Holmes tremor: a delayed complication after resection of brainstem cavernomas.

OBJECTIVE: In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs). METHODS: After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT. RESULTS: From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005). CONCLUSIONS: Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.

Aesthetic Cranial Vault Expansion in a Child With Slit Ventricle Syndrome and Eumorphic Face.

Ventricular shunting procedures represent the classical surgical treatment for hydrocephalus. Slit ventricle syndrome (SVS) with craniocerebral disproportion (CCD) and secondary craniosynostosis (SCS) is a well-known but uncommon complication following cerebrospinal fluid (CSF) shunting in children. Its general management includes shunt upgrade or revision, placement of anti-siphon devices, lumbo-peritoneal shunting, and endoscopic third ventriculostomy. Cranial expansion is generally considered a major procedure and is indicated when less invasive treatments fail. In these cases, SVS and associated SCS have been usually managed through anterior cranial vault expansion. This procedure aims to decrease the risk of further shunt revisions and to improve neurologic symptoms, but it takes the disadvantage of considerable iatrogenic alterations of the facial proportions. The authors report a case of a 6-year old boy with SVS and SCS, who maintained eumorphic face and was treated by an innovative post-coronal vault expansion ensuring a wide volume increase while avoiding any change of facial conformation.

Hydrocephalus due to a Cavernoma-Like Lesion of an Obliterated Cerebral Arteriovenous Malformation Treated by Embolization and Radiosurgery.

BACKGROUND: Gamma-Knife radiosurgery can be the treatment of choice for small cerebral arteriovenous malformations (AVMs) in eloquent brain areas or, in association with endovascular treatment, for large and complex AVMs. Among the possible delayed complications occurring after radiosurgery of AVMs, de novo formation of a cavernoma has only recently been described. The authors report a unique case of communicating hydrocephalus with highly proteinaceous cerebrospinal fluid due to a cavernoma-like lesion of an obliterated cerebral AVM treated by embolization and radiosurgery. CASE DESCRIPTION: A 43-year-old female patient with a left parieto-occipital AVM (Spetzler-Martin grade III) underwent a multimodality treatment comprising several endovascular procedures and Gamma-Knife radiosurgery. At the follow-up angiograms, the AVM was completely obliterated. Twelve years later, she came back to our attention for headache and vomit with the radiological evidence of brain edema, severe hydrocephalus, and a chronic encapsulated intracerebral hematoma. At the beginning, the drainage of hydrocephalus proved ineffective to improve symptoms and edema. Therefore, the surgical resection of both the obliterated AVM and the cavernoma-like lesion-histologically confirmed-was necessary. The hydrocephalus resolved as well as the cerebral edema after 3 weeks, without necessity of a ventriculoperitoneal shunt. CONCLUSIONS: In previous neurosurgical literature, the association of a caveroma-like lesion in an obliterated AVM and communicating hydrocephalus with highly proteinaceous cerebrospinal fluid has not yet been discussed. We believe that only the surgical resection of both the obliterated AVM and the cavernoma-like lesion can lead to complete clinical recovery of the hydrocephalus.

Isolated Pediatric Intramedullary Schwannoma: Case Report and Review of Literature.

BACKGROUND: Intramedullary (IM) schwannomas are rare entities representing 0.3%-1% of intramedullary tumors and 1.1% of spinal schwannomas. Beside many theories proposed, their rare occurrence might be related to the absence of Schwann cells in the spinal cord. Pediatric IM schwannomas are uncommon, and in the absence of neurofibromatosis they are extremely rare. To date, few cases have been reported in the literature. CASE DESCRIPTION: We describe the case of an 8-year-old female affected by a progressive paraparesis. Neuroradiologic investigations showed an oval-shaped mass at the level of T10-T11. The patient underwent surgery, performed under neurophysiologic monitoring. The patient was operated on with complete removal of the lesion. The postoperative course was uneventful. CONCLUSIONS: The clinical, neuroradiologic, and intraoperative findings are presented, along with a review of the literature. Despite the number of lesions potentially compressing the spinal cord, IM schwannoma is rare but should be taken into account in the differential diagnosis.

Giant Cell Ependymoma of Cervicomedullary Junction: A Case Report of a Long-Term Survivor and Literature Review.

BACKGROUND: Ependymoma accounts for 3%-9% of all neuroepithelial tumors. Giant cell ependymoma (GCE) is a rare and distinct variant, with only 22 cases described in the literature. The 2007 World Health Organization classification first acknowledged this rare subtype. The cytologic features of GCE include the presence of pleomorphic giant cells with several cellular atypias, which at intraoperative frozen diagnosis may appear to be high-grade glial lesions. Despite its apparently malignant histology, GCE seems to be a neoplasm with a relatively good prognosis. Extended tumor removal is the gold standard without adjuvant treatment. CASE DESCRIPTION: We describe the first case, to our knowledge, of GCE situated at the cervicomedullary junction in a 62-year-old patient. Surgery was performed with combined intraoperative monitoring of motor evoked potentials and somatosensory evoked potentials. Intraoperative frozen diagnosis revealed a high-grade glial neoplasm; however, gross total resection was achieved. The definitive diagnosis was GCE. At follow-up evaluation 11 years after surgery, the patient did not present with any tumor recurrence. CONCLUSIONS: As the intraoperative diagnosis can be misleading, whenever a cleavage plane is recognized, it is essential to perform a gross total resection with the aid of intraoperative neurophysiologic monitoring, to improve prognosis and neurologic outcome. Data reported in the literature show that prognosis is mainly influenced by grade of resection.

Recurrent lumbar disc herniation: Is there a correlation with the surgical technique? A multivariate analysis.

PURPOSE: The recurrence of a lumbar disc herniation (LDH) is a common cause of poor outcome following lumbar discectomy. The aim of this study was to assess a potential relationship between the incidence of recurrent LDH and the surgical technique used. Furthermore, we tried to define the best surgical technique for the treatment of recurrent LDH to limit subsequent recurrences. MATERIALS AND METHODS: A retrospective study was conducted on 979 consecutive patients treated for LDH. A multivariate analysis tried to identify a possible correlation between (1) the surgical technique used to treat the primary LDH and its recurrence; (2) technique used to treat the recurrence of LDH and the second recurrence; and (3) incidence of recurrence and clinical outcome. Data were analyzed with the Pearson's Chi-square test for its significance. RESULTS: In 582 cases (59.4%), a discectomy was performed, while in 381 (40.6%), a herniectomy was undertaken. In 16 cases, a procedure marked as "other" was performed. Among all patients, 110 (11.2%) had a recurrence. Recurrent LDH was observed in 55 patients following discectomy (9.45%), in 45 following herniectomy (11.8%), and in 10 (62.5%) following other surgery. Our data showed that 90.5% of discectomies and 88.2% of the herniectomies had a good clinical outcome, whereas other surgeries presented a recurrence rate of 62.5% (Pearson's χ2< 0.001). No statistical differences were observed between discectomy or herniectomy, for the treatment of the recurrence, and the incidence for the second recurrences (P > 0.05). A significant statistical correlation emerged between the use of other techniques and the incidence for the second recurrences (P < 0.05). CONCLUSIONS: The recurrence of an LDH is one of the most feared complications following surgery. Although the standard discectomy has been considered more protective toward the recurrence compared to herniectomy, our data suggest that there is no significant correlation between the surgical technique and the risk of LDH recurrence.