Carlos H. A. Carvalho, Marcus André Acioly, Bernd Will and Marcos Tatagiba
Bernhard J. Schaller
Surgical manipulation of the fifth cranial nerve during its intra-or extracranial course may lead to bradycardia or even asystole as well as arterial hypotension, a phenomenon described as the trigeminocardiac reflex (TCR). The authors studied the impact of this reflex on postoperative auditory function in patients undergoing vestibular schwannoma (VS) surgery.
One hundred patients scheduled for VS surgery were studied prospectively for parameters influencing the postoperative auditory function. The evaluation included sex, age, pre-and postoperative auditory function, preoperative mean arterial blood pressure, preoperative medical diseases or medication (for example, antiarrhythmia drugs), tumor size and localization, and the intraoperative occurrence of the TCR.
The TCR, which occurred in 11% of the patients, influenced the postoperative hearing function in the patients with Hannover Class T3 and T4 VSs.
With an overall hearing preservation of 47%, 11.1% of the patients in the TCR group and 51.4% of those in the non-TCR group experienced preserved hearing function postoperatively. In cases involving larger tumors (Hannover Class T3 and T4), an intraoperative TCR was associated with a significantly worse postoperative hearing function during VS surgery (p = 0.005).
The hypotension following TCR is a negative prognostic factor for hearing preservation in patients undergoing VS surgery. Patients' knowledge of this can be increased pre-and postoperatively. Further study of this phenomenon will advance the understanding of the underlying mechanisms and may help to improve hearing preservation by controlling the occurrence of the TCR.
Leonardo de Moura Batista, Marcus André Acioly, Carlos H. Carvalho, Florian H. Ebner and Marcos Tatagiba
✓ The ventriculus terminalis is a small cavity inside the conus medullaris that is formed during the embryonic development. Previous reports regarding cystic lesion of the ventriculus terminalis (CLVT) in adults have detailed a broad and diversified distribution in terms of clinical symptoms, clinical evolution, neurological findings, and treatment. Therefore, nonstandardized management has led to unsatisfactory outcomes. Thus, the authors propose a new classification system in which the clinical presentation is taken into account to standardize the cases and facilitate the proper management of these lesions. Two more cases are described.
The literature was reviewed, dividing the patients into 3 groups by clinical presentation as follows: CLVT Type I, patients with nonspecific neurological symptoms or nonspecific complaints; CLVT Type II, presence of focal neurological deficit; and CLVT Type III, presence of sphincter disturbances (bowel or bladder dysfunction). Two patients were classified as CLVT Type I, 3 as CLVT Type II, and 12 as CLVT Type III. In Type I, no improvement was observed in clinical evaluation after surgery, and stable symptoms were achieved with clinical management. In Type II, 2 patients had total improvement and 1 had subtotal improvement after surgery. Finally, in Type III, 92% of the patients improved postoperatively; among these 33% presented with total improvement. Only 1 case in this group was handled conservatively and no improvement was documented.
This new classification is useful to group the patients into 3 clinical types to provide guidance as to the best management options. Treatment for the Type I lesion seems to be best conducted conservatively, whereas Types II and III seem to be best handled surgically.
Flávio Nigri, Carlos Telles and Marcus André Acioly
Endoscopic third ventriculostomy (ETV) has been established as an effective method in the treatment of tumoral obstructive hydrocephalus. Delayed closure of the ETV stoma has been attributed to scarring involving the third ventricular floor. Secondary obstruction of the stoma due to intraventricular tumor seeding is an extremely rare condition, with only one case described to date. The authors report on a unique case of late closure of the ETV stoma caused by metastatic seeding of a recurrent medulloblastoma 9 years after the initial treatment. The patient was submitted to a second endoscopic procedure in which a reddish mass located just at the third ventricular floor was resected, leading to reopening of the previous ETV stoma.
To the best of the authors' knowledge, this case is the first report of an ETV obstruction due to metastatic CSF seeding of a medulloblastoma. In such cases of late failure of the ETV stoma because of tumor obstruction, a second ETV can be safely performed and lead to adequate function of the stoma, even if limited by the aggressive nature of the disease.
Marcílio Diogo de Oliveira Barbosa, Thiago de Bellis, Marcelo Sampaio Pousa, Rodrigo Sodré Calheiros da Silva, Flávio Assad Garcia and Marcus André Acioly
A 6-year-old girl was admitted to our emergency room because of a gunshot wound in the posterior craniocervical junction. On admission, she was alert, but left hemiplegia and right hemiparesis were noted. Cranial CT scanning showed a retained bullet in the cerebellomedullary cistern without bone destruction. Moreover, fourth ventricle hemorrhage was observed. There were no signs of acute hydrocephalus. The patient underwent suboccipital craniectomy and C-1 laminectomy for bullet removal. Postoperatively, the patient experienced significant neurological improvement. To the best of the authors' knowledge, this is the first documented case of a patient with a retained bullet in the cerebellomedullary cistern. The management strategies in such a unique case are discussed.