of neural canal width is a better predictor of potential spinal cord compression than the atlas-dens interval or clivus-posterior odontoid process distance and should be emphasized in screening examinations performed with plain radiography.

MR demonstrates cartilaginous megaepiphyses of the hips in Kniest dysplasia of the young child.

MR imaging of a 2-year-old girl with Kniest dysplasia revealed abnormally large cartilaginous femoral heads. Although ossification of the femoral head is delayed in Kniest dysplasia, it is nonetheless also a megaepiphyseal growth center with respect to the cartilage model.