[Surgical treatment of trigeminal pain]. / Operative Behandlung der Trigeminusneuralgie.

Surgical procedures for treating neuropathic pain, including trigeminal neuralgia (TGN), are categorized into three groups: decompression, ablation, and neuromodulation. Microvascular decompression is the only causal therapy for TGN, applicable favorably in cases of classical TGN due to a vascular nerve conflict. Ablative procedures include both percutaneous and radiosurgical methods, which are mainly used for idiopathic trigeminal neuralgia. For irreversible neuropathies of the trigeminal nerve, the algorithm for other neuropathic pain conditions should be considered, along with the potential use of neuromodulatory techniques. When selecting a therapy, diagnosis, medication side effects, individual patient risks, and treatment outcomes must all be taken into account (current S1 guideline from the German Society of Neurology).

Symptomatic Cerebral Vasospasm after Spontaneous Subarachnoid Hemorrhage: Comparison of Single and Multiple Intra-arterial Treatment with Respect to the Functional Outcome.

OBJECTIVE: In cases of spontaneous subarachnoid hemorrhage (sSAH) and symptomatic cerebral vasospasm (sCVS), multiple intra-arterial treatments (IATs) can be potentially useful for the functional outcome, even if the prognosis is initially poor. But the actual influence of the number of IATs has yet to be clarified. We wanted to assess if there are differences in the functional outcome between patients with a singular IAT and multiple IATs for sCVS after sSAH. METHODS: In a single-center study, 405 consecutive patients with nontraumatic SAH were analyzed retrospectively. A total of 126 developed sCVS, and 86 received IAT (32 singular and 54 multiple, i.e., more than one) with nimodipine with or without percutaneous transluminal angioplasty (PTA). Both groups were compared for demographic data, initial treatment (clipping or endovascular), and initial grading (World Federation of Neurosurgical Societies/Fisher classification, intraventricular hemorrhage, and intracerebral hemorrhage). The modified Rankin Scale (mRS) was used to assess functional outcome at the time of discharge and after 3 and 6 months. The development of CVS-associated infarction was assessed by computed tomography (CT). Categorical variables of the patient groups were analyzed in contingency tables using the Fisher exact test, chi-square test, and the Mann-Whitney U test. Statistical significance was accepted at p < 0.05. RESULTS: Patient groups with singular and multiple IATs were comparable concerning demographic data and initial grading. At the end of follow-up after 6 months, both groups showed comparable functional outcomes. A favorable outcome (mRS: 0-3) was observed in 14 of 26 patients (53.9%) with a single IAT and for 29 of 49 patients (59.2%) with multiple IATs. An unfavorable outcome (mRS: 4-6) occurred in 12 of 26 patients (46.1%) with a single IAT and for 20 of 49 patients (40.8%) with multiple IATs (p = 0.420). In the group with a single IAT, 22 of 32 patients (68.8%) developed CVS-associated infarction; 32 of 54 patients (59.3%) showed brain infarcts after multiple IATs (p = 0.259). CONCLUSION: For patients with sCVS after sSAH, multiple IATs (nimodipine with or without additional PTA) can be applied safely because no significant differences in functional outcome were observed compared with a singular IAT. We conclude that patients should be treated repeatedly if vasospasm reoccurs.

Isoflurane-Associated Mydriasis Mimicking Blown Pupils in a Patient Treated in a Neurointensive Care Unit.

We report a misinterpretation of bilateral mydriasis as blown pupils related to elevated intracranial pressure (ICP) under volatile sedation with isoflurane (Anesthetic Conserving Device [AnaConDa], Hudson RCI, Uppland Vasby, Sweden) in a 59-year-old patient with a severe traumatic brain injury with frontal contusion. The patient showed bilateral mydriasis and a missing light reflex 8 hours after changing sedation from intravenous treatment with midazolam and esketamine to volatile administration of isoflurane. Because cranial computed tomography ruled out signs of cerebral herniation, we assumed the bilateral mydriasis was caused by isoflurane and reduced the isoflurane supply. Upon this reduction the mydriasis regressed, suggesting the observed mydriasis was related to an overdose of isoflurane. Intensivists should be aware of the reported phenomenon to avoid unnecessary diagnostic investigations that might harm the patient. We recommend careful control of the isoflurane dose when fixed and dilated pupils appear in patients without other signs of elevated ICP.

Analysis of extracellular brain chemistry during percutaneous dilational tracheostomy: A retrospective study of 19 patients.

OBJECTIVE: The purpose of this study was to analyze changes in brain tissue chemistry around percutaneous dilational tracheostomy (PDT) in patients with acute brain injury (ABI) in a retrospective single-center analysis. PATIENTS AND METHODS: We included 19 patients who had continuous monitoring of brain tissue chemistry and intracranial pressure (ICP) during a 20h period before and after PDT. Different microdialysis parameters (lactate, pyruvate, lactate pyruvate ratio (LPR), glycerol and glutamate) and values of ICP, cerebral perfusion pressure (CPP) and brain tissue oxygenation (PBrO2) were recorded per hour. Mean values were compared between a 10h period before PDT (prePDT) and after PDT (postPDT). RESULTS: Mean values of cerebral lactate, pyruvate, LPR, glycerol and glutamate did not differ significantly between prePDT and postPDT. In addition, the rate of patients, which exceeded the known threshold was similar between prePDT and postPDT. Only one patient showed a strong increase of cerebral glycerol during the postPDT period, but analysis of subcutaneous glycerol could exclude an intracerebral event. ICP, CPP and PBrO2 did not exhibit significant changes. CONCLUSIONS: We could exclude the occurrence of cerebral metabolic crisis and the excess release of cerebral glutamate and glycerol in a series of 19 patients. Our results support the safety of PDT in patients with ABI.

Impact of percutaneous dilatational tracheostomy in brain injured patients.

OBJECTIVE: Tracheostomy is an established method in the airway management of critically ill patients with traumatic and non-traumatic brain injuries. High priority in the treatment of those patients is to protect vulnerable brain tissue. While bedside percutaneously dilatative tracheostomy (PDT) technique is increasingly used, there is disagreement about the harms of this intervention for the damaged brain. Therefore, discussions about the safety of tracheostomy in those patients must consider direct and indirect cerebral parameters. METHODS: We examined a series of 289 tracheostomies regarding vital signs, respiratory and intracranial parameters in a retrospective study. Complications were recorded and risk factors for a complicated scenario statistically determined. RESULTS: Severe complications were rare (1/289). Arterial hypotension occurred in 3 of 289 cases with a systolic blood pressure below 90mmHg. We had two patients (0.5%) with transient hypoxia, but 43 cases (15%) of severe hypercapnia during PDT. Invasive measurement of brain tissue oxygen tension (PBrO2) ruled out any cerebral hypoxia during the procedure in 39 available cases. Intracranial pressure (ICP) rose temporarily in 24% of the cases. Cerebral perfusion pressure (CPP) however remained unaffected. Surgery time and hypercapnia are capable risk factors for intraoperative ICP elevation. There is no significant difference in intraoperative ICP rises between disease entities. CONCLUSION: PDT is a safe procedure for the most common neurosurgical diseases, even for patients with respiratory insufficiency. Shortening surgical time seems to be the most important factor to avoid ICP increase.