Acta neurochirurgica
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Acta neurochirurgica · Jan 1994
Facial motor responses evoked by direct electrical stimulation of the trigeminal root. Localizing value for radiofrequency thermorhizotomy.
In Sweet's description of RF-thermocoagulation for trigeminal neuralgia, the trigeminal nerve was stimulated at 50 c/s to evoke paraesthesias, in order to check the electrode location before the thermolesion is made. In 1979, we changed the frequency to 5 c/s, so as to produce in addition twitches in the masticatory muscles (in stead of the less detectable tetanization produced by 50 c/s stimulation). Since then, we started to observe, also, twitches in the muscles innervated by the facial nerve. ⋯ So, getting EMR in the territory of the pain can be a helpful indicator for an accurate location of the electrode in the trigeminal root, according to its somatotopic organization. These EMR are hypothesized to be due to a trigemino-facial reflex. A preliminary intra-operative EMG study clearly shows that for EMR in the upper part of the face we are dealing with blink-like reflexes, whilst for EMR in the lower face, mechanisms still remain unclear and need further study to be understood.
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Acta neurochirurgica · Jan 1993
Preservation of cochlear nerve function in acoustic neurinoma surgery.
A total of 55 cases with unilateral acoustic neurinoma which were operated on by the lateral suboccipital approach was studied to elucidate factors which influence postoperative hearing acuity. We analyzed several factors: preoperative hearing level, tumour size, tumour consistency (cystic or solid), and anatomical location of the cochlear nerve. The size of the tumours ranged from 1.2 to 5.8 cm in diameter. ⋯ The distance or interrelation between the two nerves had no bearing on postoperative hearing preservation. Postoperatively, hearing acuity was improved in 6 cases (20%) with a mean value of 5.6 dB, unchanged in 3 (10%), and deteriorated in 21 (70%) among the 30 cases with remaining preoperative-hearing. When the tumour was less than 2 cm or cystic, better hearing preservation was expected.(ABSTRACT TRUNCATED AT 250 WORDS)
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Acta neurochirurgica · Jan 1993
Case ReportsSpondylectomy, microsurgical decompression and osteosynthesis in the treatment of complex disorders of the cervical spine.
In 44 patients with complex degenerative, traumatic, neoplastic and infectious disorders of the cervical spine an aggressive surgical approach was used, consisting of spondylectomy, radical microsurgical decompression and osteosynthesis. The patient group consisted of 23 patients with multisegmental cervical spondylosis, 9 patients with primary or metastatic malignant tumour disease spread along the cervical spine, 6 patients with complex cervical trauma and 6 patients with infection affecting one or more cervical segments. Considering the heterogeneity of the group of patients treated, a multitude of neurological symptoms and signs were present. ⋯ None of the patients became neurologically worse after surgery. With regard to the underlying disease, patients with MSCS and tumour had the best results with overall improvement in 62% and 75% respectively. While in patients with infection improvement could be achieved in 58%, improvement in trauma patients was demonstrable in only 34% while in 66% the pre-operative clinical status remained unchanged.(ABSTRACT TRUNCATED AT 400 WORDS)
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Acta neurochirurgica · Jan 1993
Early ischaemia after severe head injury. Preliminary results in patients with diffuse brain injuries.
Ischaemic brain lesions still have a high prevalence in fatally head injured patients and are the single most important cause of secondary brain damage. The present study was undertaken to explore the acute phase of severely head injured patients in order to detect early ischaemia using Robertson's approach of estimating cerebral blood flow (CBF) from calculated arterio-jugular differences of oxygen (AVDO2), lactates (AVDL), and the lactate-oxygen index (LOI). Twenty-eight cases with severe head injury were included (Glasgow Coma Scale Score below or equal to 8). ⋯ The ischaemia score had mean of 4.3 +/- 1.7 in the ischaemic group and 2.7 +/- 1.4 in non-ischaemic patients (p = 0.01). It is concluded that ischaemia is highly prevalent in the early period after severe head injury. Factors potentially responsible of early ischaemia are discussed.
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In a consecutive series of 1150 patients with cerebral aneurysms diagnosed in our department by angiography or autopsy between the years 1977-1990, 1007 patients underwent definitive operative treatment of their aneurysms mainly by early surgery. More than half (55%) were operated on during the first three days after subarachnoid haemorrhage (SAH), and more than three quarters (77%) during the first week. The surgical mortality at 30 days was 9%; at one-year follow-up 13% had died. ⋯ Early surgery did not prevent delayed ischaemic deficits. During the first 72 hours patients in Grades I-III can be operated on safely with good results. The results in Grades IV-V are poor, and we suggest that only cases with large haematomas or considerable hydrocephalus or those improving should be operated on in the first days after SAH, with limited hopes of functional recovery.