Florian Roser, Luigi Rigante and Mohamed Samy Elhammady
Procedures on cavernous malformations of the brainstem are challenging due to their eloquent location. This accounts especially for recurrent cavernomas as surgical scars, adhesions, and functional shift might have occurred since primary surgery. We report on a 38-year-old female patient with a large recurrent brainstem cavernoma, who underwent previous successful surgery and experienced recurrent bleeding about 2 years later. She harbored a large associated developmental venous anomaly (DVA) traversing the cavernoma through the midline of the brainstem. In order to visualize complete resection and preservation of the DVA at the same time, endoscopic-assisted resection within the brainstem after decompression in the semisitting position was performed.
The video can be found here: https://youtu.be/K1p-Sx7jUpA.
Florian Roser and Marcos S. Tatagiba
Florian Roser, Florian H. Ebner, Marina Liebsch, Klaus Dietz and Marcos Tatagiba
The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway.
Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain).
All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30–50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range.
Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.
Matthias H. Morgalla, Bernd E. Will, Florian Roser and Marcos Tatagiba
A decompressive craniectomy can be a life-saving procedure to relieve critically increased intracranial pressure. The survival of a patient is important as well as the subsequent and long-term quality of life. In this paper the authors' goal was to investigate whether long-term clinical results justify the use of a decompressive craniectomy.
Thirty-three patients (20 males and 13 females) with a mean age of 36.3 years (range 13–60 years) with severe traumatic brain injury (Grades III and IV) and subsequent massive brain swelling were examined. For postoperative assessment the Barthel Index was used. A surgical intervention was based on the following criteria: 1) The intracranial pressure could not be controlled by conservative treatment and constantly exceeded 30 mm Hg (cerebral perfusion pressure < 50 mm Hg). 2) Transcranial Doppler ultrasonography revealed only a systolic flow pattern or systolic peaks. 3) There were no other major injuries. 4) The patient was not older than 60 years.
One-fifth of all patients died and one-fifth remained in a vegetative state. Mild deficits were seen in 6 of 33 patients. A full rehabilitation (Barthel Index 90–100) was achieved in 13 patients (39.4%). Five patients could resume their former occupation, and another 4 had to change jobs.
Age remains to be one of the most important exclusion factors. Decompressive craniectomy provided good clinical results in nearly 40% of patients who were otherwise most likely to die. Therefore, long-term results justify the use of decompressive craniectomy in this case series.
Florian Roser, Rainer Ritz, Matthias Morgalla, Marcos Tatagiba and Antje Bornemann
✓ The authors report on a patient in whom monoradicular pain was caused by ganglionitis of a spinal nerve. Neuroimaging and intraoperative findings identified what were thought to be tumorlike changes in the affected nerve root. The neuropathological examination, however, revealed typical signs of ganglionitis. This rare inflammation usually appears with viral infections, as part of paraneoplastic symptoms, or in the presence of Sjögren disease. Because all of these differential diagnoses were negative in the treated patient, chronic nerve root compression due to disc herniation was suspected as the causative factor for the spinal ganglionitis.
Florian Roser, Makoto Nakamura, Almuth Brandis, Volkmar Hans, Peter Vorkapic and Madjid Samii
✓ The authors describe the first case of an intracranial transition of a melanocytoma into a primary malignant melanoma within a short time. A 37-year-old woman presented with progressive brainstem syndrome due to a tumor, originally diagnosed and treated 12 years earlier, that extended from the petroclival area to the anterior craniocervical junction. The histological workup following subtotal tumor resection of the initial tumor had revealed the typical features of a fibrous melanocytic meningioma without increased proliferation. Ten years after the patient had completed treatment for the melanocytic meningioma, control neuroimaging demonstrated growth of the residual tumor with compression of the brainstem. Another neurosurgical intervention revealed a dark tumor of hard consistency. At this time immunohistochemical examinations demonstrated melanocytic features (expression of vimentin, S100 protein, and melan A) of the lesion with focally increased proliferation (5% of Ki-67—positive cells) but no higher mitotic activity. Clinical signs of deterioration along with imaging-confirmed tumor progression precipitated another operation within 7 months. A neuropathological examination revealed epithelial and anaplastic changes and indicated that the MIB-1 indices were greater than 25%. Pleomorphic changes and a focal high mitotic activity led to the diagnosis of a primary cerebral malignant melanoma. The patient's later clinical course consisted of a rapid diffuse meningeal spread of the lesion throughout the entire brain and spine. Despite whole-brain and stereotactic radiation therapy as well as chemotherapy, the patient died 4 months after the last neuropathological diagnosis. Although grossly resembling a meningioma, melanocytomas lack the former's histological and immunohistochemical features. The biological behavior of a melanocytoma is variable and recurrence may happen after subtotal resection, but intracranial transition into a malignant melanoma has not been observed previously.
Makoto Nakamura, Florian Roser, Mehdi Dormiani, Madjid Samii and Cordula Matthies
Object. Meningiomas of the cerebellopontine angle (CPA) can either arise from or secondarily grow into the inner auditory canal (IAC). This location may have a great impact on hearing function following surgery to remove these lesions. The aim of this retrospective study was to investigate the reliability and predictive importance of auditory brainstem responses (ABRs) for the determination of postoperative auditory function in patients with CPA meningiomas in comparison with results obtained in patients who undergo surgery for vestibular schwannomas.
Methods. In a consecutive series of 1800 meningiomas surgically treated between 1978 and 2002, 421 lesions were located in the CPA. In 38 patients with CPA meningiomas involving the IAC, the findings of intraoperative ABR monitoring and the hearing status of each patient before and after surgery were retrospectively analyzed.
On analysis, ABR monitoring demonstrated stable findings in 24 patients throughout tumor resection and fluctuating signals in 10 patients. Among the 24 patients with stable ABRs, postoperative hearing function improved in three patients, remained the same in 15, and worsened in six patients, including one patient who displayed postoperative deafness. There was even one patient recovering from preoperative deafness. Among the 10 patients with unstable ABRs, intermittent decreases in amplitude and deformations of variable duration in the ABR wave were noted. The risk of deafness was considerably higher in patients with prolonged phases of intermittent ABR deterioration.
Conclusions. The presence and absence of ABRs during surgery for CPA meningiomas reliably predicted the presence and absence of postoperative auditory function. Intermittent deterioration of ABRs may result in postoperative deafness, depending on the duration of these events during surgery. Improvements in hearing are only seen when the ABRs are stable for amplitudes and latencies throughout surgery.