Cerebellar Ptosis Research Articles

Chiari Type I Revision Decompressive Surgery Indications and Operative Technique: Experience in a Large Adult Cohort

IntroductionChiari Malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, frequently resulting in strain related headaches, and motor/sensory dysfunction. Chiari decompression technique varies significantly, possibly contributing to frequent revisions. We reviewed revision Chiari decompressions at our institution to determine the primary indications for revision and outcomes after revision. MethodWe retrospectively reviewed patients who underwent revision of Chiari decompression at our institution from 2005-2020. Demographics, indications for revision surgery, operative techniques, imaging findings, and pre-/post-operative symptoms were collected. Chi-squared test was performed to determine statistical significance using a p<0.05. Independent predictors of operative outcomes were identified. ResultA total of 46 patients (91% female, mean age 38.8 years) were included for analysis. The median time to revision surgery was 69.1 months (range 0-364 months) with headache (n=37, 80%) being the most commonly recurring symptom. Large craniectomy (n=28, 61%) was the most frequent indication for revision surgery. Thirty-two (70%) patients underwent cranioplasty, 20 (43%) required duraplasty, 15 (33%) required arachnoid dissection, and 15 (33%) required tonsillar reduction during revision surgery. Post-revision follow-up (at 8.9 ± 5.2 months average, range 1-18 months), revealed an average reduction in all Chiari-related symptoms relative to symptoms before the revision. ConclusionThe most common indication for revision Chiari decompression was a large craniectomy resulting in cerebellar ptosis. We found that tonsillar reduction paired with modest craniectomy achieved near-complete resolution of symptoms with minimal complications. For patients with recurrent or persistent sequelae of Chiari malformation after decompression, revision may reduce symptom severity.

Symptomatic Cerebellar Ptosis After Wide Foramen Magnum Decompression for Chiari I Malformation

We present the case of a 22-year-old who developed severe neck pain within two weeks after undergoing posterior fossa decompression for a symptomatic Chiari I malformation. A diagnosis of cerebellar ptosis was made after magnetic resonance imaging (MRI) and he underwent a partial cranioplasty, following which his symptoms resolved. The pathology, diagnostic criteria, and management options are discussed.

Development and treatment of CSF fistula, post-operative headache, cerebellar ptosis in 62 patients who underwent posterior fossa cranioplasty or not following posterior fossa surgery

Objective: The approaches in posterior fossa surgery are used for accessing various tumors and vascular lesions including neuro-glial tumors, vestibular Schwannomas, inclusion tumors, meningiomas. &#x0D; Materials and Methods: A total of 62 patients who underwent operation due to infra-tentorial intra-cranial mass lesion in Neuro-Surgery Clinic between 2014 and 2018 were included in the study.&#x0D; Result: The study was conducted with 62 patients of whom 61.3% (n=38) were males and 38.72% (n=24) were females between 2014 and 2018. While 33.9% (n=21) of the patients underwent cranioplasty, 66.1% (n=41) did not undergo cranioplasty.&#x0D; Conclusion: The preliminary study suggests that cranioplasty is useful for headache and cerebellar ectopy however insufficient for prevention of CNF fistula development.

Inferiorly Directed Posterior Cranial Vault Distraction for Treatment of Chiari Malformations.

The authors present a case series of patients with Chiari I malformations treated with distraction osteogenesis of the posterior cranial vault, utilizing a vertical distraction vector for appropriate cranial vault expansion while mitigating the risks of scaphocephaly and cerebellar ptosis. Patients with syndromic and nonsyndromic Chiari I malformations treated with vertical-vector distraction osteogenesis of the posterior cranial vault were identified from 2008 to 2014. Demographics, preoperative and postoperative clinical symptoms, and perioperative details were assessed. Long-term esthetic outcomes, complications, and symptomatic improvement were evaluated in conjunction with neurosurgery. Nine patients were identified. Five had known syndromes, 2 likely had unidentified syndromes, and 2 were nonsyndromic. Seven had prior Chiari-related surgeries. Most presented with hydrocephalus, motor symptoms, and developmental delay. Operatively, 2 to 3 internal distraction fixators were applied such that the vector of distraction was along a cephalad-caudad axis. Devices were activated on postoperative day 5 and distracted 1mm per day. Three postoperative complications were found within the first 3 months which included a dislodged distraction arm, a device extrusion, and a local cellulitis. No complications affected the clinical outcome. Radiographic follow-up showed good bone formation, decompression of the posterior fossa, improved cerebrospinal fluid flow, and no cerebellar ptosis. Neurological surveillance showed improvement in intracranial pressure, hydrocephalus, motor symptoms, and behavioral problems. The authors have presented 9 patients with Chiari I malformations treated with distraction osteogenesis, along with a novel technique to safely and effectively expand the posterior fossa while minimizing the risk of cerebellar ptosis. Level II (prognostic/risk studies).

Symptomatic ptosis cerebelli after suboccipital craniectomy in a patient with severe brain trauma

ABSTRACTPrimary objective: To report the first case of symptomatic cerebellar ptosis after a large suboccipital craniectomy in a patient with severe brain trauma and a review of the literature. Patient and methods: A 36-year-old man suffered severe traumatic brain injury after a four-metre fall. He underwent a large suboccipital craniectomy because his computed tomography scan revealed a posterior fossa subdural haematoma and cerebellar swelling. Four weeks after admission, he developed communicating hydrocephalus, and a ventriculoperitoneal shunt was placed. Although he experienced good recovery, seven months after the trauma he complained of cephalea, dizziness, recurrent vomiting and diplopia. Magnetic resonance imaging (MRI) showed descent of the cerebellum through a wide bone defect.Results: We performed a posterior fossa cranioplasty after other causes of delayed worsening were ruled out, such as shunt malfunction, overdrainage and ischaemic lesions. The patient improved, and a post-operative MRI confirmed the upward migration of the cerebellum. Conclusions: Cerebellar ptosis must be considered in cases of delayed symptoms after large suboccipital craniectomy regardless of pathology. Posterior fossa cranioplasty to provide structural support to slumped cerebellum can improve or resolve symptoms.

Inferiorly-Directed Posterior Cranial Vault Distraction for Treatment of Chiari Malformations

PURPOSE: Chiari I malformations involve a small posterior fossa and subsequent herniation of the hindbrain, causing altered cerebrospinal fluid flow and intracranial hypertension (Figure 1). Traditional decompressive management uses a posterior fossa craniectomy, which carries limitations and complication risks, including over-correction or the need for re-operation. A large single-stage craniectomy can lead to cerebellar ptosis and new or recurrent symptoms. Distraction of the posterior vault has been effective for relieving intracranial pressure in small case series.1,2 The authors present the largest series of patients with Chiari I malformations treated with posterior cranial vault distraction osteogenesis. Also introduced is a previously unpublished technique utilizing a vertical distraction vector for vault expansion while mitigating the risks of scaphocephaly and cerebellar ptosis.Figure 1: Pre-operative MRI.METHODS: This multi-center study included patients with syndromic and non-syndromic Chiari I malformations treated with vertical-vector distraction osteogenesis of the posterior cranial vault from 2008 to 2014. All patients had follow-up of at least 1 year except one who recently completed the full protocol. Demographics, pre- and post-operative clinical symptoms, and perioperative details were assessed. Postoperative aesthetics, complications, and symptomatic improvement were evaluated with neurosurgery. RESULTS: Nine patients were identified. Five had known syndromes, two likely had unidentified syndromes, and two were non-syndromic. Seven had prior Chiari-related surgeries. Most presented with hydrocephalus, motor symptoms, and developmental delay. Operatively, internal distraction fixators were applied with the distraction vector following a cephalad-caudad axis. Devices were activated on POD5 and distracted 1 mm/day. Three post-operative complications included a dislodged distraction arm, device extrusion, and local cellulitis. No complications affected the clinical outcome. All patients completed the distraction protocol. Radiographic follow-up showed good bone formation, posterior fossa decompression, improved CSF flow, and no cerebellar ptosis (Figure 2). Neurological surveillance showed improvement in intracranial pressure, hydrocephalus, motor symptoms, and behavioral problems. Importantly, with average follow-up of 3.5 years, no patient required reoperation for persistent or recurrent symptoms.Figure 2: Post-Operative MRI.CONCLUSION: The authors have presented the largest experience to date of Chiari I malformations treated with distraction osteogenesis, along with a novel technique to safely and effectively expand the posterior fossa while minimizing risk of cerebellar ptosis, scaphocephaly, and reoperations. With excellent functional, aesthetic, and clinical outcomes from this technique, it appears valuable as an initial or secondary operation for symptomatic Chiari I malformations.

Titanium mesh-assisted dural tenting for an expansile suboccipital cranioplasty in the treatment of Chiari 1 malformation

Cerebellar ptosis and dural prolapse are known complications after posterior craniocervical decompression of Chiari 1 malformation (CM1), and are associated with larger craniectomies, epidural scarring and intradural adhesions. Although management of these complications has been well documented, little has been reported in regards to their prevention. We describe our variation of the posterior fossa decompression technique for CM1 using a titanium mesh-assisted dural tenting expansile cranioplasty to prevent both cerebellar ptosis and dural prolapse. A watertight dural augmentation patch is performed after posterior craniocervical decompression. A titanium mesh cranioplasty is performed to cover the superior aspect of the craniectomy. The duraplasty is then tented to the titanium mesh plate with several interrupted sutures. The titanium mesh plate was intended to prevent postoperative cerebellar ptosis or sag, while the dural tenting was performed to prevent delayed collapse and restenosis of the cistern magna. Four patients with CM1 underwent this technique without complication. Postoperative MRI did not demonstrate cerebellar ptosis, restenosis or collapse of the cisterna magna. The expansile suboccipital cranioplasty with titanium mesh-assisted dural tenting technique is a simple and efficient strategy that may be useful to prevent cerebellar ptosis and dural prolapse and maintain the patency of the surgically created neo-cisterna magna.

Failed Foramen Magnum Decompression for Chiari Malformation: The Challenge of Postoperative Brainstem Shift and Cerebellar Ptosis

Failed Foramen Magnum Decompression for Chiari Malformation: The Challenge of Postoperative Brainstem Shift and Cerebellar Ptosis

Different Types of Syringomyelia and Their Management

Surgical Procedures Posterior Fossa Decompression There are many ways to perform posterior fossa decompression (PFD), although indications for each technique are not clear, and its application depends on clinical manifestations, radiologic findings, dynamics of cerebrospinal fluid (CSF) and especially, the surgeon’s preference. OccipitalCraniectomy.This is the simplest procedure, and it consists of performinganoccipital craniectomywide enough to allow for both decompression and maintenance of the posterior fossaneural elements. The extent of bone removal is very important, because performing a wide occipital window has a high risk of formation of a pseudomeningocele and the socalled cerebellar ptosis; in these cases, symptomsmaynot only recur but even become associated with other cerebellar manifestations. Themost recommendedaverage size for the craniectomy is approximately 2.5 to 3 cm on each side of the midline immediately below the inionup to the foramenmagnumand, depending on the extension of cerebellar tonsillar herniation, it is usually associated with resection of the posterior arch of C1 and sometimes, the lamina of C2 (Figure 1). Most patients with type I Chiari malformation experience improvement in their symptomswith this simpleprocedure. This improvement is because pathologic analysis has shown an increase in collagen fibers, hyaline nodules, and calcification in thedural band of the craniovertebral junction, so bone removal promotes liberationof all these elements andallows restorationofCSF flow. However, if this procedure is chosen as the only treatment, it Different Types of Syringomyelia and Their Management: Part II

Association of Chiari malformation type I and tethered cord syndrome: preliminary results of sectioning filum terminale

Objective The pathogenesis of CM-I is incompletely understood. We describe an association of CM-I and TCS that occurs in a subset of patients with normal size of the PCF. Methods The prevalence of TCS was determined in a consecutively accrued cohort of 2987 patients with CM-I and 289 patients with low-lying cerebellar tonsils (LLCT). Findings in 74 children and 244 adults undergoing SFT were reviewed retrospectively. Posterior cranial fossa size and volume were measured using reconstructed 2D computed tomographic scans and MR images. Results were compared to those in 155 age- and sex-matched healthy control individuals and 280 patients with generic CM-I. The relationships of neural and osseus structures at the CCJ and TLJ were investigated morphometrically on MR images. Intraoperative CDU was used to measure anatomical structures and CSF flow in the lumbar theca. Results Tethered cord syndrome was present in 408 patients with CM-I (14%) and 182 patients with LLCT (63%). In 318 patients undergoing SFT, there were no significant differences in the size or volume of the PCF as compared to healthy control individuals. Morphometric measurements demonstrated elongation of the brain stem (mean, 8.3 mm; P < .001), downward displacement of the medulla (mean, 4.6 mm; P < .001), and normal position of the CMD except in very young patients. Compared to patients with generic CM-I, the FM was significantly enlarged ( P < .001). The FT was typically thin and taut (mean transverse diameter, 0.8 mm). After SFT, the cut ends of the FT distracted widely (mean, 41.7 mm) and CSF flow in the lumbar theca increased from a mean of 0.7 cm/s to a mean of 3.7 cm/s ( P < .001). Symptoms were improved or resolved in 69 children (93%) and 203 adults (83%) and unchanged in 5 children (7%) and 39 adults (16%) and, worse, in 2 adults (1%) over a follow-up period of 6 to 27 months (mean, 16.1 months ± 4.6 SD). Magnetic resonance imaging 1 to 18 months after surgery (mean, 5.7 months ± 3.8 SD) revealed upward migration of the CMD (mean, 5.1 mm, P < .001), ascent of the cerebellar tonsils (mean, 3.8 mm, P < .001), reduction of brain stem length (mean, 3.9 mm, P < .001), and improvement of scoliosis or syringomyelia in some cases. Conclusions Chiari malformation type I/TCS appears to be a unique clinical entity that occurs as a continuum with LLCT/TCS and is distinguished from generic CM-I by enlargement of the FM and the absence of a small PCF. Distinctive features include elongation and downward displacement of the hindbrain, normal position of the CMD, tight FT, and reduced CSF flow in the lumbar theca. There is preliminary evidence that SFT can reverse moderate degrees of tonsillar ectopia and is appropriate treatment for cerebellar ptosis after Chiari surgery in this cohort.

Endoscopic Suboccipital Decompression on Pediatric Chiari Type I

To minimize the invasiveness and maximize the adequacy of Chiari decompression on pediatric patients, 0 degrees and 30 degrees endoscopes were adapted to perform the procedure of suboccipital craniectomy and upper cervical laminectomies. Via a 2-cm midline skin incision, craniectomy and C1 laminectomies were performed by using 0 degrees and 30 degrees lens endoscopes. From October 2003 to December 2006, twenty-six pediatric patients underwent the endoscopic procedure; 16 were male and 10 female, whose ages ranged from 18 months to 16 years (mean+/-SD: 8.07+/-4.45 years). Ten of the 26 patients experienced suboccipital headache and cervical pain, 11 presented with dysphagia, choking, frequent nausea/gaging and vomiting, 6 presented with development delay in fine motor function and speech, 5 experienced ataxia, 6 with synrinx, 4 with hydrocephalus, 1 with pseudotumor cerebri and other symptoms including diplopia, weakness and numbness in extremities, nystagmus, and sleep apnea. Intraoperative monitoring of somatosensory evoked potentials (SSEPs) was used for the procedures in 11 patients. The follow-up period ranged from 4 to 39 months (mean+/-SD: 20.69+/-10.10 months). Postoperative improvement including complete and partial resolution of preoperative symptoms was shown in 92.3% of patients. Two cases have gained no improvement and one experienced postoperative complications - bacterial meningitis - which was successfully controlled with antibiotics. No mortality, cerebrospinal fluid (CSF) leak, pseudomeningocele, cerebellar ptosis and postoperative hydrocephalus were seen in this series. The average length of hospital stay was 2 nights. The use of the endoscope through a suboccipital craniectomy and upper cervical laminectomies has made Chiari decompression in pediatric population comparable with the conventional procedure in terms of minimal surgical invasiveness, recovery time, and complexity of the procedure.

Acute respiratory arrest following partial suboccipital cranioplasty for cerebellar ptosis from Chiari malformation decompression

Cerebellar ptosis is a rare complication following Chiari malformation decompression, and generally is the result of a very large suboccipital craniectomy. This can lead to the descent of the cerebellum through the craniectomy defect, which in turn may result in cerebellar herniation through the surgical defect as well as the reestablishment of contact between the cerebellar tonsils and the brainstem. In addition, dorsal adherence of the herniated cerebellum to the dura mater or dural patch and an associated obstruction of cerebrospinal fluid flow at the cervicomedullary junction may ensue. Such a result is not desirable, in that it reproduces or mimics the pathoanatomical relationships that existed prior to the surgical decompression.

Delayed pseudomyelomeningocele: a rare complication after foramen magnum decompression for Chiari malformation

Background A variety of complications after FMD with or without duraplasty for Chiari malformation have been described. Although cerebellar ptosis through the dural opening and pseudomeningocele are well-known rare complications of this procedure, spinal cord herniation manifesting as pseudomyelomeningocele formation has not previously been cited in the literature. In this report, we present a case of delayed pseudomyleomeningocele after FMD. Case Description A 22-year-old man presented with progressive spinal cord compression symptoms 7 years after undergoing FMD for Chiari malformation. Craniocervical MRI of the patient revealed pseudomyelomeningocele at C1 level together with cord distortion. The patient underwent untethering surgery for spinal cord adhesions; neural tissue was freed microsurgically from the adjacent structures and duraplasty was performed with synthetic graft. In the early postoperative period, his symptoms resolved moderately. Conclusion Neural tissue shift including the spinal cord through the dural opening may occur after a large posterior fossa decompression without duraplasty for Chiari malformation. Postoperative inadequate CSF circulation due to arachnoid scarring around the decompression area may facilitate this type condition. Early diagnosis of such a complication is of vital importance to prevent serious neurologic deficits, and release surgery with proper duraplasty and also restoration of CSF circulation is the choice of treatment.

Posterior Cranial Fossa Box Expansion Leads to Resolution of Symptomatic Cerebellar Ptosis Following Chiari I Malformation Repair

Chiari I malformation occurs when the cerebellar tonsils herniate downward through the foramen magnum into the upper cervical spinal canal. If the posterior fossa craniectomy during corrective surgery leads to excessive enlargement of the foramen magnum, the complication of cerebellar ptosis may result. To treat this difficult problem a posterior cranial fossa box expansion was devised and studied. Patients who developed symptomatic cerebellar ptosis (confirmed by MRI) following cranial vault decompression for Chiari I malformations underwent a posterior fossa box expansion (n=7). This procedure involved coverage of posterior aspect of the enlarged foramen magnum with a split-thickness calvarial bone graft box. The box reconstruction provided separation between the neck musculature, soft tissues from the neural tissue; prevention of cerebellar prolapse; and expansion of the posterior cranial vault. Patients had a mean of 12+/-1 months between initial suboccipital craniectomy and confirmation of symptomatic cerebellar ptosis. Mean age at the time of posterior fossa box reconstruction was 31+/-9 years (range of 14 to 44 years). Preoperative symptoms of headache (7/7, 100%), upper extremity numbness (5/7, 71%) or paresthesias (3/7, 43%), respiratory disturbance (2/7, 29%) and inability to walk (2/7, 29%) improved in all patients postoperatively. At more than 12 month follow-up 6/7 patients (86%) were both disease-free (MRI confirmation) and symptom-free. One out of seven patients had return of headache in a more mild form. Thus, in our patient group the posterior fossa box reconstruction led to resolution of symptomatic cerebellar ptosis following Chiari I malformation repair.

MRT peculiarities of posterior cranial fossa in family syringomyelia

It was found that syringomyelic patients and clinically healthy people out of the families with MRT-features of Chiari malformation, type I, had a confident decrease of depth and square of posterior cranial fossa. Relatives of patients, having no signs of Chiari malformation, type I, had the same changes as well. There was made a conclusion about presence of posterior cranial fossa hypoplasia in all patients with hereditary syryngomyelia and in members of their families, both having MRT-features of Chiari malformation type I, and having no malformation. It was supposed that posterior cranial fossa hypoplasia is a neurovisual reflection of its hereditary phonotype, and the latter in some cases leads to cerebellar tonsil ptosis, and if there are some endogenic and exogenic factors to development of family syringomyelia.

Management of cerebellar ptosis following craniovertebral decompression for Chiari I malformation.

In this report the authors review their experience in the treatment of seven patients with symptomatic cerebellar ptosis following craniovertebral decompression (CVD) for Chiari I malformation. The mean age of the patients was 37 years and the average amount of time between the initial suboccipital craniectomy and evaluation for cerebellar ptosis was 6.8 years. Five patients presented primarily with intractable headache and the remaining two patients with neurological deficits caused by recurrent syringomyelia. Three different surgical modalities were used to treat these patients: ventriculoperitoneal shunt placement (one patient), syringoperitoneal shunt placement (two patients), and partial suboccipital cranioplasty with or without intradural exploration (four patients). The mean follow-up period was 51 months. The three patients who underwent shunt placement procedures experienced poor results, with no evidence of symptom relief and continued neurological deterioration. In contrast, all four patients who underwent cranioplasty experienced good or excellent clinical outcomes. Postoperative magnetic resonance imaging studies revealed a reduction in the size of the syrinx cavity in patients who simultaneously underwent intradural exploration. The emergence of symptomatic cerebellar ptosis following CVD for Chiari I malformation is primarily caused when the suboccipital craniectomy is too large for the specific patient. The cerebellar ptosis usually presents with severe headache and/or neurological deficit due to persistent or recurrent syringomyelia. Partial suboccipital cranioplasty, with or without intradural exploration, is effective in treating this condition.