1/8. Headaches, shunts, and obstructive sleep apnea: report of two cases.OBJECTIVE: This report describes two shunted patients evaluated with continuous intracranial pressure (ICP) monitors for worsening headaches and subsequently diagnosed with obstructive sleep apnea. CLINICAL PRESENTATION AND INTERVENTION: ICPs were monitored with strain-gauge sensors inserted into the frontal cortex. After the initial diagnosis of sleep apnea, 8-hour attended polysomnography was performed in each patient. Both patients showed apnea-hypopnea indices greater than 15. Consequently, a "split-night study" was performed to evaluate treatment with titrated nasal continuous positive airway pressure. Patient 1 was a 42-year-old woman (body mass index, 34.1) with a 16-year history of idiopathic intracranial hypertension treated with lumboperitoneal and ventriculoperitoneal shunts. Patient 2 was a 20-year-old man (body mass index, 64.4) with the Arnold-Chiari II malformation. The patient had had a low-pressure shunt since birth. Neurological examinations were normal or unchanged before evaluation. Neurophthalmological examinations were normal. Computed tomographic scans failed to show progressive ventriculomegaly. Awake ICPs were less than 15 mm Hg. Nighttime ICPs during rapid eye movement sleep showed multiple Lundberg A waves associated with obstructive sleep apnea and hypoxemia. blood pressure did not change during these episodes. polysomnography showed apnea-hypopnea indices of 31 and 41, respectively. continuous positive airway pressure reduced apnea-hypopnea indices to 17 and 0, respectively; headaches resolved with outpatient therapy. CONCLUSION: These observations suggest adequate shunting with reduced cerebral compliance in both patients. Altered respiratory mechanics associated with hypoxemia may have triggered cerebral vasodilation and increases in cerebral blood volume, particularly during rapid eye movement sleep. In noncompliant systems, these changes precipitated sustained elevations in ICP and intermittent headaches relieved by continuous positive airway pressure. The clinical patterns also suggest that obstructive sleep apnea should be considered in shunted patients with isolated symptoms of increasing headaches.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
2/8. trigeminal neuralgia secondary to Chiari's malformation--treatment with ventriculoperitoneal shunt.BACKGROUND: trigeminal neuralgia (TN) is most commonly related to vascular compression of the trigeminal nerve. trigeminal neuralgia associated with Chiari's malformation and associated hydrocephalus are rare. CASE DESCRIPTION: A 31-year-old male presented with classical TN affecting the mandibular division of the right trigeminal nerve. His symptoms were poorly controlled with increasing doses of carbamazepine. magnetic resonance imaging scan of brain revealed Chiari's type I malformation and associated hydrocephalus. Approximately 1 month after insertion of a programmable ventriculoperitoneal shunt, his TN resolved. CONCLUSIONS: Chiari's malformation and hydrocephalus are rare associates of TN. The pathophysiology of TN in these cases may be due to neurovascular conflict, related to raised intracranial pressure from the hydrocephalus and/or the small posterior fossa volume in these patients. drainage of associated hydrocephalus may be an effective surgical treatment.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
3/8. sleep apnea and vocal cord paralysis secondary to type I Chiari malformation.A previously healthy 13-year-old boy without myelodysplasia who had mild scoliosis was seen with complaints of nasal congestion, noisy nighttime breathing, and difficulty sleeping. Flattening of the inspiratory loop on the flow-volume curve was found on pulmonary function testing, suggesting a variable extrathoracic obstruction due to a laryngeal lesion. Bilateral abductor vocal cord paralysis and sleep apnea developed precipitously following general anesthesia. Further workup demonstrated a type-I Chiari malformation with syringomyelia. Brainstem abnormalities such as Chiari malformation with secondary tenth cranial nerve deficits should be considered in previously healthy children and adolescents with signs and symptoms of upper airway obstruction and apnea.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
4/8. Ventricular volume reduction technique--a new surgical concept for the intracranial transposition of encephalocele.The authors propose a new operative technique for the intracranial transposition of an encephalocele by using the associated hydrocephalic state. In the first stage, the intracranial pressure buffering effect of the encephalocele sac is reduced by the closing of the dural defect. The repaired dural defect allows intraventricular pulse pressure to produce ventriculomegaly. In the second stage or in infants with hydrocephalus, the extracranially herniated brain is transposed into the intracranial cavity during ventricular shunting with appropriate drainage of cerebrospinal fluid.- - - - - - - - - - ranking = 4keywords = volume (Clic here for more details about this article) |
5/8. Intraoperative cardiovascular collapse in an infant with arnold-chiari malformation.We report a case of an infant with a diagnosis of arnold-chiari malformation who developed acute cardiovascular collapse during posterior fossa decompression surgery. Haemodynamic manifestations were hypotension and bigeminy characterized by resistance to conventional resuscitation. The aetiology was considered to be due to brainstem compression exerted to control surgical bleeding from an inadvertently lacerated sinus at an unusual site, the rim of the foramen magnum. Restoration of blood pressure and disappearance of arrhythmia immediately followed removal of the brainstem compression rather than volume or pharmacological resuscitation.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
6/8. 'Sneeze syncope', basilar invagination and Arnold-Chiari type I malformation.syncope precipitated by sneezing in an adult male associated with an Arnold-Chiari type I malformation and basilar invagination presents a clinical problem in the differential diagnosis and pathological anatomy of Valsalva-related syncope. An abnormally acute clivoaxial angle, small foramen magnum, and type I arnold-chiari malformation appear to be a combination of features intolerant of Valsalva-induced changes in cerebral volume, brain-stem position, CSF fluid dynamics, or blood vessel relationships. Proposed mechanisms of pressure transmission to the area of intracranial pathology are discussed.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
7/8. Chronic respiratory failure in a patient with type I arnold-chiari malformation (ACM1) and syringomyelia.We present the case of a young adult with type I arnold-chiari malformation (AMC1) and syringomyelia who developed central sleep apnoea and chronic respiratory failure, successfully treated with nocturnal noninvasive positive pressure ventilation ventilation (NIPPV). An extensive syringomyelic cavity (from bulbar to L4 segment) with severe impairment of the IX cranial nerve was documented and remains, although reduced, after the neurosurgical treatment. At baseline evaluation, the patient showed a moderate restrictive ventilatory defect, severe hypercapnic respiratory failure, abnormal control of breathing characterized by the absence of response to hypoxia and hypercapnia, and severe nocturnal central apnoeas. Nocturnal NIPPV was then started in the A/C mode with an improvement in blood gas values. Further evaluations were performed 10 and 18 months later. A progressive significant improvement of lung volumes, both in sitting and supine position, associated with a slight improvement of blood-gas values were observed. Nonetheless, the breathing pattern abnormalities persisted. Polysomnographic evaluation during mechanical ventilation showed a normalization of breathing pattern with arterial oxygen saturation (SaO2) > 90% throughout the night.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
8/8. Herniation of cerebellar tonsils following supratentorial shunt placement.Acquired Chiari 1 following ventriculoperitoneal shunting is an extremely unusual event. We report the case of an 8-year-old boy who presented with clinical and radiological signs of cerebellar tonsil herniation shortly after the placement of a cystoperitoneal shunt. Quantitative analysis of posterior fossa volumes (PFV) revealed that the patient had a smaller posterior fossa than age-matched normal controls. This abnormality, expressed as a decreased ratio between the posterior fossa and the supratentorial cavities (PFR), had already been present when the preoperative MRI was done. Our results suggest that preexisting structural abnormalities in the posterior fossa may constitute an important factor in the development tonsillar herniation following supratentorial shunts.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |