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Objective: Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear., Methods: PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158)., Results: The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion., Conclusions: Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.

Patients with metastatic colorectal cancer have a 5-year overall survival of less than 10%. Approximately 45% of patients with metastatic colorectal cancer harbor KRAS mutations. These mutations not only carry a predictive role for the absence of response to anti-EGFR therapy, but also have a negative prognostic impact on the overall survival. There is a growing unmet need for a personalized therapy approach for patients with KRAS -mutant colorectal cancer. In this article, we focus on the therapeutic strategies targeting KRAS - mutant CRC, while reviewing and elaborating on the discovery and physiology of KRAS.

We analyse clinical characteristics, presurgical investigations, surgical procedures and outcome of 137 patients operated-on for a drug-resistant partial epilepsy, in Grenoble from January 1990 to December 1993. Moreover we present data of 63 patients suffering from a "pure" temporal lobe epilepsy selected using the following criteria: 1. surgery limited to temporal lobe structures 2. totally cured after surgery (Engel's class la).

24 deep toxic comas with respiratory assistance were studied by brain-stem reflex and BAEP. Laboratory analysis showed several simultaneous toxics (phenobarbital, benzodiazepines, tricyclic antidepressants...). Three groups of patients were defined: Twelve patients with normal BAEP and with relatively preserved brain-stem reflex (oculocephalic and oculovestibular are often disturbed but photomotor is present). Eleven patients with delayed BAEP and with more disturbed brain-stem reflex (photomotor is missing 3 times). In 2 cases (one of which is mentioned above in group B) brain-stem reflex and BAEP disappear and these patients die. Cerebral anoxia is associated here with toxics. Causes of delayed latencies (group B) are discussed (hypothermia, toxics). BAEP seems important in diagnosis and prognosis of toxic coma.

Results of a study concerning the trigeminal nerve impairment as the one caused by trichlorethylene chronic intoxication by somatosensory evoked potential reveal three kinds of anomalies: increase of the stimulation voltage, excessive latency delay with morphological anomalies and excessive graph amplitude. These anomalies confirm clinical disturbance (hypoesthesia in the trigeminal area) and open a debate about the real mechanism of the trichlorethylene neurotoxicity.

From the study of 65 severe traumatic comas, the authors describe the syndrome of mesodiencephalic dysfunction, because of its frequency and its particular clinical signs. This peculiar level of loss of consciousness is characterized by a coma without mimic and without awakening after painful stimulation, by a stereotyped motor pattern in extension, by a perseverance of the photomotor reflex, while fronto-orbicular and vertical oculo-vestibular reflexes are lacking. This level of deterioration appears to be a critical point in the natural history of comatose patients. If this level is not surpassed, the probability of early death due to evolutive neurological lesion is low (18%). One half of these patients have a good prognosis, more than 75% have an excellent recovery. This high probability of recovery is decreased by a half when the level of mesencephalic dysfunction is reached.

Industrial intoxication by trichloroethylene can produce neurological disturbance of the trigeminal nerve. Therefore, among 105 workers exposed to this toxin, we recorded cortical responses after stimulation of the trigeminal nerve (TSEP) and we compared our results with a control group of 52 subjects. We considered the physical examination exploring, the facial sensitivity and reflexes, the levels of urinary metabolites of trichloroethylene and TSEP. We can describe 4 groups of workers: group A, 13 subjects with perturbations of clinical and evoked responses; group B, 27 subjects with normal physical examination though with disturbed TSEP; group C, 6 subjects had an abnormal examination though evoked responses were normal; group D, 59 subjects had normal clinical examination and TSEP. Disturbed TSEP (particularly delayed responses) are found among the older workers with the longest duration of exposure and higher level of exposure. The alteration of TSEP may appear before clinical disturbance. TSEP could represent a useful test for the supervision of the exposed workers and the clinical diagnosis of the trigeminal impairment.

The authors describe the EEG recordings of 107 patients with acute severe cranial trauma and signs of axial lesions. The initial EEG included: sleep patterns, alternating tracings, alpha band tracings which were either nonreactive pseudo-alpha or modulated alpha often reactive, and diffuse slow wave tracings. They found no particular tracing corresponding to a precise level of rostrocaudal destructuration, but some associations were seen more frequently. EEG sleep patterns and alternating tracings were never observed in brain stem lesions, the activity recorded being of low voltage, rigid, and non-reactive. The presence of spontaneous fluctuations (with sleep rhythms in some cases) and reactivity in other levels (mesodiencephalic junction, diencephalic and cortical-subcortical) are good prognostic signs. Focalised EEG signs are seen especially in the more rostral levels.

The authors studied four children with Reye's syndrome aged 16 months, 6 years, 8 years and 11 years respectively with severe liver failure and progressive coma. The laboratory investigations in all of them showed a marked elevation of serum transaminases, hyperammoniaemia and a prolongation of the prothrombin time. The electroencephalograms showed a grossly abnormal picture with generalised continuous delta activity. Three children survived with return to normal of the liver function tests whilst the fourth child died. In the last two patients an electroencephalogram carried out every six hours has enabled certain prognostic features to be determined. Improvement in the E.E.G. correlates closely with clinical improvement and vice versa. The authors also advocate serial E.E.G. recordings in Reye's syndrome. The role of hyperammonaemia in the genesis of encephalopathy and the electroencephalographic changed is discussed. The role played by raised intracranial pressure is stressed and the importance of controlling it in order to prevent further damage and improve the prognosis of this serious illness.

The authors present a comparative analysis of the characteristics of the V wave of the brain stem auditory evoked potentials in relation to the degree of transverse shifting of the third ventricle. The investigations were carried out in 48 patients with non-traumatic intracerebral haematoma. A high correlation was found between the size of the amplitude and ventricle shift. No such correlation was observed with the interpeak time of the I--V waves.