“Acquired” Chiari I malformation

1994 ◽  
Vol 80 (6) ◽  
pp. 1099-1102 ◽  
Author(s):  
Paul P. Huang ◽  
Shlomo Constantini
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Chiari I Malformation ◽  
Congenital Defect ◽  
Content Type ◽  
Chiari I ◽  
Gait Abnormalities ◽  
Cerebellar Tonsils ◽  
Tonsillar Descent ◽  
Fine Print

✓ Tonsillar descent of the cerebellum in Chiari I malformations is often considered a congenital defect. A patient is presented in whom magnetic resonance (MR) imaging revealed normally positioned cerebellar tonsils; however, 1 year later MR imaging was repeated for evaluation of gait abnormalities and showed descent of the cerebellar tonsils. This case illustrates worsening symptoms with progressive descent of the cerebellar tonsils and suggests that Chiari I malformations can evolve postnatally.

Elucidating the pathophysiology of syringomyelia

1999 ◽  
Vol 91 (4) ◽  
pp. 553-562 ◽  
Author(s):  
John D. Heiss ◽  
Nicholas Patronas ◽  
Hetty L. DeVroom ◽  
Thomas Shawker ◽  
Robert Ennis ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Subarachnoid Space ◽  
Foramen Magnum ◽  
Chiari I Malformation ◽  
Content Type ◽  
Cine Mr ◽  
Spinal Subarachnoid Space ◽  
Chiari I ◽  
Cerebellar Tonsils ◽  
Fine Print

Object. Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy.Methods. The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, cervical subarachnoid, and lumbar intrathecal spaces and syrinx. Six months after surgery, clinical examinations, MR imaging studies, and CSF pressure recordings were repeated. Clinical examinations and MR imaging studies were repeated annually. For comparison, 18 healthy volunteers underwent T1-weighted MR imaging, cine MR imaging, and cervical and lumbar subarachnoid pressure testing.Compared with healthy volunteers, before surgery, the patients had decreased anteroposterior diameters of the ventral and dorsal CSF spaces at the foramen magnum. In patients, CSF velocity at the foramen magnum was increased, but CSF flow was reduced. Transmission of intracranial pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was partially obstructed. Spinal CSF compliance was reduced, whereas cervical subarachnoid pressure and pulse pressure were increased. Syrinx fluid flowed inferiorly during systole and superiorly during diastole on cine MR imaging. At surgery, the cerebellar tonsils abruptly descended during systole and ascended during diastole, and the upper pole of the syrinx contracted in a manner synchronous with tonsillar descent and with the peak systolic cervical subarachnoid pressure wave. Following surgery, the diameter of the CSF passages at the foramen magnum increased compared with preoperative values, and the maximum flow rate of CSF across the foramen magnum during systole increased. Transmission of pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was normal and cervical subarachnoid mean pressure and pulse pressure decreased to normal. The maximum syrinx diameter decreased on MR imaging in all patients. Cine MR imaging documented reduced velocity and flow of the syrinx fluid. Clinical symptoms and signs improved or remained stable in all patients, and the tonsils resumed a normal shape.Conclusions. The progression of syringomyelia associated with Chiari I malformation is produced by the action of the cerebellar tonsils, which partially occlude the subarachnoid space at the foramen magnum and act as a piston on the partially enclosed spinal subarachnoid space. This creates enlarged cervical subarachnoid pressure waves that compress the spinal cord from without, not from within, and propagate syrinx fluid caudally with each heartbeat, which leads to syrinx progression. The disappearance of the abnormal shape and position of the tonsils after simple decompressive extraarachnoidal surgery suggests that the Chiari I malformation of the cerebellar tonsils is acquired, not congenital. Surgery limited to suboccipital craniectomy, C-1 laminectomy, and duraplasty eliminates this mechanism and eliminates syringomyelia and its progression without the risk of more invasive procedures.

Spontaneous decompression of syringomyelia: magnetic resonance imaging findings

1991 ◽  
Vol 74 (2) ◽  
pp. 283-286 ◽  
Author(s):  
Clifford R. Jack ◽  
Emre Kokmen ◽  
Burton M. Onofrio
Keyword(s):  
Magnetic Resonance ◽  
Complete Resolution ◽  
Chiari I Malformation ◽  
Minimal Change ◽  
Imaging Findings ◽  
Resonance Imaging ◽  
Content Type ◽  
Magnetic Resonance Studies ◽  
Chiari I ◽  
Fine Print

✓ The case of a 30-year-old woman with Chiari I malformation and a cervicothoracic syrinx is presented. The patient was followed clinically over a 2½-year period. Spontaneous and complete resolution of the syrinx, as documented by serial magnetic resonance studies, was accompanied by only a minimal change in objective symptomatology.

Tonsillectomy without craniectomy for the management of infantile Chiari I malformation

2002 ◽  
Vol 97 (5) ◽  
pp. 1018-1022 ◽  
Author(s):  
Jorge A. Lazareff ◽  
Marcelo Galarza ◽  
Tooraj Gravori ◽  
Theodore J. Spinks
Keyword(s):  
Failure To Thrive ◽  
Vocal Cord Palsy ◽  
Chiari I Malformation ◽  
Cortical Atrophy ◽  
Limb Weakness ◽  
Content Type ◽  
Time Period ◽  
Chiari I ◽  
Cerebellar Tonsils ◽  
Fine Print

Object. The authors report their experience with 15 pediatric patients who underwent resection or shrinkage of the cerebellar tonsils without craniectomy or laminectomy, for the management of Chiari I malformation. Methods. The procedure was performed in six boys and nine girls with a mean age of 10 years. Thirteen patients presented with the congenital form of this disorder and two patients with Chiari I malformation caused by lumboperitoneal shunting. Clinical complaints included headaches (seven patients), scoliosis (four patients), numbness of the extremities (four patients), and upper-limb weakness (two patients). Two patients presented with failure to thrive and one with vocal cord palsy. Eight patients (six girls and two boys) had syringomyelia. The patients' symptoms had developed within a mean time period of 21 months (range 1–70 months). In all patients the cerebellar tonsils were exposed through a dura mater—arachnoid incision at the occipitoatlantal space. In seven patients the tonsils were resected and in the remaining eight patients the tonsils were shrunk by coagulating their surfaces. All patients improved postoperatively. Gliosis with cortical atrophy was observed in the resected neural tissue. Syringomyelia was reduced in seven of eight patients. The mean length of the follow-up period was 7 months. Conclusions. Removal of herniated cerebellar tonsils can be sufficient for alleviating symptoms in patients with Chiari I malformations.

Percutaneous thecoperitoneal shunt for syringomyelia

1991 ◽  
Vol 74 (5) ◽  
pp. 827-831 ◽  
Author(s):  
Umesh S. Vengsarkar ◽  
Venilal G. Panchal ◽  
Parimal D. Tripathi ◽  
Sushil V. Patkar ◽  
Alok Agarwal ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Clinical Improvement ◽  
Clinical Presentation ◽  
Simple Procedure ◽  
Chiari I Malformation ◽  
Magnetic Resonance Images ◽  
Content Type ◽  
The Third ◽  
Chiari I ◽  
Fine Print

✓ Between January and April, 1990, three consecutive cases of syringomyelia were treated by percutaneous placement of thecoperitoneal shunts. Two of these patients had undergone craniovertebral decompression earlier at other centers and the third was treated primarily by a thecoperitoneal shunt. In each case, the syrinx was associated with Chiari I malformation, although the clinical presentation was due to a myelopathy. All three patients obtained unequivocal benefit from this simple procedure. Postoperative magnetic resonance images showed considerable shrinkage of the cysts corresponding with clinical improvement.

Tonsillar ectopia and Chiari malformations: monozygotic triplets

1995 ◽  
Vol 82 (3) ◽  
pp. 497-500 ◽  
Author(s):  
Richard K. Cavender ◽  
John H. Schmidt
Keyword(s):  
Magnetic Resonance ◽  
Chiari I Malformation ◽  
Unique Case ◽  
Content Type ◽  
Tonsillar Ectopia ◽  
Chiari I ◽  
Disease Entities ◽  
Criteria For Diagnosis ◽  
Chiari Malformations ◽  
Fine Print

✓ A unique case of monozygotic triplets, each of whom exhibits variable degrees of tonsillar ectopia, is reported. Patient X presented with a Chiari I malformation and associated syringomyelia; examination of patients Y and Z showed 4 mm and 2.5 mm of tonsillar ectopia, respectively. No such case has been reported in the literature. The discussion defines the current magnetic resonance criteria for diagnosis of hindbrain malformations and addresses the question of whether these disorders represent a spectrum or separate disease entities, with specific emphasis on genetic predisposition. Due to the 100% concordance in this case the presence of a common hereditary factor in the etiology of these malformations is highly suggested.

Paroxysmal rage as a presenting symptom of the Chiari I malformation

1999 ◽  
Vol 91 (2) ◽  
pp. 328-329 ◽  
Author(s):  
Roger J. Hudgins
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chiari I Malformation ◽  
Cervical Pain ◽  
Resonance Imaging ◽  
Meningeal Irritation ◽  
Content Type ◽  
Chiari I ◽  
Fine Print ◽  
New Onset

✓ Signs of meningeal irritation including occipital and cervical pain are common in symptomatic children with the Chiari I malformation. The author reports on two children with Chiari I malformations who presented with a previously undescribed symptom presumably caused by intermittent meningeal irritation: paroxysmal rages. In both cases the rages stopped after decompressive surgery. Evaluation including magnetic resonance imaging should be considered in children with new onset of paroxysmal behavioral disorders.

Cerebral dissection from syringomyelia demonstrated using cine magnetic resonance imaging

2001 ◽  
Vol 94 (2) ◽  
pp. 318-321 ◽  
Author(s):  
June Ho Lee ◽  
Chun-Kee Chung ◽  
Hyun Jib Kim
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chiari I Malformation ◽  
Magnetic Resonance Images ◽  
Resonance Imaging ◽  
Content Type ◽  
Suboccipital Craniectomy ◽  
Upper Cervical ◽  
Chiari I ◽  
Fine Print

✓ A 16-year-old boy presented at the authors' emergency department with a sudden deterioration of respiration. He had been paraparetic for 3 years and had become quadriplegic 2 days previously. Magnetic resonance images revealed a Chiari I malformation and a hydromyelic cavity extending from C-1 to T-11. Rostrally, a small cylindrically shaped lesion extended from the cervicomedullary junction to the left semioval center. The patient made a dramatic neurological recovery following suboccipital craniectomy and upper cervical laminectomies with augmentation duraplasties followed by placement of a syringoperitoneal shunt.

Chiari I malformation with syringomyelia

1988 ◽  
Vol 68 (5) ◽  
pp. 726-730 ◽  
Author(s):  
Ulrich Batzdorf
Keyword(s):  
Magnetic Resonance ◽  
Chiari I Malformation ◽  
Adult Onset ◽  
Thoracic Region ◽  
Content Type ◽  
Suboccipital Craniotomy ◽  
Operative Complications ◽  
Upper Cervical ◽  
Chiari I ◽  
Fine Print

✓ Five patients with a Chiari I-syringomyelia complex of adult onset were evaluated by magnetic resonance (MR) imaging. All patients underwent suboccipital craniotomy with upper cervical (C-1 and part of C-2) laminectomy, arachnoid retraction, and duraplasty. Postoperative MR studies of four patients disclosed collapse of the syringomyelic cavity, even when the cavity extended into the thoracic region. This appeared to be a progressive process taking place over several weeks. Operative complications are noted and physiological implications are discussed.

Rapid development of Chiari I malformation in an infant with Seckel syndrome and craniosynostosis

2003 ◽  
Vol 98 (5) ◽  
pp. 1113-1115 ◽  
Author(s):  
Timothy E. Hopkins ◽  
Stephen J. Haines
Keyword(s):  
Mr Imaging ◽  
Posterior Fossa ◽  
Rapid Development ◽  
Chiari I Malformation ◽  
Tonsillar Herniation ◽  
Seckel Syndrome ◽  
Content Type ◽  
Chiari I ◽  
Csf Diversion ◽  
Fine Print

✓ To illustrate the rapidity with which a child can develop a severe, symptomatic Chiari I malformation, the authors present the case of a 3-month-old infant with Seckel syndrome (microcephaly, micrognathia, craniosynostosis, and multiple other abnormalities) and posterior sagittal and bilateral lambdoid synostosis. The infant underwent magnetic resonance (MR) imaging shortly after birth; the initial image demonstrated the cerebellar tonsils in the posterior fossa, with no herniation. He subsequently developed severe apneic episodes and bradycardia; repeated MR imaging at 3 months demonstrated severe tonsillar herniation with compression of the brainstem. The child underwent posterior fossa remodeling surgery, including release of the posterior sagittal and lambdoid sutures and decompression of the Chiari I malformation. The patient's apnea gradually improved; however, he died of complications of pneumonia and sepsis several weeks later. The authors identified from the literature 21 patients in whom there was a documented MR image or other neuroimage that did not reveal evidence of a Chiari I malformation, followed by a subsequent study with clear documentation of the presence of Chiari I malformation. The interval between the initial study and the development of the tonsillar herniation ranged from 11 days to 18.5 years. In most cases, a lumbar cerebrospinal fluid (CSF) diversion had been performed. This patient developed a severely symptomatic Chiari I malformation during a 3-month period. These reports illustrate that the Chiari I malformation can develop rapidly in the face of increased intracranial pressure, craniosynostosis, and spinal CSF diversion.

Retrospective study of surgery-related outcomes in patients with syringomyelia associated with Chiari I malformation: clinical significance of changes in the size and localization of syrinx on pain relief

2004 ◽  
Vol 100 (3) ◽  
pp. 241-244 ◽  
Author(s):  
Masaya Nakamura ◽  
Kazuhiro Chiba ◽  
Takashi Nishizawa ◽  
Hirofumi Maruiwa ◽  
Morio Matsumoto ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Chiari I Malformation ◽  
Preoperative Pain ◽  
Content Type ◽  
Postoperative Changes ◽  
Pain Status ◽  
Chiari I ◽  
Postoperative Improvement ◽  
Pain Improvement ◽  
Fine Print

Object. Pain is one of the major symptoms in patients with syringomyelia; however, its origin is not fully understood, and postoperative improvement of pain is difficult to predict. The objectives of this study were to assess the surgery-related results obtained in patients who underwent treatment for syringomyelia associated with Chiari I malformation, particularly related to pain status, and to identify factors that may influence improvement in postoperative pain by comparing pre- and postoperative magnetic resonance (MR) imaging findings. Methods. The correlation between pre- and postoperative changes in the size and the location of the syrinx and pain improvement was investigated in 25 patients. The shapes of the syringes were classified into three types: central, enlarged, and deviated. In most cases in which the syrinx deviated toward the posterolateral aspect of the spinal cord at the level corresponding to dermatomal distribution of preoperative pain, the lesion remained at the same position postoperatively, and improvement in pain was poor. On the other hand, enlarged-type syringes were the most frequently observed prior to surgery, exhibited diverse changes postoperatively, and improvement in pain status was difficult to predict. When postoperative MR imaging revealed a transformation to the deviated type, poor pain improvement was noted. Conclusions. Neurons in the dorsal horn were thought to be involved in the development of pain as a result of the deafferentiation mechanism in cases of syringomyelia.

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